AJP - Endocrinology and Metabolism, Vol 266, Issue 3 E366-E371, Copyright © 1994 by American Physiological Society
Nutritional influence on the recovery of 14CO2 in critically ill trauma patients
M. Jeevanandam, N. J. Holaday and S. R. Petersen
Trauma Center, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013.
Several factors, including age, nutritional and metabolic status, and
underlying pathological conditions, should be considered in estimating the
correction factor for labeled CO2 retention. We have evaluated the
nutritional influence of this correction factor in a group of severely
injured (injury severity score = 33 +/- 5), hypermetabolic, and highly
catabolic adult trauma patients. Primed-constant infusion of NaH14CO3 was
used, and the breath 14CO2 radioactivity was measured. The experiment was
conducted once in the fasting condition during the early catabolic "flow"
phase of injury and again during and after a week of intravenous feeding.
The mean value of the 14CO2 recovery (85.2 +/- 2.7%) in the basal fasting
condition was higher than the value of 81% commonly used in normal
subjects. During intravenous nutritional support the recovery was 100.8 +/-
1.7%. Recovery of tracer increased linearly with O2 uptake and CO2
production. The linear expression obtained between recovery and CO2
production could estimate the recovery within 3% in trauma patients, and
that obtained by multiple regression with CO2 production and O2 uptake
would predict the recovery within 1.5%.
