Con: Tight Perioperative Glycemic Control: Poorly Supported and Risky

Outcomes of diabetic and nondiabetic patients undergoing general and vascular surgery

Aims. Preoperative diabetic and glycemic screening may or may not be cost effective. Although hyperglycemia is known to compromise surgical outcomes, the effect of a diabetic diagnosis on outcomes is poorly known. We examine the effect of diabetes on outcomes for general and vascular surgery patients. Methods. Data were collected from the Michigan Surgical Quality Collaborative for general or vascular surgery patients who had diabetes. Primary and secondary outcomes were 30-day mortality and 30-day overall morbidity, respectively. Binary logistic regression analysis was used to identify risk factors. Results. We identified 177,430 (89.9%) general surgery and 34,006 (16.1%) vascular surgery patients. Insulin and noninsulin diabetics accounted for 7.1% and 9.8%, respectively. Insulin and noninsulin dependent diabetics were not at increased risk for mortality. Diabetics are at a slight increased odds than non-diabetics for overall morbidity, and insulin dependent diabetics more so than non-insulin dependent. Ventilator dependence, 10% weight loss, emergent case, and ASA class were most predictive. Conclusions. Diabetics were not at increased risk for postoperative mortality. Insulin-dependent diabetics undergoing general or vascular surgery were at increased risk of overall 30-day morbidity. These data provide insight towards mitigating poor surgical outcomes in diabetic patients and the cost effectiveness of preoperative diabetic screening.

Preinduction glycemia and body mass index are important predictors of perioperative insulin management in patients undergoing cardiac surgery

STUDY OBJECTIVE

To investigate whether preinduction glucose is an important predictor for perioperative insulin management in patients undergoing cardiac surgery.

DESIGN

Prospective cohort study.

SETTING

Large community hospital.

PATIENTS

80 consecutive patients scheduled for cardiac surgery.

INTERVENTIONS

Patients were subdivided into those with a preinduction blood glucose of 110 mg/dL or lower with or without history of diabetes (group 1) and those with a preinduction blood glucose of above 110 mg/dL with or without history of diabetes (group 2). In group 1, there were no known diabetics. In group 2, 31% (11/35) had diabetes (group 2DM), while 24/35 (69%) did not (group 2NDM). An insulin infusion was started intraoperatively and adjusted according to a strict protocol in order to maintain normoglycemia (80-110 mg/dL) until discharge from intensive care.

MEASUREMENTS AND MAIN RESULTS

In patients with preinduction glucose above 110 mg/dL, whether or not previously treated for diabetes, perioperative insulin requirements were higher, and intraoperative insulin management was more difficult than in those with lower preinduction glucose. In patients with a preinduction glucose above 110 mg/dL, hospital stay was longer, and inhospital mortality was significantly higher than in those with lower preinduction glucose. Multivariate analyses showed that preinduction glycemia was a good predictor of intraoperative insulin consumption, as was the body mass index (BMI) for intensive care and total insulin needs.

CONCLUSIONS

In cardiac surgical patients with a preinduction glucose above 110 mg/dL, even if diabetes was not previously suspected, perioperative insulin requirements were higher, and intraoperative insulin management is more difficult than in those with a preinduction glucose 110 mg/dL or lower. Preinduction glycemia and BMI are good predictors of perioperative insulin management. Preinduction glycemia above 110 mg/dL predicts difficult perioperative glucose control and, moreover, that a preinduction blood glucose of 110 mg/dL or lower is associated with less insulin need.

Diabetes mellitus and anesthesia

Diabetes mellitus is an extremely common condition with specific associated comorbidity. Its incidence is rising. Diabetic patients have more perioperative complications than nondiabetic patients. These complications may be related to the presence of organ damage secondary to the diabetes, rather than the defects in carbohydrate metabolism themselves, or to perioperative hyperglycemia. Several new drugs are available for the treatment of diabetes, and these are associated with specific and significant side effects, and varying lengths of action with which the anesthetist should be familiar. Few data are available regarding recommendations for fasting in the presence of these newer drugs. In the postoperative period and during cardiac surgery, hyperglycemia has been shown to be detrimental, and should probably be sought and managed aggressively. The incidence of intraoperative hyperglycemia in noncardiac surgery patients is not as well-defined, nor are the effects of aggressive management.

Achieving tight glycaemic control

The implementation of tight glycaemic control (TGC) is becoming accepted best practice within intensive care units throughout the world. It is recommended by the Surviving Sepsis Campaign and is included in the sepsis care bundle. The major impact of TGC is currently thought to be associated with reduced morbidity and mortality. The process of achieving TGC is, however, not without risk. In particular, the need for frequent, accurate blood glucose measurement and the possibility of prolonged, unrecognised hypoglycaemia are of concern. There is also the potential for patients who exhibit significant insulin resistance to require the administration of large amounts of insulin. The transfer of patients from the intensive care unit to the operating theatre or for computerised tomography during intensive insulin therapy is also hazardous. The purpose of this paper is to describe a series of nurse led pilot studies which aimed to introduce the process of TGC whilst maintaining patient safety. The results demonstrate the effectiveness of a staged approach and the achievement of TGC.

Achieving Tight Glycemic Control in the Operating Room: Lessons Learned from 12 Years in the Trenches of a Paradigm Shift in Anesthetic Care

Intensive insulin therapy to control perioperative hyperglycemia has become the new standard of care for cardiac surgery patients. Although there are several published protocols for achieving tight glycemic control in the postoperative period, there are no such published protocols or even suggested methods for intraoperative control. At Providence St. Vincent Hospital in Portland, Oregon, we have been using postoperative insulin infusions under study protocol since 1992 and have been using intravenous insulin to control intraoperative glucose levels since 1995. Over the past 12 years of tight intraoperative glycemic control with intravenous insulin, four distinct, equally effective methods of intraoperative insulin administration have evolved at our institution. All four have evolved in the hands of experienced cardiac anesthesiologists. Each of these anesthesiologists was faced with the daily task of individualizing patient therapy with the common goal of eliminating intraoperative hyperglycemia. In this article we will describe each of these four generalized methodologies to give the practicing anesthesiologist a starting point from which they can develop and hone their own technique further.