Presentation on theme: "Dr Dunia Alhashimi Consultant pediatrician"— Presentation transcript:
1 Dr Dunia Alhashimi Consultant pediatrician ToxicologyDr Dunia AlhashimiConsultant pediatrician
2 Important areas to be covered Activated charcoal, mechanism of action, indications, contraindicationsCarbon monoxide Poisoning, signs and managementEthylene glycol, common forms, signs and symptoms,Hydrocarbons, types, Mgt
5 Q1A 10kg 14 month old boy is brought to the A&E by his parents. His parents claim that he possibly ingested paracetamol, as six 500mg tablets were found to be missing from the family’s paracetamol container. This possible ingestion occurred within a 60-min window efore their presentation to the Emergency department. Which of th following is the most appropriate management action?Measure plasma paracetamol levelsAdminister ipecauanha to induce emesisPerform a gastric lavageAdminster N-acetyl cysteineAdminister activated charcoal
6 Q1 Ans E: Administer activated charcoal The most appropriate management in this instance would be to administer activated charcoal, to limit further absorption of paracetamol, Inducing emesis with ipecuanha is now generally contraindicated. Measurement of plasma paracetmol level is useful only after 4 hours of ingestion. A gastric lavage maybe beneficial, but when you are given these five choices it would not be the first choice of treatment. N-acetylcysteine would not be the first line of treatment either.
7 Q2The nomogram is used to determine when a patient is give N-acetyl cysteine is administered in patients even if their levels are below the nomogram line. Which one of the following is not a risk factor?Alcoholismpatient on isoniazidept on cimetidinefastingmalnutrition
8 Q2 Ans: CIf the serum level falls between the two nomogram lines, consider giving NAC if the patient is at increased risk for toxicity; e.g. the patient is alcoholic, malnourished or fasting or is taking drugs that induce P-450 2E1 activity (e.g. isoniazide INH); after multiple or subacute overdoses; or the patient is considered uncertain or unreliable.
11 Q3A 3 year old boy was found with a empty packet of extended-release paracetamol tablet. The parents claim that he took 8 500mg tablet. You are called in the emergency and decide to do a drug level. When is the best time to do a paracetamol drug level in the patientsImmediately as the dose is very highA level stat and one after 4 hoursA level 4 hours after ingestionA level 8 hours after ingestionA level 8 hours and another after 12 hours
12 Q3 Ans:EAfter ingestion of extended release tablets, which are designed for prolonged absorption, there may be a delay before the peak paracetamol level is reached. This can also occur after co-ingestion of drugs is reached. In such circumstances, repeat the serum paracetamol level at 8 hours and possible after 12 hours.
13 Q4Which statement is true regarding liver toxicity from paracetamol overdose?It is likely because paracetamol plasma half-life is approximately 2 to 3 hours.It usually is evident 12 to 24 hours after ingestionFor a given toxic plasma level, children have a higher incidence of hepatic aminotransferase elevation than adults have.Hepatic toxicity results from N-acetyl-p-benzoquinonemime (NAPQ1)Diet, nutritional status, and age are not related to liver toxicity.
14 Q4 Ans: DLiver toxicity results when NAPQ1, a reactive intermediary, is formed by cytochrome P-450 activity. Glutathione conjugates NAPQ1 to nontoxic conjugates. In an overdose, glutathione is depleted, and NAPQ1 binds covalently with hepatocytes to produce hepatic necrosis.
15 N-acetylcysteine Most effective within 8 hours Precursor for glutathione productionCan cause anaphylactoid reactionsConsider starting before paracetamol result if:Presenting > 8 hrs & >150mg/kg takenStaggered overdose
16 Patient X15 year old girl who presents after taking 24 paracetamol over a period of 24 hoursNo drug historyFit and wellBlood level 20mg/l
17 Staggered overdose. (www.pharmweb.net) In patients who have taken several overdoses of paracetamol over a short period of time, the plasma paracetamol concentration will be more difficult to interpret as the treatment graph relates to a single acute ingestion.Such patients should be considered as at serious risk and considered for treatment with N-acetylcysteine (NAC).They can be discharged after NAC treatment or 24 hours from the last paracetamol dose provided they are asymptomatic and the International Normalised Ratio (INR), plasma creatinine and ALT are normal.
