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ACUTE POISONING Major C J Porter RAMC Army Medical Directorate Emergency Medicine Registrar Bristol Royal Infirmary Outline of lecture • • • • • • • Epidemiology Toxidromes History, examination and detective work General management Specific management Antidotes Scenarios EPIDEMIOLOGY • 4000 UK deaths per year (1/3 CO) • Most deaths outside hospital • 100,000 Hospital admissions (12%) • Not just overdoses: Illicit drugs, Alcohol EPIDEMIOLOGY • Self poisoning: • F>M • 1/3 >one drug • Taken with alcohol: F: 40% M: 60% • Repeated self-poisoning: 11% of admissions SUICIDE • 2% of male deaths • 1% of female deaths • Method: • Female: • Male: Poisoning 40% Gas / Hanging / Suffocation • Self-harm parasuicide: • 1% dead after 12 months • 3-5% dead after 5-10 years Toxidromes • Patterns of signs and symptoms • Useful to help in diagnosis and treatment of unknown poisons Opiates • • • • • • • Respiratory depression Cardiovascular depression Reduced level consciousness Pinpoint pupils Pulmonary oedema Hypothermia (Rapid response to Naloxone) Common causes • Opiates – heroin, morphine etc Sympathomimetics / Stimulants • • • • • • • • Agitation/delusions/paranoia Fight/Flight response Tachycardia Hypertension Arrhythmias Dilated pupils Seizures Hyperpyrexia Common causes • • • • Cocaine Amphetamines Decongestants Ecstasy Anticholinergic • • • • • • • • Tachycardia Arrhythmias Pupils: mid-point or dilated / divergent Confusion / drowsiness / coma Seizures Dry flushed skin Urine retention Hypertonia, Hyper-reflexia, Myotonic jerks Anticholinergic signs • • • • • Hot as a hare Blind as a bat Dry as a bone Red as a beet Mad as a hatter Common causes • • • • • Antidepressants-Tricyclics Antihistamines Atropine Antipsychotics Antispasmodics Serotonin Syndrome • Similar to anticholinergic syndrome – loss of consciousness: – sweating and tremor: • • • • • Agitation Delirium Hypertonia / myoclonus Tachycardia Tachypnoea uncommon common Common Causes • SSRIs • MAOIs (Hyperpyrexia / Hypertensive crisis) Cholinergic • • • • • • • Brady/tachycardia Confusion/reduced GCS Pinpoint pupils Seizures Weakness SLUDGE Pulmonary oedema SLUDGE • • • • • • S L U D G E sweating salivation lacrymation urinary frequency urgency diarrhoea gastrointestinal discomfort eyes pinpoint Common causes • • • • Organophosphates Physostigmine Some mushrooms Nerve agents Salicylism: Aspirin • • • • • Impaired hearing Tinnitus Sweating Warm skin Hyperventilation • Cinchonism: Quinine (salicylism + blindness) MANAGEMENT Management Overview • History & assessment of vital signs • ANY concerns: move patient to RESUS A • • • • • B C DEFG D Supportive care (O2, IV Fluids) Prevent absorption Increase elimination Antidotes PSYCHOLOGICAL ASSESSMENT History • • • • • What? When? How much? (mg/kg) What else? Why? Collateral history • • • • Paramedics Family / friends Notes Look in pockets – carefully!!! Detective work • • • • • • BNF Toxbase Tablet identification aids: TICTAC Poisons advice: NPIS Plant identification books National teratology information service Initial examination • • • • • • Treat problems as you find them!! Airway Breathing Circulation Disability – GCS/AVPU and Pupils DON’T EVER FORGET GLUCOSE Observations • • • • • • Saturations and respiratory rate Pulse and blood pressure GCS Pupils Temperature GLUCOSE Investigations • All Patients – Glucose – U&E – Paracetamol & Salicylate • As indicated – – – – – – LFT Co-ag / INR CK ABG / VBG ECG CXR • Urine toxicology screen Reduce absorption • • • • Emesis – No role Activated charcoal within 1 hour Gastric lavage – rarely Whole bowel irrigation - rarely Increase elimination • • • • • Urinary alkalinisation Multi-dose Activated Charcoal Haemodialysis Haemoperfusion Plasma exchange • Forced alkaline diuresis (no longer recommended) Paracetamol • • • • • • Very common: 40% poisons admissions Often asymptomatic Can be lethal – 200-300 deaths/year Check blood level at 4 hours Two treatment lines normal and high risk Given IV N-acetylcysteine Paracetamol metabolism • Metabolised by glucuronidation (60%), Sulphation (35%) and oxidation (10%) • Cytochrome p450 produces NAPQI • NAPQI toxic causes hepatocellular necrosis – irreversible binding • NAPQI detoxified by conjugation with glutathione Prescott Nomogram High Risk • Increased oxidation – Chronic alcohol use – Drugs • Reduces glutathione stores – Malnutrition – Eating disorders – Chronic liver disease N-acetylcysteine • • • • Most effective within 8 hours Precursor for glutathione production Can cause anaphylactoid reactions Consider starting before paracetamol result if: – Presenting > 8 hrs & >150mg/kg taken – Staggered overdose To treat or not to treat? Patient 1 • 20 year old woman who takes a handful of paracetamol tablets • No drug history • No