Pneumonia Clinical Trials

Experimental: Transpulmonary pressure group

The overall concept of this group is to individualize PEEP. After enrollment, all patients underwent placement of an gastric tube for esophageal pressure monitoring.Tidal volume is adjusted to achieve a target tidal volume of 6 mL/kg predicted body weight (PBW) while controlling end-inspiratory transpulmonary pressure ≤ 20 cmH₂O. PEEP is adjusted to maintain end-expiratory transpulmonary pressure between 0 and 2 cmH₂O. FiO₂ is titrated to keep the patient's SpO₂ at 90%-95%. Respiratory rate is adjusted to maintain pH between 7.30 and 7.45 and PaCO₂ ≤ 60 mmHg.~If end-inspiratory transpulmonary pressure exceeds 20 cmH₂O, tidal volume may be reduced to 4 mL/kg PBW as necessary. For patients with severe dyspnea or respiratory acidosis, tidal volume may be increased up to 8 mL/kg PBW provided that end-inspiratory transpulmonary pressure remains ≤ 20 cmH₂O.

No_intervention: Control group

In this group, PEEP was titrated using the low PEEP:FiO₂ table method. Volume-assist control (V-A/C) ventilation was adopted, with tidal volume maintained at approximately 6 mL/kg predicted body weight (PBW) and plateau pressure controlled at ≤ 30 cmH₂O. PEEP was adjusted to maintain the oxygenation target of SpO₂ 90%-95% while using the lowest possible PEEP:FiO₂ combination in the table. Respiratory rate was adjusted to maintain pH between 7.30 and 7.45 and PaCO₂ ≤ 60 mmHg.~Esophageal pressure monitoring was simultaneously performed in this group to calculate and record end-inspiratory and end-expiratory transpulmonary pressures; however, ventilator parameters were not adjusted based on these measurements, and crossover to the transpulmonary pressure (Ptp) group was not permitted.~If plateau pressure exceeded 30 cmH₂O, tidal volume could be reduced to 4 mL/kg PBW as necessary. For patients with severe dyspnea or respiratory acidosis, tidal volume could be increased up to 8 mL/kg PBW