Efecto de diferentes niveles de presión positiva al final de la espiración sobre el gasto energético en reposo medido por calorimetría indirecta en pacientes con ventilación en presión control

Summary Objective: To identify variations during measurements of resting energy expenditure (REE), oxygen consumption (VO 2 ) and CO 2 production (VCO 2 ) by indirect calorimetry (IC) in patients with pressure-controlled ventilation and different levels of positive end expiratory pressure (PEEP). Design: Prospective and comparative study. Setting: Intensive care unit (ICU) of a university-affiliated hospital. Measurements and Main Results: REE, VO2, and VCO2 were measured by IC in nine patients with pressure- controlled ventilation and different levels of PEEP. Paired t Wilcoxon and coeficient of variation tests for all measurements were carried out. Decrease in REE, VCO 2 , and VO 2 was observed with increments in PEEP, these changes related with a concomitant reduction in VE. Coefficient of variation during IC was above 6%, and was lower in three patients who maintained the same VE throughout the study. Conclusions: Measurement of REE by IC is reliable at various levels of PEEP, and it improves if VE remains constant throughout measurement. Respiratory quotient (RQ) in this setting is not accurate.