Background: Side-clamping of the ascending aorta during off-pump coronary artery bypass surgery (OPCAB) may be associated with a significant increase in systemic blood pressure which may rarely result in aortic dissection. We evaluated whether topical application of lidocaine on the ascending aorta could reduce the rise in systemic blood pressure during side-clamping of the aorta in OPCAB.
Methods: Forty-four patients scheduled for OPCAB were randomly allocated to receive gauze soaked with 10 ml of 4% lidocaine (n = 22) or normal saline (n = 22) on the side-clamping site of the aorta. Sodium nitroprusside (SNP) was infused as necessary to maintain the systolic blood pressure at around 100 mmHg immediately prior to and during side-clamp of the aorta. The requirement and frequency of use of SNP, as well as haemodynamic variables, were recorded serially.
Results: The number of patients requiring an SNP infusion and the average amount of infused SNP were significantly less in the lidocaine group. Systolic blood pressure increased significantly during side-clamping in the control group, but not in the lidocaine group.
Conclusion: Topical application of lidocaine on the surface of the aorta is a simple and effective method to reduce the risk of a sudden increase in systemic blood pressure during side-clamping of the aorta.