aka Toxicology Conundrum 029
A 2 year-old boy is brought into the emergency department by his worried mother. While they were at a nearby cafeteria, the boy’s mother noticed two white tablets on the next table. A few minutes later the tablets were missing. She is sure that her son swallowed the tablets, probably about 30 minutes ago. He is currently well (searching the cubicle for something to put in his mouth) and has age-appropriate vital signs….Now what?
Questions
Q1. What is the risk assessment?
The ingestion of two unidentified tablets by a toddler is a challenging scenario.
With a completely well looking child, it is tempting to be reassured. Indeed most of the time the child will be completely fine. However, depending on whether the tablets were actually ingested, and the nature of the tablets, there is the potential for life-threatening toxicity. If there are tablets left over, these may be identifiable – but it may not be wise to assume that the ingested tablets were all the same…
Risk assessment in pediatric poisoning can be difficult because ingestion is often unwitnessed, making the determination of dosage and time of ingestion inaccurate, and often the exact agent ingested is uncertain.
Risk assessment, at least initially should be based on the ‘worst case scenario’:
- assume the time of ingestion is the latest time possible.
- assume all agents that are unaccounted for or missing were ingested.
- spillage is difficult to estimate – do not try to account for it.
- when more than one child is involved, assume that each child ingested all of the unaccounted for agent(s).
Consulting the Poison information Centre is always a good idea!
Q2. What tablets can be life-threatening even if only one or two are ingested by a small child?
The exact drugs on the ‘two pills can kill’ list will vary from place to place. In Australia they includes:
- Sodium channel blockers
- chloroquine (and hydroxychloroquine)
- dextropropoxyphene
- propanolol
- tricyclic antidepressants
- diphenoxylate/ atropine
- Calcium channel blockers
- verapamil, diltiazem
- Theophylline SR
- Sulfonylureas
- Recreational sympathomimetic drugs
- amphetamines and ecstasy
- Opiates
- methadone
- morphine
- oxycodone
Q3. When would you expect toxicity to develop for each of the agents listed in Q2?
Early toxicity (within a few hours)
- Sodium channel blockers:
- tricyclics, chloroquine, dextropropoxyphene, propanolol
- Amphetamines and ecstasy
Delayed toxicity
- Up to 8 hours for hypoglycemia from sulfonylurea toxicity
- Up to 12 hours for slow release formulations of:
- Calcium channel blockers
- Opioids
- Theophylline SR
Q4. What are the features of toxicity to look for in poisoning by the agents listed in Q2?
- Amphetamines and ecstasy
- agitation, confusion, hypertension, hyperthermia
- Calcium channel blockers
- delayed onset of bradycardia, hypotension, conduction defects, refractory shock
- see Toxicology Conundrum #028: Verapamil and high-dose insulin euglycemic therapy
- Chloroquine
- rapid onset of coma, seizures and cardiovascular collapse
- Dextropropoxyphene
- ventricular tachycardia
- Opioids
- coma, respiratory depression. May be delayed with controlled-release morphine or diphenoxylate/ atropine
- see Toxicology Conundrum #006: Buprenorphine
- Propanolol
- coma, seizures, ventricular dysrhythmias, hypoglycemia
- Sulfonylureas
- hypoglycemia
- Theophylline SR
- seizures, supraventricular tachycardia, vomiting
- see Toxicology Conundrum #014: Theophyline
- Tricyclic antidepressants
- coma, seizures, hypotension, ventricular dysrhythmias
- see Toxicology Conundrum #022: Tricyclic antidepressant
Q5. Described your approach to the management of this child?
If there are no immediate life-threats or resuscitation issues then the following management principles apply:
- Admit for at least 12 hours observation.
- Admit to a health facility that has the appropriate resources to observe, resuscitate and treat the child if evidence of toxicity occurs
- IV access can be deferred until early evidence of toxicity is apparent
- Check bedside glucose level:
- on presentation
- if there is any clinical evidence of hypoglycemia
- and at discharge
- Staff looking after the patient should be briefed on the clinical features for which the patient is being observed
- Monitor the following:
- level of consciousness
- vital signs (pulse rate, blood pressure and respiratory rate)
- early clinical features of hypoglycemia
- Perform an ECG and institute cardiac monitoring if there is any abnormality of conscious state or vital signs, or the child appears unwell
- Only discharge the patient during the day
Q6. What is the role of decontamination in this scenario?
