Comparative study of variations in blood pressure and heart rate among normotensive patients and hypertensive patients receiving angiotensin receptor blockers during surgery under spinal anesthesia

Most of the general and spinal anesthetic drugs reduce the influence of sympathetic tone on the cardiovascular system. [...]under anesthetic influence, there is increased reliance on the renin-angiotensin system (RAS) for the maintenance of BP. [...]the drugs that antagonize RAS, angiotensinconverting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs) block the RAS response to hypotension and increase the risk of hypotension intraoperatively. [...]his surgery was canceled after 6 min of administering spinal anesthesia. [...]although 17 patients had a drop of 30% in SBP, only 15 received mephentermine.