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Hyperglycemia & Critical Illness. Definition. Normal fasting glucose 70-110 mg/dl Diabetic fasting glucose > 126 mg/dl or random glucose > 200 mg/dl. Pathophysiology. Metabolic changes in response to stress of illness insulin secretion
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Definition • Normal fasting glucose 70-110 mg/dl • Diabetic fasting glucose > 126 mg/dl or random glucose > 200 mg/dl
Pathophysiology • Metabolic changes in response to stress of illness • insulin secretion • stress hormones (cortisol, catecholamines, GH, glucagon) • cytokines (TNFα , IL-1) • Results in gluconeogenesis, glycogenolysis, lipolysis, proteolysis
INSULIN RESISTANCE Pressors Corticosteroids Sepsis Uremia Cirrhosis Obesity Bed rest INSULIN DEFICIENCY Advanced age Hypothermia Hypoxemia DM Pancreatitis Causes of…
Other Causes • TPN – 50% pts. receiving dextrose > 4mg/kg/min develop hyperglycemia • Meds in fat emulsions (i.e. Propofol) • Dextrose containing dialysis solutions • Immunosuppressants (i.e. Tacrolimus)
Symptoms of Hyperglycemia • Osmotic diuresis • Dehydration • Ketonemia/-uria • Pseudohyponatremia • AMS • GI symptoms • Respiratory abnormalities • Metabolic acidosis • Difficulty weaning from ventilator
Hyperglycemia & Infection • Granulocyte chemotaxis, complement activity, and phagocytic function are decreased by hyperglycemia • Hyperglycemia > 220 on POD #1 threefold increase in infections • Risk of sternal wound infections s/p CABG decreased by 58% in pts whose BG = 150-200 with insulin gtt
Hyperglycemia & Stroke • Associated with worse prognosis • May reflect the intensity of the stress hormone response • 3x mortality in pts with BG>144 • Independent predictor of hemorrhagic transformation of ischemic stroke s/p TPA (overall rate 9%, BG > 200 rate 25%)
Prevention • Hypocaloric TPN (1000 kcal and 1g/kg protein) + lipid infusion (provide 30% daily kcal) lowers incidence of hyperglycemia • Insulin in TPN + ISS • Hyperglycemia itself compounds insulin resistance and production so prevention is key
Treatment • MDA target range 100-150 mg/dl • Insulin sliding scale protocol • If >150/24 hours advance to insulin drip protocol • Hold treatment if nutritional support is stopped or held
Intensive v. Conventional Insulin Therapy • 1548 SICU ventilated pts. • CIT: drip started at BG > 215, target range 180-200 • IIT: drip started at BG > 110, target range 80-110 • Mortality in long stay (>5d in ICU) pts CIT 20.2% v. IIT 10.6% • Parenterally fed pts required 26% higher insulin doses to maintain target BG than those fed enterally
Hypoglycemia • BG < 40 CIT 0.8% v. 5.2% IIT • 90% of all episodes occurred after target BG reached • 62% due to interrupted enteral feeds • Episodes were brief with no serious or permanent consequences
Kudos to Insulin? • Repletes intracellular calcium and prevents arryhthmias • Limits myocardial damage by enhancing energy delivery to ischemic areas • Anabolic effects promote tissue repair
References • Finney, SJ, et al. Glucose control & mortality in critically ill patients. JAMA 290:15, 2003. • McGowen, KC, et al. Stress induced hyperglycemia. Critical Care Clinics 17:1, 2001. • Montori, VM, et al. Hyperglycemia in acutely ill patients. JAMA 288:17, 2002. • Van den Berghe, G. Insulin therapy for the critically ill patient. Clinical Cornerstone 5:2, 2003. • Van den Berghe, G, et al. Outcome benefit of intensive insulin therapy in the critically ill: Insulin dose vs. glycemic control. Critical Care Medicine 31:2, 2003.