A previously healthy, 36-year-old man is hospitalized following a motor vehicle collision. He sustained a concussion and fracture of the right femur, and open reduction and internal fixation of the fracture are planned. Medical history is insignificant, and the patient takes no medications for chronic conditions. Blood pressure is 150/90 mm Hg and pulse is 70/min. Oxygen saturation is 98% on room air. BMI is 24 kg/m2. Laboratory results are as follows:
| Hemoglobin | 12.7 g/L |
| Sodium | 140 mEq/L |
| Potassium | 3.8 mEq/L |
| Bicarbonate | 24 mEq/L |
| Chloride | 104 mEq/L |
| Glucose | 145 mg/dL |
| Blood urea nitrogen | 22 mg/dL |
| Creatinine | 1.2 mg/dL |
| Calcium | 9.1 mg/dL |
Finger-stick glucose measurement is 156 mg/dL. Hemoglobin A1c is 5.5%. Which of the following is the best next step in management of this patient's glucose values?
Stress hyperglycemia | |
Presentation |
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Risk factors |
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Treatment |
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This patient has an elevated blood glucose but a normal hemoglobin A1c (ie, no chronic hyperglycemia). In the context of major trauma, this presentation is consistent with stress hyperglycemia. Stress hyperglycemia is a transient elevation in blood glucose caused by metabolic stress in patients without preexisting diabetes mellitus. It is common in the intensive care unit and is typically seen in patients with sepsis, burns, or major trauma/hemorrhage.
Severe stress triggers the release of cortisol and catecholamines (primarily epinephrine and norepinephrine), which act on the liver to increase glycogenolysis and gluconeogenesis, an effect that can be enhanced by glucagon. The free glucose is then released from the liver into the blood.
Mild glucose elevations, such as in this patient, are generally considered to be an adaptive physiologic response and do not warrant intervention. However, severe elevations (eg, >180-200 mg/dL) are associated with increased mortality and should be corrected with short-acting insulin in most cases (Choice C). A mildly elevated target glucose of 140-180 mg/dL (rather than normoglycemia) is recommended to minimize the risk of insulin-induced hypoglycemia.
(Choice A) A calorie-restricted diet is not recommended for critically ill or injured patients, who typically have high metabolic requirements and complex care plans (eg, surgical interventions).
(Choices B and D) Sulfonylureas (eg, glipizide) induce continued insulin secretion despite normalization of blood glucose, potentially leading to hypoglycemia. Metformin does not cause hypoglycemia but is not recommended for critically ill patients or those anticipating major surgery due to the risk of lactic acidosis. In general, oral antidiabetic agents are withheld in hospitalized patients until they are fully stabilized and on a predictable diet.
Educational objective:
Stress hyperglycemia is a transient elevation in blood glucose that occurs as a physiologic response to severe illness or injury. Mild elevations do not require treatment. Marked elevations (eg, >180-200 mg/dL) are associated with increased mortality and should be corrected with short-acting insulin, with a target glucose of 140-180 mg/dL.