BISOPROLOL VERSUS ENALAPRIL ON HEMODYNAMICS UNDER GENERAL ANESTHESIA

Abstract

Background: Systemic arterial hypertension is a common disease in patients undergoing surgery. Bisoprolol and Enalapril are anti-hypertensive drugs that affect the perioperative hemodynamics (blood pressure and pulse rate) in different manners. Objectives: The aim of the present study was to compare the effect of general anesthesia on the hemodynamics of hypertensive patients undergoing elective surgery and controlled on Enalapril versus Bisoprolol as a primary outcome, and criteria of discharge from recovery room, postoperative pain assessment, and adverse effects as a secondary outcome. Patients and Methods: In this comparative clinical randomized study, thirty hypertensive patients of both sexes, aged from 40 to 60 years, according to the American Society of Anesthiologists (ASA) physical status class II, undergoing elective surgery under general anesthesia of less than two hours duration (Abdominal and upper limb surgery), and controlled on antihypertensive medication regularly administered for at least six months duration (Enalapril versus Bisoprolol) were enrolled in the study. The study started from January, 2016 to February, 2018. Patients were randomly allocated into equal two groups, group (A) hypertensive patients controlled on Enalapril 10 mg and group (B) hypertensive patients controlled on Bisoprolol 5 mg. To evaluate intraoperative arterial blood pressure:( systolic arterial blood pressure, diastolic arterial blood pressure and mean arterial blood pressure) and Heart rate as follow: preoperative basal arterial blood pressure and pulse rate reading (0), immediately after induction, (1), every 5 minutes for 20 minutes and every 15 minutes till the end of the operation. Results: Hypertensive patients controlled on Enalapril (group E) had more statistically significant decrease in blood pressure (systolic-diastolic-mean) after induction of general anesthesia and more hypotensive episodes in the first 30 minutes after induction than patients treated with Bisoprolol 5 mg (group B) while, group A had more increase in blood pressure post-intubation, post-extubation and on exposure to noxious stimuli. When comparing heart rate changes between both studied groups the results showed that hypertensive patients controlled on Bisoprolol (group B) had more statistically significant heart rate control (decrease) all over the operation especially at periods of intraoperative stress as post-intubation, 1st 30 minutes of operation and post extubation than hypertensive patients controlled on Enalapril (group A). The remaining intraoperative periods of the operation are nearly comparable between both studied groups (A and B) as regard blood pressure and heart rate. Patients of both groups (A and B) had no statistically significant difference as regard criteria of discharge from recovery room, postoperative pain assessment and adverse effects. Conclusion: Bisoprolol as a beta blocking antihypertensive drug was associated with effective control of pulse rate and blood pressure and attenuation of pressor response to all stressful events all over the operation especially after laryngoscopy, intubation, extubation and the first 30 minutes of operation ensuring more hemodynamic stability under general anesthesia when compared to hypertensive patients controlled on Enalapril. Recommendation: Beta blockers (Bisoprolol) are recommended before surgery even for those who do not use them when exposed to anesthesia unless there are contraindications.