超声心动图评估新生儿出生72h内肺动脉压力生理性变化

Evaluation of physiological changes of neonatal pulmonary artery pressure within 72 hours after birth by echocardiography

目的采用超声心动图评估新生儿出生后72h内肺动脉压力的生理性变化。方法对76名正常新生儿分别于出生后2、6、12、24、48、72h进行超声心动图检查,并于各时间点超声检查后测量新生儿上肢肱动脉血压。采用大血管压差法估测肺动脉收缩压(PASP)、肺动脉舒张压(PADP),计算平均肺动脉压(PAMP),并确定其出生后各时间点PASP的95%参考值范围上限。结果出生24h后,76名新生儿开始出现动脉导管生理性闭合,至72h时72名闭合,4名未闭。出生后2h动脉导管内均为双向分流;24h后均为单纯左向右分流。新生儿出生后随时间延长,肺动脉压力逐渐降低,各时间点PASP、PADP、PAMP差异均有统计学意义(P<0.05)。各时间点PASP的95%参考值范围上限分别为:出生后2h88.52mmHg,6h80.70mmHg,12h67.38mmHg,24h57.25mmHg,48h49.20mmHg,72h43.15mmHg。结论正常新生儿出生后肺动脉压力呈进行性下降趋势,72h仍超出成人正常水平(PASP<30mmHg)。

Objective To evaluate the physiological changes of pulmonary artery pressure within 72 hours after birth by echocardiography.Methods A total of 76 normal newborns were enrolled. Echocardiography was performed at 2, 6, 12, 24, 48, and 72 hours after birth, respectively. The blood pressures of the brachial artery were measured at each time point after ultrasound examination. The pulmonary artery systolic pressure （PASP） and pulmonary artery diastolic pressure （PADP） were evaluated by great blood vessel pressure gradient method, and the mean pulmonary artery pressure （PAMP） were calculated. The upper 95% limit of PASP after birth at each time point were determined.Results The physiological closure of arterial duct occurred successively from 24 h after birth. There were 72 newborns with closed duct and 4 newborns with unclosed duct until 72 h after birth. In all of 76 newborns, bidirectional shunts were found at 2 h after birth, and the unidirectional left to right shunts were found after 24 h. With the increasing of neonatal day-age, pulmonary artery pressure decreased gradually. The differences of PASP, PADP and PAMP among each time points had statistical significance （all P〈0.05）. The upper 95% limit of PASP in newborns of different time period was 88.52 mmHg within 2 h, 80.70 mmHg within 6 h, 67.38 mmHg within 12 h, 57.25 mmHg within 24 h, 49.20 mmHg within 48 h and 43.15 mmHg within 72 h after birth, respectively.Conclusion Normal newborns pulmonary artery pressure decline gradually after birth. And the pressure of 72 h after birth is still higher than that of normal adults （PASP〈30 mmHg）.