Computer control versus manual control of systemic hypertension during cardiac surgery

Background: We recently demonstrated the feasibility of computer controlled infusion of vasoactive drugs for the control of systemic hypertension duri ng cardiac surgery. The objective of the current study was to investigate t he effects of computer controlled blood pressures on hemodynamic stability when compared to conventional manual control. Method: Systemic artery blood pressures were managed either by computer (80 patients) or by a well-trained anesthesiologist (80 patients). The vasodil ator drugs sodium nitroprusside and nitroglycerin were used. Hemodynamic st ability was determined from the standard deviation of the mean arterial pre ssure samples and from the percentages of time that arterial pressure was h ypertensive or hypotensive. Results: The average standard deviation of the mean arterial pressure sampl es was smaller fur the computer controlled than for the manually controlled group: 7.5 +/-2.2 (mean +/- SD) versus 8.9 +/-2.3 mmHg (P <0.0001). The sy stemic artery pressure was less hypertensive and less hypotensive in the co mputer controlled than in the manually controlled group: 9.4 +/-5.7 versus 13.1 +/-6.0% (P <0.0001) and 8.0 +/-5.9 versus 11.8 +/-7.4% (P <0.0001), re spectively. Conclusion: We conclude that, compared with manual control, computer contro l of systemic hypertension significantly improved hemodynamic stability dur ing cardiac surgery.