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Emergency department (ED) presentations for paediatric exploratory ingestions (PEIs) are common.[[1]] The ingestion of harmful substance(s) is one of the most common causes of injury in children.[[2]] Unintentional poisoning and foreign-body ingestion in children result in significant morbidity and mortality internationally.[[3–4]] Thousands of hospitalisations in New Zealand occur each year due to unintentional childhood poisonings. Of these, some have resulted in significant harm, as there are a number of medications, often described as “one pill can kill,” that have the potential for significant toxicity at low doses.[[3]]  

There is no consistent definition for PEIs in the literature; this study defines PEIs as ingestion of non-food items that children find in their environment as a part of investigative behaviour. These do not include ingestions with the intent of self-harm or ingestions where an incorrect dose of intended medications was administered by an adult.

There is evidence that suggests that children are most likely to have PEIs between the ages of 6 months and 6 years, as this period encompasses the stage of exploratory development. Children ingest a variety of substances, including medications and other non-edible foreign bodies, like coins, pins, button batteries, magnets and other household items.[[1,4]]  

A 1999 study in Christchurch Hospital, New Zealand, by Dillon and Gee found that paracetamol was the most commonly ingested substance in those children presenting to ED.[[1]] Similarly, another New Zealand-based study that investigated childhood and adolescent poisonings reported to the National Poisons Centre between 2000 and 2009 found that 86% of poisonings were reported in children under 5 years old, and the substances most implicated in the reports were therapeutic agents (medications).[[3]] More recent New Zealand-based research studying enquiries to the National Poisons Centre in 2018 found that paracetamol was the most reported substance in all calls, as well as the most searched substance on the website (TOXINZ).[[5]]

Although past literature has shown that paracetamol is often implicated in PEIs, the research by Dillon and Gee found that there is likely to be variation in the substances implicated in PEIs over the course of time.[[1]] Hence, there is a need for current research that quantifies and describes types of paediatric exploratory ingestion presentations to inform clinical management and future public health initiatives.

Methods

Study design

A retrospective descriptive study was conducted on data of paediatric exploratory ingestion presentations to Christchurch Hospital ED between 1 January and 31 December 2019. Results of this study were compared to the 1999 study by Dillon and Gee.[[1]]

Setting

Christchurch Hospital is a tertiary level hospital in Canterbury, New Zealand, which covers a population of approximately 550,000. The emergency department at Christchurch Hospital is the sole major acute referral centre in the region, with over 100,000 presentations each year.[[6]]  

The model of care for paediatric presentations at Christchurch Hospital involves initial assessment and management in the ED, and then admission to Children’s Acute Assessment (CAA) for children who require >4 hours of observation/care. Those requiring admission >12 hours are transferred to the paediatric medical ward. Children requiring infusions such as N-acetylcysteine (NAC) or high levels of observation are admitted to the Paediatric High Dependency Unit (PHDU).

Participants

Initially, data were extracted from the Canterbury District Health Board (CDHB) data warehouse for patients aged under 14 years who had an arrival complaint of “alcohol/drug intoxication or withdrawal, overdose of drug, ingestion of potentially harmful entity or noxious inhalation” or a discharge diagnosis of “Poisoning caused by drug AND/OR medicinal substance (disorder) or Drug overdose (disorder).” However, no PEIs were found in those aged 7 years or older. Therefore, the cut-off age for participants was set at <7 years. At Christchurch Hospital, patients who are not admitted to inpatient wards do not receive formal ICD (or similar) coding. Therefore, for patients who are not admitted, arrival complaints are recorded by experienced ED triage nurses, and discharge diagnoses are recorded by ED medical staff. All PEI presentations to ED by patients under 7 years of age during 2019 were studied and compared with data from all paediatric presentations during 2019. Presentations that were classified as deliberate self-harm or alcohol and substance abuse (intentional rather than exploratory) were excluded from the PEI group.

Data collection

Data were extracted from routinely collected administrative data and medical notes from Christchurch Hospital’s electronic medical record system. The variables included were age, gender, ethnicity, admission status, triage code, time of presentation, time to presentation, substance ingested, place of access to substance, adverse effects from substance, management during presentation and follow-up/sequalae. Ethnicity data accessed in this study are parent or guardian reported and are routinely collected by experienced ED administrative staff. Each PEI patient’s index of deprivation was determined using their residential addresses. New Zealand index of deprivation is displayed as deciles 1–10. Here decile 1 represents least deprived scores and decile 10 represents most deprived scores.[[7]]

Analysis method

Collected data under each variable were coded into sub-groups for analysis. Simple descriptive statistical analysis was undertaken. This allowed factors around PEIs to be compared as percentages alongside the results of the 1999 study.[[1]] The 1999 paper examined presentations in <6 year olds over a six-month period, whereas this paper looked at patients <7 years of age in 2019. Therefore, a chi square test for independence was used to compare the proportions of these groups presenting with PEIs. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by comparing PEIs to other paediatric presentations in 2019. Statistical Packages for Social Sciences version 26 (SPSSv26, IBM, Armonk, NY) was used for analyses.[[8]] Canterbury population data for 1999 and 2019 were not available. Therefore, to estimate the incidence of PEIs per Canterbury population in 2019, 2018 census data by Stats NZ were used.[[9]]

By using CDHB population data from an Official Information Act request (reference #10466), a chi square test for goodness of fit was performed to compare PEI ethnicity as a proportion of the total population of children aged 0–4 years in CDHB.[[ 10]] Data were available for 0–4 and 5–9 age groups but not for the 0–6 age group. Since the majority of PEIs in this study were in the 0–4 age group, numbers were approximated using data for the 0–4 age group.

To analyse PEIs relative to CDHB population in terms of index of deprivation, data for the Canterbury population were obtained by contacting Environmental Health Indicators New Zealand (EHINZ).[[7]] The exact deprivation data for Canterbury children under 7 years of age were not available, so PEIs were compared to deprivation data for Canterbury children under 6 years of age using a chi square test for goodness of fit.

Ethics

This study was granted ethical approval under the Minimal Risk Health Research University of Otago Human Ethics Application (No. H20/109). In addition to ethical approval, CDHB locality authorisation and Māori consultation were undertaken. The project was consequently approved by both CDHB and the local iwi.

Results

In total, there were 111 PEI presentations in children aged under 7 years to Christchurch Hospital ED during 2019. This accounted for 1.2% of total ED paediatric presentations (9,445) of children under 7 during 2019. Using data from the 2018 census, the estimated incidence of PEIs in children under 7 in 2019 was 223.8 per 100,000.[[8]]

Fifty-six males and 55 females presented with PEIs during 2019, with no significant gender difference when compared to all other paediatric presentations (Table 1). In terms of age, for exploratory presentations, 2 year olds presented most commonly (44.1%), followed by 1 year olds (21.6%); whereas for other paediatric presentations, <1 year olds presented most commonly (30.2%), followed by 1 year olds (20.5%). Compared to <1 year olds, 2 year olds were most likely to have PEIs (p<0.05), followed by 1 year olds (p<0.05) and 3 year olds (p<0.05), whereas 4, 5 and 6 year olds were not significantly more likely to present with PEIs.  

Of patients who presented with PEIs, 58.6% were European, 27.0% were Māori, 9.9% Asian, 3.6% Pacific and 0.9% other ethnicities. This was similar to the proportions of ethnicities represented in other paediatric presentations. Relative to children of European ethnicity, Asian (p<0.05) and Pacific (p<0.05) children were less likely to present with PEIs, whereas children of Māori and other ethnicities were not significantly less likely to present with PEIs. A chi square test for goodness of fit that compared the observed ethnicities of presentations to the expected percentages of ethnicities in the CDHB general population in ages 0–4 (Appendix Table 1) demonstrated that Māori children were overrepresented in PEIs and Asian children were underrepresented. Children of Pacific and other ethnicities were represented at an expected rate in PEIs.

The majority (81.1%) of the exploratory presentations had a triage code of three, with 13.5% being coded at higher priority (ie, triage one or two). Comparatively, 66.8% of other paediatric presentations were coded as triage three, with 7.6% being coded at a higher priority. Using triage one as the reference group, there were no significant differences between PEIs and other paediatric presentations in terms of triage. Of the exploratory presentations, 56.8% were admitted to hospital. This was similar to admission rates of other paediatric presentations (Table 1).

