Pre-operative intercostal nerve blockade for minimally invasive coronary bypass surgery: a standardised anaesthetic regimen for rapid emergence and early extubation

Abstract

Background: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has become a popular adjunct to cardiac bypass surgery in selected patients. Although MIDCAB without cardiopulmonary bypass is considered to be a relatively noninvasive procedure, the trauma to the muscle tissue caused by the anterolateral thoracotomy often leads to more pain than that of patients undergoing routine sternotomy. The purpose of our study was to evaluate the pre-operative application of an intercostal nerve blockade, combined with general anaesthesia for peri- and postoperative pain control, and its efficacy for early extubation.

Methods and results: Nine consecutive patients undergoing MIDCAB surgery were evaluated. Pre-operative ipsilateral intercostal nerve blockade was employed in all patients. After induction, isofluran (0.4-0.8%) and nitrous oxide in combination with the pre-operative nerve blockade provided sufficient anaesthesia throughout the procedure (mean operative time: 147 min). Only 2/9 patients required additional small doses of narcotics. All patients could be safely extubated within 15 minutes of skin suture. Postoperative discomfort and pain were minimal.

Conclusion: From our initial experience with preoperative intercostal nerve blockade for the MIDCAB procedure, we concluded that it provides profound somatic analgesia as an effective adjunct to general anaesthesia with reduced doses of narcotics and sedatives. MIDCAB impresses with its ease of technical performance, its reliability and safety. The minimised chest-wall pain improves patients' chances of early tracheal extubation. In accordance with the minimally invasive surgical approach, it provides a contribution towards 'minimally invasive anaesthesia'. The surgeons' and the patients' acceptance is excellent. Because the results of this study are based on observation and verbalisation of the investigators' impressions, and no objective measurements were made which would have allowed a comparison between the MIDCAB technique and the golden standard of general anaesthesia with opioid analgesia, a further study should be conducted to prove our theory.