Modi N, Hutton J L
Department of Paediatrics, University of Liverpool, U.K.
Early Hum Dev. 1990 Jan;21(1):11-20. doi: 10.1016/0378-3782(90)90106-s.
The relationship between sodium handling and alveolar-arterial oxygen gradient (AaDO2) was studied in 26 preterm babies requiring ventilation from birth. The difference between sodium intake and urinary sodium excretion was determined in sequential, four hourly periods throughout the course of the respiratory illness. Sodium retention changed from positive (mean 1.42 mmol kg-1 day-1) during the phase of deteriorating respiratory function to negative (mean - 1.99 mmol kg-1 day-1) during improving respiratory function. This difference is highly significant (P less than 0.001). A temporal relationship is also shown, in the form of individual time plots of AaDO2 and sodium retention for each baby; changes in sodium handling parallel changes in AaDO2. The diuresis that accompanies improving respiratory function is characterised as a natriuresis, with free water clearance remaining unchanged before and after the point of improvement. We suggest that a primary change in sodium handling, triggered by postnatal respiratory adaptation, may initiate the contraction in extracellular fluid volume that characterises early postnatal existence.
对26例自出生起即需通气治疗的早产儿的钠代谢与肺泡-动脉氧分压差（AaDO2）之间的关系进行了研究。在整个呼吸系统疾病过程中，每4小时为一个时间段，连续测定钠摄入量与尿钠排泄量之间的差异。钠潴留情况在呼吸功能恶化阶段呈正值（平均1.42 mmol·kg⁻¹·d⁻¹），而在呼吸功能改善阶段变为负值（平均-1.99 mmol·kg⁻¹·d⁻¹）。这种差异具有高度显著性（P<0.001）。还呈现出一种时间关系，以每个婴儿的AaDO2和钠潴留的个体时间图的形式表示；钠代谢的变化与AaDO2的变化平行。伴随呼吸功能改善出现的利尿表现为利钠，在改善点前后自由水清除率保持不变。我们认为，由出生后呼吸适应引发的钠代谢的原发性变化，可能启动了以出生后早期细胞外液量收缩为特征的过程。
