Epidural anesthesia and postoperative analgesia with ropivacaine and fentanyl in off-pump coronary artery bypass grafting: a randomized, controlled study

Abstract

Background: Our aim was to assess the efficacy of thoracic epidural anesthesia (EA) followed by postoperative epidural infusion (EI) and patient-controlled epidural analgesia (PCEA) with ropivacaine/fentanyl in off-pump coronary artery bypass grafting (OPCAB).

Methods: In a prospective study, 93 patients were scheduled for OPCAB under propofol/fentanyl anesthesia and randomized to three postoperative analgesia regimens aiming at a visual analog scale (VAS) score < 30 mm at rest. The control group (n = 31) received intravenous fentanyl 10 μg/ml postoperatively 3-8 mL/h. After placement of an epidural catheter at the level of Th2-Th4 before OPCAB, a thoracic EI group (n = 31) received EA intraoperatively with ropivacaine 0.75% 1 mg/kg and fentanyl 1 μg/kg followed by continuous EI of ropivacaine 0.2% 3-8 mL/h and fentanyl 2 μg/mL postoperatively. The PCEA group (n = 31), in addition to EA and EI, received PCEA (ropivacaine/fentanyl bolus 1 mL, lock-out interval 12 min) postoperatively. Hemodynamics and blood gases were measured throughout 24 h after OPCAB.

Results: During OPCAB, EA decreased arterial pressure transiently, counteracted changes in global ejection fraction and accumulation of extravascular lung water, and reduced the consumption of propofol by 15%, fentanyl by 50% and nitroglycerin by a 7-fold, but increased the requirements in colloids and vasopressors by 2- and 3-fold, respectively (P < 0.05). After OPCAB, PCEA increased PaO2/FiO2 at 18 h and decreased the duration of mechanical ventilation by 32% compared with the control group (P < 0.05).

Conclusions: In OPCAB, EA with ropivacaine/fentanyl decreases arterial pressure transiently, optimizes myocardial performance and influences the perioperative fluid and vasoactive therapy. Postoperative EI combined with PCEA improves lung function and reduces time to extubation.

Trial registration: NCT01384175.

Figure 1

Flowchart showing algorithm for hemodynamic monitoring and perioperative management. MAP: mean arterial pressure; HR: heart rate; GEDVI: global end-diastolic volume index; CI: cardiac index; SVRI: systemic vascular resistance index. During anesthesia, this algorithm was used to correct HR and MAP only if the doses of propofol 3-5 mg/kg/h and fentanyl 2-4 μg/kg/h were unable to maintain HR within 50-90 beats/min and MAP within 60-80 mm Hg. For perioperative management, we used the following doses of intravenous agents: ephedrine 5-10 mg, phenylephrine 0, 05-1 mg, nitroglycerine 0, 3-3 mg/h and furosemide 10-20 mg.

Figure 2

Flowchart of the study groups. EI: epidural infusion group; PCEA: patient-controlled epidural analgesia group.