Molecular Mechanisms by Which Metabolic Control May Improve Outcomes

Nutrition support and the chronic critical illness syndrome

Critical illness can be viewed as consisting of 4 distinct stages: (1) acute critical illness (ACI), (2) prolonged acute critical illness, (3) chronic critical illness, and (4) recovery. ACI represents the evolutionarily programmed response to a stressor. In ACI, substrate is shunted away from anabolism and toward vital organ support and inflammatory proteins. Nutrition support in this stage is unproven and may ultimately prove detrimental. As critical illness progresses, there is no evolutionary precedent, and man owes his life to modern critical care medicine. It is at this point that nutrition and metabolic support become integral to the care of the patient. This paper (1) delineates and develops the 4 stages of critical illness using current evidence, clinical experience, and new hypotheses; (2) defines the chronic critical illness syndrome (CCIS); and (3) details an approach to the metabolic and nutrition support of the chronically critically ill patient using the metabolic model of critical illness as a guide. It is our hope that this clinical model can generate testable hypotheses that can improve the outcome of this unique population of patients.

Glycemic control and nutrition in the intensive care unit

PURPOSE OF REVIEW

Hospital clinicians frequently encounter hyperglycemia due to diabetes or the stress of critical illness in patients who are receiving nutrition support.

RECENT FINDINGS

A growing body of evidence suggests that hyperglycemia in the hospital is associated with adverse outcomes (e.g. disability after acute cardiovascular events, infection and death) and that improvement in outcomes can be achieved with improved glycemic control or insulin. Therefore, familiarity with the implications of hyperglycemia and with its treatment are essential for clinicians practicing in hospital settings.

SUMMARY

Questions persist regarding the optimal glucose goal range in differing patient groups. In addition, while the technology to deliver glycemic control in intensive care unit settings is widely available, data are limited about effective and safe insulin infusions. Research should focus on the risks and benefits of providing nutrition support in this group of patients, optimal glucose goal ranges, and on methods of achieving desired glucose goal ranges.

Diabetes and Stroke: Part two—Treating diabetes and stress hyperglycemia in hospitalized stroke patients

It is well established that strict glycemic control for the hospitalized stroke patient is associated with improved outcome compared with poor control. This is particularly true for the stroke patients because hyperglycemia can adversely affect ischemic damage. A blood sugar level of less than 110 mg/dL is recommended for critically ill patients and should be achieved by intravenous insulin administration in an intensive care unit setting. Many stroke patients are unable to swallow, and insulin requirement must be readjusted carefully to conform to the nutritional state of the patient. The transition from intravenous insulin to subcutaneous insulin or oral antihyperglycemic agents must be carefully monitored. Careful discharge planning of diabetic care for the stroke patient is necessary to prevent long-term sequelae of inadequate control.

Systematic strategies for improved outcomes for the hyperglycemic hospitalized patient with diabetes mellitus

Diabetes mellitus is reaching epidemic proportions in the United States. It is now the fourth most common comorbid condition complicating hospital discharges. There is a rapidly evolving body of literature assessing the short-term and long-term effects of strict glycemic control in the hospital setting. Results from several landmark studies have challenged the long-held notion that stress hyperglycemia is beneficial. This article will focus on these studies, postulated mechanisms of action, and finally, description of an insulin infusion protocol developed at a community hospital for patients undergoing cardiac surgery.

Inpatient management of hospitalized patients with type 2 diabetes

Over the past 4 years, the scientific literature addressing issues relevant to inpatient hyperglycemia and its management has grown dramatically but remains incomplete. The growing interest in inpatient diabetes management is particularly pertinent given the epidemic rise in the prevalence of type 2 diabetes and the associated increase in the proportion of inpatients carrying this diagnosis. The benefits of aggressive glucose control are well-established in certain admission categories. These benefits likely apply to many other admission diagnoses, but remain unproven at this time. Similarly, the best methods of glucose control remain uncertain in the various inpatient settings. Intensive insulin infusion therapy is becoming the standard care in the intensive care unit setting. Its use is also growing in less acute inpatient settings but requires further study. Inpatient subcutaneous insulin recommendations are general based on experience gained in the outpatient setting but offer a practical, physiologic approach.