Vasoactive modulators during and after craniotomy: relation to postoperative hypertension

Area of Science:

• Neurosurgery
• Anesthesiology
• Cardiovascular Physiology

Background:

• Hypertension is a common complication following craniotomy.
• Vasoactive modulators are suspected contributors to this postoperative hypertension.

Purpose of the Study:

• To investigate the association between specific vasoactive substances and the development of hypertension after craniotomy.
• To compare plasma concentrations of vasoactive modulators in hypertensive versus normotensive patients post-craniotomy.

Main Methods:

• Twelve patients undergoing supratentorial brain tumor craniotomy were monitored.
• Arterial blood pressure, heart rate, and plasma concentrations of norepinephrine, epinephrine, renin, aldosterone, atrial natriuretic peptide, endothelin, and cortisol were measured preoperatively and postoperatively.
• Patients were categorized into hypertensive (group H) and normotensive (group N) based on mean arterial pressure (MAP) changes.

Main Results:

• Postoperative plasma concentrations of measured vasoactive substances were significantly higher than preoperative levels.
• Six patients developed postoperative hypertension (MAP > 20% above baseline).
• Group H patients exhibited higher postoperative levels of catecholamines, aldosterone, renin, and endothelin compared to group N. Renin levels were also higher intraoperatively in group H.

Conclusions:

• Increased sympathetic nervous system activity and activation of the renin-angiotensin aldosterone system are implicated in the pathogenesis of postoperative hypertension after craniotomy.
• Monitoring and potentially modulating these systems may be crucial for managing blood pressure in patients after brain surgery.