Inpatient Glycemic Management of Non-cardiac CVD: Focus on Stroke and PVD

Strategies for intraoperative glucose management: a scoping review

PURPOSE

Perioperative hyperglycemia is associated with adverse outcomes for patients with and without diabetes. Guidelines and published protocols for intraoperative glycemic management have substantial variation in their recommendations. We sought to characterize the current evidence-guiding intraoperative glycemic management in a scoping review.

SOURCES

Our search strategy included MEDLINE (Ovid and EBSCO), PubMed, PubMed Central, EMBASE, CINAHL, Cochrane Library, SciVerse Scopus, and Web of Science and a gray literature search of Google, Google Scholar, hand searching of the reference lists of included articles, OAISter, institutional protocols, and ClinicalTrails.gov.

PRINCIPAL FINDINGS

We identified 41 articles that met our inclusion criteria, 24 of which were original research studies. Outcomes and exposures were defined heterogeneously across studies, which limited comparison and synthesis. Investigators often created arbitrary and differing categories of glucose values rather than analyzing glucose as a continuous variable, which limited our ability to combine results from different studies. In addition, the study populations and surgery types also varied considerably, with few studies performed during day surgeries and specific surgical disciplines. Study populations often included more than one type of surgery, indication, and urgency that were expected to have varying physiologic and inflammatory responses. Combining low- and high-risk patients in the same study population may obscure the harms or benefits of intraoperative glycemic management for high-risk procedures or patients.

CONCLUSION

Future studies examining intraoperative glycemic management should carefully consider the study population, surgical characteristics, and pre- and postoperative management of hyperglycemia.

Rethinking the necessity of low glucose intervention for cerebral ischemia/reperfusion injury

Glucose is the essential and almost exclusive metabolic fuel for the brain. Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in severe glucose deprivation with subsequent induction of cellular homeostasis disturbance and eventual neuronal death. To make up ischemia-mediated adenosine 5′-triphosphate depletion, glucose in the ischemic penumbra area rapidly enters anaerobic metabolism to produce glycolytic adenosine 5′-triphosphate for cell survival. It appears that an increase in glucose in the ischemic brain would exert favorable effects. This notion is supported by in vitro studies, but generally denied by most in vivo studies. Clinical studies to manage increased blood glucose levels after stroke also failed to show any benefits or even brought out harmful effects while elevated admission blood glucose concentrations frequently correlated with poor outcomes. Surprisingly, strict glycaemic control in clinical practice also failed to yield any beneficial outcome. These controversial results from glucose management studies during the past three decades remain a challenging question of whether glucose intervention is needed for ischemic stroke care. This review provides a brief overview of the roles of cerebral glucose under normal and ischemic conditions and the results of managing glucose levels in non-diabetic patients. Moreover, the relationship between blood glucose and cerebral glucose during the ischemia/reperfusion processes and the potential benefits of low glucose supplements for non-diabetic patients are discussed.

Insulin Therapy in Hospitalized Patients

BACKGROUND

Hyperglycemia is prevalent and is associated with an increase in morbidity and mortality in hospitalized patients. Insulin therapy is the most appropriate method for controlling glycemia in hospital, but is associated with increased risk of hypoglycemia, which is a barrier to achieving glycemic goals.

AREAS OF UNCERTAINTY

Optimal glycemic targets have not been established in the critical and noncritical hospitalized patients, and there are different modalities of insulin therapy. The primary purpose of this review is to discuss controversy regarding appropriate glycemic targets and summarize the evidence about the safety and efficacy of insulin therapy in critical and noncritical care settings.

DATA SOURCES

A literature search was conducted through PubMed with the following key words (inpatient hyperglycemia, inpatient diabetes, glycemic control AND critically or non-critically ill patient, Insulin therapy in hospital).

RESULTS

In critically ill patient, blood glucose levels >180 mg/dL may increase the risk of hospital complications, and blood glucose levels <110 mg/dL have been associated with an increased risk of hypoglycemia. Continuous intravenous insulin infusion is the best method for achieving glycemic targets in the critically ill patient. The ideal glucose goals for noncritically ill patients remain undefined and must be individualized according to the characteristics of the patients. A basal-bolus insulin strategy resulted in better glycemic control than sliding scale insulin and lower risk of hypoglycemia than premixed insulin regimen.

CONCLUSIONS

Extremes of blood glucose lead to poor outcomes, and target glucose range of 110-180 mg/dL may be appropriate for most critically ill patients and noncritically ill patients. Insulin is the most appropriate pharmacologic agent for effectively controlling glycemia in hospital. A continuous intravenous insulin infusion and scheduled basal-bolus-correction insulin are the preferred modalities for glycemic control in critically and noncritically ill hospitalized patients, respectively.