Page 30 - Critical Care Notes

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BASICS

Nutrition Issues in Critical Care
Primary Concerns
■ Malnutrition, starvation, and catabolism
■ Stress hypermetabolism
■ Fluid volume deficit
■ Fluid volume excess
Stress and Nutrition
Prolonged or continual stress depletes glycogen stores → hypermetabolic
state.
Metabolic rate increases with the release of catecholamines + glucagon +
cortisol → hyperglycemia and “stress diabetes.”
Protein is lost via gluconeogenesis → decrease in serum protein (albumin).
Lipolysis → increase in free fatty acids.
Nitrogen excretion increases.
Body weight decreases.
1 kg body weight = 1 liter of fluid retained or lost.
Impaired immune function.
Body Mass Index
BMI is a simple means of classifying sedentary (physically inactive) individuals
of average body composition and may indicate obesity. It is calculated by the
following: Body mass index (BMI) = weight (kg) ÷ height (meters) 2
1 kg = 2.2 lb Normal BMI = 20–25 kg/m 2
A BMI >30 kg/m 2 indicates obesity; >40 kg/m 2 indicates morbid obesity. An
increase in BMI has been associated with heart disease and diabetes.
A BMI <18.5 kg/m 2 suggests a person is underweight. A BMI <17.5 may indi-
cate the person has anorexia or a related disorder.
BMI does not take into account factors such as frame size and muscularity.
Signs and Symptoms of Fluid Volume Deficit:
Hypovolemia
■ Dry mucous membranes; dry, coated, cracked or fissured tongue
■ Thirst; thick, scant saliva
■ Poor skin turgor
■ Sunken eyeballs
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