Table 1: Demographics, admission status and triage coding with odds ratios and 95% confidence intervals of PEIs compared to other paediatric presentations in 2019. View Table 1.

Children from an address with a higher level of deprivation were not more likely to present for PEIs than children from an address with a lower level of deprivation, even after the data were adjusted for rates of deprivation among children aged 0–5 in the CDHB (55.5% PEI presentations vs 59.3% of all CDHB children aged 0–5 were within deciles 1 to 5, p=0.40).

Among those admitted to hospital for exploratory ingestion (63 patients), only seven patients had a length of stay greater than 24 hours (Table 2). Ninety-seven percent of patients with PEIs attended ED between 08:00–00:00hrs, with only three presentations being between 00:00–08:00hrs (Table 2). Fifty-six percent of patients presented within two hours of ingestion; however, in 20.7% of cases, this variable was not recorded.

Table 2: Arrival time, time between exposure and arrival and admission length for PEI patients in 2019.

Paracetamol was the single most commonly ingested substance (15.3%), followed by opioids, which accounted for 11.7% of cases. Of note, 18.0% of the cases involved ingestion of a medication that had the potential to affect the central nervous system (CNS), including psychiatric medications, benzodiazepines, zopiclone and other CNS medications (Table 3). There were four cases where patients had ingested more than one medication, four cases of ingesting essential oils and two cases of ingesting plants. There were no exploratory alcohol or cannabis ingestions. Twenty-three-point-four percent involved other substances, including ointments, cleaning liquids, batteries (three ingestions) and other household items. Most (87.4%) of the patients had gained access to the substances at home, six patients accessed them at a grandparent’s house and eight at other places.

Table 3: Substances ingested, severity of clinical course and management of PEIs in 2019.

Among the 63 patients who were admitted, there were eight admissions for ingesting paracetamol, seven for opioids, two for non-steroidal anti-inflammatory drugs (NSAIDs), five inclusive of benzodiazepines and zopiclone, six for psychiatric medications, four for other CNS medications, five for cardiac medications, three for multiple medications, three for essential oils, two for plant-based products, eight for other medications and ten for other substances.

Most patients who presented with PEIs either had no symptoms (66 patients) or minor symptoms such as nausea, vomiting, abdominal pain, diarrhoea or cough (18 patients). Twenty-seven patients had concerning symptoms that had the potential to affect their airway, breathing, circulation or neurological status. Examples of these symptoms included agitation, unsteadiness, lethargy, drowsiness or slurred speech. There were no significant cardiovascular or renal complications, no requirements for respiratory support or narcotic antagonists and no deaths from PEIs.

Thirteen-point-five percent of patients with PEIs were assessed and discharged; 79.3% were observed and given symptomatic treatment, such as anti-emetics; 3.6% had NAC and another 3.6% had activated charcoal (Table 3). Eighty-nine-point-two percent of patients did not require formal paediatric follow-up, four were followed-up as paediatric outpatients and eight by other agencies.

The proportion of PEI presentations decreased from 120 out of 3,085 (3.9%) in 1999 to 111 out of 9,445 (1.2%) in 2019 (X[[2]]=94.7, p<0.001). The proportion of PEIs that were paracetamol ingestions in 2019 was approximately half compared to 1999 (Table 4). However, there was a significant increase in the proportion of PEI presentations for opioids and other drugs that have the potential to affect the CNS.

Table 4: Comparison of substances ingested in percentages between 2019 and 1999.[[1]]

Discussion

ED presentations for PEIs at Canterbury Hospital reduced over the 20-year period between 1999 and 2019. Increased awareness of the risks, safety packaging of medications and effective National Poisons Centre advice may be possible explanations for this reduction of PEIs.

In this study, European and Māori children accounted for more PEIs compared to Asian and Pacific children. Previous literature suggests the factors implicated in greater PEIs include increased accessibility of medications to children, differing levels of knowledge about medication toxicity, poorer home environment, differences in medical care and a lack of information resources.[[11–12]] However, there was no significant difference in PEI presentations between children living in high- vs low-decile areas in CDHB. Alternatively, there may have been protective factors present in other households that reduced PEIs.

This study found PEIs to be most common among 2 year old children. A previous study on paediatric emergency presentation with acute poisoning also found a peak among 2 year old children.[[13]] The reasons for this are multifactorial and relate predominately to development milestones, the environment and parental supervision. Children approaching 2 years of age become increasingly exploratory and inquisitive, which is aided by their greater mobility and dexterity.[[14]]

In 2019, ED presentations due to paracetamol ingestions had decreased compared to 1999, but there were more benzodiazepine, opioid and psychiatric medication ingestions.[[1]] This information suggests there was an increase in the availability of opioids and medications that affect the CNS to Canterbury children. Although it seems that safety and awareness around paracetamol storage may have improved, it is important to consider that other more harmful medications came into play over these 20 years.

In 2018, there were two studies (Koren and Nachmani in the United States; Wright and Falkland in Australia) that updated lists of drugs which one to two standard doses of could be fatal to a toddler—“one pill can kill.”[[15–16]] These lists include opioids, cardiac medications, diabetes medications and psychiatric medications such as antipsychotics and antidepressants. Approximately 34.2% of PEIs in this study included medications (cardiac medications, opioids and medications affecting the CNS) present on the one pill can kill lists.[[15–16]] This is concerning, given the previous literature by the Child and Youth Mortality Review Committee (CYMRC) found that opioids accounted for a high rate of mortality in young people due to unintentional poisonings.[[17]] Hence it is imperative that safety measures, such as increased awareness of potential toxicity and further child-proofing of these medication, are implemented to prevent PEIs with these medications as they can be potentially fatal.

Many commonly ingested substances have an unpalatable taste, and with increased safety methods having been incorporated into household items and medicines over the years, it is uncommon for significant amounts of any substance to be ingested. Hence PEIs are more likely to be poison scares rather than actual poisonings.[[18]] In this study, the majority of PEIs were triage three, meaning that these were not deemed to be immediately life-threatening. The fact that most patients experienced no symptoms or only minor symptoms during admission further indicates that the PEIs were relatively non-severe.  

Only a small proportion of patients received NAC, the antidote for paracetamol toxicity or activated charcoal. This study showed the single most commonly ingested substance was paracetamol, yet few received NAC or activated charcoal, suggesting that insufficient quantities were ingested to cause hepatotoxicity warranting active management. Dillon and Gee in 1999 found that 12% of children presenting with PEIs were treated with activated charcoal, whereas 88% received no decontamination.[[1]] Our study shows that the percentage treated with activated charcoal had declined markedly in 2019 compared to 1999. The reduction in active gastrointestinal decontamination likely reflects medical awareness that it is rare for PEIs to result in significant toxicity, and that the risks of the decontamination procedure may outweigh the risk of poison exposure.[[1,18,19]] In the last 20 years it has been recognised that children have a lower risk than adults of paracetamol toxicity for equivalent doses per weight. This is due to immature liver biotransformation enzymes. This has raised the dose thresholds to investigate and to treat children with paracetamol ingestions.[[20-21]]

Dillon and Gee also reported that 28% of PEIs were admitted to hospital, and that the majority were admitted for less than six hours.[[1]] Admission rates in 2019 for PEIs were double that reported in 1999, but of those admitted the majority (58.7%) were admitted for eight hours or less. The increased admission rate but comparable length of admission compared to 1999 may in part be due to the shift away from active gastrointestinal decontamination procedures towards observation followed by discharge. However, there was no significant difference in admission rates between PEIs and other paediatric presentations, suggesting that, of all the paediatric presentations, PEIs are not disproportionately admitted. In this study, the majority of those patients admitted went to CAA rather than PHDU. This further indicates the majority of PEIs seen in this study were low severity, which is consistent with the literature reporting the rarity of toxicity in PEI.[[1,18]]

Strengths and limitations

This study was conducted at Christchurch Hospital, which is a tertiary centre in New Zealand covering a large population. However, being a single-centre study, its generalisability may be affected by some likely variation in population demographics throughout New Zealand. Also note that exact comparable data for the 0–6 age group were unavailable for ethnicity and level of deprivation, and therefore numbers were estimated using available data.

