Gastrointestinal Decontamination: Common Sense vs. Limited Science Robert S. Hoffman, MD Director, NYC Poison Center Associate Professor Emergency Medicine.

Gastrointestinal Decontamination: Common Sense vs. Limited Science

Robert S. Hoffman, MDDirector, NYC Poison Center

Associate Professor Emergency Medicine and Medicine

NYU School of Medicine

Common Sense

• There are two ways to prevent the action of poisonings on the alimentary canal:

– Cause them to be rejected upwards or downwards

– Neutralize them

Oliva 1818

Common Sense

• In theory:– The proper use of emesis, lavage,

adsorption, catharsis and/or whole bowel irrigation on a select group of patients should reduce the amount of toxin available for absorption

– The less toxin available, the less toxicity

Common Sense

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What to Do When Evidence Is Lacking

• “Syrup of ipecac should not be administered routinely in the management of poisoned patients.”

• Gastric lavage should not be employed routinely, if ever, in the management of poisoned patients.

Complications

Kulig: Ann Emerg Med 1985;14:562

• Patients who were lavaged within one hour of ingestion had a clinically significantly improved outcome– Improvement in 16/17 vs 3/5 (p < 0.05)

Pond: Med J Australia 1995;163:345

• Overall deteriorated– Emptied: 6% Not emptied: 9%

• Overall improved– Emptied: 16% Not emptied: 13%

• Presented in 1 hour and deteriorated– Emptied: 10% Not emptied: 12%

• Presented in 1 hour and improved– Emptied: 16% Not emptied: 3% p=0.02

Activated Charcoal

Mechanisms of Action

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• “Single-dose activated charcoal should not be administered routinely in the management of poisoned patients.

• Based on volunteer studies, the administration of activated charcoal may be considered if a patient has ingested a potentially toxic amount of a poison (which is known to be adsorbed to charcoal) up to one hour previously.”

“In conclusion, based on experimental and clinical studies, multiple-dose activated charcoal should be considered only if a patient has ingested a life-threatening amount of carbamazepine, dapsone, phenobarbital, quinine, or theophylline.”

Complications

Complications

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Based on volunteer studies, WBI should be considered for potentially toxic ingestions of sustained-release or enteric-coated drugs particularly for those patients presenting greater than two hours after drug ingestion. WBI should beconsidered for patients who have ingested substantial amounts of iron

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Real 10-Year TrendsTherapeutic Nihilism

• Almost no ipecac use• Significant reduction in orogastric lavage• Less multiple dose activated charcoal

(MDAC)• Less single dose activated charcoal• Some whole bowel irrigation• Overall trend towards non-intervention

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What Is Poisoned?

Audience Test

• 25 year old man• Presents to the ER 1 hour after ingesting

100 (325 mg) enteric coated aspirin• CC: abdominal pain / looks well• ABG normal, ASA non detectable • What do you do?

It Depends on Who You Ask

• Telephone survey of 99% of North American poison centers and 7 toxicologists who drafted position statements

• Given this case to manage• 36 different courses of action

– Some harmful

– Juurlink DN and McGuigan MA J Toxicol Clin Toxicol 2000; 38(5): 465-470

So What’s New?

Am J Emerg Med

2004:22:548-554

• We found that AC is most effective when given immediately after drug ingestion but has statistically significant effects even when given as long as 4 h after drug intake.

• AC appears to be most effective when given in a large dose

Study Design

• Single blinded (n=422)• Placebo controlled• Single dose AC vs MDAC• Outcomes:

– Deaths– Life-threatening events

MDAC over 72 h reduced the death rate by 69%.

NNT = 18 patients [95% CI 10–90]).

Lancet 2008; 371: 579–87

• Referral patients– Most seen in previous hospital– Many already had GI decontamination– Overall presentation late– Poor supportive care– Not typical pharmaceuticals

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[Ann Emerg Med. 2007;50:593-600.]

“Despite widespread use of multiple gastric lavages for OP pesticide poisoning across Asia, there is currently no high-quality evidence to support its clinical effectiveness.”

Summary

• Many patients can be managed without GI decontamination

• Position Papers and Consensus Statements are based on poor evidence

• Logic must prevail• Try to identify people who are likely to

benefit from decontamination

Integration

• Where are you on the dose response curve?

• What is the likelihood that there is toxin in your gut?

• What are the risks and benefits of the procedure you are considering?

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Questions