Perioperative blood pressure control in hypertensive and normotensive patients undergoing off-pump coronary artery bypass grafting: prospective study of current anesthesia practice

Aim

To analyze blood pressure changes during intra- and immediate postoperative period in patients undergoing off-pump coronary artery bypass grafting.

Methods

The study included 355 consecutive patients undergoing off-pump coronary artery bypass grafting between January 5, 2004 and December 30, 2005. Out of these patients, 325 were allocated into groups with preoperative history of hypertension (n = 115) and without preoperative history of hypertension (n = 210). Systolic, diastolic, and mean arterial blood pressure was measured at the following four time points: on the day before surgery, before anesthesia induction, after the last graft, and on entry to intensive care unit.

Results

Mean arterial pressure was significantly higher in patients with a history of hypertension on the day before surgery (97 vs 92 mm Hg, P = 0.003, Mann-Whitney test) and before anesthesia induction (107 vs 98 mm Hg; P = 0.003). It was higher at all measuring points (after the last graft, 79 vs 78 mm Hg; and on entry to intensive care unit, 88 vs 86 mm Hg), but this difference was neither statistically nor clinically significant. The study showed that mean arterial pressure followed similar dynamics over time in both patient groups (P<0.001 both), with no significant time-dependent between-group differences.

Conclusion

Current anesthesia techniques that include deep opioid analgesia in combination with vasodilators provide a satisfactory control of intraoperative hypertension. Management of blood pressure changes during intra- and immediate postoperative period in off-pump coronary artery bypass grafting patients with preoperative hypertension was no more difficult than in patients without preoperative hypertension.Monitoring of hemodynamic stability, especially blood pressure and heart rate during perioperative period, is an important consideration (1). During conventional open heart surgery, hypertension can occur at almost any time, ie before, during, or after surgery, and is most commonly mediated by an increase in sympathetic tone.Off-pump coronary artery bypass grafting is a procedure that may achieve better in-hospital outcome, including shorter length of stay (2,3). Hypertension associated with off-pump coronary artery bypass grafting is typically not a result of dramatic increase in systemic vascular resistance (4).The reported incidence of perioperative hypertension associated with conventional coronary artery bypass grafting (CABG) ranges from 30 to 80%, and this wide range may explain different definitions of the condition and preoperative comorbid states (5).To the best of our knowledge, there are no studies dealing with off-pump coronary artery bypass grafting. The aim of our study was to analyze perioperative hypertensive response in patients undergoing off-pump coronary artery bypass grafting. We hypothesized that it was more difficult to control perioperative hypertension in these patients who had been preoperatively hypertensive than in those who had not.