Comparative Regimens of Lipid Rescue From Bupivacaine-Induced Asystole in a Rat Model

It is currently unknown whether bupivacaine-induced asystole is better resuscitated with lipid emulsion (LE) administered peripherally or centrally, and whether different LE regimens administered peripherally demonstrated similar effects. In this study, we compared the effects of various regimens of lipid administration in a rat model of bupivacaine-induced asystole.

Forty-five adult male Sprague-Dawley rats were subjected to bupivacaine-induced asystole and randomly divided into 3 lipid regimens groups: (1) 20% LE was administered continuously via the internal jugular vein (CV-infusion group); (2) 20% LE was administered continuously via the tail vein (PV-infusion group); and (3) 20% LE was administered as divided boluses via the tail vein (PV-bolus group). The maximum dose of LE did not exceed 10 mL·kg(-1). External chest compressions were administered until the return of spontaneous circulation (ROSC) or the end of a 40-minute resuscitation period.

The survival rate, rate of ROSC, systolic blood pressure, heart rate, heart rate-blood pressure product, and coronary perfusion pressure during 2-40 minutes in the CV-infusion and PV-bolus groups were significantly higher than those in the PV-infusion group (P < .01), and the plasma total bupivacaine concentration and myocardial bupivacaine content were significantly lower (P < .05). Time to heartbeat return and time to ROSC in the CV-infusion and PV-bolus groups were significantly shorter than those in the PV-infusion group (P < .05).

In the rat model of bupivacaine-induced asystole, a divided LE bolus regimen administered peripherally provided a better resuscitation outcome than that of a continuous LE infusion regimen peripherally, and performed in a similar fashion as the continuous LE infusion regimen administered centrally.