Effect of protective mechanical ventilation on lung compliance and oxygenation in patients undergoing total knee replacement surgery
LI Juan1, ZHANG Wei2, CHEN Yu1, TIAN Ye1, and LV Hao1
1.Department of Anesthesiology, PLA Navy General Hospital, Beijing 100048, China; 2.Department of Anesthesiology, Maternal and Child Care Centre of Miyun District, Beijing 101500, China
Abstract:Objective To investigate the effect of protective mechanical ventilation on lung compliance and oxygenation in patients undergoing total knee replacement surgery.Methods Forty patients undergoing total knee replacement surgery were randomly divided into two groups: protective mechanical ventilation group (Group V) and conventional ventilation group (Group C). All the patients were subjected to intermittent positive ventilation at an oxygen concentration of 70%, oxygen flow rate of 2 L/min and inhalation and exhalation ratio of 1:2. After induction, patients in Group V received protective mechanical ventilation, while those in Group C were under conventional ventilation. Pplat was monitored at the following time points: 5 min after general anesthesia (T0), the start of surgery(T1), 5min after bone cement inplantation (T2), the end of surgery (T3), and 15 min after extubation (T4). Moreover, arterial blood samples were collected for the oxygenation index (OI) and compliance of the lung (CL) at these five time points.Results Compared with T0, Pplat at T2 and T3 increased (P<0.05), but OI decreased at T2 to T4 (P<0.05) in Group C. In Group V, OI decreased at T4 only (P<0.05). Patients in Group V showed a lower Pplat at T2 and T3, and a higher OI and CL between T2 and T4 than in Group C (P<0.05).Conclusions Protective mechanical ventilation may contribute to lung compliance and oxygenation, thus protecting lung function of patients undergoing total knee replacement surgery.
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