Intra-operative hypotension; induction of anesthesia in patients continuing their routine dose of angiotensin system inhibitor therapy before surgery

ABSTRACT

To determine the frequency of intra-operative hypotension following induction of Anesthesia in patients continuing their routine dose of angiotensin system inhibitor therapy before surgery. Cross-sectional study. Department of Anaesthesiology, Combined Military Hospital, Quetta. One year from 20-08-2010 to 19-08-2011. Total 92 hypertensive patients were included in this study. Diagnostic criteria for patients was those cases receiving ACEI/ARA therapy for at least 3 months with admission preoperative arterial blood pressure of >150/90mmHg. Mean age of the patients was 47.70 +/- 8.47 years. Out of 92 patients, 38 patients [41.3%] were male while remaining 54 patients [58.7%] were female. Distribution of cases by hypotension after induction of anesthesia shows, hypotension at 30 minute in 55 patients [59.8%] and hypotension at 60 minute in 37 patients [40.2%]. Out of 55 hypotensive patients [at 30 minute] 17 patients [30.9%] had mild hypotension, 32 patients [58.2%] had moderate hypotension and 6 patients [10.9%] had severe hypotension. Out of 37 hypotensive patients [at 60 minute] 8 patients [21.6%] had mild hypotension, 25 patients [67.6%] had moderate hypotension and 4 patients [10.8%] had severe hypotension. Hypertensive patients continuing their routine angiotensin system inhibitors therapy [<10 hr preoperative] have a variable risk of developing moderate hypotension within 30 minutes after induction. This moderate hypotension proved to be of little clinical significance as it responded to conventional therapy