title: Oxygen cost of breathing in postoperative patients. Pressure support ventilation vs continuous positive airway pressure.
abstract: In seven postoperative patients with normal preoperative pulmonary function tests, we evaluated the oxygen cost of breathing (VO2resp) during continuous positive pressure ventilation (CPAP) and during a 15 cm H2O inspiratory pressure support ventilation (IPSV). For both periods, VO2 resp was estimated as the difference between total oxygen uptake of the period (VO2tot), measured by a mass-spectrometer system, and that during controlled ventilation. During CPAP ventilation, VO2resp was found to be 11.2 +/- 1.4 percent of VO2tot. During IPSV, VO2resp was found insignificant. It is concluded that a 15 cm H2O IPSV takes over the major part of the work of breathing in postoperative patients without preexisting pulmonary disease.
mesh_terms: D002245:Carbon Dioxide / Q000502:physiology; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D010100:Oxygen / Q000502:physiology*; D011175:Positive-Pressure Respiration; D011182:Postoperative Care; D011312:Pressure; D012119:Respiration; D012121:Respiration, Artificial; D014939:Work of Breathing
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen