MARS: will liver dialysis prove beneficial in massive diltiazem overdose
May 20, 2012, 8:35 pm
Survival despite extremely high plasma diltiazem level in a case of acute poisoning treated by the molecular-adsorbent recirculating system. Belleflamme M et al. Europ J Emerg Med 2012 Feb;19:59-61
No abstract available
The molecular-adbsorbent recirculating system (MARS) is a form of liver dialysis, a detoxification treatment for liver failure that can also be used to enhance elimination of protein-bound poisons. It a somewhat simplistic way, it can be thought of as an artificial liver, similarly to the way hemodialysis can be considered a form of artificial kidney.
MARS has been used in scattered case reports to treat poisoning from acetaminophen, Amanita phalloides, phenytoin, lamotrigine, theophylline, and calcium channel blockers. This report describes a 70-year-old woman who ingested an unknown amount of sustained-release diltiazem and presented with shock and lactic acidosis. Her diltiazem level on admission was 2209 ng/ml (therapeutic, 50-200 ng/ml). The level continued to rise, reaching over 20,000 ng/ml at approximately 12 hours after admission. The authors report that the patient’s hemodynamic status did not improve after multiple interventions, including hyperinsulinemic-euglycemic therapy; unfortunately, they give no details about the dose of insulin administered, so it is impossible to determine whether that claim is accurate. When MARS therapy was started approximately 45 hours after admission, the diltiazem level, which had remained significantly elevated, decreased dramatically.
Unfortunately, it is not clear from this anecdotal report whether the patient’s ultimate complete recovery could be attributed to the use of MARS. The authors are circumspect in their conclusion: “The apparent clinical and toxicolkinetic improvement obtained by the use of the MARS technique has to be confirmed by further observations”.
My own feeling is that MARS is an expensive adjunct that will not be generally available anytime in the foreseeable future. It might have utility in specialized hepatic centers as bridge therapy until a patient’s liver recovers or a transplant is done. Certainly there is not nearly enough information to evaluate its use as a means of enhanced poison elimination, and there probably won’t be an any of our lifetimes.
Those with further interest in MARS are referred to a comprehensive but annoyingly unfocused recent review article.