Conclusion

The findings of this study are reassuring. Paediatric presentations due to exploratory ingestions in Canterbury reduced between 1999 and 2019. In Canterbury, most PEI presentations were in children 2 years of age. The majority of ingestions occurred at home, were low severity and did not require gastrointestinal decontamination. The decrease in paracetamol presentations over the years could be due to improved parental awareness and better National Poisons Centre triage. Unfortunately, the proportion of presentations with other, potentially more harmful medications, like opioids and psychiatric medications, increased. These medications are included on one pill can kill lists. Therefore, there is a need for increased awareness and safety around storage of these medications.

Appendix

Appendix Table 1: PEI ethnicity as a proportion of total population in children aged 0–4 years in CDHB.

[[a]] Expected % based on CDHB Official Information Act request reference #10466 using ages 0–4.[[b]] p-values based on chi square test for goodness of fit for each ethnicity.

Summary

Abstract

Aim

To quantify and describe presentations to a New Zealand tertiary hospital emergency department (ED) associated with paediatric exploratory ingestions (PEIs) during 2019 in comparison to 1999.

Method

A retrospective descriptive study was conducted of PEI presentations by children under 7 years of age to Christchurch Hospital ED between 1 January and 31 December 2019. Data were studied for demographic and management details and compared to data from 1999.

Results

There were 111 PEI presentations in children under 7 years during 2019, out of 9,445 presentations for this age group (1.2%). The estimated incidence of PEIs was 223.8 per 100,000. PEI presentations relative to total paediatric presentations had reduced compared to 1999 (X^2=94.7, p<0.001). Two year olds were most likely to have PEIs (odds ratio (OR)=15.01, 95% confidence interval (CI)=6.78, 33.22). Children of Asian (OR=0.50, 95% CI=0.26, 0.95) and Pacific (OR=0.34, 95% CI=0.12, 0.93) ethnicity were less likely to present with PEIs. Paracetamol was the most commonly ingested substance (15.3%), followed by opioids (11.7%).¬¬¬

Conclusion

Paediatric presentations due to exploratory ingestions reduced between 1999 and 2019. However, there was a concerning increase in ingestions of medications like opioids that have a significant risk of toxicity at low doses.

Author Information

Aditya Raina: House Officer, Capital and Coast District Health Board. Brennan Carne: House Officer, Canterbury District Health Board. Roshit Bothara: House Officer, Canterbury District Health Board. Andrew McCombie: Department of General Surgery, Canterbury District Health Board. Paul Gee: Emergency Department, Canterbury District Health Board. Laura Joyce: Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board.

Acknowledgements

The authors would like to thank Melanie Browne, Information Analyst, Canterbury District Health Board, for help in acquiring the data for this study.

Correspondence

Dr Laura Joyce, Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board

Correspondence Email

laura.joyce@cdhb.health.nz

Competing Interests

Nil.

1) Dillon, C, & Gee, P. Gastrointestinal decontamination in paediatric exploratory ingestions. The New Zealand Medical Journal. 2002;115(1155), 260–262.

2) Mintegi S, Fernandez A, Alustiza J, Canduela V, Mongil I, Caubet I et al. Emergency Visits for Childhood Poisoning. Pediatric Emergency Care. 2006;22(5):334-338.

3) Fan, AY, Che, AH, Pan, B, Yang, C, Coulter, CV, Shieffelbien, L, Temple, W, & Braund, R. (2013). Investigating Childhood and Adolescence poisoning exposures in New Zealand reported to the National Poisons Centre during 2000-2009. Asia Pacific Journal of Medical Toxicology. 2013; 2: 52-57.

4) Khorana J, Tantivit Y, Phiuphong C, Pattapong S, Siripan S. Foreign Body Ingestion in Pediatrics: Distribution, Management and Complications. Medicina. 2019;55(10):686.

5) Kumpula E, Shieffelbien L, Pomerleau A. Enquiries to the New Zealand National Poisons Centre in 2018. Emergency Medicine Australasia. 2020.

6) Ford K, Foulds J, Coleman O, Ardagh M, Pearson S, Droste N, et al. Alcohol-related emergency department attendances after the introduction of the Sale and Supply of Alcohol Act 2012. New Zealand Medical Journal. 2018;131(1483):40-9.

7) Socioeconomic deprivation profile [Internet]. Ehinz.ac.nz. 2021 [cited 5 March 2021]. Available from: https://ehinz.ac.nz/indicators/population-vulnerability/socioeconomic-deprivation-profile/

8) IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.

9) 2018 Census place summaries | Stats NZ [Internet]. Stats.govt.nz. 2020 [cited 1 November 2020]. Available from: https://www.stats.govt.nz/tools/2018-census-place-summaries/canterbury-region#ethnicity-culture-and-identity

10) Population projections for Canterbury | Canterbury DHB [Internet]. Canterbury DHB. 2021 [cited 5 March 2021]. Available from: https://www.cdhb.health.nz/about-us/document-library/cdhb-10466-population-projections-canterbury/

11) Glik DC, Greaves PE, Kronenfeld JJ, Jackson KL. Safety hazards in households with young children. Journal of Pediatric Psychology. 1993;18(1):115-31.

12) Hapgood R, Kendrick D, Marsh P. How well do socio-demographic characteristics explain variation in childhood safety practices? Journal of Public Health Medicine. 2000;22(3):307-11.

13) Lamireau T, Llanas B, Kennedy A, Fayon M, Penouil F, Favarell-Garrigues J.C, Demarquez J.L. Epidemiology of poisoning in children: a 7-year survey in a paediatric emergency care unit, European Journal of Emergency Medicine. 2002; 9 (1):9-14.

14) Dosman CF, Andrews D, Goulden KJ. Evidence-based milestone ages as a framework for developmental surveillance. Paediatric Child Health. 2012;17(10):561-8.

15) Koren G, Nachmani A. Drugs that Can Kill a Toddler with One Tablet or Teaspoonful: A 2018 Updated List. Clinical Drug Investigation. 2018;39(2):217-220.

16) Wright N, Falkland M. Practice update: Preventing poisoning: Which pills can kill?. The Australian Journal of Pharmacy. 2018;99(1178):74-77.

17) Health Quality & Safety Commission New Zealand. Unintentional deaths from poisoning in young people. Wellington: Health Quality & Safety Commission New Zealand; 2013 p. 1-42.

18) Peden M. World report on child injury prevention. Geneva, Switzerland: World Health Organization; 2008.

19) Eldridge D. Methods of hospital and prehospital gastrointestinal decontamination in children. Pediatric Health. 2009;3(4):359-367.

20) Tenenbein M. Acetaminophen: the 150 mg/kg myth. Journal of toxicology. Clinical toxicology. 2004;42(2): 145-148.

21) Caravati EM. Unintentional acetaminophen ingestion in children and the potential for hepatotoxicity. Journal of toxicology. Clinical toxicology. 2000;38(3):291-296.

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Emergency department (ED) presentations for paediatric exploratory ingestions (PEIs) are common.[[1]] The ingestion of harmful substance(s) is one of the most common causes of injury in children.[[2]] Unintentional poisoning and foreign-body ingestion in children result in significant morbidity and mortality internationally.[[3–4]] Thousands of hospitalisations in New Zealand occur each year due to unintentional childhood poisonings. Of these, some have resulted in significant harm, as there are a number of medications, often described as “one pill can kill,” that have the potential for significant toxicity at low doses.[[3]]  

There is no consistent definition for PEIs in the literature; this study defines PEIs as ingestion of non-food items that children find in their environment as a part of investigative behaviour. These do not include ingestions with the intent of self-harm or ingestions where an incorrect dose of intended medications was administered by an adult.

There is evidence that suggests that children are most likely to have PEIs between the ages of 6 months and 6 years, as this period encompasses the stage of exploratory development. Children ingest a variety of substances, including medications and other non-edible foreign bodies, like coins, pins, button batteries, magnets and other household items.[[1,4]]  

A 1999 study in Christchurch Hospital, New Zealand, by Dillon and Gee found that paracetamol was the most commonly ingested substance in those children presenting to ED.[[1]] Similarly, another New Zealand-based study that investigated childhood and adolescent poisonings reported to the National Poisons Centre between 2000 and 2009 found that 86% of poisonings were reported in children under 5 years old, and the substances most implicated in the reports were therapeutic agents (medications).[[3]] More recent New Zealand-based research studying enquiries to the National Poisons Centre in 2018 found that paracetamol was the most reported substance in all calls, as well as the most searched substance on the website (TOXINZ).[[5]]

Although past literature has shown that paracetamol is often implicated in PEIs, the research by Dillon and Gee found that there is likely to be variation in the substances implicated in PEIs over the course of time.[[1]] Hence, there is a need for current research that quantifies and describes types of paediatric exploratory ingestion presentations to inform clinical management and future public health initiatives.

