ICU nutrition

Many of you may not know what a nutrition support dietitian does.  An RD in nutrition support works with patients that cannot eat on their own.  They may require feeding tubes and/or IVs to be fed.  Dietitians in nutrition support recommend and prescribe specialized nutrition for critically ill patients or patients that have undergone major surgery.   It takes knowledge in anatomy, physiology, digestion and confidence!  I refer to this type of work as my "meat and potatoes" because I work in a government hospital and am paid fairly well for my expertise.

This patient was a case study for UC College of Medicine students doing a rotation in surgery.  Below are my answers in italics.  While this work is stressful at times (who wants to see someone on a big blue breathing machine...?), I enjoy teaching doctors in training and taking care of patients in this high risk category:

75 year old patient s/p CABG day no 3, intubated, sedated in the CVIC. PMHx- DM, HTN, GERD. Labs today- alb 3.1, Glu-250-400 on insulin, Ca- 9.5, Na/K- 130/4.5. BUN/Cr- 35/1.5. The MD is unsure about extubating the patient. He is looking at your suggestions. Ht- 5’8”, wt- 220 lbs

1. Should the patient be considered for enteral  or parenteral nutrition?

Enteral nutrition.  If his gut works, use it unless contraindicated (patient is on pressors, suspected ileus or SBO post op, etc).  Feeding below his stomach (into small bowel) would be more appropriate given hx GERD, diabetes (risk for gastroparesis) and obesity.  This would reduce the patient's aspiration risk while intubated.

2. Determine energy and protein needs- show your calculations

Energy needs can be based on IBW of 154 lbs as pt is obese and on mechanical ventilation.   (22-25 kcal/kg and 1.2-1.5 gm pro/kg post op).  Calorie needs are lower to prevent overfeeding and increased CO2 production in the setting of mechanical ventilation.  Protein needs are higher to support wound healing and prevent muscle loss.

Estimated needs:  1550-1750 kcal, 84-105 gm pro

A high protein formula (such as Vital 1.2) could be used and run at a lower rate.  The patient's BUN/creat need to be monitored for changes as well as his hyponatremia  Too much protein and/or fluid could worsen renal fxn.

3. What do you know about current evidence that is accumulating in treating hyperglycemia in critically ill patients in the ICU with reference to nutrition support?

Hyperglycemia is controversial in the ICU.  You want "good control" but you need to prevent hypoglycemia.  An acceptable range of blood sugar in the ICU is ~150-180 mg/dL.  In this patient, scheduled insulin or an insulin drip would be appropriate once tube feeding is initiated.  Hyperglycemia in the ICU leads to increased infection risk and increased mortality.