title: Instrumentation for monitoring gas exchange and metabolic rate in critically ill patients.
abstract: In the critically ill patient the monitoring of oxygen consumption (VO2) and carbon dioxide production (VCO2) can identify abnormalities in tissue perfusion and metabolism. A patient's metabolic utilization can be calculated by indirect calorimetry, once VO2 and VCO2 are measured. This paper evaluates a compact instrument designed for monitoring VO2 and VCO2 in the critically ill adult. Accuracy was measured under controlled laboratory conditions using oxygen-enriched air, PEEP, and intermittent mandatory ventilation (IMV). Accuracy averaged 1.3% for VO2 and 0.9% for VCO2 when room air was used. Accuracy was 11.7% for VO2 and 6.8% for VCO2 when 80% oxygen was used. PEEP of 30 cm H2O had little effect on accuracy. IMV at 2 breath/min (room air) resulted in an accuracy of 4.0% and 4.1% for VO2 and VCO2, respectively.
mesh_terms: D001481:Basal Metabolism; D004864:Equipment and Supplies; D006801:Humans; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D012044:Regression Analysis