Methods

Study design

A retrospective descriptive study was conducted on data of paediatric exploratory ingestion presentations to Christchurch Hospital ED between 1 January and 31 December 2019. Results of this study were compared to the 1999 study by Dillon and Gee.[[1]]

Setting

Christchurch Hospital is a tertiary level hospital in Canterbury, New Zealand, which covers a population of approximately 550,000. The emergency department at Christchurch Hospital is the sole major acute referral centre in the region, with over 100,000 presentations each year.[[6]]  

The model of care for paediatric presentations at Christchurch Hospital involves initial assessment and management in the ED, and then admission to Children’s Acute Assessment (CAA) for children who require >4 hours of observation/care. Those requiring admission >12 hours are transferred to the paediatric medical ward. Children requiring infusions such as N-acetylcysteine (NAC) or high levels of observation are admitted to the Paediatric High Dependency Unit (PHDU).

Participants

Initially, data were extracted from the Canterbury District Health Board (CDHB) data warehouse for patients aged under 14 years who had an arrival complaint of “alcohol/drug intoxication or withdrawal, overdose of drug, ingestion of potentially harmful entity or noxious inhalation” or a discharge diagnosis of “Poisoning caused by drug AND/OR medicinal substance (disorder) or Drug overdose (disorder).” However, no PEIs were found in those aged 7 years or older. Therefore, the cut-off age for participants was set at <7 years. At Christchurch Hospital, patients who are not admitted to inpatient wards do not receive formal ICD (or similar) coding. Therefore, for patients who are not admitted, arrival complaints are recorded by experienced ED triage nurses, and discharge diagnoses are recorded by ED medical staff. All PEI presentations to ED by patients under 7 years of age during 2019 were studied and compared with data from all paediatric presentations during 2019. Presentations that were classified as deliberate self-harm or alcohol and substance abuse (intentional rather than exploratory) were excluded from the PEI group.

Data collection

Data were extracted from routinely collected administrative data and medical notes from Christchurch Hospital’s electronic medical record system. The variables included were age, gender, ethnicity, admission status, triage code, time of presentation, time to presentation, substance ingested, place of access to substance, adverse effects from substance, management during presentation and follow-up/sequalae. Ethnicity data accessed in this study are parent or guardian reported and are routinely collected by experienced ED administrative staff. Each PEI patient’s index of deprivation was determined using their residential addresses. New Zealand index of deprivation is displayed as deciles 1–10. Here decile 1 represents least deprived scores and decile 10 represents most deprived scores.[[7]]

Analysis method

Collected data under each variable were coded into sub-groups for analysis. Simple descriptive statistical analysis was undertaken. This allowed factors around PEIs to be compared as percentages alongside the results of the 1999 study.[[1]] The 1999 paper examined presentations in <6 year olds over a six-month period, whereas this paper looked at patients <7 years of age in 2019. Therefore, a chi square test for independence was used to compare the proportions of these groups presenting with PEIs. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by comparing PEIs to other paediatric presentations in 2019. Statistical Packages for Social Sciences version 26 (SPSSv26, IBM, Armonk, NY) was used for analyses.[[8]] Canterbury population data for 1999 and 2019 were not available. Therefore, to estimate the incidence of PEIs per Canterbury population in 2019, 2018 census data by Stats NZ were used.[[9]]

By using CDHB population data from an Official Information Act request (reference #10466), a chi square test for goodness of fit was performed to compare PEI ethnicity as a proportion of the total population of children aged 0–4 years in CDHB.[[ 10]] Data were available for 0–4 and 5–9 age groups but not for the 0–6 age group. Since the majority of PEIs in this study were in the 0–4 age group, numbers were approximated using data for the 0–4 age group.

To analyse PEIs relative to CDHB population in terms of index of deprivation, data for the Canterbury population were obtained by contacting Environmental Health Indicators New Zealand (EHINZ).[[7]] The exact deprivation data for Canterbury children under 7 years of age were not available, so PEIs were compared to deprivation data for Canterbury children under 6 years of age using a chi square test for goodness of fit.

Ethics

This study was granted ethical approval under the Minimal Risk Health Research University of Otago Human Ethics Application (No. H20/109). In addition to ethical approval, CDHB locality authorisation and Māori consultation were undertaken. The project was consequently approved by both CDHB and the local iwi.

Results

In total, there were 111 PEI presentations in children aged under 7 years to Christchurch Hospital ED during 2019. This accounted for 1.2% of total ED paediatric presentations (9,445) of children under 7 during 2019. Using data from the 2018 census, the estimated incidence of PEIs in children under 7 in 2019 was 223.8 per 100,000.[[8]]

Fifty-six males and 55 females presented with PEIs during 2019, with no significant gender difference when compared to all other paediatric presentations (Table 1). In terms of age, for exploratory presentations, 2 year olds presented most commonly (44.1%), followed by 1 year olds (21.6%); whereas for other paediatric presentations, <1 year olds presented most commonly (30.2%), followed by 1 year olds (20.5%). Compared to <1 year olds, 2 year olds were most likely to have PEIs (p<0.05), followed by 1 year olds (p<0.05) and 3 year olds (p<0.05), whereas 4, 5 and 6 year olds were not significantly more likely to present with PEIs.  

Of patients who presented with PEIs, 58.6% were European, 27.0% were Māori, 9.9% Asian, 3.6% Pacific and 0.9% other ethnicities. This was similar to the proportions of ethnicities represented in other paediatric presentations. Relative to children of European ethnicity, Asian (p<0.05) and Pacific (p<0.05) children were less likely to present with PEIs, whereas children of Māori and other ethnicities were not significantly less likely to present with PEIs. A chi square test for goodness of fit that compared the observed ethnicities of presentations to the expected percentages of ethnicities in the CDHB general population in ages 0–4 (Appendix Table 1) demonstrated that Māori children were overrepresented in PEIs and Asian children were underrepresented. Children of Pacific and other ethnicities were represented at an expected rate in PEIs.

The majority (81.1%) of the exploratory presentations had a triage code of three, with 13.5% being coded at higher priority (ie, triage one or two). Comparatively, 66.8% of other paediatric presentations were coded as triage three, with 7.6% being coded at a higher priority. Using triage one as the reference group, there were no significant differences between PEIs and other paediatric presentations in terms of triage. Of the exploratory presentations, 56.8% were admitted to hospital. This was similar to admission rates of other paediatric presentations (Table 1).

Table 1: Demographics, admission status and triage coding with odds ratios and 95% confidence intervals of PEIs compared to other paediatric presentations in 2019. View Table 1.

Children from an address with a higher level of deprivation were not more likely to present for PEIs than children from an address with a lower level of deprivation, even after the data were adjusted for rates of deprivation among children aged 0–5 in the CDHB (55.5% PEI presentations vs 59.3% of all CDHB children aged 0–5 were within deciles 1 to 5, p=0.40).

Among those admitted to hospital for exploratory ingestion (63 patients), only seven patients had a length of stay greater than 24 hours (Table 2). Ninety-seven percent of patients with PEIs attended ED between 08:00–00:00hrs, with only three presentations being between 00:00–08:00hrs (Table 2). Fifty-six percent of patients presented within two hours of ingestion; however, in 20.7% of cases, this variable was not recorded.

Table 2: Arrival time, time between exposure and arrival and admission length for PEI patients in 2019.

Paracetamol was the single most commonly ingested substance (15.3%), followed by opioids, which accounted for 11.7% of cases. Of note, 18.0% of the cases involved ingestion of a medication that had the potential to affect the central nervous system (CNS), including psychiatric medications, benzodiazepines, zopiclone and other CNS medications (Table 3). There were four cases where patients had ingested more than one medication, four cases of ingesting essential oils and two cases of ingesting plants. There were no exploratory alcohol or cannabis ingestions. Twenty-three-point-four percent involved other substances, including ointments, cleaning liquids, batteries (three ingestions) and other household items. Most (87.4%) of the patients had gained access to the substances at home, six patients accessed them at a grandparent’s house and eight at other places.

