Abstract:

Objective · To investigate the effects of applying low tidal volume mechanical ventilation and lung recruitment maneuver during general anesthesia on early pulmonary infection after abdominal operations in elderly patients. Methods · Sixty elderly patients (ASAⅠ-Ⅱ) aged 60-75 years undergoing elective
digestive tract operations ( ≥2 h) were randomly assigned to the standard ventilation group and the protective ventilation group with 30 cases in each group.
The standard ventilation group received a tidal volume of 8 mL/kg ideal body weight and zero-positive end-expiratory pressure. The protective ventilation
group received a tidal volume of 6 mL/kg ideal body weight, 5 cm H2O positive end-expiratory pressure (PEEP), and recruitment maneuvers pressure. Patients underwent conventional induction of anesthesia, endotracheal intubation, mechanical ventilation with an initial respiratory rate of 12 breaths/min and a stable tidal volume. The respiratory rate was adjusted according to EtCO2. Blood gas analysis parameters (PH, PO2, PCO2, HCO3-, oxygenation index), clinical pulmonary infection score (CPIS), procalcitonin (PCT), and C-reactive protein (CRP) were recorded before and 24 h after operation. Intraoperative adverse events were also documented. Results · CPIS and CRP 24 h after operation were significantly lower in the protective ventilation group than in the standard ventilation group. However, no significant differences in PCT, blood gas analysis parameters, and intraoperative adverse events were found. Conclusion · Low tidal volume mechanical ventilation and recruitment maneuver can reduce early postoperative CPIS and CRP, and the risk of early postoperative pulmonary infection in elderly patients.

Key words: low tidal volume, geriatric patients, clinical pulmonary infection score, procalcitonin, C-reactive protein