18 PARACETAMOL DEADLY PITFALLS The Prescott Nomogram High Risk Line Staggered OverdosesManagement of late presentationRecheck U&E, LFT, INR after N-acetylcysteine
19 Q5A mother brings in her 1-year-old after he drank from a Dettol bottle. What is the most common cause of mortality after Dettol ingestion?Neurological depressionAspiration pneumoniaGastric stricturesUncontrolled seizuresHypoglycemia
20 Q5 Ans: BDettol liquid (chloroxylenol 4.8%, pine oil and isopropyl alcohol) is a commonly used household disinfectant.Labeled nonpoisonous,Serious complications were reported in up to 8% of cases of ingestionincluded aspirations with gastric content resulting in pneumonia,cardiopulmonary arrest, bronchospasm, adult respiratory distress syndromesevere laryngeal edema with upper airways obstruction."Burning" in the mouth and throat with nausea and vomiting. Later contaminated skin becomes erythematous and there is redness, swelling and superﬁcial ulceration in the mouth and upper alimentary tract. The larynx may also be involved leading to breathlessness and stridor.
21 Q6Which of the following ingestions could be seen with an increased anion gap?ParacetamolIsopropanolEthylene glycolEthylene dibromideMethane
22 Q6 Ans: CThe etiologies of metabolic acidosis with elevated anion gap can be recalled with the mnemonic MUD-PILES:Methanol, Uremia,Diabetic ketoacidois, paraldehyde, Iron, Isoniazid or Inhlaants, Lactic Acidosis, Ethylene glycol or chronic Ethanol abuse, Salicylates or Solvents.In paracetamol poisoning metabolic acidois is uncommon.Isopropyl alcohol results in high srum keones with little or no acidosis
23 Q7Ethylene glycol poisoning is characterized by all of the following except:Metabolic acidosisIncreased anion gapHypocalemiaHypomagnesemiaHypokalemia
24 Q7 Ans: EMetabolic acidosis with increased anion gap is suggestive of methanol and ethylene glycol ingestion. Ethylene glycol toxicity results from its metabolite oxalate, which chelates calcium ion to form insoluble calcium oxalate crystals and results in hypocalcaemia. Hyopmagmasemia usually occurs with hypocalcemia. However, hyperkalemia results from muscle necrosis, the development of acute tubular necrosis and renal failure, and metabolic acidosis.
25 Q8A 13-year-old girl comes to the A&E with a history of ingesting a bottle of diphenhydramine (Benadryl) tablets. Which of the following signs and symptoms would be expected on examining the patient?Sweating, lacrimation, salivation, miosis, an blurred vision.Lethargy, slow respiration, hypotension, and lured vision.Agitation, tachycardia, sweating, and mydriasisFlushed face, agitation, dry mucous membrane, and dilated pupilsHeadache, tachycardia, tachypnoea, cherry red mucous membrane, and dim vision.
26 Q8 Ans: D Benadryl (diphenhydramine) is an anticholinergic agent. Toxidrome: Hot as a hare, Blind as a bat, Dry as a bone, Red as a beet, and Mad as a hatterA: anticholinesterase inhibitors or cholinergic agents (organophoshates)B: narcotic overdoseC: sympathomimetic agents (amphetamines)E: carbon monoxide poisoning
27 Common causes Antidepressants-Tricyclics Antihistamines Atropine AntipsychoticsAntispasmodics
31 Q9A 2-year old is brought to the A&E by his mother, who says her son may have ingested a few CBZ (Tegretol) chewable tablets used by his sibling. Which of the following clinical findings would best support the possibility of an ingestion?VomitingConfusion and excitationTachycardiaHyperreflexiaNystagmus
32 Q9 Ans: EDizziness, ataxia, and nystagmus with deviating pupils are the classic triad seen in CBZ toxicity.Although vomiting, confusion and excitement, tachycardia, and hyperreflexia are all possible signs of toxicity, the are nonspecific.
