Computerized substrate utilization determinations from respiratory functions alone.

Non-invasive substrate utilization using expiratory gases is a cost effective and informative procedure in the nutritional management of the critically ill patient. In addition, the effect of feeding on the respiratory system depends on the substrates utilized and therefore provides information for an optimal regimen in nutritional support. However, metabolic systems to assess substrate utilization are often expensive. Hence, the program described here, in combination with the necessary instrumentation (ventilation meter, O2 and CO2 analyzer), will allow a rapid and quantitatively reliable assessment of substrate utilization.