Thomson A, Silverman M
Crit Care Med. 1985 Jan;13(1):4-8. doi: 10.1097/00003246-198501000-00002.
The expiratory time constant of the respiratory system (Trs) and the total respiratory system compliance (Crs) were measured from the analysis of a flow-volume loop during relaxed expiration, and the total respiratory system resistance (Rrs) was derived from the relationship: Rrs = Trs/Crs. In ten intubated and mechanically ventilated very low birth weight infants, the values obtained for compliance (0.21 to 0.71 ml/cm H2O) were similar to those found using an occlusion technique during spontaneous breathing. The values of Trs were 0.03 to 0.14 sec. These Trs values were altered by adding known resistive loads. The corresponding derived values for Rrs were close to the values of the added resistance loads, suggesting that resistance values found in this group of ventilated babies (120 to 380 cm H2O/L X sec) were accurate.
通过对呼气放松时流量-容积环的分析，测量呼吸系统的呼气时间常数（Trs）和总呼吸系统顺应性（Crs），并根据公式Rrs = Trs/Crs得出总呼吸系统阻力（Rrs）。在10例接受气管插管并机械通气的极低出生体重儿中，所获得的顺应性值（0.21至0.71 ml/cm H2O）与在自主呼吸时使用阻断技术所测得的值相似。Trs值为0.03至0.14秒。通过添加已知的阻力负荷可改变这些Trs值。相应得出的Rrs值与添加的阻力负荷值接近，这表明在这组接受通气的婴儿中所测得的阻力值（120至380 cm H2O/L×秒）是准确的。
