Mechanical Power Differs Between Pressure-Controlled Ventilation and Different Volume-Controlled Ventilation Modes

Abstract

OBJECTIVES: Mechanical power (MP) is a way of estimating the energy delivered by the ventilator to the patient. For both volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) methods have been described to calculate the MP. The pressure-volume (PV) loop, from which the MP is calculated, is different for VCV compared with PCV. We aimed to compare the MP of VCV with zero pause time (VCV-0), VCV with 10% pause time (VCV-10), and PCV within patients in different patient categories based on severity of lung injury. DESIGN: In a proof-of-concept study, we enrolled 46 mechanically ventilated patients without spontaneous breathing efforts. Baseline measurements were done in pressure-controlled mode. Subsequently, measurements were done in VCV-0 and VCV-10. Tidal volume and all other settings were kept the same. SETTING: ICU, single university medical center. PATIENTS: Fifty-eight cases in 46 patients on controlled ventilation modes. INTERVENTIONS: Comparison between the MP of PCV, VCV-0, and VCV-10. MEASUREMENT AND MAIN RESULTS: < 0.05 for all comparisons). CONCLUSIONS: In patients ventilated in a controlled mode, VCV without pause time had the lowest MP followed by PCV. VCV with 10% pause time had the highest MP.