Diurnal blood pressure variation in adults after abdominal surgery-An observational cohort study.

OBJECTIVE: To describe the prevalence of various circadian blood pressure patterns in adults recovering from abdominal surgery, and to evaluate the association between loss of normal circadian variation in blood pressure and hypotension during the initial 2 postoperative days. DESIGN: A post-hoc analysis of data obtained from two randomized trials. SETTING: Operating rooms of the Cleveland Clinic. PATIENTS: Adults having abdominal surgery from 2015 to 2019 with at least one overnight stay. Participants were continuously monitored by wearable vital signs monitors starting in the post-anesthesia care unit and for the first 48 postoperative hours. INTERVENTIONS: None. The exposure of interest was the degree of nocturnal decrease in blood pressure - normal nocturnal decrease in blood pressure ("normal dipping", more than 10% decrease compared to day-time), no nocturnal decrease ("non-dipping", less than 10% nocturnal decrease), or nocturnal increase in blood pressure ("rising"). MEASUREMENTS: Postoperative hypotension, defined by the time weighted average (TWA) area under a mean arterial pressure (MAP) threshold of 70 mmHg. RESULTS: In total, 590 patients were eligible for analysis (mean(SD) age 50(15) years, 56% females, median [IQR] surgery duration 4.0 [2.7, 5.8] hours). Median TWA area under a MAP threshold of 70 mmHg was 0.96 (95%CI 0.59, 1.33) mmHg*minute per monitoring hour lower in patients with either no nocturnal blood pressure decrease (N = 317, 54%), or an increase in nocturnal blood pressure (N = 211, 36%), than in the reference group of patients with normal nocturnal decrease (N = 62, 11%), P < 0.001 for both. CONCLUSIONS: Abnormal diurnal blood pressure patterns are common in adults during the initial 2 days after abdominal surgery. Lack of normal night-time decrease in blood pressure is associated with less postoperative hypotension. Future studies should evaluate whether abnormal postoperative diurnal blood pressure patterns are associated with worse outcomes.

Perioperative challenges in management of diabetic patients undergoing non-cardiac surgery.

Prediabetes and diabetes are important disease processes which have several perioperative implications. About one third of the United States population is considered to have prediabetes. The prevalence in surgical patients is even higher. This is due to the associated micro and macrovascular complications of diabetes that result in the need for subsequent surgical procedures. A careful preoperative evaluation of diabetic patients and patients at risk for prediabetes is essential to reduce perioperative mortality and morbidity. This preoperative evaluation involves an optimization of preoperative comorbidities. It also includes optimization of antidiabetic medication regimens, as the avoidance of unintentional hypoglycemic and hyperglycemic episodes during the perioperative period is crucial. The focus of the perioperative management is to ensure euglycemia and thus improve postoperative outcomes. Therefore, prolonged preoperative fasting should be avoided and close monitoring of blood glucose should be initiated and continued throughout surgery. This can be accomplished with either analysis in blood gas samples, venous phlebotomy or point-of-care testing. Although capillary and arterial whole blood glucose do not meet standard guidelines for glucose testing, they can still be used to guide insulin dosing in the operating room. Intraoperative glycemic control goals may vary slightly in different protocols but overall the guidelines suggest a glucose range in the operating room should be between 140 mg/dL to 180 mg/dL. When hyperglycemia is detected in the operating room, blood glucose management may be initiated with subcutaneous rapid-acting insulin, with intravenous infusion or boluses of regular insulin. Fluid and electrolyte management are other perioperative challenges. Notably diabetic ketoacidosis and hyperglycemic hyperosmolar nonketotic state are the two most serious acute metabolic complications of diabetes that must be recognized early and treated.