[Treatment of the hypertensive response during coronary surgery: comparison of high-dose propofol to propofol with nitroprusside].

OBJECTIVE

To determine the efficacy of high doses of propofol for controlling hypertension during coronary surgery and to compared cardiovascular stability with propofol to that observed under lower doses of propofol with nitroprusside.

PATIENTS AND METHODS

Forty patients were studied prospectively. The patients had good ventricular function and were scheduled for coronary surgery, randomized to two groups. Group P (n = 20) received 0.3 mg/kg propofol plus a 10 mg/kg/h perfusion. Hypertensive responses were treated with boluses of 0.3 mg/kg of propofol and progressive increases in the perfusion dose of 2.5 mg/kg/h at intervals of 2 minutes (maximum 15 mg/kg/h). If hypertension persisted it was treated with nitroprusside. Group N (n = 20) received propofol in perfusion at a dose of 8 mg/kg/h and hypertension was controlled directly with nitroprusside. During extracorporeal circulation, the propofol dose was reduced to 3 mg/kg/h in both groups and was adjusted in response to changes in arterial pressure, with nitroprusside added as needed. We recorded the number of patients becoming hypertensive during sternotomy and mediastinal dissection, the maximum doses of propofol and nitroprusside and the time taken to achieve control of hypertension. Arterial pressure and heart rate were recorded at intervals of one minute throughout the operation.

RESULTS

Eight patients in group P and eleven in group N suffered hypertension (NS). Increasing the dose of propofol in group P controlled arterial hypertension in one patient. We found no significant differences between groups in amount of nitroprusside needed or time taken to bring episodes under control. Differences between the two groups in rates of intraoperative hypertension (65% in group P and 85% in group N) and hypotension (75% in group P and 55% in group N) and in duration of episodes were not statistically significant.

CONCLUSIONS

Using high doses of propofol rather than moderate doses in combination with nitroprusside in coronary surgery does not improve control of either hypertension or hemodynamic stability.