Neonatology and Neonatal Intensive Care Unit, Department of Medical and Surgical Sciences, St, Orsola-Malpighi Hospital - University of Bologna, Via Massarenti, 11 40138 Bologna, Italy.
Ital J Pediatr. 2014 Jun 21;40:60. doi: 10.1186/1824-7288-40-60.
Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow.
To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support.
A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4-5 cmH2O) because they developed RDS within the first 24-72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4-5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support.
No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ=0.11, p=0,657; RVO: ρ=-0.307, p=0.216; SVC: ρ=-0.13, p=0.197).
Central blood flow doesn't change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants.
目前的文献资料对于早产儿使用双水平持续气道正压通气（Bi-level CPAP）支持时可能发生的血流动力学变化提供的数据有限。然而，呼气末正压的应用可能会传递到心脏和大血管，导致中央血流发生变化。
评估患有呼吸窘迫综合征（RDS）的婴儿在使用双水平 CPAP 支持时中央血流的变化。
这是一项前瞻性研究，纳入了 18 名极低出生体重儿，他们在生命的前 24-72 小时内因 RDS 而接受经鼻 CPAP 支持（4-5 cmH2O）。每个患儿均切换至双水平 CPAP 支持（Phigh 8 cmH2O，Plow 4-5 cmH2O，Thigh 0.5-0.6 秒，20 次/分），持续 1 小时。在更换呼吸支持前后进行超声心动图研究和毛细血管血气分析。
在左心室输出（LVO，222.17 ± 81.4 与 211.4 ± 75.3 ml/kg/min）、右心室输出（RVO，287.8 ± 96 与 283.4 ± 87.4 ml/kg/min）和上腔静脉血流（SVC，135.38 ± 47.8 与 137.48 ± 46.6 ml/kg/min）方面，n-CPAP 和双水平 CPAP 之间无差异。动脉导管的血流动力学特征相似。双水平 CPAP 通气后 pCO2 水平显著降低；pCO2 变化与中央血流变化无关（LVO：ρ=0.11，p=0.657；RVO：ρ=-0.307，p=0.216；SVC：ρ=-0.13，p=0.197）。
双水平 CPAP 支持期间中央血流无变化，这可能成为治疗早产儿 RDS 的一种血流动力学安全的工具。