Table 3: Substances ingested, severity of clinical course and management of PEIs in 2019.

Among the 63 patients who were admitted, there were eight admissions for ingesting paracetamol, seven for opioids, two for non-steroidal anti-inflammatory drugs (NSAIDs), five inclusive of benzodiazepines and zopiclone, six for psychiatric medications, four for other CNS medications, five for cardiac medications, three for multiple medications, three for essential oils, two for plant-based products, eight for other medications and ten for other substances.

Most patients who presented with PEIs either had no symptoms (66 patients) or minor symptoms such as nausea, vomiting, abdominal pain, diarrhoea or cough (18 patients). Twenty-seven patients had concerning symptoms that had the potential to affect their airway, breathing, circulation or neurological status. Examples of these symptoms included agitation, unsteadiness, lethargy, drowsiness or slurred speech. There were no significant cardiovascular or renal complications, no requirements for respiratory support or narcotic antagonists and no deaths from PEIs.

Thirteen-point-five percent of patients with PEIs were assessed and discharged; 79.3% were observed and given symptomatic treatment, such as anti-emetics; 3.6% had NAC and another 3.6% had activated charcoal (Table 3). Eighty-nine-point-two percent of patients did not require formal paediatric follow-up, four were followed-up as paediatric outpatients and eight by other agencies.

The proportion of PEI presentations decreased from 120 out of 3,085 (3.9%) in 1999 to 111 out of 9,445 (1.2%) in 2019 (X[[2]]=94.7, p<0.001). The proportion of PEIs that were paracetamol ingestions in 2019 was approximately half compared to 1999 (Table 4). However, there was a significant increase in the proportion of PEI presentations for opioids and other drugs that have the potential to affect the CNS.

Table 4: Comparison of substances ingested in percentages between 2019 and 1999.[[1]]

Discussion

ED presentations for PEIs at Canterbury Hospital reduced over the 20-year period between 1999 and 2019. Increased awareness of the risks, safety packaging of medications and effective National Poisons Centre advice may be possible explanations for this reduction of PEIs.

In this study, European and Māori children accounted for more PEIs compared to Asian and Pacific children. Previous literature suggests the factors implicated in greater PEIs include increased accessibility of medications to children, differing levels of knowledge about medication toxicity, poorer home environment, differences in medical care and a lack of information resources.[[11–12]] However, there was no significant difference in PEI presentations between children living in high- vs low-decile areas in CDHB. Alternatively, there may have been protective factors present in other households that reduced PEIs.

This study found PEIs to be most common among 2 year old children. A previous study on paediatric emergency presentation with acute poisoning also found a peak among 2 year old children.[[13]] The reasons for this are multifactorial and relate predominately to development milestones, the environment and parental supervision. Children approaching 2 years of age become increasingly exploratory and inquisitive, which is aided by their greater mobility and dexterity.[[14]]

In 2019, ED presentations due to paracetamol ingestions had decreased compared to 1999, but there were more benzodiazepine, opioid and psychiatric medication ingestions.[[1]] This information suggests there was an increase in the availability of opioids and medications that affect the CNS to Canterbury children. Although it seems that safety and awareness around paracetamol storage may have improved, it is important to consider that other more harmful medications came into play over these 20 years.

In 2018, there were two studies (Koren and Nachmani in the United States; Wright and Falkland in Australia) that updated lists of drugs which one to two standard doses of could be fatal to a toddler—“one pill can kill.”[[15–16]] These lists include opioids, cardiac medications, diabetes medications and psychiatric medications such as antipsychotics and antidepressants. Approximately 34.2% of PEIs in this study included medications (cardiac medications, opioids and medications affecting the CNS) present on the one pill can kill lists.[[15–16]] This is concerning, given the previous literature by the Child and Youth Mortality Review Committee (CYMRC) found that opioids accounted for a high rate of mortality in young people due to unintentional poisonings.[[17]] Hence it is imperative that safety measures, such as increased awareness of potential toxicity and further child-proofing of these medication, are implemented to prevent PEIs with these medications as they can be potentially fatal.

Many commonly ingested substances have an unpalatable taste, and with increased safety methods having been incorporated into household items and medicines over the years, it is uncommon for significant amounts of any substance to be ingested. Hence PEIs are more likely to be poison scares rather than actual poisonings.[[18]] In this study, the majority of PEIs were triage three, meaning that these were not deemed to be immediately life-threatening. The fact that most patients experienced no symptoms or only minor symptoms during admission further indicates that the PEIs were relatively non-severe.  

Only a small proportion of patients received NAC, the antidote for paracetamol toxicity or activated charcoal. This study showed the single most commonly ingested substance was paracetamol, yet few received NAC or activated charcoal, suggesting that insufficient quantities were ingested to cause hepatotoxicity warranting active management. Dillon and Gee in 1999 found that 12% of children presenting with PEIs were treated with activated charcoal, whereas 88% received no decontamination.[[1]] Our study shows that the percentage treated with activated charcoal had declined markedly in 2019 compared to 1999. The reduction in active gastrointestinal decontamination likely reflects medical awareness that it is rare for PEIs to result in significant toxicity, and that the risks of the decontamination procedure may outweigh the risk of poison exposure.[[1,18,19]] In the last 20 years it has been recognised that children have a lower risk than adults of paracetamol toxicity for equivalent doses per weight. This is due to immature liver biotransformation enzymes. This has raised the dose thresholds to investigate and to treat children with paracetamol ingestions.[[20-21]]

Dillon and Gee also reported that 28% of PEIs were admitted to hospital, and that the majority were admitted for less than six hours.[[1]] Admission rates in 2019 for PEIs were double that reported in 1999, but of those admitted the majority (58.7%) were admitted for eight hours or less. The increased admission rate but comparable length of admission compared to 1999 may in part be due to the shift away from active gastrointestinal decontamination procedures towards observation followed by discharge. However, there was no significant difference in admission rates between PEIs and other paediatric presentations, suggesting that, of all the paediatric presentations, PEIs are not disproportionately admitted. In this study, the majority of those patients admitted went to CAA rather than PHDU. This further indicates the majority of PEIs seen in this study were low severity, which is consistent with the literature reporting the rarity of toxicity in PEI.[[1,18]]

Strengths and limitations

This study was conducted at Christchurch Hospital, which is a tertiary centre in New Zealand covering a large population. However, being a single-centre study, its generalisability may be affected by some likely variation in population demographics throughout New Zealand. Also note that exact comparable data for the 0–6 age group were unavailable for ethnicity and level of deprivation, and therefore numbers were estimated using available data.

Conclusion

The findings of this study are reassuring. Paediatric presentations due to exploratory ingestions in Canterbury reduced between 1999 and 2019. In Canterbury, most PEI presentations were in children 2 years of age. The majority of ingestions occurred at home, were low severity and did not require gastrointestinal decontamination. The decrease in paracetamol presentations over the years could be due to improved parental awareness and better National Poisons Centre triage. Unfortunately, the proportion of presentations with other, potentially more harmful medications, like opioids and psychiatric medications, increased. These medications are included on one pill can kill lists. Therefore, there is a need for increased awareness and safety around storage of these medications.

Appendix

Appendix Table 1: PEI ethnicity as a proportion of total population in children aged 0–4 years in CDHB.

[[a]] Expected % based on CDHB Official Information Act request reference #10466 using ages 0–4.[[b]] p-values based on chi square test for goodness of fit for each ethnicity.

Summary

Abstract

Aim

To quantify and describe presentations to a New Zealand tertiary hospital emergency department (ED) associated with paediatric exploratory ingestions (PEIs) during 2019 in comparison to 1999.

Method

A retrospective descriptive study was conducted of PEI presentations by children under 7 years of age to Christchurch Hospital ED between 1 January and 31 December 2019. Data were studied for demographic and management details and compared to data from 1999.

