General approachResuscitate if neededRisk assessment – is what they have taken dangerous?Supportive Care and Monitoring depending on your risk assessmentInvestigations Everyone: Paracetamol level ECG Other as indicatedDecontamination – very rareAntidotesEnhanced elimination - rareSeek and treat complicationsDisposition – usually psych. Psych does the psych risk assessment forus.
ToxinologyCritters rather than drugs/chemicalsWe have one rare annoying, non-life threateningspider in NZ.Katipo = red back – painful bite and sweating +/-back pain -> analgesia + antivenom.Controversial whether antivenom actually works.
ToxicologyDrugs and chemicalsNot going to cover them all!
ToxidromeWhat’s a toxidrome?What are some examples?
ToxidromeClinical toxicological syndromeie you can examine a patient +/- look at their ECG orother bedside tests and get a good idea of what theyhave takenEgOpioidAnticholinergicCholinergic syndromeSerotonin syndromeNa channel blockade
ToxidromesOpioid: resp depression, decr LOC, miosisAnticholinergic: hot as a hare, mad as a hatter, red as a beet,dry as a bone eg daturaCholinergic syndrome eg organophosphate, nerve gas SLUDGEM: salivation, lacrimation, urinarination,diarrhoea, GI upset, emesis, miosis + muscle spasm Or DUMBELLS: diarrhoea, urination, miosis/muscleweakness, bronchorrhoea/bradycardia, emesis,lacrimation, salivation/sweatingSerotonin syndrome eg SSRI: sweating, agitation, increasemuscle tone, feverNa channel blockade eg tricyclic: hypotension, decr LOC,widened QRSRapidly alternating apnoea and coma eg GHB
Tox examHRRRPupil size and reactivity and look for nystagmusArmpits for sweatReflexes and test for clonusTempECGBSLLabs: almost everyone gets a paracetamol level Cheap test. Treatment very efficacious.
Some specific drugs / chemicalsCommon or important ones.
Paracetamol/acetominphenNB different units from UKCommonAlmost always reversible with antidoteHigh survival even from liver failureHow to you risk stratify and treat these ingestions?What is the antidote?
Paracetamol/Acetominophen Most common scenario: single ingestion, reasonable idea of time. < 10g or 200mg/kg ingested within 8 hours does not need investigation Otherwise or unknown: < 2 hours post ingestion of non-liquid and cooperative patient ->single dose activated charcoal. < 4 hours post ingestion: wait and take blood for paracetamol level at4 hours post ingestion. N-acetylcysteine (NAC) if over 1000µmol/L. 4-8 hours. Take level. NAC if over threshold on nomogram. 8-24 hours. Take level and start NAC. Stop treatment if undertreatment threshold. 24+ hours or unknown. Take level, VBG, LFT, glucose, INR, renalfunction. Start NAC. Stop NAC if ALT normal. If liver failure d/wliver unit
NACN-acetylcysteineVery safe and effectiveBoxes in ED with dose schedule written on them3 different rates over 24 hoursFairly frequent anaphylactoid reactionEg erythema, urticaria, pruritis, hypotensionThought to be from histamine release rather than trueanaphylaxisIf mild reaction half rate +/- give IV antihistamineIf severe reaction. Stop infusion. Give IV antihistamine +/-bronchodilators, fluids etc. Once asymptomatic for 1 hourrestart infusion at ¼ rate and titrate up
DispositionIn this hospital all patients requiring NAC getadmitted to ward under medical team.Inform psych of admission. They say they will seepatient before “medically cleared”
SSRIsUsually no significant toxicityMain risk is serotonin syndromeWhat is serotonin sydrome?
Serotonin SyndromeRareExcess serotonin usually from over dose of SSRI orcombination of serotonergic agentsEgSSRI, St John’s wortAntipsychoticsLithiumPethidineTramadolLSDEcstacy and other amphetamines
Serotonin SyndromeSerotonergic drug +Mild: Tremor, anxiety, nauseaModerate: agitation and hyperreflexia and clonusSevere: severe: fever, seizures, respiratory failure,rhabdomyolysis, renal failure, DIC
Serotonin syndromeManagementMild: observe for 4-6 hoursModerate: IV fluids, benzodiazepine, +/-cyproheptadineSevere: cooling, IV benzodiazepine, IV fluid. May needRSI
So for all overdoses of serotonergicagent need ...RecordTemperatureToneReflexesClonus
CCB or Beta BlockerHypotension and bradycardiaMost beta blockers fairly benignException: propranolol: Na channel blocking effect:manage as for tricyclic + Beta blockerCalcium channel blockers: nastyTreatment?
