BNF for Children 2011-2012

BNFC 2011–2012 Emergency treatment of poisoning 25sants, some antipsychotics, and some antihistamines.Arrhythmias often respond to correction of underlyinghypoxia, acidosis, or other biochemical abnormalities,but ventricular arrhythmias that cause serious hypotensionmay require treatment (section 2.3.1). If theQT interval is prolonged, specialist advice should besought because the use of some anti-arrhythmic drugsmay be inappropriate. Supraventricular arrhythmias areseldom life-threatening and drug treatment is best withhelduntil the child reaches hospital.Body temperatureHypothermia may develop in patients of any age whohave been deeply unconscious for some hours, particularlyfollowing overdose with barbiturates or phenothiazines.It may be missed unless core temperature ismeasured using a low-reading rectal thermometer or bysome other means. Hypothermia should be managed byprevention of further heat loss and appropriate rewarmingas clinically indicated.Hyperthermia can develop in children taking CNSstimulants; children are also at risk when taking therapeuticdoses of drugs with antimuscarinic properties.Hyperthermia is initially managed by removing allunnecessary clothing and using a fan. Sponging withtepid water will promote evaporation. Advice should besought from the National Poisons Information Serviceon the management of severe hyperthermia resultingfrom conditions such as the serotonin syndrome.Both hypothermia and hyperthermia require urgenthospitalisation for assessment and supportive treatment.ConvulsionsSingle short-lived convulsions do not require treatment.If convulsions are protracted or recur frequently, lorazepam100 micrograms/kg (max. 4 mg) or diazepam (preferablyas emulsion) 300–400 micrograms/kg (max.20 mg) should be given by slow intravenous injectioninto a large vein. Benzodiazepines should not be givenby the intramuscular route for convulsions. If the intravenousroute is not readily available, midazolam [unlicenseduse] can be given by the buccal route or diazepamcan be administered as a rectal solution (section4.8.2).Active elimination techniques Repeated doses ofactivated charcoal by mouth may enhance the eliminationof some drugs after they have been absorbed;repeated doses are given after overdosage with:CarbamazepineDapsonePhenobarbitalQuinineTheophyllineVomiting should be treated (e.g. with an antiemeticdrug) since it may reduce the efficacy of charcoaltreatment. In cases of intolerance, the dose may bereduced and the frequency increased but this maycompromise efficacy.Other techniques intended to enhance the elimination ofpoisons after absorption are only practicable in hospitaland are only suitable for a small number of severelypoisoned patients. Moreover, they only apply to a limitednumber of poisons. Examples include:. haemodialysis for ethylene glycol, lithium, methanol,phenobarbital, salicylates, and sodium valproate. alkalinisation of the urine for salicylates.Removal from the gastro-intestinal tract Gastriclavage is rarely required as benefit rarely outweighs risk;advice should be sought from the National PoisonsInformation Service if a significant quantity of iron orlithium has been ingested within the previous hour.Whole bowel irrigation (by means of a bowel cleansingpreparation) has been used in poisoning with certainmodified-release or enteric-coated formulations, insevere poisoning with lithium salts, and if illicit drugsare carried in the gastro-intestinal tract (‘body-packing’).However, it is not clear that the procedure improvesoutcome and advice should be sought from a poisonsinformation centre.The administration of laxatives alone has no role in themanagement of the poisoned child and is not a recommendedmethod of gut decontamination. The routineuse of a laxative in combination with activated charcoalhas mostly been abandoned. Laxatives should not beadministered to young children because of the likelihoodof fluid and electrolyte imbalance.Emergency treatment of poisoningRemoval and eliminationPrevention of absorptionGiven by mouth, activatedcharcoal can adsorb many poisons in the gastro-intestinalsystem, thereby reducing their absorption.The sooner it is given the more effective it is, but it maystill be effective up to 1 hour after ingestion of thepoison—longer in the case of modified-release preparationsor of drugs with antimuscarinic (anticholinergic)properties. It is particularly useful for the prevention ofabsorption of poisons that are toxic in small amountssuch as antidepressants.A second dose may occasionally be required whenblood-drug concentration continues to rise suggestingdelayed drug release or delayed gastric emptying.For the use of charcoal in active elimination techniques,see below.CHARCOAL, ACTIVATEDCautions drowsy or comatose child (risk of aspiration—ensureairway protected); reduced gastrointestinalmotility (risk of obstruction); not for poisoningwith petroleum distillates, corrosive substances,alcohols, malathion, and metal salts including iron andlithium saltsSide-effects black stoolsIndication and doseReduction of absorption of poisons. By mouthNeonate 1 g/kgChild 1 month–12 years 1 g/kg (max. 50 g)Child 12–18 years 50 g