Lipid emulsion infusion is an emerging antidotal therapy for toxin-induced cardiac arrest. To compare the efficacy of resuscitation from bupivacaine-induced asystole using lipid emulsion infusion vs. vasopressin, alone and with epinephrine.
Prospective, randomized, animal study.
University research laboratory.
Adult, male Sprague-Dawley rats.
Instrumented rats were given an intravenous bolus of 20 mg/kg bupivacaine to induce asystole (zero time). Rats (n = 6 for all groups) were ventilated with 100% oxygen, given chest compressions, and randomized to receive 30% lipid emulsion (L, 5 mL/kg bolus then 1.0 mL/kg/min infusion) and vasopressin 0.4 U/kg bolus alone (V) or combined with epinephrine, 30 μg/kg (V + E); boluses (L, V, or V + E) were repeated at 2.5 and 5 minutes for a rate–pressure product (RPP) less than 20% baseline.
The arterial blood pressure and electrocardiogram were measured continuously for 10 minutes when blood was drawn for arterial blood gas analysis, lactate content, and central venous oxygen saturation (ScvpO2). Hemodynamic parameters of the L group at 10 minutes (30,615 ± 4782 mm Hg/min; 151 ± 19.1 mm Hg; 197 ± 8.6 min−1; RPP, systolic blood pressure and heart rate, respectively) exceeded those of the V group (5395 ± 1310 mm Hg/min; 85.8 ± 12 mm Hg; 61 ± 10.8 min−1) and the V + E group (11,183 ± 1857 mm Hg/min−1; 75.5 ± 12.9 min−1, RPP and heart rate, respectively; systolic blood pressure was not different). Metrics indicated better tissue perfusion in the L group (7.24 ± 0.02; 83% ± 3.5%; 2.2 ± 0.36 mmol/L; pH, ScvpO2, lactate, respectively) than V (7.13 ± 0.02; 29.9% ± 4.4%; 7.5 ± 0.6 mmol/L) and V + E groups (7.07 ± 0.03; 26.2% ± 8.9%; 7.7 ± 1 mmol/L). Wet-to-dry lung ratios in V (8.3 ± 0.6) and V + E (8.7 ± 0.2) were greater than that in the L group (6.2 ± 05) (mean ± sem; p < 0.05 for all shown results).
Lipid emulsion in this rat model provides superior hemodynamic and metabolic recovery from bupivacaine-induced cardiac arrest than do vasopressors. Systolic pressure was not a useful metric in the vasopressor groups. Vasopressin was associated with adverse outcomes.
From the Department of Anesthesiology (GDG), University of Illinois College of Medicine at Chicago, University of Padova, Italy; Department of Anesthesiology (DS, RR, KK, DLF); Departments of Pharmacology and Anesthesiology (RDM); Department of Surgery (MM), University of Illinois College of Medicine at Chicago, Chicago, IL; Department of Anesthesiology and Pharmacology (CO), University of Padova, Padova, Italy; and Department of Anesthesiology (GLW), University of Illinois College of Medicine at Chicago and Jesse Brown VA Medical Center, Chicago, IL.
Supported, in part, by Veteran's Administration Merit Award, Veteran's Administration Central Research and Development Office, Washington, DC (Weinberg).
Dr. Weinberg holds a US patent related to lipid therapy. He has no financial relationship with any commercial entity and has received no salary or support from any company. The remaining authors have not disclosed any potential conflicts of interest.
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Lipid emulsion is superior to vasopressin in a rodent model of resuscitation from toxin-induced cardiac arrest: Erratum
In the article on page 993, the wrong version of Figure 2 was posted. It is available below.
This erratum is published in the July 2009 issue of the journal.