Results

There were 111 PEI presentations in children under 7 years during 2019, out of 9,445 presentations for this age group (1.2%). The estimated incidence of PEIs was 223.8 per 100,000. PEI presentations relative to total paediatric presentations had reduced compared to 1999 (X^2=94.7, p<0.001). Two year olds were most likely to have PEIs (odds ratio (OR)=15.01, 95% confidence interval (CI)=6.78, 33.22). Children of Asian (OR=0.50, 95% CI=0.26, 0.95) and Pacific (OR=0.34, 95% CI=0.12, 0.93) ethnicity were less likely to present with PEIs. Paracetamol was the most commonly ingested substance (15.3%), followed by opioids (11.7%).¬¬¬

Conclusion

Paediatric presentations due to exploratory ingestions reduced between 1999 and 2019. However, there was a concerning increase in ingestions of medications like opioids that have a significant risk of toxicity at low doses.

Author Information

Aditya Raina: House Officer, Capital and Coast District Health Board. Brennan Carne: House Officer, Canterbury District Health Board. Roshit Bothara: House Officer, Canterbury District Health Board. Andrew McCombie: Department of General Surgery, Canterbury District Health Board. Paul Gee: Emergency Department, Canterbury District Health Board. Laura Joyce: Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board.

Acknowledgements

The authors would like to thank Melanie Browne, Information Analyst, Canterbury District Health Board, for help in acquiring the data for this study.

Correspondence

Dr Laura Joyce, Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board

Correspondence Email

laura.joyce@cdhb.health.nz

Competing Interests

Nil.

1) Dillon, C, & Gee, P. Gastrointestinal decontamination in paediatric exploratory ingestions. The New Zealand Medical Journal. 2002;115(1155), 260–262.

2) Mintegi S, Fernandez A, Alustiza J, Canduela V, Mongil I, Caubet I et al. Emergency Visits for Childhood Poisoning. Pediatric Emergency Care. 2006;22(5):334-338.

3) Fan, AY, Che, AH, Pan, B, Yang, C, Coulter, CV, Shieffelbien, L, Temple, W, & Braund, R. (2013). Investigating Childhood and Adolescence poisoning exposures in New Zealand reported to the National Poisons Centre during 2000-2009. Asia Pacific Journal of Medical Toxicology. 2013; 2: 52-57.

4) Khorana J, Tantivit Y, Phiuphong C, Pattapong S, Siripan S. Foreign Body Ingestion in Pediatrics: Distribution, Management and Complications. Medicina. 2019;55(10):686.

5) Kumpula E, Shieffelbien L, Pomerleau A. Enquiries to the New Zealand National Poisons Centre in 2018. Emergency Medicine Australasia. 2020.

6) Ford K, Foulds J, Coleman O, Ardagh M, Pearson S, Droste N, et al. Alcohol-related emergency department attendances after the introduction of the Sale and Supply of Alcohol Act 2012. New Zealand Medical Journal. 2018;131(1483):40-9.

7) Socioeconomic deprivation profile [Internet]. Ehinz.ac.nz. 2021 [cited 5 March 2021]. Available from: https://ehinz.ac.nz/indicators/population-vulnerability/socioeconomic-deprivation-profile/

8) IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.

9) 2018 Census place summaries | Stats NZ [Internet]. Stats.govt.nz. 2020 [cited 1 November 2020]. Available from: https://www.stats.govt.nz/tools/2018-census-place-summaries/canterbury-region#ethnicity-culture-and-identity

10) Population projections for Canterbury | Canterbury DHB [Internet]. Canterbury DHB. 2021 [cited 5 March 2021]. Available from: https://www.cdhb.health.nz/about-us/document-library/cdhb-10466-population-projections-canterbury/

11) Glik DC, Greaves PE, Kronenfeld JJ, Jackson KL. Safety hazards in households with young children. Journal of Pediatric Psychology. 1993;18(1):115-31.

12) Hapgood R, Kendrick D, Marsh P. How well do socio-demographic characteristics explain variation in childhood safety practices? Journal of Public Health Medicine. 2000;22(3):307-11.

13) Lamireau T, Llanas B, Kennedy A, Fayon M, Penouil F, Favarell-Garrigues J.C, Demarquez J.L. Epidemiology of poisoning in children: a 7-year survey in a paediatric emergency care unit, European Journal of Emergency Medicine. 2002; 9 (1):9-14.

14) Dosman CF, Andrews D, Goulden KJ. Evidence-based milestone ages as a framework for developmental surveillance. Paediatric Child Health. 2012;17(10):561-8.

15) Koren G, Nachmani A. Drugs that Can Kill a Toddler with One Tablet or Teaspoonful: A 2018 Updated List. Clinical Drug Investigation. 2018;39(2):217-220.

16) Wright N, Falkland M. Practice update: Preventing poisoning: Which pills can kill?. The Australian Journal of Pharmacy. 2018;99(1178):74-77.

17) Health Quality & Safety Commission New Zealand. Unintentional deaths from poisoning in young people. Wellington: Health Quality & Safety Commission New Zealand; 2013 p. 1-42.

18) Peden M. World report on child injury prevention. Geneva, Switzerland: World Health Organization; 2008.

19) Eldridge D. Methods of hospital and prehospital gastrointestinal decontamination in children. Pediatric Health. 2009;3(4):359-367.

20) Tenenbein M. Acetaminophen: the 150 mg/kg myth. Journal of toxicology. Clinical toxicology. 2004;42(2): 145-148.

21) Caravati EM. Unintentional acetaminophen ingestion in children and the potential for hepatotoxicity. Journal of toxicology. Clinical toxicology. 2000;38(3):291-296.

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Emergency department (ED) presentations for paediatric exploratory ingestions (PEIs) are common.[[1]] The ingestion of harmful substance(s) is one of the most common causes of injury in children.[[2]] Unintentional poisoning and foreign-body ingestion in children result in significant morbidity and mortality internationally.[[3–4]] Thousands of hospitalisations in New Zealand occur each year due to unintentional childhood poisonings. Of these, some have resulted in significant harm, as there are a number of medications, often described as “one pill can kill,” that have the potential for significant toxicity at low doses.[[3]]  

There is no consistent definition for PEIs in the literature; this study defines PEIs as ingestion of non-food items that children find in their environment as a part of investigative behaviour. These do not include ingestions with the intent of self-harm or ingestions where an incorrect dose of intended medications was administered by an adult.

There is evidence that suggests that children are most likely to have PEIs between the ages of 6 months and 6 years, as this period encompasses the stage of exploratory development. Children ingest a variety of substances, including medications and other non-edible foreign bodies, like coins, pins, button batteries, magnets and other household items.[[1,4]]  

A 1999 study in Christchurch Hospital, New Zealand, by Dillon and Gee found that paracetamol was the most commonly ingested substance in those children presenting to ED.[[1]] Similarly, another New Zealand-based study that investigated childhood and adolescent poisonings reported to the National Poisons Centre between 2000 and 2009 found that 86% of poisonings were reported in children under 5 years old, and the substances most implicated in the reports were therapeutic agents (medications).[[3]] More recent New Zealand-based research studying enquiries to the National Poisons Centre in 2018 found that paracetamol was the most reported substance in all calls, as well as the most searched substance on the website (TOXINZ).[[5]]

Although past literature has shown that paracetamol is often implicated in PEIs, the research by Dillon and Gee found that there is likely to be variation in the substances implicated in PEIs over the course of time.[[1]] Hence, there is a need for current research that quantifies and describes types of paediatric exploratory ingestion presentations to inform clinical management and future public health initiatives.

Methods

Study design

A retrospective descriptive study was conducted on data of paediatric exploratory ingestion presentations to Christchurch Hospital ED between 1 January and 31 December 2019. Results of this study were compared to the 1999 study by Dillon and Gee.[[1]]

Setting

Christchurch Hospital is a tertiary level hospital in Canterbury, New Zealand, which covers a population of approximately 550,000. The emergency department at Christchurch Hospital is the sole major acute referral centre in the region, with over 100,000 presentations each year.[[6]]  

The model of care for paediatric presentations at Christchurch Hospital involves initial assessment and management in the ED, and then admission to Children’s Acute Assessment (CAA) for children who require >4 hours of observation/care. Those requiring admission >12 hours are transferred to the paediatric medical ward. Children requiring infusions such as N-acetylcysteine (NAC) or high levels of observation are admitted to the Paediatric High Dependency Unit (PHDU).

