Methods: Between January 2016 and June 2016, a total of 60 patients with the American Society of Anesthesiologists Physical Status Class III (27 males, 33 females; mean age 63 years; range, 49 to 77 years) with an ejection fraction of above 50% who underwent elective coronary artery bypass grafting were included. The patients were divided into two groups following admission to the intensive care unit. Group 1 (n=30) was administered intravenous fentanyl citrate with patient-controlled analgesia protocol, while Group 2 (n=30) was administered 0.1% bupivacaine hydrochloride analgesia protocol with catheter placed between the sternum and subcutaneous tissue.

Results: In Group 1, pain intensity scores at two h and visual analog scale scores except at 24, 36, and 48 h were higher than Group 2 (p<0.05). The length of intensive care unit stay and urine cortisol levels were higher in Group 1 than Group 2 (78±12 h and 631±505 ?g at 24 h vs. 66±13 h and 401±297 ?g at 24 h, respectively p<0.05). Partial pressure of oxygen levels at 10 and 16 h during the postoperative intensive care unit stay were lower, while partial pressure of carbon dioxide levels at 24 h was higher in Group 1 than Group 2 (p<0.05).

Conclusion: The bupivacaine protocol is a relatively more useful analgesic method which produces improved results in blood gas analysis by reducing the effects of pain and shortens the length of intensive care unit stay. Low levels of free cortisol also confirm this finding.