alcohol use • Fit and well • Blood level is 80mg/l No need to treat • Patient is not high risk • Level at 4 hours is below even the high risk line Patient 2 • 70 year old man • Takes 20 paracetamol 6 hours before presenting • Alcoholic • No drug history • Blood level 100mg/l Treat • Patient is high risk • Level is above the high risk line • Delayed presentation means need to act fast Patient 3 • 17 year old epileptic • 25 codydramol 2 hours before attendance • Taking carbamazepine • Blood level at 4 hours is 120mg/l Treat • High risk patient • Level above the high risk line Patient 4 • 35 year old man who presents after taking 24 paracetamol over a period of 24 hours • No drug history • Fit and well • Blood level 20mg/l Treat • • • • Staggered overdoses are difficult Poisons advice is to give IV acetylcysteine Levels are not that helpful Need to monitor Liver function, clotting and renal function • May need discussing with Liver Unit if abnormal PARACETAMOL DEADLY PITFALLS • • • • The Prescott Nomogram High Risk Line Staggered Overdoses Management of late presentation Recheck U&E, LFT, INR after N-acetylcysteine Tricyclics • • • • Antidepressants Dangerous: US 60-70% fatal ODs UK commonest fatal OD per prescription 10% unconscious patient will fit – Treat fits with diazepam/lorazepam Tricyclic effects • Anticholinergic toxidrome • The 3 C’s – Coma – Convulsion – Cardiac Tricyclics cardiac effects • Quinidine effects lead to arrhythmias • ECG – – – – Sinus tachycardia Broad QRS: RBBB Prolonged QT interval Right axis deviation • Severe poisoning – VT, bradycardia, heart block • QRS > 160mS = ↑↑risk of seizures and cardiac toxicity Tricyclics • ABG – Hypoxaemia – Metabolic acidosis – Respiratory acidosis Tricyclics • Management: – EARLY ITU REFERRAL – SODIUM BICARBONATE • If hypotension resistant to fluid challenge • Dysrhythmias • Convulsions – Consider IV Magnesium for resistant dysrhythmia Salicylate • Salicylism • • • • • Dehydration Confusion /coma Seizures Haemetemesis Hypoglycaemia Salicylate • Metabolic and acid-base disturbance • Complex • Respiratory alkalosis – direct stimulation to over breathe • Metabolic acidosis- acid, impaired normal metabolism, production of lactic acid • Check ABG / VBG Salicylate • Severity of ingested dose: • >150 mg/kg: • >250 mg/kg: • >500 mg/kg: mild moderate severe Salicylate management • Tailor treatment to symptoms • Fluids • Reduce absorption: • Activated charcoal • Gastric lavage (>500 mg/kg and <1 hour) • Increase elimination: • Urinary alkalinisation • Cooling • Glucose if hypoglycaemic Salicylate management • • • • <350mg/L: oral fluids >350mg/L: urinary alkalinisation >700mg/L: haemodialysis DISCUSS WITH NPIS Salicylate DEADLY PITFALL • Salicylate levels can continue to rise following admission (10% of cases) – Repeat levels every until peaked Opiates • • • • • Common Act on μ-receptors Reversible with Naloxone Naloxone pure opioid antagonist Naloxone • Short half life: may need repeated doses • Give IV +/- IM & may need IVI Antidotes • • • • • • • • Opiates – naloxone Paracetamol – acetylcysteine/methionine Beta-blockers – glucagon Insulin – glucose Iron – desferrioxamine Carbon monoxide – oxygen Methanol - ethanol (Benzodiazepines – flumazenil) Scenario 1 • 20 year old IVDU found by ambulance crew unconscious • Needle lying by side • Resp rate 6, Sats 94% on air • 60bpm BP 100/55 • Responds to pain What next? • • • • A – Give naloxone B – Check airway C – Take history D – Give flumazenil Check airway • • • • • Check airway patent Give oxygen Call for senior help Check glucose Give naloxone IM and IV Scenario 2 • • • • • 30 year old woman Taken some white tablets 4 hours earlier Feels completely well Felt depressed after argument with partner Usually fit and well What next? • • • • A – Start N-Acetylcysteine B – Discharge as she is obviously well C – Find out what the tablets are D –Take blood for paracetamol levels Take bloods • Early treatment is essential in paracetamol overdose • Need to know what her levels are as soon as possible Scenario 3 • 45 year old man works in local aquarium • Put right hand into tank and got stung by a lion fish • Respiratory rate 16 sats 100% on air • Pulse 100 bpm 160/80 • Fully conscious • Extreme pain in hand Lion fish What next? • A – Panic you know nothing about lion fish! • B – Look on Toxbase • C – Ring local zoo • D – Ask a senior who also knows nothing about Lion fish! Toxbase • • • • • Patient needs cardiovascular monitoring Analgesia Hand in water as hot as can tolerate Lion fish toxin is heat labile Carefully remove spines if present • Few hours later patient feels much better goes home Summary • Common • Approach using: • • • • • ABCD DEFG Consider the toxidromes Early senior help / Early ITU referral Supportive Care Antidotes Psychological assessment Questions ?