Participants

Initially, data were extracted from the Canterbury District Health Board (CDHB) data warehouse for patients aged under 14 years who had an arrival complaint of “alcohol/drug intoxication or withdrawal, overdose of drug, ingestion of potentially harmful entity or noxious inhalation” or a discharge diagnosis of “Poisoning caused by drug AND/OR medicinal substance (disorder) or Drug overdose (disorder).” However, no PEIs were found in those aged 7 years or older. Therefore, the cut-off age for participants was set at <7 years. At Christchurch Hospital, patients who are not admitted to inpatient wards do not receive formal ICD (or similar) coding. Therefore, for patients who are not admitted, arrival complaints are recorded by experienced ED triage nurses, and discharge diagnoses are recorded by ED medical staff. All PEI presentations to ED by patients under 7 years of age during 2019 were studied and compared with data from all paediatric presentations during 2019. Presentations that were classified as deliberate self-harm or alcohol and substance abuse (intentional rather than exploratory) were excluded from the PEI group.

Data collection

Data were extracted from routinely collected administrative data and medical notes from Christchurch Hospital’s electronic medical record system. The variables included were age, gender, ethnicity, admission status, triage code, time of presentation, time to presentation, substance ingested, place of access to substance, adverse effects from substance, management during presentation and follow-up/sequalae. Ethnicity data accessed in this study are parent or guardian reported and are routinely collected by experienced ED administrative staff. Each PEI patient’s index of deprivation was determined using their residential addresses. New Zealand index of deprivation is displayed as deciles 1–10. Here decile 1 represents least deprived scores and decile 10 represents most deprived scores.[[7]]

Analysis method

Collected data under each variable were coded into sub-groups for analysis. Simple descriptive statistical analysis was undertaken. This allowed factors around PEIs to be compared as percentages alongside the results of the 1999 study.[[1]] The 1999 paper examined presentations in <6 year olds over a six-month period, whereas this paper looked at patients <7 years of age in 2019. Therefore, a chi square test for independence was used to compare the proportions of these groups presenting with PEIs. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by comparing PEIs to other paediatric presentations in 2019. Statistical Packages for Social Sciences version 26 (SPSSv26, IBM, Armonk, NY) was used for analyses.[[8]] Canterbury population data for 1999 and 2019 were not available. Therefore, to estimate the incidence of PEIs per Canterbury population in 2019, 2018 census data by Stats NZ were used.[[9]]

By using CDHB population data from an Official Information Act request (reference #10466), a chi square test for goodness of fit was performed to compare PEI ethnicity as a proportion of the total population of children aged 0–4 years in CDHB.[[ 10]] Data were available for 0–4 and 5–9 age groups but not for the 0–6 age group. Since the majority of PEIs in this study were in the 0–4 age group, numbers were approximated using data for the 0–4 age group.

To analyse PEIs relative to CDHB population in terms of index of deprivation, data for the Canterbury population were obtained by contacting Environmental Health Indicators New Zealand (EHINZ).[[7]] The exact deprivation data for Canterbury children under 7 years of age were not available, so PEIs were compared to deprivation data for Canterbury children under 6 years of age using a chi square test for goodness of fit.

Ethics

This study was granted ethical approval under the Minimal Risk Health Research University of Otago Human Ethics Application (No. H20/109). In addition to ethical approval, CDHB locality authorisation and Māori consultation were undertaken. The project was consequently approved by both CDHB and the local iwi.

Results

In total, there were 111 PEI presentations in children aged under 7 years to Christchurch Hospital ED during 2019. This accounted for 1.2% of total ED paediatric presentations (9,445) of children under 7 during 2019. Using data from the 2018 census, the estimated incidence of PEIs in children under 7 in 2019 was 223.8 per 100,000.[[8]]

Fifty-six males and 55 females presented with PEIs during 2019, with no significant gender difference when compared to all other paediatric presentations (Table 1). In terms of age, for exploratory presentations, 2 year olds presented most commonly (44.1%), followed by 1 year olds (21.6%); whereas for other paediatric presentations, <1 year olds presented most commonly (30.2%), followed by 1 year olds (20.5%). Compared to <1 year olds, 2 year olds were most likely to have PEIs (p<0.05), followed by 1 year olds (p<0.05) and 3 year olds (p<0.05), whereas 4, 5 and 6 year olds were not significantly more likely to present with PEIs.  

Of patients who presented with PEIs, 58.6% were European, 27.0% were Māori, 9.9% Asian, 3.6% Pacific and 0.9% other ethnicities. This was similar to the proportions of ethnicities represented in other paediatric presentations. Relative to children of European ethnicity, Asian (p<0.05) and Pacific (p<0.05) children were less likely to present with PEIs, whereas children of Māori and other ethnicities were not significantly less likely to present with PEIs. A chi square test for goodness of fit that compared the observed ethnicities of presentations to the expected percentages of ethnicities in the CDHB general population in ages 0–4 (Appendix Table 1) demonstrated that Māori children were overrepresented in PEIs and Asian children were underrepresented. Children of Pacific and other ethnicities were represented at an expected rate in PEIs.

The majority (81.1%) of the exploratory presentations had a triage code of three, with 13.5% being coded at higher priority (ie, triage one or two). Comparatively, 66.8% of other paediatric presentations were coded as triage three, with 7.6% being coded at a higher priority. Using triage one as the reference group, there were no significant differences between PEIs and other paediatric presentations in terms of triage. Of the exploratory presentations, 56.8% were admitted to hospital. This was similar to admission rates of other paediatric presentations (Table 1).

Table 1: Demographics, admission status and triage coding with odds ratios and 95% confidence intervals of PEIs compared to other paediatric presentations in 2019. View Table 1.

Children from an address with a higher level of deprivation were not more likely to present for PEIs than children from an address with a lower level of deprivation, even after the data were adjusted for rates of deprivation among children aged 0–5 in the CDHB (55.5% PEI presentations vs 59.3% of all CDHB children aged 0–5 were within deciles 1 to 5, p=0.40).

Among those admitted to hospital for exploratory ingestion (63 patients), only seven patients had a length of stay greater than 24 hours (Table 2). Ninety-seven percent of patients with PEIs attended ED between 08:00–00:00hrs, with only three presentations being between 00:00–08:00hrs (Table 2). Fifty-six percent of patients presented within two hours of ingestion; however, in 20.7% of cases, this variable was not recorded.

Table 2: Arrival time, time between exposure and arrival and admission length for PEI patients in 2019.

Paracetamol was the single most commonly ingested substance (15.3%), followed by opioids, which accounted for 11.7% of cases. Of note, 18.0% of the cases involved ingestion of a medication that had the potential to affect the central nervous system (CNS), including psychiatric medications, benzodiazepines, zopiclone and other CNS medications (Table 3). There were four cases where patients had ingested more than one medication, four cases of ingesting essential oils and two cases of ingesting plants. There were no exploratory alcohol or cannabis ingestions. Twenty-three-point-four percent involved other substances, including ointments, cleaning liquids, batteries (three ingestions) and other household items. Most (87.4%) of the patients had gained access to the substances at home, six patients accessed them at a grandparent’s house and eight at other places.

Table 3: Substances ingested, severity of clinical course and management of PEIs in 2019.

Among the 63 patients who were admitted, there were eight admissions for ingesting paracetamol, seven for opioids, two for non-steroidal anti-inflammatory drugs (NSAIDs), five inclusive of benzodiazepines and zopiclone, six for psychiatric medications, four for other CNS medications, five for cardiac medications, three for multiple medications, three for essential oils, two for plant-based products, eight for other medications and ten for other substances.

Most patients who presented with PEIs either had no symptoms (66 patients) or minor symptoms such as nausea, vomiting, abdominal pain, diarrhoea or cough (18 patients). Twenty-seven patients had concerning symptoms that had the potential to affect their airway, breathing, circulation or neurological status. Examples of these symptoms included agitation, unsteadiness, lethargy, drowsiness or slurred speech. There were no significant cardiovascular or renal complications, no requirements for respiratory support or narcotic antagonists and no deaths from PEIs.

Thirteen-point-five percent of patients with PEIs were assessed and discharged; 79.3% were observed and given symptomatic treatment, such as anti-emetics; 3.6% had NAC and another 3.6% had activated charcoal (Table 3). Eighty-nine-point-two percent of patients did not require formal paediatric follow-up, four were followed-up as paediatric outpatients and eight by other agencies.

