呼吸机撤离后不同体位对新生儿氧合功能的影响

目的：国内外学者已经对多种疾病状态下新生儿体位进行了研究，但对呼吸机撤机后这一关键时期新生儿应采取何种体位尚无报道，该实验通过撤机后最初6 h新生儿仰、俯卧位与其氧合关系的研究，来评价呼吸机撤离后最初6 h内新生儿仰、俯卧位对其氧合功能的影响。方法：受试者随机分为仰卧位组或俯卧位组。吸氧，确保SPO2在正常范围。监测撤机后6 h内的SPO2，记录撤机后1 h及6 h的FiO2，于撤机后1 h及6 h各测动脉血气一次，记录PaO2、PaCO2，并计算A-aDO2、PaO2/FiO2、RI。结果：于撤机后1 h及6 h，俯卧位组FiO2（1 h俯0.4415±0.1152，仰0.5289±0.0986；6 h 俯0.3414±0.1120,仰0.4750±0.1120）、A-aDO2（1 h俯171.06±86.55,仰253.62±71.56；6 h俯105.85±78.18,仰208.48±86.80）及RI(1 h俯2.16±1.24,仰3.74±1.68；6 h俯1.35±1.11,仰3.65±1.28)均明显低于仰卧位组。PaO2(1 h俯88.70±32.65，仰73.43±17.68；6 h俯84.10±13.95,仰70.20±20.27)及PaO2/FiO2 (1 h俯213.49±88.96，仰141.54±43.25；6 h俯275.23±108.83,仰160.62±63.03) 明显高于仰卧位组，均有统计学差异。结论：俯卧位可以改善撤机后最初6 h内新生儿的氧合功能。

Effect of position on oxygenation in neonates after weaning from mechanical ventilation

OBJECTIVE: What is the best suitable position for neonates who were weaned from mechanical ventilation has not been identified. This study aimed to evaluate the effect of the supine and prone positions on oxygenation in neonates within 6 hrs after weaning from mechanical ventilation. METHODS: Sixty neonates who were weaned from mechanical ventilation were randomly given prone or supine position (n=30 each). They all received oxygen inspiration and SPO2 was maintained in a normal range by adjusting the oxygen flow rate (FiO2). Blood PaO2 and PaCO2 levels were measured 1 and 6 hrs after weaning and then the alveolodouble ended arrowarterial oxygen partial pressure difference (A-aDO2), respiratory index and oxygenation index were calculated. RESULTS: Mean FiO2 used in the prone position group was significantly lower than that in the supine position group 1 and 6 hrs after weaning (P<0.01). The value of A-aDO2 in the prone position group 1 hr (171.06+/-86.55 vs 253.62+/-71.56; P<0.01) and 6 hrs after weaning (105.85+/-78.18 vs 208.48+/-86.80; P<0.01) were significantly lower than that in the supine position group. The respiratory index in the prone position group 1 and 6 hrs after weaning (2.16+/-1.24 and 1.35+/-1.11) was also reduced compared to 3.74+/-1.68 and 3.65+/-1.28 in the supine position group (P<0.01). In contrast, PaO2 in the prone position group 1 hr (88.70+/-32.65 vs 73.43+/-17.68; P<0.01) and 6 hrs (84.10+/-13.95 vs 70.20+/-20.27; P<0.01) after weaning was significantly higher than that in the supine position group. The oxygenation index in the prone position group 1 and 6 hrs after weaning (213.49+/-88.96 and 275.23+/-108.83) increased significantly compared to 141.54+/-43.25 and 160.62+/-63.03 in the supine position (P<0.01). CONCLUSIONS: The prone position is better than the supine position for the improvement of oxygenation within 6 hrs after weaning from mechanical ventilation in neonates.