Preoperative Characteristics Predicting Intraoperative Hypotension and Hypertension Among Hypertensives and Diabetics Undergoing Noncardiac Surgery

Abstract

We prospectively studied patients with hypertension and diabetes undergoing elective noncardiac surgery with general anesthesia to test the hypothesis that patients at high risk for prognostically significant intraoperative hemodynamic instability could be identified by their preoperative characteristics. Specifically we hypothesized that patients with a low functional capacity, decreased plasma volume, or significant cardiac comorbidity would be at high risk for intraoperative hypotension and those with a history of severe hypertension would be at risk for intraoperative hypertension. Patients who had a preoperative mean arterial pressure (MAP) greater than or equal to 110, a walking distance of less than 400 m, or a plasma volume less than 3000 cc were at increased risk of intraoperative hypotension (i.e., more than 1 hour of greater than or equal to 20 mmHg decreases in the MAP). Hypotension was also more common among patients having intra-abdominal or vascular surgery, and among those who had operations longer than 2 hours. Patients older than 70 years or with a decreased plasma volume were at increased risk of having more than 15 minutes of intraoperative elevations of greater than or equal to 20 mmHg over the preoperative MAP in combination with intraoperative hypotension; this was also more common when surgery lasted more than 2 hours. Patients who had intraoperative hypotension tended to have an immediate decrease in MAP at the onset of anesthesia and were often purposefully maintained at MAPs less than their usual level during surgery with fentanyl and neuromuscular blocking agents. Patients who had intraoperative hyper/hypotension tended to have repeated elevations in MAP above their preoperative levels during the course of surgery, and such elevations precipitated interventions with neuromuscular blocking agents and/or fentanyl. Neither pattern was more common among patients who developed net intraoperative negative fluid balances. Both hypotension and hyper/hypotension were associated with increased renal and cardiac complications after operation. Patients with cardiac disease, especially diabetics, and those with negative fluid balances also had increased complications. Preoperative characteristics influence the susceptibility to intraoperative hypotension and hypertension, which are related to postoperative complications.

Does premedication with dexmedetomidine provide perioperative hemodynamic stability in hypertensive patients?

“…It is well known that perioperative hemodynamic fluctuations are observed more often in hypertensive patients than in normotensive patients [20]. These fluctuations can occur for the duration of anesthesia and are well tolerated in healthy individuals; however, these pressure changes and increased sympathetic activity can have harmful effects on hypertensive patients [21].…”

The impact of acute preoperative beta-blockade on perioperative cardiac morbidity and all-cause mortality in hypertensive South African vascular surgery patients

“…We suspect that these results are related to perioperative haemodynamic instability. Hypotension is a common perioperative complication in vascular surgery patients with a history of poorly controlled hypertension, with a study by Charlson et al [10] reporting a higher incidence of perioperative hypotension in patients who had preoperative mean arterial blood pressures ≥110 mmHg than in those with preoperative mean arterial blood pressures of <100 mmHg. In another study by Charlson et al, [11] a decrease in mean arterial blood pressure of ≥20 mmHg for ≥5 minutes was associated with an increased incidence of perioperative cardiac complications in non-cardiac surgery patients.…”

Pronounced unexplained preoperative tachycardia heralding serious cardiac events: a series of three cases

“…Although no data exist on the relationships between preoperative and intraoperative tachycardia, and preoperative tachycardia and complications, previous studies have found associations between preoperative and intraoperative BP, and preoperative BP and perioperative complications. [11][12][13] It is therefore possible that a similar relationship exists for preoperative and intraoperative HR. For preoperative tachycardia due to a known etiology (e.g., pain or anxiety), appropri-ately treating the causative factor should eliminate this association.…”