极早产儿俯卧位机械通气对呼吸功能的影响

目的 探讨极早产儿俯卧位机械通气对呼吸功能的影响。方法 83例经口气管插管机械通气极早产儿随机分为仰卧位组和俯卧位组，4例退出研究，79例完成治疗和观察（仰卧位组37例，俯卧位组42例），以容量辅助/控制模式机械通气。俯卧位组患儿每仰卧位通气4 h行俯卧位通气2 h。分组干预之前以及分组干预后仰卧位组每6 h、俯卧位组每于转换为俯卧位后的1 h，分别记录呼吸机参数、动脉血气分析和生命体征。结果 俯卧位组FiO₂、气道峰压，平均气道压、机械通气时间低于仰卧位组，差异有统计学意义（P < 0.05）；两组潮气量、呼气末正压的差异无统计学意义（P > 0.05）；俯卧位组的PO₂/FiO₂比值高于仰卧位组，而氧合指数、呼吸频率较低，差异均有统计学意义（P < 0.05）。两组PaO₂、pH、BE、心率和有创动脉血压平均压的差异无统计学意义（P > 0.05）。结论 俯卧位与仰卧位交替通气能改善机械通气极早产儿的氧合功能，降低吸入氧体积分数，缩短机械通气时间。

Effect of prone positioning on respiratory function in very preterm infants undergoing mechanical ventilation

Objective To explore the effect of prone positioning on respiratory function in very preterm infants undergoing mechanical ventilation.Methods A total of 83 very preterm infants treated with mechanical ventilation were enrolled in the study and were randomly assigned to supine group and prone group. Four infants withdrew from the study and 79 infants completed treatment and observation (37 in the supine group and 42 in the prone group). Infants in both groups were mechanically ventilated in a volume assist-control mode. Infants in the prone group were ventilated in the supine position for 4 hours and in the prone position for 2 hours. Ventilator parameters, arterial blood gas analysis, and vital signs were recorded before grouping, every 6 hours in the supine group, and every hour after conversion into the prone position in the prone group, respectively.Results Fraction of inspired oxygen (FiO₂), peak inspiratory pressure, mean inspiratory pressure, and duration of ventilation were significantly lower in the prone group than in the supine group (P < 0.05); there were no significant differences in tidal volume or positive end-expiratory pressure between the two groups (P > 0.05). The prone group had a significantly higher PO₂/FiO₂ ratio but significantly lower oxygenation index and respiratory rate than the supine group (P < 0.05). There were no significant differences in arterial oxygen tension, pH, base excess, heart rate, or mean blood pressure between the two groups (P > 0.05).Conclusions Alternating ventilation between the prone position and supine position can improve oxygenation function, decrease the fraction of inspired oxygen, and shorten the duration of mechanical ventilation in very preterm infants undergoing mechanical ventilation.