Presentation on theme: "ACUTE POISONING IN ADULTS"— Presentation transcript:
1ACUTE POISONING IN ADULTS Leilah DareSpR Emergency Medicine
2Acute Poisoning in the Emergency Department Common - 3-5% of ED attendances2000 Deaths per yearSome of the highest rates of deliberate poisoning in EuropeOften multiple drugsDON’T FORGET ALCOHOL !!
3Summary of LectureGeneral Principles in the Management of ANY PoisoningSpecific management options with certain substancesParacetamolOpiates (Heroin, Methadone, Morphine)Salicylates (Aspirin)Tricyclic Antidepressants (e.g Dothiepin)
4General Management -History Applies to ANY episode of PoisoningWHATHOW MUCH (Ideally mg/Kg)WHENWHAT ELSE (Including Alcohol)WHYUse Paramedics, friends, relatives, anyone!!
5General Management -1 A (Airway) B (Breathing) C (Circulation) D (Disability-AVPU/ Glasgow Coma Scale)DEFG ( Don’t ever forget the Glucose)GET A SET OF BASIC OBSERVATIONS
6General Management -2 Use all your senses, search for the clues LOOK Track MarksPupil SizeFEELTemperature, SweatingSMELLAlcohol
7Specific Management Options-1 DECREASING DRUG ABSORPTIONGastric Lavage ( Unpopular - need to protect the airway, may push drug through pylorus into small bowel.)Absorbants ( Activated Charcoal , usually within 1 hour of ingestion, longer repeated doses in drugs that delay gastric emptying e.g. Aspirin)
8Specific Management Options -2 INCREASING DRUG ELIMINATIONAlkaline Diuresis (Aspirin)Haemodialysis (Aspirin)
9Specific Management Options - 3 ANTAGONISING THE EFFECTS OF THE POISONDesferrioxamine (IRON)Naloxone (OPIATES)N Acetylcysteine (PARACETAMOL)
10Specific Poisons- Paracetamol Commonest drug used50% of all Self Poisoning Episodesdeaths per yearDANGEROUS AND PEOPLE DON’T KNOW IT. YOU FEEL WELL AND THEN THE LIVER FAILURE SETS IN..
11Paracetamol-Normal Metabolism Paracetamol converted to:N-Acetyl-p-benzoquinonamine (TOXIC)This is conjugated with GlutathioneGlutathione stored in the bodyProduces a NON TOXIC metabolite
12Paracetamol Metabolism in Overdose Glutathione stores are used up by the excess ParacetamolToxic Metabolite build upBinds IRREVERSIBLY to Hepatic Cell membranesResulting in LIVER NECROSIS
13Paracetamol Overdose-management Initial ABC ( usually well systemically)Get a good historyTIME TAKEN, AMOUNTAny other medicationHistory of Liver diseaseN-Acetylcysteine. Shown to be advantageous if given in the first 10 hours
14N - Acetylcysteine Specific antidote used for Paracetamol Provides the Sulphydryl groups needed to increase the availability of GlutathioneSo that Body can turn the TOXIC metabolite into the non toxic form and prevent Liver Cell Damage and NECROSISProblem: Not shown to be effective after 15 hours
15Paracetamol Management Able to measure levels of Paracetamol in the blood.Helps to guide whether amount taken is enough to be HepatotoxicIF IN DOUBT start treatment before the Paracetamol levels get back to save time
16Paracetamol Management-Pitfalls Patients with Liver Disease/ AlcoholicsDepleted stores of Glutathione will start to get toxic build up sooner than healthy peopleStaggered OverdosesLevels unreliableAfter 15 hours- what do you do??
17Paracetamol Management TIMEBOMB WAITING TO HAPPENIF HAVE LATE PRESENTATION HAVE TO MONITOR FOR IMPENDING LIVER FAILUREREFER TO SPECIALIST LIVER UNITPEOPLE DIE FROM THIS
18Opiate Poisoning- Features Common (particularly in BRI)Heroin, Methadone, Analgaesics in ElderlyAction on the mu receptors giving the effects in overdose.1. PINPOINT PUPILS2. RESPIRATORY DEPRESSION3.COMA
20Opiate Overdose-Management 2 NALOXONEOpioid antagonistHigh Affinity for the opiate receptorsLittle other effectsRapid onsetEffects last 2-4 hrs, may need repeated dosesGive I-M or I-V
21Salicylate (Aspirin) Poisoning Toxicity occurs due to disturbance in Acid-Base Balance1. Respiratory Alkalosis2. Metabolic Acidosis
22Aspirin Poisoning- mechanism 1 1.Direct stimulation of the respiratory centre makes you overbreathe. Hyperventilation and Respiratory Alkalosis.2. Kidney attempts to compensate for the alkalosis by excreting alkali to give you a metabolic Acidosis3. Aspirin inhibits the normal metabolic pathways
23Aspirin poisoning- mechanism 2 3. Aspirin inhibits the normal metabolic pathways, so you get failure of the normal metabolism of CHO, Fats and Protein.Build up of Organic AcidsKETONES, LACTATE AND PYRUVATECAUSES MORE METABOLIC ACIDOSISMETABOLIC ACIDOSIS, BAD NEWS
25Aspirin Overdose-Management Initial Supportive therapy. If small amounts and asymptomatic may need no treatmentManagement tailored according to the amount takenAble to take Salicylate levels to help guide treatment options
27Aspirin Management - Specific When extremely high levels of Aspirin have been ingested and the patients are symptomatic steps may be taken to-1. DECREASE ABSORPTION2. INCREASE DRUG ELIMINATION
28Aspirin- Decreasing absorption Activated CharcoalGiven in those who have taken more than 250mg/Kg body weight less than 1 hour agoGastric LavageMay be considered in those who have taken more than 500mg/kg body less than 1 hour ago. Steps must be taken to protect the airway
29Aspirin-Increasing Drug Elimination Urinary AlkalinisationIf you increase urinary pH from 5 to 8 there is a fold increase in the renal salicylate clearanceThis is done by giving an infusion of Sodium Bicarbonate. Care must be taken because this in itself is dangerous and can cause severe Acid Base Disturbances
30Aspirin- Increasing Drug Elimination HAEMODIALYSISUsed in severe life threatening overdoseAims to correct the Acid Base disturbances while removing the Salicylate
31Tricyclic Antidepressants Seen relatively frequentlyCan be fatalCan be very symptomatic, effects made worse by alcoholMain effects are on the Heart and BrainEffects are1. Anticholinergic2. Quinidine like
32TCA Overdose- Clinical features ANTICHOLINERGIC EFFECTSDry Mouth, Dry Eyes, Dilated Pupils, Urinary Retention, Blurred Vision, Dizziness, Palpitations, Pyrexia without sweatingCNS Effects- Confusion, Delerium, Coma, Convulsions, Myoclonus and Respiratory Depression
34TCA Overdose- Management 1 Mainstay of initial management is Supportive. Try not to give other drugs ontop with a few specific exceptionsA- May need intubatingBC- Give IV fluids if low BPD -Control convulsions with Diazepam
35TCA Overdose Management 2 Activated Charcoal if more than 4 mg/Kg within 1 hour.N.B WATCH OUT FOR THE AIRWAYCorrect Hypoxia with OxygenCorrect Acidosis with Na BicCorrect any arrythmias with Na Bic (i.e start by controlling the acid base disturbance)
37SUMMARY Get as much history as you can, know your enemy Mainstay of any poisoning is SupportiveDon’t Forget the ABCFor specific substances there maybe antidotesFor Specific circumstances consider decreasing the absorption or increasing the elimination of the drug.