33 Q10A grandmother brings in her 15-month-old toddler who may have swallowed one clonidine tablet (0.1mg) about 30minutes ago. The child is sitting quietly on her lap with heart rate (HR) 80 beats per minute, her blood pressure (BP) 130/80 mm Hg, and respiratory rate (RR) 20 breaths per minute. Which of the following would be the most appropriate management of this patient?The patient can be discharged afte initial assessmentLook for other ingestants because hypertension is unlikely with a clonidine overdoseNalaxone 0.1mg/kg IV boluis should be given because the patient is bradycardiacEmesis should be immediately attempted with syrup of ipecacOnly supportive care and monitoring are needed because most patients recover in 12 to 24 hours
34 Q10 Ans: EAll children who are symptomatic after clonidine ingestion require admission, monitoring, and supportive care because symptoms may persist for up to 24 hours.Although the toxic dose of clonidine is not known, significant toxicity has resulted with as little as 0.1mg 30 minutes after ingestion.The central effects of clonidine predominate and cause tachycardia and hypotension, but initially there maybe peripheral α2 stimulation and reduced uptake of epinephrine, resulting in benign, transient paradoxic hypertension.
35 Q11A 2-year old who swallowed digoxin tablets is found to have bradycardia. An electrocardiogram (ECG) shows ventricular bigeminy. Which of the following is true?ECG findings of T wave depression and scooped ST segment correlate with significant digoxin toxicityDigoxin immune FAB (Digibind) is indicated for life-threatening dysrhythmiasThere is a wide margin between therapeutic and toxic dosesHyperkalemia is not affected by digoxin immune FAB (Digibind) therapyForced alkaline diuresis may increase renal excretion
36 Q11 Ans: BDigoxin immune FAB (Digibind) is indicated for use in treating life-threatening digoxin-induced dysrhythmias and for hyperkalemia. The ECG finding of T wave depression and scooped ST segemnts ar known as digitalis effect but do not indicate toxicity. Alkaline diuresis is not useful in digitalis elimination.
37 Q12Which of the following regarding caustic injury to the esophagus is true?Acid burns are usually deeper than alkali burns in the esophagus and thus cause greater long-term complicationsIf there are no orophayngeal lesions, esophagoscopy is not required because esophageal burns are unlikelyPatients who ingest caustics appear to have an increased risk of esophageal carcinomaOnly 50% of all stricture formation results within 2 months of ingestionAbout 10% of first-degree burns results in esophageal strictures
38 Q12 Ans: CDrain pipe cleaners usually contain sodium hydroxide as their principal components.Patients who ingest caustics have an increased risk of developing esophageal carcinoma.In the esophagus, acid burns usually cause a superficial coagulation necrosis with eschar formation of the mucosa, which limits penetration of the injury.However, bases causes liquefaction necrosis of the fat and protein involving the mucosa, submucosa, and muscle and penetrate deeply, causing the potential for greater tissue damage.Oropharyngeal lesions do not predict esophageal burns as only a third of patients with oral lesions develop esophageal burns, and about 10% to 15% of those with esophageal burns have no oral lesions.First degree burns do not develop strictures; 15% to 30% of second-degree do; and almost 100% of third-degree burns do
39 Q13A frantic mother calls you saying that her 2-year-old child just swallowed some household bleach. She gave him milk, which he drank without any drooling or vomiting. Which of the following is the most appropriate action to take?Tell the mother to give her son syrup of ipecac immediatelyTell the mother to bring her child to the A&E for endoscopy to rule out esophageal stricturesReassure the mother that it is a mild irritant and that her son will do fine as he has been drinking without problemsWarn the mother that because household bleach is an alkali, it can cause esophageal strictures even if oral lesions are not seenTell the mother to give her son antacid to buffer the effect of the bleach
40 Q13 Ans: CHousehold bleach contains chlorine or sodium hypochlorin, which is a mild irritant and usually causes no tissue destruction.Immediate dilution with water or milk is all that is required.
