Objective: Atelectasis, which affects oxygenation, is always occurred after craniotomy under general anesthesia. The commonly used protective ventilation strategy, which includes recruitment maneuver and higher level of positive end-expiratory pressure (PEEP), can effectively reduce atelectasis after heart and abdominal surgery, but increase intracranial pressure and reduce cerebral perfusion in patients undergoing craniotomy. We hypothesized individualized PEEP ventilation between tumor resection and dural suture in craniotomy could effectively reduce postoperative atelectasis, improve PaO2/FiO2 ratio, and without reducing the regional cerebral oxygen saturation (rScO2).
Patients and methods: 96 patients underwent tumor craniotomy in supine position were randomized into the control group (C group) and individualized PEEP group (P group). In the C group, the tidal volume (VT) was set at 8 mL/kg of predicted body weight, but PEEP were not used. In the P group, VT was set at 6 mL/kg of predicted body weight combined with individualized PEEP between tumor resection and dural suture, while in other periods of general anesthesia, VT was set at 8 mL/kg of predicted body weight. PaO2/FiO2 ratio, lung ultrasound score (LUS) and rScO2 were measured before induction, 1 h and 24 h after extubation.
Results: Individual PEEP in the P group was 7.0 (4.0-9.0). The PaO2/FiO2 ratio and rScO2 in the P group were significantly higher than that of the C group (395 ± 62 vs. 344 ± 40, 67 ± 5 vs. 61 ± 4, respectively, p < 0.05) and the LUS of the experimental group was significantly lower than that of the C group [7.5 (5.3-8.3) vs. 10.0 (9.0-12.0), p < 0.05] 1 h after extubation.
Conclusion: Mechanical ventilation with individualized PEEP between tumor resection and dural suture in craniotomy can reduce atelectasis, improve PaO2/FiO2 ratio and rScO2 1 h after extubation.
Keywords: Atelectasis; Craniotomy; Individualized; PaO(2)/FiO(2)ratio; Positive end-expiratory pressure.
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