2 out of 5 stars
Accuracy of Trans-Abdominal Ultrasound in a Simulated Massive Acute Overdose. Sullivan S et al. Am J Emerg Med 2016 Apr 23 [Epub ahead of print]
As soon as emergency portable bedside ultrasound became feasible approximately three decades ago, toxicologists wondered if it would be a useful modality for visualizing pills in the stomach of overdose patients.
The answer, clearly, is no it would not. This misguided paper illustrates why.
This randomized study had a study group (N=10) and a control group (N=10) ingest 50 enteric-coated placebo capsules plus 1 L fluid, or or 1 L fluid only. Ultrasound imaging of the stomach was performed and interpreted by 3 emergency ultrasound-trained sonographers attires 0, 60, and 90 minutes after ingestion. All subjects fasted for at least 6 hours before the study.
Without going into the weeds with precise numbers (consult the abstract if you’re really interested,) we can say that even under these ideal conditions, the sensitivity and specificity of the test were lousy. This is consistent both with the results of a previous pilot study and with common sense. Furthermore, the authors’ premise is ill-considered:
In many cases, traditional ED decontamination therapy with activated charcoal, whole bowel irrigation with polyethylene glycol, and gastric lavage are limited to the first hour post-ingestion. . . .If effective, ultrasound would allow visualization of ingested capsules in the stomach, and could potentially be used to expand the window of decontamination therapy beyond 60 minutes.
NO! As we’ve discussed before, gastric lavage and whole bowel irrigation (WBI) are outmoded, potentially dangerous interventions that should go the way of ipecac and free-range chicken dung as therapeutic options in poisoned patients.(To read our stand on this issue, click here.) The risk is that visualizing something that looks like it may be pills on the ultrasound might motivate the clinician to take unwise measures to go fishing for it. As for charcoal, the concept that a potential benefit might me limited to 1-hour post-ingestion never made any sense. If there are no contraindications (such as altered mental status or an unprotected airway) activated charcoal is relatively safe and easy to administer and is a reasonable option in potentially serious overdoses even hours after the fact.
We should note that, as the authors mention, most overdose patients do not drink 1 L fluid before presentation to improve imaging of the stomach. Also, they usually are not thoughtful enough to be NPO for at least 6 hours. Wo with poor results under ideal conditions, and no rational justification to pursue the topic, do the authors throw in the towel. NO! They conclude:
Further studies that have larger numbers of participants, recruited from actual patient populations, and address the non-fasting status of emergency department patients would be of benefit to make definitive conclusions.
No, it would not be of benefit. This is madness. Please stop. No more studies are needed. This is a blind alley.
Incidentally, in the course of their work the authors made an observation that confirms common sense: ” . . . although it was not a primary endpoint, we did develop a subjective appreciation for how difficult it is to swallow 50 enteric-coated capsules.
Use of ultrasound in toxic ingestions: good idea or wild-goose chase?