Amrinone is superior to epinephrine in reversing bupivacaine-induced cardiovascular depression in sevoflurane-anesthetized dogs.

BACKGROUND

Bupivacaine-induced cardiovascular depression is known to be difficult to treat, and the efficacy of epinephrine for treatment of bupivacaine-induced cardiovascular depression is in doubt. We compared the efficacy of amrinone with that of epinephrine for the treatment of bupivacaine-induced cardiovascular depression in anesthetized dogs.

METHODS

In dogs receiving 1.5-2% sevoflurane anesthesia, 0.5% bupivacaine was infused at a rate of 0.5 mg.kg-1.min-1 intravenously until mean arterial blood pressure decreased to 40 mmHg or less. In the amrinone group (n = 9), amrinone (4 mg.kg-1, intravenously) was given immediately after cardiovascular depression, followed by intravenous infusion at a rate of 0.1 mg.kg-1.min-1. In the epinephrine group (n = 9), epinephrine (0.01 mg.kg-1, intravenously) was given as a bolus, and the same dose was given again as required.

RESULTS

All nine dogs that received amrinone survived. Of the nine dogs that received epinephrine, five survived; fatal cardiovascular depression developed in the four remaining animals (P < 0.05). Only one animal in the amrinone group showed tachyrhythmia with wide QRS complexes during resuscitation, whereas all nine animals in the epinephrine group showed tachyrhythmia with wide QRS complexes during resuscitation.

CONCLUSIONS

Amrinone is superior to epinephrine for the treatment of bupivacaine-induced cardiovascular depression in sevoflurane-anesthetized dogs.