Barton Aimee M, Abubakar M Kabir, Berg Jennifer, Keszler Martin
Department of Pediatrics, Georgetown University Hospital, 3800 Reservoir Road NW, M3400, Washington, DC 20007, USA.
Pulm Med. 2011;2011:189205. doi: 10.1155/2011/189205. Epub 2011 Jul 3.
Objective. To validate the empiric observation that pH has an important effect on oxygenation in infants receiving iNO. Study Design. Demographics, ventilator settings, arterial blood gases (ABG), and interventions for up to 96 hours of life were extracted from the charts of 51 infants receiving iNO. Need for ECMO and survival to discharge were noted. Mean blood pressure (MBP) and mean airway pressure (MAP) were recorded. The arterial/alveolar (a/A) ratio was used as the primary outcome. Analysis was by simple linear regression and multiple linear regression analyses and Fisher's exact test. pH responsiveness was arbitrarily defined as a correlation coefficient (CC) of >0.40 with P < 0.05. Results. Mean gestational age was 38.8 weeks and mean birth weight was 3300 g. All patients had clinical diagnosis of PPHN. Clear responsiveness to pH was found in 31/51 infants. MAP and MBP did not correlate with a/A ratio. Three responders had a critical pH > 7.55. Of 11 patients requiring ECMO, only 3 exhibited responsiveness at any time in their course. Three responders required ECMO. Conclusion. This small study suggests that failure or inability to optimize pH may account for observed unresponsiveness to iNO. Maintaining a pH > 7.5 using hyperventilation is not recommended.
目的。验证pH值对接受吸入一氧化氮（iNO）治疗的婴儿氧合有重要影响这一经验性观察结果。研究设计。从51例接受iNO治疗的婴儿病历中提取出生人口统计学资料、呼吸机设置、动脉血气（ABG）以及出生后96小时内的干预措施。记录是否需要体外膜肺氧合（ECMO）以及出院存活率。记录平均血压（MBP）和平均气道压（MAP）。动脉/肺泡（a/A）比值用作主要结局指标。采用简单线性回归、多元线性回归分析和Fisher精确检验进行分析。pH反应性被任意定义为相关系数（CC）>0.40且P<0.05。结果。平均胎龄为38.8周，平均出生体重为3300克。所有患者均有持续性肺动脉高压（PPHN）的临床诊断。51例婴儿中有31例对pH有明显反应。MAP和MBP与a/A比值无关。3例有反应者的临界pH>7.55。在11例需要ECMO的患者中，只有3例在病程中的任何时候表现出反应性。3例有反应者需要ECMO。结论。这项小型研究表明，未能优化pH值或无法优化pH值可能是观察到的对iNO无反应的原因。不建议使用过度通气维持pH>7.5。
