Gastric lavage: more harm than good?

We all know that sinking feeling when a patient has been known to have ingested highly toxic material and all effort to induce emesis had been unsuccessful. So, the next logical step is to perform a gastric lavage, isn’t it?

Maybe not….

In recent reviews of the effectiveness of gastric lavage^1-3 – using animal and human oral poisoning data over 50 years – it appears the procedure does more harm than good in most cases.

In fact, gastric lavage has been associated with worse patient outcomes (especially with aspiration pneumonia) and intensive care admission, while the omission of the procedure is not associated with poorer patient outcomes.

Exceptions to the rule

Saying that, some uncommon cases may benefit from gastric lavage, including:

• those that have ingested highly toxic material AND presented within 10 to 30 minutes from the time of ingestion
• toxic material that causes a delayed gastric emptying effect
• toxic material that is slow to dissolve and, thus, release its toxin
• toxins that form gastric concretions (chocolate, for example)
• extremely toxic substances such that even a small reduction is likely to result in substantial clinical benefits (for example, lily and paracetamol ingestion in cats)

The cases unlikely to benefit are those where it has been more than 60 to 120 minutes from the time of ingestion and toxins that are rapidly absorbed (ethanol, propanol, isopropanaol, ethylene glycol and aspirin, for example).

Last resort

Gastric lavage should only be considered if other less invasive and less risky techniques (oral activated charcoal or nasogastric aspiration) are not feasible, or if the potential benefit of lavage outweighs the potential risks.

Single-dose activated charcoal treatment has been found to be at least as effective as gastric lavage and significantly less risky in most situations.

Due to the inherent risks of gastric lavage, it should never be used for the sole purpose of collecting a toxicological sample.

If you find yourself having to perform a gastric lavage, here are some things I do to reduce the risk of aspiration:

• Elevate the tail end of the platform the patient is lying on 5° to 10°. This allows fluid to exit the mouth, rather than pooling around the pharyngeal area. I have seen patients aspirate despite an inflated endotracheal tube.
• I avoid administering activated charcoal down the stomach tube after lavage. Despite the fact it can save a hassle later, it is not uncommon for patients to vomit activated charcoal during recovery from anaesthetic.
• Empty as much of the lavage fluid from the stomach as possible before removing the stomach tube. I kink the tube as I remove it.
• Clear the pharynx of any fluid or oral secretion with suction or swabs before removing the endotracheal tube.