Management of Hyperglycemia in the Critically Ill

Chapter 51 Management of Hyperglycemia in the Critically Ill



Matthew P. Gilbert, DO, MPH , Alison Schneider, MD




1 Who is at risk for development of hyperglycemia?


Hyperglycemia can occur in patients with known or undiagnosed diabetes mellitus. Hyperglycemia during acute illness can also occur in patients with previously normal glucose tolerance, a condition called stress hyperglycemia.



2 How common is hyperglycemia in critically ill patients?


Acute hyperglycemia is common in critically ill patients. It is estimated that in 90% of all patients blood glucose concentrations >110 mg/dL develop during critical illness. Stress-induced hyperglycemia has been associated with adverse clinical outcomes in patients with trauma, acute myocardial infarction, and subarachnoid hemorrhage.



3 What causes hyperglycemia in critically ill patients?


In healthy individuals, blood glucose concentrations are tightly regulated within a narrow range. The cause of hyperglycemia in critically ill patients is multifactorial. Physiologic and emotional stress leads to intense activation of counterregulatory hormones such as cortisol and epinephrine. The release of inflammatory cytokines causes an increase in peripheral insulin resistance and hepatic glucose production. The use of glucocorticoids and parenteral and enteral nutrition is an important contributor to hyperglycemia.



4 What is the relationship between hyperglycemia and acute illness?


The relationship between hyperglycemia and acute illness is complex. Severe hyperglycemia (>250 mg/dL) has been shown to have a negative impact on the vascular, hemodynamic, and immune systems. Hyperglycemia can also lead to electrolyte imbalance, mitochondrial injury, and both neutrophil and endothelial dysfunction. Acute illness increases the risk for hyperglycemia through the release of counterregulatory hormones, increased insulin resistance, and immobility. Figure 51-1 illustrates the relationship between acute illness and hyperglycemia.


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Figure 51-1 Hyperglycemia and acute illness.



5 Should oral medications used to treat diabetes be continued in the intensive care unit (ICU)?


Given the high incidence of renal and hepatic impairment, oral medication to treat diabetes should not be continued in the ICU. Medications such as metformin are contraindicated in patients with renal or hepatic dysfunction and congestive heart failure. Long-acting formulations of sulfonylureas have been associated with episodes of prolonged severe hypoglycemia in hospitalized patients. Oral medications are not easily titrated to meet glycemic targets and may take weeks to effectively lower blood glucose levels.



6 Should injectable, noninsulin medications be used in the ICU?


Noninsulin, injectable medications such as exenatide, liraglutide, and pramlintide have similar limitations as oral agents and should not be used in the ICU setting.



7 What is the most effective way to treat hyperglycemia in the ICU?


An intravenous insulin infusion is the safest and most effective way to treat hyperglycemia in critically ill patients. Because of the short half-life of circulating insulin (minutes), an insulin infusion can be frequently adjusted to match the often-variable insulin requirements of critically ill patients. Intravenous insulin therapy should be administered by validated written or computerized protocols that outline predefined adjustments in the insulin dose based on frequent measurement of blood glucose concentrations.



8 When should treatment with an intravenous insulin infusion be initiated?


Intravenous insulin therapy should be initiated for the treatment of persistent hyperglycemia starting at a blood glucose concentration of no greater than 180 mg/dL.



9 What is the appropriate glycemic target for critically ill patients?


Recognizing the importance of glycemic control in critically ill patients, a number of professional societies have developed treatment guidelines and/or consensus statements that provide evidence-based glycemic targets. Although the glycemic targets are not identical, all of the groups advocate for good glycemic control while avoiding hypoglycemia (see Table 51-1).


Table 51-1 Summary of glycemic targets from the medical literature





















Professional society/consensus statement Glycemic target for critically ill patients
American Diabetes Association 140-180 mg/dL
American Association of Clinical Endocrinologists 140-180 mg/dL
Surviving Sepsis Campaign 150-180 mg/dL
American College of Physicians 140-200 mg/dL
American Thoracic Society <180 mg/dL (in patients undergoing cardiac surgery)
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Jul 6, 2016 | Posted by in CRITICAL CARE | Comments Off on Management of Hyperglycemia in the Critically Ill

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