Detoxification protocols – Current practice guidelines on gastric lavage and charcoal usage

1. Detoxification protocols –Current practice guidelines on gastric lavage and charcoal usage Dr Binila Chacko MBBS, MD Gen Med, DNB, FCICM, DM Crit Care Professor Medical ICU Christian Medical College, Vellore 632004

2. Introduction • No good evidence to show that "routine” GI decontamination improves outcomes • Historically many approaches • Gastric evacuation • Forced emesis • Gastric lavage • Intragastric binding • Activated charcoal • Speeding transit • Whole bowel irrigation

3. Usual questions in toxicology • Is the ingestion is potentially dangerous? • The evidence • Does it actually work? • Is it safe? Benefits versus risk

4. Gastric lavage and activated charcoal

5. Outline • What do the guidelines say? • The evidence • Should I use it or consider it?

6. Gastric lavage

7. History • 1822 • Juke’s exhausting pump and Bush’s gastric exhauster for opium ingestion • Standard approach until the 1990s • Difficulty in performing procedure on children • Limited evidence of benefit

8. The “recommended” procedure • Protect airway if impaired level of consciousness • Left decubitus position with 20° head down • 36-40 Flubricated lavage tube • 200 mL aliquot of warm water or NS • Repeat administration and drainage until the effluent is clear • 2 main contraindications include ingestion of corrosives and hydrocarbons

11. Over the years, steady decline in the use of gastric lavage • The evidence • The contraindications • The complications

12. The evidence-1 • Animal studies • No studies since 2004 • Does not mimic human exposure since • Most animals are anesthetised/analgesia-slows motility • Single drug dosage

13. The evidence-2 • Experimental studies • Volunteers Recoveries of radiolabelled markers 84% 5 minutes after ingestion to 30% at 19 minutes….

14. The evidence-2 • Experimental studies • Volunteers • Poisoned patients • Case reports ✔

15. The evidence-2 • Experimental studies • Volunteers • Poisoned patients • Case reports • Clinical studies

16. Complications • 2004 position statement • Aspiration pneumonia • Laryngospasm • Arrhythmia • Esophageal or stomach perforation • Fluid and electrolyte imbalance • Conjunctival hemorrhages 50% developed likely aspiration 3 died soon after the procedure Also a risk of propulsion of gastric contents into the small intestine ??may facilitate drug absorption

17. To summarise • Would I use gastric lavage in poisoning? • No • Why not? • Several studies have shown lavage was ineffective in altering clinical course after 2-3 hours after ingestion • Even if performed early • 30% toxin removal when performed within the first 20 minutes and 8% within 60 minutes • Risks outweigh the benefits –NOT RECOMMENDED • Any situation where one may use it? • No • ??role in hypothermia in the setting of a poisoned patient

18. Activated charcoal 2 crazy French professors 1831

19. What is it? • Highly adsorbent powder • Superheated, porous particles produced by pyrolysis of organic material. • Carbon-based network • Adsorbs chemicals within minutes of contact • Extensive surface area • 175000m2per 50 g bottle

20. Stoichiometric relationship • Higher ratio of charcoal : drug will more effectively inhibit systemic absorption • 10:1 is ideal but some reports suggest that a 40:1 might be superior

21. The dose • AC : toxin ratio of 10:1 to be effective • Generally • <1 year : 10 to 25 g, or 0.5 to 1.0 g/kg • 1 to 12 years : 25 to 50 g, or 0.5 to 1.0 g/kg (max 50 g) • Adolescents and adults: 25 to 100 g (with 50 g representing the usual adult dose)

22. Different ways in which AC is used in toxicology • Evidence • Indications • Complications

24. Position statement 2005 • SDAC should not be administered routinely to poisoned patients. • No evidence that charcoal administration improves clinical outcome. • Unless a patient has an intact or protected airway, the administration of charcoal is contraindicated.

26. What did that say? • As with all medical interventions, SDAC should be given • Only to patients in whom its use can reasonably be expected to reduce morbidity • Benefit must outweighits risks.

27. The evidence • Animal studies • Volunteers • 50g SDAC • 47.3% at 30mins • 40.1% at 60mins • 16.5% at 120 mins

28. In poisoned patients • 2 randomised trials • Benzodiazepines, paracetamol and SSRI • >80% presented 4h after ingestion • No differences between AC and no decontamination (LOS/Mortality)

29. Other reports • Several case series on anti-depressant overdose (citalopram, sertraline, venlafaxine) • Decreased drug bioavailability even when administered within 4 hours of ingestion • No study has looked at efficacy of SDAC if given promptly 1-2 hours

30. Recommendations based on the evidence Toxin Patient Alert, co-operative patient Absence of ileus or intestinal obstruction • Substance known to adsorb to AC • Lack of specific antidote • Serious toxicity anticipated • Favorable stoichiometry (40:1) • Modified release product • Recent ingestion up to 4 hours

31. Multi-dose Activated charcoal Purpose- to increase poison elimination rather than decrease absorption

32. Volunteer studies • Significant decreases in elimination t1/2 of • Phenytoin • Nortryptiline • Aminophiline • Phenobarbitone • Carbamazepine • Digoxin • Dapsone

33. The median time to reach a subtoxiclevel (p = 0.049) Control arm 41.1 hours (range, 11.6-196) Charcoal arm 19.3 hours (range, 13-33)

34. Reduce absorption • Activated charcoal • Large open labelled RCT in Sri Lanka • 3 groups – 50 gm 4 hourly of charcoal, placebo, 50 gm single dose • Total of 4632 patients • no charcoal (n=1554), • one dose of charcoal (n=1545) and • 3 doses of charcoal (n=1533) Eddleston M, Juszack E, Buckley NA et al. Multi-dose activated charcoal in acute self-poisoning: a randomised controlled trial. Lancet 2008; 371: 579-587

35. Reduce absorption Eddleston M, Juszack E, Buckley NA et al. Multi-dose activated charcoal in acute self-poisoning: a randomised controlled trial. Lancet 2008; 371: 579-587

36. Editorial

37. MDAC - As of now.. Not useful May be useful Carbamazepine Phenobarbitone Phenytoin Dapsone Quinine Theophylline • OP poisoning • Oleander poisoning

38. Complications of activated charcoal • Generally safe • Pulmonary aspiration-very low risk • More with excessive dosing 300mg over a 6 hour period • GI complications more with MDAC • Bezoars • Stercoliths • Bowel obstruction

39. Contra-indications SDAC and MDAC

40. Where will charcoal not work? • Acids and alkalis • Corrosives • Metals • Iron • Lithium • Potassium • Lead

41. Charcoal hemoperfusion

42. What is it? • AC-containing cartridge added to the circuit of a hemodialysis machine. • Indications • Toxins that are adsorbed to activated charcoal. • Small volume of distribution • Can also remove plasma protein bound toxins • Hemoperfusion used to be preferred to hemodialysis • Reports of benefit with • Theophylline • Aluminum • Phenobarbital • Aspirin • Now with high flux filters dialysis is preferred

45. Take home message • Gastric lavage • Not recommended by International toxicology societies • Activated charcoal • No strong evidence to refute or validate SDAC • Can be considered for toxins up to 4 hours post ingestion with no antidote • MDAC possible role in anti-epileptic overdose(phenobarb, phenytoin, carbamazepine) • Charcoal hemoperfusion recent benefit in paraquat poisoning