INTRA-OPERATIVE HYPOTENSION;

INDUCTION OF ANESTHESIA IN PATIENTS CONTINUING THEIR ROUTINE DOSE OF ANGIOTENSIN SYSTEM INHIBITOR THERAPY BEFORE SURGERY

Abstract

Objective: 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. Study design: Cross-sectional study. Setting: Department of
Anaesthesiology, Combined Military Hospital, Quetta. Duration of study: One year from 20-08-2010 to 19-08-2011. Subjects and methods:
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. Results: 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. Conclusions: 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.