Beta blocker + CCBResuscitate if required: ABCsRisk assessment: look up to see how toxic the dose could be.Supportive care and monitoring: if moderate risk: resus bay, IVaccess, cardiac monitoring, IV fluids, trial of atropine, calciumgluconate, pressors eg dopamine. If high risk likely to needintubationInvestigations: ECG, paracetamol level, lactate, glucose.Decontamination: Whole bowel irrigation likely to be neededeg Polyethylene glycol via NG tube
Beta blocker + CCBAntidote/specific treatments: could call calcium anantidote to CCB, glucagon 5mg IV, high dose insulin 1unit/kg then 1unit/kg/hourEnhanced elimination: dialysis ineffective. Multidoseactivated charcoal may be effective for CCB.Seek and treat complications: Likely to need ICUcare. Monitor for MOF, rhabdo etc
If all of the above wasn’t working what else could bedone?
Intraarterial balloon pumpBypass/ECMOMost life threatening drug ingestions causetemporary CVS collapse – if we can support themthrough this the patient should do well
SulphonylureasAntidote: IV glucose then IV octreotide
IronWhat’s important about ironWhat’s the antidote
IronCan be life threatening and yet the patient isasymptomatic, or has recoveredLook it upMost accidental ingestions not harmfulOver a threshold ingestion -> iron levels usefulLow threshold for whole bowel irrigationAntidote: desferoxamine
DigoxinWhat are the 2 main types of toxicity?What are the classic signs and symptoms?What is the antidote?
Digoxin2 main types of toxicity: Acute ingestion – rare Chronic – usually due to dehydration/renal impairment Consider this in any patient on digoxin who is unwell. Check ECG, K+ anddigoxin levelClassic signs and symptoms Yellowed vision Nausea and vomiting Confusion Cardiac automaticity (ectopics or tachyarrythmia) and blockWhat is the antidote? Digoxin FAB fragments – “digibind” Expensive but cost effective
Indications for Digoxin FABHemodynamically unstable or life-threateningdysrhythmia,Hyperkalemia > 6 mmol/L (6 mEq/L)Plasma digoxin level > 20 nmol/L (15.6 ng/mL) at 6hours post-ingestionDigoxin level > 10 nmol/L (7.8 ng/mL) or elevateddigoxin level + renal impairment + symptoms inchronic toxicity
Local anaestheticEg femoral nerve block -> intraarterialClassic signs?
Local anaestheticPerioral tinglingOthers:Visual disturbanceSeizureVTAntidote?
Local anaestheticIntralipid? Lipid sink? Cardiac fuel
Blue apnoeic patient dumped at the front door.He has pin point pupilsHow will you manage this patient?
IV opioid toxicityLots of techniquesBVM ventilate400mcg IM naloxone200mcg IN naloxone
Oral opioid toxicityIf significant respiratory/LOC depression usuallyrequire naloxone infusionTitrate IV nalaxone boluses to get just adequatereversal – don’t make the patient withdraw and runInfusion of 2/3 of reversal dose/hour
Neuroleptic Malignant SyndromeWhat is it?What do you do about it?
Neuroleptic malignant syndromeRareUsually an idiosyncratic reaction to standard/highdoses of antispychotic rather than a result ofoverdosage.Life threatening“Malignant Parkinson’s”Parkinsonism + fever + autonomic instabilityDoesn’t have the agitation, hyperreflexia or clonus ofserotonin syndrome
Neuroleptic malignant syndromeIf temp > 39.5 or rigidity compromising ventilation ->RSICool to 38-39˚BenzodiazepinesTreat hypoglycaemiaBromocriptine +/or dantrolene
“My child might have taken some of granny’spills”Try to work out what Granny is onDefaultBlood sugarBPECGIf abnormal or toxidrome: IV line and treat empirically.If normal: Observe 12 hours. Discharge if BP and BSLnormal
FlumazenilAntidote to benzosAlmost never usedOnly used if we caused the ODFor chronic benzo users or coingestion with aproconvulsant (eg TCA) flumazenil may cause seizureBenzos almost never need treatment or intubationRecovery position, wait for them to wake up
AlcoholAlmost never needs intubationRecovery position and observeLOC should improve hourly – if not consider otherdiagnosis eg head injury
Activated charcoalAlmost never usedLittle proof of efficacyHas killed people - aspiration
Hydrofluoric acidNasty. 2% BSA exposure can kill
WarfarinVitamin K and prothrombin complex(prothrombinex)