41 Salicylate DEADLY PITFALL Salicylate levels can continue to rise following admission (10% of cases)Repeat levels every until peaked
42 Q14Which statement most accurately describes the effects of insecticides?Carbamates create an irreversible bond with cholinesteraseOrganophosphates stimulate the release of excessive amounts of acetylcholine at the synaptic junctionInsecticide poisoning can be confirmed by a rise in cholinesterase level in the bloodHumans have no biotransformation mechanism for metabolizinig (detoxifying) insecticidesOrganophosphates inhibit the degradation of acetylcholine
43 Q14 Ans: EOrganophosphates exert their effect by interfering with the enzyme cholinesterase, which degrades acetylcholine but rather cause its accumulation by preventing degradation.Insecticide poisoning causes cholinesterase levels to fall, and this test can be used to confirm the clinical impression of insecticide poisoning.Humans are, in fact able to detoxify organophosphates by conjugation in the liver.Carbamates form a reversible bond with cholinesterase.In contrast, organophosphates irreversibly bind to cholinesterase via phosphorylation.
44 Q15Which statement most accurately characterizes the differences between organophosphate and carbamate poisoning?Carbamate exposure is more common than organophosphate exposureCarbamate poisoning is usually of shorter durationPralidoxime must be started sooner to be effective in carbamate poisoningOnly organophosphates are absorbed through the skimBoth answers B and C are correct.
46 Q16Which of the following statements concerning cholinergic poisoning treatment is most correct?Pralidoxime is used to prevent irreversible deactivation of cholinesteraseAtropine restores the biologic activity of cholinesteraseThe dose of atropine should not exceed 2 mgPralidoxime is more useful as a treatment for Carbamate exposure than for organophosphate exposureBronchorrhea must be treated by loop diuretics because atropine is ineffective for this
47 Q16 Ans: APralidoxime reactivates cholinesterase by competing for the phosphate moiety of the organophosphate compound, thus releasing if from the cholinesterase enzyme.Atropine counteracts the effects of acetylcholine excess but has no effect on the biological activity of cholinesterase.There is no maximum dose of atropine in insecticide poisoning.Rather, the dose is titrated to the patient’s clinical response.Loop diuretics such as frusemide should be avoided in insecticide poisoning because they exacerbate already excessive urinary output.Bronchorrhea generally is controlled with ventilation and atropine.
48 Q17A 22-month-old, 15-kg girl is found with an empty bottle of chewable vitamin tablets (15 mg of elemental iron per tablet). Although originally 100 tablets were in the bottle, the mother believes that at least 75 tables are found on the floor in the house. The child is asymptomatic when she comes to the ED 90minutes after the ingestion. Which of the following is the next most appropriate action?Administer an immediate dose of activated charcoal and observe for 6 hoursObtain a serum iron level, complete blood count, serum electrolytes, and liver function test and observe the patient for 6 hours in the EDObtain an abdominal radiograph, and if no iron tablets are seen, discharge the patient.Administer syrup of ipecac and observe for 6 hours in the EDAdminister a desferoxamine challenge of 50mg/kg intramuscularly
50 Q18Which of the following regarding Naloxone (Narcan) is most correct?It can be administered intravenously, intramuscularly, and endotracheally, but not intraosseouslyIt is often effective in reversing miosis associated with barbiturate overdoseIt can reverse the respiratory depression of a clonidine overdoseIt is effective with natural and semisynthetic opioids and is ineffective with synthetic opioidIt has agonist as well as antagonist effects at higher doses
52 Q18Naloxone has been shown to be effective antidote in narcotic and clonidine overdose, although its effect with clonidine is less consistent.Naloxone can be safely administered via all routes, including all intraosseous infusion.It is effective against all forms of opiods, including synthetic ones, but has no effect on barbiturate reversal.Naloxone is a pure antagonist with no agonist effects.
