Gastrointestinal Decontamination: Common Sense vs. Limited Science Robert S. Hoffman, MD Director, 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

5 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

16

“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

22 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 be considered for patients who have ingested substantial amounts of iron

23

Real 10-Year Trends Therapeutic 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

25 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):

So What’s New?

Am J Emerg Med 2004:22:

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

41

[Ann Emerg Med. 2007;50: ]

“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?

47

Questions