Blomqvist H, Frostell C, Pieper R, Hedenstierna G
Department of Anaesthesia and Intensive Care, Danderyd Hospital, Sweden.
Acta Anaesthesiol Scand. 1990 Jul;34(5):370-6. doi: 10.1111/j.1399-6576.1990.tb03105.x.
An expression (LN) is presented for the net fluid leakage from the intravascular to the extravascular space in the lung. It is based on a new dog model and is the sum of rate of change in extravascular lung water content (EVLW), thoracic lymph flow, and pleural fluid formation. The rate of change of EVLW (delta EVLW) in ml/kg/h was calculated from repeated measurements of EVLW with a double-indicator dilution technique (dye/cold) and corrected according to the relation between EVLW measured by this technique and gravimetry. LN was studied in lung-healthy mechanically ventilated dogs during a prolonged period of mechanical ventilation with and without the application of a positive end-expiratory pressure of 10 cmH2O (1.0 kPa). During mechanical ventilation, LN was found to be 0.3 ml/kg/h in the basal condition, increasing to 0.5 ml/kg/h (P less than 0.01) after a mean period of 7 h. After the application of a positive end-expiratory pressure (PEEP) of 10 cmH2O (1 kPa) for 0.5-2 h, LN was found to increase significantly, from a mean of 0.3 ml/kg/h to 0.9 ml/kg/h (P less than 0.01). We conclude that LN is a useful quantitative expression in experimental studies on lung fluid balance.
本文给出了一个表示肺内血管内液体向血管外间隙净渗漏的表达式（LN）。它基于一种新的犬模型，是血管外肺水含量（EVLW）变化率、胸淋巴流量和胸腔积液形成量之和。EVLW的变化率（δEVLW，单位为ml/kg/h）通过双指示剂稀释技术（染料/冷）对EVLW进行重复测量来计算，并根据该技术测量的EVLW与重量法之间的关系进行校正。在长时间机械通气期间，对肺健康的机械通气犬进行了研究，通气过程中分别施加和不施加10 cmH₂O（1.0 kPa）的呼气末正压。在机械通气期间，发现基础状态下LN为0.3 ml/kg/h，平均7小时后增加到0.5 ml/kg/h（P＜0.01）。在施加10 cmH₂O（1 kPa）的呼气末正压（PEEP）0.5 - 2小时后，发现LN显著增加，从平均0.3 ml/kg/h增加到0.9 ml/kg/h（P＜0.01）。我们得出结论，LN在肺液体平衡的实验研究中是一个有用的定量表达式。
