Perioperative hypertension associated neurohumoral stress response in craniotomy patients: Effects of β-blocker and angiotensin converting enzyme inhibitor

Background: Development of perioperative hypertension in craniotomy procedures is commonly associated with activation of sympathetic events through renin-angiotensin-aldosterone system (RAAS). Preemptive therapy with β-blockers or angiotensin converting enzyme (ACE) inhibitors may attenuate this hypertensive response. We conducted a randomized, double blind; placebo controlled study to compare the effect of β-blocker (atenolol) and an ACE inhibitor (Lisinopril) on perioperative hypertension in patients undergoing for the craniotomy and also studied biochemical markers of these two systems. Methods: Eighty five patients undergoing craniotomy for supratentorial tumor removal were screened and randomized into three groups to receive either (atenolol; lisinopril or placebo). Blood analysis of renin, aldosterone, norepinephrine and sodium levels was drawn 12 h prior to surgery, at the time of dural opening, and at the time of extubation. Differences in mean arterial pressure (MAP), hear rate (HR) and biochemical markers between three groups were analyzed using one-way ANOVA. Results: Perioperative hemodynamic changes were highly associated with biochemical markers in all the three groups. Specifically, HR was significantly attenuated by atenolol in the immediate extubation period (p < 0.01) persisted till 12 h postoperatively and this was associated with low plasma renin levels at the extubation. MAP was lowered by lisinopril and both aldosterone and norepinephrine levels were significantly lower (p < 0.01) at dural incision and extubation periods. Conclusions: Pretreatment with atenolol or lisinopril significantly attenuated perioperative hypertension in patients undergoing craniotomy procedures. Lisinopril was better in lowering perioperative MAP while atenolol attenuated HR changes. RAAS inhibition may be the possible mechanism responsible for this hypertension effect in craniotomy procedures.