The proportion of PEI presentations decreased from 120 out of 3,085 (3.9%) in 1999 to 111 out of 9,445 (1.2%) in 2019 (X[[2]]=94.7, p<0.001). The proportion of PEIs that were paracetamol ingestions in 2019 was approximately half compared to 1999 (Table 4). However, there was a significant increase in the proportion of PEI presentations for opioids and other drugs that have the potential to affect the CNS.

Table 4: Comparison of substances ingested in percentages between 2019 and 1999.[[1]]

Discussion

ED presentations for PEIs at Canterbury Hospital reduced over the 20-year period between 1999 and 2019. Increased awareness of the risks, safety packaging of medications and effective National Poisons Centre advice may be possible explanations for this reduction of PEIs.

In this study, European and Māori children accounted for more PEIs compared to Asian and Pacific children. Previous literature suggests the factors implicated in greater PEIs include increased accessibility of medications to children, differing levels of knowledge about medication toxicity, poorer home environment, differences in medical care and a lack of information resources.[[11–12]] However, there was no significant difference in PEI presentations between children living in high- vs low-decile areas in CDHB. Alternatively, there may have been protective factors present in other households that reduced PEIs.

This study found PEIs to be most common among 2 year old children. A previous study on paediatric emergency presentation with acute poisoning also found a peak among 2 year old children.[[13]] The reasons for this are multifactorial and relate predominately to development milestones, the environment and parental supervision. Children approaching 2 years of age become increasingly exploratory and inquisitive, which is aided by their greater mobility and dexterity.[[14]]

In 2019, ED presentations due to paracetamol ingestions had decreased compared to 1999, but there were more benzodiazepine, opioid and psychiatric medication ingestions.[[1]] This information suggests there was an increase in the availability of opioids and medications that affect the CNS to Canterbury children. Although it seems that safety and awareness around paracetamol storage may have improved, it is important to consider that other more harmful medications came into play over these 20 years.

In 2018, there were two studies (Koren and Nachmani in the United States; Wright and Falkland in Australia) that updated lists of drugs which one to two standard doses of could be fatal to a toddler—“one pill can kill.”[[15–16]] These lists include opioids, cardiac medications, diabetes medications and psychiatric medications such as antipsychotics and antidepressants. Approximately 34.2% of PEIs in this study included medications (cardiac medications, opioids and medications affecting the CNS) present on the one pill can kill lists.[[15–16]] This is concerning, given the previous literature by the Child and Youth Mortality Review Committee (CYMRC) found that opioids accounted for a high rate of mortality in young people due to unintentional poisonings.[[17]] Hence it is imperative that safety measures, such as increased awareness of potential toxicity and further child-proofing of these medication, are implemented to prevent PEIs with these medications as they can be potentially fatal.

Many commonly ingested substances have an unpalatable taste, and with increased safety methods having been incorporated into household items and medicines over the years, it is uncommon for significant amounts of any substance to be ingested. Hence PEIs are more likely to be poison scares rather than actual poisonings.[[18]] In this study, the majority of PEIs were triage three, meaning that these were not deemed to be immediately life-threatening. The fact that most patients experienced no symptoms or only minor symptoms during admission further indicates that the PEIs were relatively non-severe.  

Only a small proportion of patients received NAC, the antidote for paracetamol toxicity or activated charcoal. This study showed the single most commonly ingested substance was paracetamol, yet few received NAC or activated charcoal, suggesting that insufficient quantities were ingested to cause hepatotoxicity warranting active management. Dillon and Gee in 1999 found that 12% of children presenting with PEIs were treated with activated charcoal, whereas 88% received no decontamination.[[1]] Our study shows that the percentage treated with activated charcoal had declined markedly in 2019 compared to 1999. The reduction in active gastrointestinal decontamination likely reflects medical awareness that it is rare for PEIs to result in significant toxicity, and that the risks of the decontamination procedure may outweigh the risk of poison exposure.[[1,18,19]] In the last 20 years it has been recognised that children have a lower risk than adults of paracetamol toxicity for equivalent doses per weight. This is due to immature liver biotransformation enzymes. This has raised the dose thresholds to investigate and to treat children with paracetamol ingestions.[[20-21]]

Dillon and Gee also reported that 28% of PEIs were admitted to hospital, and that the majority were admitted for less than six hours.[[1]] Admission rates in 2019 for PEIs were double that reported in 1999, but of those admitted the majority (58.7%) were admitted for eight hours or less. The increased admission rate but comparable length of admission compared to 1999 may in part be due to the shift away from active gastrointestinal decontamination procedures towards observation followed by discharge. However, there was no significant difference in admission rates between PEIs and other paediatric presentations, suggesting that, of all the paediatric presentations, PEIs are not disproportionately admitted. In this study, the majority of those patients admitted went to CAA rather than PHDU. This further indicates the majority of PEIs seen in this study were low severity, which is consistent with the literature reporting the rarity of toxicity in PEI.[[1,18]]

Strengths and limitations

This study was conducted at Christchurch Hospital, which is a tertiary centre in New Zealand covering a large population. However, being a single-centre study, its generalisability may be affected by some likely variation in population demographics throughout New Zealand. Also note that exact comparable data for the 0–6 age group were unavailable for ethnicity and level of deprivation, and therefore numbers were estimated using available data.

Conclusion

The findings of this study are reassuring. Paediatric presentations due to exploratory ingestions in Canterbury reduced between 1999 and 2019. In Canterbury, most PEI presentations were in children 2 years of age. The majority of ingestions occurred at home, were low severity and did not require gastrointestinal decontamination. The decrease in paracetamol presentations over the years could be due to improved parental awareness and better National Poisons Centre triage. Unfortunately, the proportion of presentations with other, potentially more harmful medications, like opioids and psychiatric medications, increased. These medications are included on one pill can kill lists. Therefore, there is a need for increased awareness and safety around storage of these medications.

Appendix

Appendix Table 1: PEI ethnicity as a proportion of total population in children aged 0–4 years in CDHB.

[[a]] Expected % based on CDHB Official Information Act request reference #10466 using ages 0–4.[[b]] p-values based on chi square test for goodness of fit for each ethnicity.

Summary

Abstract

Aim

To quantify and describe presentations to a New Zealand tertiary hospital emergency department (ED) associated with paediatric exploratory ingestions (PEIs) during 2019 in comparison to 1999.

Method

A retrospective descriptive study was conducted of PEI presentations by children under 7 years of age to Christchurch Hospital ED between 1 January and 31 December 2019. Data were studied for demographic and management details and compared to data from 1999.

Results

There were 111 PEI presentations in children under 7 years during 2019, out of 9,445 presentations for this age group (1.2%). The estimated incidence of PEIs was 223.8 per 100,000. PEI presentations relative to total paediatric presentations had reduced compared to 1999 (X^2=94.7, p<0.001). Two year olds were most likely to have PEIs (odds ratio (OR)=15.01, 95% confidence interval (CI)=6.78, 33.22). Children of Asian (OR=0.50, 95% CI=0.26, 0.95) and Pacific (OR=0.34, 95% CI=0.12, 0.93) ethnicity were less likely to present with PEIs. Paracetamol was the most commonly ingested substance (15.3%), followed by opioids (11.7%).¬¬¬

Conclusion

Paediatric presentations due to exploratory ingestions reduced between 1999 and 2019. However, there was a concerning increase in ingestions of medications like opioids that have a significant risk of toxicity at low doses.

Author Information

Aditya Raina: House Officer, Capital and Coast District Health Board. Brennan Carne: House Officer, Canterbury District Health Board. Roshit Bothara: House Officer, Canterbury District Health Board. Andrew McCombie: Department of General Surgery, Canterbury District Health Board. Paul Gee: Emergency Department, Canterbury District Health Board. Laura Joyce: Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board.

Acknowledgements

The authors would like to thank Melanie Browne, Information Analyst, Canterbury District Health Board, for help in acquiring the data for this study.

Correspondence

Dr Laura Joyce, Department of Surgery, University of Otago; Emergency Department, Canterbury District Health Board

Correspondence Email

laura.joyce@cdhb.health.nz

Competing Interests

Nil.

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