Responsiveness to Infusion Load under Regional Anesthesia after Off-Pump Coronary Artery Bypass Graft Surgery

Abstract

Objective. To evaluate the effect of erector spinae plane block (ESPB) and epidural anesthesia on responsiveness to infusion load after coronary bypass surgery on a beating heart. Materials and methods . A prospective randomized single-center study included 45 patients who were grouped into 3 equal arms based on anesthesia techniques: general anesthesia in combination with ESPB (GA+ESPB), general anesthesia and epidural anesthesia (GA+EA) and general anesthesia without regional techniques (GA). Patient’s response to volume loading was assessed using dynamic and orthostatic tests after transfer from the operating room and at the end of the first postoperative day. Passive leg raise (PLR) and standard bolus injection tests were done at the first stage; changes in hemodynamic parameters during verticalization were additionally evaluated at the second stage. Patients with >10% cardiac index (CI) increase after PLR test and >15% increase after bolus injection test were categorized as responders. Results . The concordance of obtained results in PLR and bolus injection tests for the GA+ESPB, GA+ EA and GA groups at the first stage was 0.53 (95% CI 0.12-0.94), 0.68 (95% CI 0.30-1.00) and 0.61 (CI 0.24-0.99), at the second stage - 0.70 (0.32-1.00), 0.84 (95% CI 0.55-1.00) and 0.82 (95% CI 0.47-1.00), respectively. There were no differences in distribution of responders between the groups. CI dynamics did not differ between the groups during verticalization, and there were no associations of CI changes during verticalization with the preceding PLR test results. The dynamics of troponin T and NT-proBNP did not differ between the groups. Conclusion . Methods of regional anesthesia (SPB or EA) do not significantly affect the responsiveness to infusion therapy in the postoperative period after coronary bypass surgery on a beating heart.