53 Q19A 13-year old boy comes in 3 hours after ingestion of salicylate. The maximal amount ingested is 35g of salicylate. He is complaining of tinnitus, nausea, and vomiting. At the time he arrives in the A&E his vital signs are BP 108/68 mmHg, P 124 beats per minute, and RR 26 breaths per minute. An arterial blood gas reveals a pH of 7.44, and his serum salicylate level is 44 mg/dl. Which of the following would not be expected in this patient?Normal anion gap metabolic acidosisElevateion of prothrombin time (PT)Lsctic acidosisHypoglycemiaDecreased serum ionized calcium
54 Q19 Ans :AA quick calculation indicates that the child in the scenario ingested approximately 20mg of elemental iron per kilogram. This is the lower range at which toxicity can occur.However, this child is currently asymptomatic. Because we cannot base our management approach on history alone, it is best to observe the child in the ED for symptoms while we wait for laboratory tests.Iron does not bind to activated charcoal, and its administration will not be helpful.An abdominal radiograph is useful when it is positive, but a negative abdominal radiograph is more commonly seen with chewable tablet ingestions.The use of ipecac is questionable in this case.A desferoxamine challenge test would be overly aggressive in this asymptomatic child with an estimated ingestion of 20 mg/kg.
55 Q20Which of the following statements concerning the patient described is most accurate?Activated charcoal is unlikely to be of value in this patient’s management because of the length of time since ingestionThe patient should not receive IV dextrose and NAHCO3 concomitantly because of the risk of cerebral edemaAlkalinization of the urine is unnecessary into his case because the salicylate level places the patient in the “mild” categoryEffective alkalinization of the urine will require adequate replacement of potassiumNaHCO3 therapy should be avoided because the patient’s serum is already alkaline
57 Q21Which of the following statements concerning the patient described is correct?Hemodialysis and hemoperfusion would be about equally effective in removing salicylate from this patientThe serum salicylate level indicates that dialysis will not be neededAn acute ingestion of salicylates is more likely to require dialysis than a chronic ingestionHypothermia, seizures, and renal failure are indications for dialysisIf pulmonary edema develops, dialysis should be avoided
59 Q22Which of the following statements concerning the patient described is correct?Hemodialysis and hemoperfusion would be about equally effective in removing salicylate from this patientThe serum salicylate level indicates that dialysis will not be neededAn acute ingestion of salicylates is more likely to require dialysis than a chronic ingestionHypothermia, seizures, and renal failure are indications for dialysisIf pulmonary edema develops, dialysis should be avoided
61 Q23Which of the following metabolic complications is most likely to occur in the setting of both therapeutic use and overdose of valproic acid?Elevated ammoniaElevated calciumElevated carnitineLow sodiumMetabolic alkalosis
62 Q23 Ans:A Disruption of urea cycle Metabolic acidosis, hypernatremia, hypocalcemia, low carnitine, elevated ammonia (complication of therapeutic use)Hyperammonia: MS changesSometimes hepatitis with bumps in AST/ALT.Carnitine may be beneficial.Very rarely renal failure, urea elevation
63 Q24 Activated Charcoal will adsorb all the following meds except: PhenobarbitalTheophyllineFerrous sulfateVerapamilSalicylates
64 Q24 Activated Charcoal will adsorb all the following meds except: PhenobarbitalTheophyllineFerrous sulfateVerapamilSalicylates
65 Q25A 10-month boy is brought in by his parents after he turned blue at home. The mother says he has been fussy recently, which she presumed to be caused by teething; she has been treating him with a topical teething gel. On exam, the boy has marked cyanosis, including the perioral area and nail beds, mild tachypnea and tachycardia, room air O2 sat 88% does not improve with oxygen. Lungs are clear; work of breathing and heart sounds are normal.
66 Q25Which treatment is most likely to be successful in treating the cyanosis?Botulinum antitoxinDeferoxamineMethylene blueProstaglandin E1Sodium bicarbonateRR normal, not ANo gi symptoms. No signs of iron toxProst E1 heart nlAsa? 02 normally improves.