In this case, I would not perform decontamination at this stage.
Decontamination in pediatric poisonings should never be a routine procedure. The decision to decontaminate should only be made if the benefits are thought to outweigh the risks. It is rarely indicated in asymptomatic children with normal vital signs, even if the risk assessment is based on the ‘worst case scenario’.
However decontamination should be performed if there is clinical evidence of early toxicity that may be life-threatening, or if the risk assessment indicates that supportive care and antidotal therapy alone will not be sufficient to ensure a good outcome.
References
- Bar‐Oz B, Levichek Z, Koren G. Medications that can be fatal for a toddler with one tablet or teaspoonful. Paediatric Drugs 2004. 6123–126. PMID: [15035652]
- Little G L, Boniface K S. Are 1–2 dangerous? Sulfonylurea exposure in toddlers. J Emerg Med 2005 Apr;28(3):305-10 [15769574]
- McCoubrie D, Murray L, Daly FF, & Little M (2006). Toxicology case of the month: ingestion of two unidentified tablets by a toddler. Emerg Med J. 23(9):718-20 PMID: 16921090 PMCID: PMC2564221
- Ranniger C, Roche C. Are one or two dangerous? Calcium channel blocker exposure in toddlers. J Emerg Med. 2007 Aug;33(2):145-54. Epub 2007 Jul 5. Review. PubMed PMID: 17692766.
- Rosenbaum T G, Kou M. Are one or two dangerous? Tricyclic antidepressant exposure in toddlers. J Emerg Med 2005. 28169–174. PMID: 15707813
- Sachdeva D K, Stadnyk J M. Are one or two dangerous? Opioid exposure in toddlers. J Emerg Med 2005. 2977–84. PMID: 15961014
- Smith E R, Klein‐Schwartz W K. Are 1–2 dangerous? Chloroquine and hydroxychloroquine exposure in toddlers. J Emerg Med 2005. 28437–443. PMID: 15837026
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About Chris Nickson
Thanks for the useful and coherent summary of a large amount of information!
I think there may be a small typo though. In the answer for #1 you wrote “Risk assessment in pediatric poisoning can be difficult because ingestion is often witnessed, making the determination of dosage and time of ingestion inaccurate, …” while I believe you meant to say, “ingestion is often UNwitnessed…”
Thanks again!
Karli-Rae -- you are correct of course -- glad someone is awake!
I have made the correction.
Thanks for the quality control (the blessing of web 2.0)…
Chris
Great summary! but . . . I’d never say that GI decontamination “should” be performed. It’s always a judgment call, and more and more I’ve found it difficult to image a scenario where the intoxication is severe enough where decon might be justified, yet not severe enough to cause manifestations that would make decon more risky. Obviously, ipecac-induced emesis is out, gastric lavage — in my opinion — is basically out, so that leaves charcoal. Usually safe and easy, so fine. But If the patient can not take the charcoal on his or her own, or is so groggy that the airway is or might turn out to be an issue, better for forego it and concentrate on basic support and any appropriate antidotes, or enhanced elimination. My motto: don’t just do something, stand there.
Can’t argue with your sage advice Leon. I completely agree.
Just to clarify things, in case my answer to Q6 has confused some readers, in the setting you mentioned regarding the groggy patient -- say from a tricyclic ingestion -- I would perform decontamination with activated charcoal to try to limit the severity of toxicity -- BUT only after securing the airway by intubating first and giving bicarbonate if indicated.
To be honest, I’ve very rarely given activated charcoal to an unintubated patient -- and have never given ipecac or performed gastric lavage… but I’m still a bit of a spring chicken you know
.
I think your comment nicely illustrates the tension between benefit and risk in the decision to decontaminate, and highlights that decon is generally much less important that meticulous supportive care and the infrequent occasions when specific antidotes or enhanced elimination may be of benefit.
Chris
would it help if the mother (or someone) actually ‘investigate’ further from the people sitting on the next table of what the medication it was?
Hi Pilocarpine,
Deeper investigation to obtain as complete a history as possible is crucial in trying to get as accurate a risk assessment as possible in tox cases. Unfortunately this particular scenario of a toddler swiping some pills that are lying around often doesn’t yield much more info -- e.g. the pills were left on an empty table, or if the pills are ‘dodgy’ no one is willing to volunteer any further information.
Regards,
Chris
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