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) .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 .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 .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 Dr. Charlson was a Henry J. 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. W x r HILE MOST STUDIES have demonstrated that intraoperative hypotension increases the risk of postoperative cardiacl'5 and renal6'7 complications, there is less agreement about the impact of other intraoperative hemodynamic patterns (e.g., hypertension alone or hypertension and hypotension).8'10 We have shown that patients with hypertension or diabetes whose intraoperative mean arterial pressure (MAP) decreased .20 mmHg below their preoperative MAP for more than 1 hour had increased cardiac and renal complications.' ''-In addition patients who experienced both 15 minutes or more of elevated MAP (.20 mm above their usual MAP) and less than 1 hour of .20 mmHg decreases in their MAP hour had increased complications. "'-4 Tog...

Predictors of Intraoperative Hypotension and Bradycardia

“…These criteria were chosen based on their previous use in other published studies and because they were deemed clinical relevant by anaesthesiologists. [13][14][15][16] Bradycardia was defined as having a HR of <60 beats per minute for at least 2 sequential measurements, more than 5 minutes apart. Our criteria used for bradycardia are consistent with previously published papers.…”

Impact of intraoperative hypotension on hospital stay in major abdominal surgery

“…In the previous randomized trial of deliberate hypotension, no significant additional morbidity risk at 4 months postoperatively was found. Although various studies have evaluated the relationship between preoperative risk factors and outcomes, the postoperative effect of intraoperative hemodynamic abnormalities has been less well defined [10,[17][18][19].…”

Anesthetic considerations in diabetic patients. Part II: intraoperative and postoperative management of patients with diabetes mellitus

“…It is important to prevent hemodynamic instability during surgery in diabetic patients, especially in those prone to develop renal and cardiac complications postoperatively [10]. Thus, anesthesiologists should be aware of the preoperative presence of diabetic neuropathy and be extra cautious about preventing severe hypotension during anesthesia induction and the perioperative period.…”