Lipid rescue: a step forward in patient safety? Likely so!

John C. Rowlingson, MD In this issue of Anesthesia & Analgesia appear three case reports that add to an emerging literature documenting the resuscitation of patients from local anesthetic toxicity by the administration of lipid emulsion. These case reports follow the sentinel clinical report of Rosenblatt et al. and a subsequent report of ropivacaine toxicity reversal by Litz et al., that are the culmination of basic science investigation over the past 10 yr. The scholarly underpinning of this therapy has truly been evolving, and because we as doctors are also of the scientific mindset, we should respect and be inspired by the logical maturation of lipid emulsion therapy to the point of its application in the management of local anesthetic toxicity in humans. These case reports are particularly important now, given the prevalence of regional anesthesia and analgesia techniques in contemporary practice, and the fact that they sustain the creative use of a therapy that upholds the clearly established, commanding role that anesthesiology has taken in matters of patient safety. We must all take note of this significant advance in patient care. But first, a bit of the history that puts lipid emulsion therapy into perspective. Weinberg et al. investigated the possible metabolic connection of toxicity from only 22 mg of bupivacaine in a patient who was subsequently found to have carnitine deficiency. In their experimental model, it was demonstrated that inducing cardiotoxicity was profoundly more difficult in rats that had been pretreated with lipid. This led to intentional studies in rats, and then dogs, which established that animals given preor follow-up treatment with lipids for bupivacaine overdose recovered remarkably well. These data, originally from 1998, which suggested that lipid infusion had the potential to be a “. novel treatment of bupivacaineinduced cardiotoxicity,” set the scene for a trial of such therapy in actual patient management (which came 8 yr later! ). Rosenblatt et al. reported the first clinical application of such therapy in 2006, and Litz et al.’s report soon followed. Rosenblatt et al. reached the point of preparing to initiate cardiopulmonary bypass in the management of a 58-yr-old man who developed local anesthetic toxicity after an interscalene block with 20 mL 0.5% bupivacaine and 20 mL 1.5% mepivacaine, and who was failing to respond to routine cardiopulmonary resuscitation (CPR) measures. The administration of lipid emulsion was suggested. The classic medications used in resuscitation worked far better after a bolus of 100 mL of 20% Intralipid followed by an infusion of 0.5 mL kg 1 min . Their patient recovered completely, in spite of an impressive history of coronary artery disease (CAD), as did Litz et al.’s (after 40 mL 1% ropivacaine was used in an axillary block in an 84-yr-old woman). The case reports in this issue not only manifest similar clinical success but also broaden our appreciation for the potential benefits from the application of lipid emulsion therapy beyond that described previously. Litz et al. used 30 mL 1% mepivacaine in a 91-yr-old man with chronic obstructive pulmonary disease, hypertension, CAD, and reflux esophagitis From the UVA Health System, Charlottesville, Virginia. Accepted for publication July 17, 2007. Address correspondence and reprint requests to John C. Rowlingson, MD, UVA Health System, 1215 Lee St., Charlottesville, VA 22908. Address e-mail to jcr3t@ virginia.edu. Copyright © 2008 International Anesthesia Research Society DOI: 10.1213/01.ane. 0000282824.92276. 10