68 MetHbCyanosis: increased deoxygenated Hb or abnormal pigments, e.g. silver (argyria)Oxidation of Fe in Hb from ferrous 2+ to ferric 3+: cannot bind O2, impairs 02 release from remaining normal Hb, shifting curve leftOverdose: benzocaine (teething gels), amyl nitrate, pyridium, sulfonamidesChocolate-brown bloodMethylene blue accelerates NADPH-methemoglobin reductase, contraindicated in G6PD, need exchange transfusion
71 Common Non toxic ingestions A variety of product commonly found around the home are completely nontoxic or have little or no toxicity after typical accidental ingestionTreatment is rarely required because the ingredients are non toxic or potentially harmful material is present in minimal doses
72 Confirm ingredientsIn all cases, attempt to confirm the identity and/or ingredients of the productEnsue no other toxic product was involvedAdvise parents that mild GI upset may occurWater or other liquid may be given to reduce the taste and texture of the product
73 Non toxic products Crayons Clay Silica gel Supergle Wax Zinc oxide ointment
74 Non toxic products with minimal gastrointestinal irritation Antibiotic ointmentBaby soapBar soapBleach ( household, less than 6% hypochlorite)Hair shampooPrednisoloneToothpaste
75 Other low toxicity products Oral contraceptives:In excessive amounts may cause GI upsetin females even prepubertal my cause vaginal spottingThermometer:Household thermometers contain less than 0.5ml liquid mercury which is harmless if swallowed. Clean cautiously to avoid dispersing mercury as mist or vapor (i.e. Do not vacuum)
76 Q26Whole bowel irrigation is recommended in all of the following ingestions except:Lead paint chipsCocaine packetsButton batteriesHydrocarbonsSustained-release lithium tablets
77 Q26 Ans:DWhole bowel irrigation is recommended in all of the following ingestions except:Lead paint chipsCocaine packetsButton batteriesHydrocarbonsSustained-release lithium tablets
78 GI Decontamination Whole Bowel Irrigation Heavy metals Sustained-release medsGoLytely500 – 2000 ml/hr25cc/kg/hr peds+/- metoclopropamide4-6 hours durationMay adsorb some methanol, ethylene glycol
79 Q27A 14-year-old girl comes to the ED I hour after ingesting 36g of sustained release-enteric coated aspirin tablets. Which of the following statements concerning this patient’s condition is true?It is unlikely that any aspirin remains in the stomach at the time the patients arrivesPeak serum levels of aspirin will occur at approximately 6 hoursThe pills should be visible on a plain radiograph of the abdomenManagement should be withheld until a serum drug level confirms the overdose or the patient becomes symptomaticArrangements should be initiated to perform hemoperfusion for the patient.
81 Q27Enteric-coated tablets are often visible on plain x-ray films, especially enteric –coated salicylate tablets.Salicylate induces pyloric spasm and forms concretions that adhere to the gastric mucosa, thereby making it probable that some aspirin remains in the stomach.Although the Done nomogram uses 6 hours for the peak level in salicylate overdoses, this is an overdose of enteric-coated tablets, and the nomogram is therefore unreliable because it is unlikely that the peak level will achieved in 6 hours.Because this is a potentially serious overdose, management should begin as soon as possible pending the results of the drug level.The definitive treatment of choice for salicylate poisoning is hemodialysis, not hemoperfusion.Arrangements need not be instituted until the levels are obtained from this patient because it is early in the poisoning and hemodialysis might not be necessary.
83 Salicylate Metabolic and acid-base disturbance Complex Respiratory alkalosis – direct stimulation to over breatheMetabolic acidosis- acid, impaired normal metabolism, production of lactic acidCheck ABG / VBG
84 Salicylate Severity of ingested dose: >150 mg/kg: mild >250 mg/kg: moderate>500 mg/kg: severe
85 Salicylate management Tailor treatment to symptomsFluidsReduce absorption:Activated charcoalGastric lavage (>500 mg/kg and <1 hour)Increase elimination:Urinary alkalinisationCoolingGlucose if hypoglycaemic
87 Q28Which of the following household substance, if ingested by a toddler, should cause the most concern?Silica gel (dehumidifying packets)Pencil leadEye make upMercury from a broken thermometerA whole cigarette
89 Q28A whole cigarette can produce symptomatic nicotine poisoning in a small child.Pencil lead, of course is not lead but carbon.Silica gel and eye make up are nontoxicThe amount of mercury ingested from a broken thermometer would also be non toxic, especially because its absorption would be minimal.