Effects of intravenous ulinastatin on perioperative lung function in patients undergoing off-pump coronary artery bypass grafting

Objective To investigate the effects of intraoperative intravenous ulinastatin infusion on perioperative lung function in patients undergoing off-pump coronary artery bypass grafting (OPCABG). Methods Twenty-four NYHA class Ⅰor Ⅱ patients aged 65-75 y undergoing elective OPCABG were randomly divided into 2 groups(n=12 each): control group (C) and ulinastatin group (U). In group U, after tracheal intubation the patients received iv injection of ulinastatin 6 000 U/kg over 30 min followed by iv ulinastatin infusion at 1 000 U·kg-·h-1 until the end of surgery. In group C equal vohtme of normal saline was administered iv instead of ulinastatin. Radial artery and right internal jugular vein were cannulated for BP and CVP monitoring and blood sampling. The patients were premeditated with intramuscular morphine 10 mg. Anesthesia was induced with midazolam 0.1 mg/kg, fentanyl 10 μg/kg and pipecuronium 0.1 mg/kg and maintained with 1%-2% sevoflurane in 70% O2 and intermittent iv boluses of fentanyl and pipecuronium. Blood samples were taken before (T1) and at the end of operation (T2) and at 4, 8, 20 h after operation (T3.5) for determination of plasma CD11/CD18 expression, plasma IL-6 and serum NO concentrations, and blood gases. P(A-a) O2 and respiratory index (RI) (RI=P(A-a)O2/PaO2) were calculated. Mechamcal ventilation time in ICU was recorded. Results The two groups were comparable with respect to age, sex, body weight, duration of anesthesia and surgery, and the number of bypass grafts. The plasma level of IL-6, and expression of CD11 b/CDI8 were significantly increased while serum NO level was significantly decreased after operation as compared to the baseline values before operation (T1) in group C. There was no significant change in the plasma levels of IL-6, CD11b/CDI8 expression and serum levels of NO after operation in group U. P(A-a)O2 and RI were significantly increased after operation in both groups and were significandy lower in group U than in group C. The mechanical ventilation time in ICU was significantly shorter in group U than in group C. Conclusion Intravenous ulinastatin inihsion can significantly protect lung function during OPCABG by inhibiting inflammatory response. Key words: Trypsin inhibitors;  Infusions, intravenous;  Coronary artery bypass, off-pump;  Respiratory function tests