Valta P, Takala J, Foster R, Weissman C, Kinney J M
Department of Intensive Care, Kuopio University Hospital, Finland.
Chest. 1992 Jul;102(1):234-8. doi: 10.1378/chest.102.1.234.
To assess the accuracy of the respiratory inductive plethysmography in the measurement of PEEP-induced changes in end-expiratory lung volume during mechanical ventilation and its accuracy and stability in the measurement of ventilation during controlled mechanical ventilation and spontaneous breathing.
An open comparison between two methods using a criterion standard. Either a pneumotachometer (mechanically ventilated patients) or a spirometer (spontaneously breathing subjects) was used as the reference method.
Tertiary care center; a multidisciplinary intensive care unit and a metabolic research unit.
Six mechanically ventilated, paralyzed postoperative open heart surgery patients, six spontaneously breathing COPD patients, and eight healthy volunteers.
Stepwise increases and reductions of PEEP from zero to 12 cm H2O during controlled mechanical ventilation; repeated validation of the calibration of the respiratory inductive plethysmography (RIP) in both mechanically ventilated and spontaneously breathing subjects.
The baseline drift of the RIP in vitro was 10 ml/150 min and in a ventilated model it was 20 ml/150 min. In mechanically ventilated patients, the mean error of the calibration after 150 min was within +/- 5 percent. Change in end-expiratory lung volume (EELV) during the stepwise increase of PEEP up to 12 cm H2O was 849 +/- 136 ml with the RIP and 809 +/- 125 ml with the pneumotachometer (PT), and during the stepwise reduction of PEEP it was 845 +/- 124 ml and 922 +/- 122, respectively (not significant [NS]. The mean difference between methods in the measurement of change in EELV was -6.6 +/- 3.5 percent during increasing and 6.6 +/- 6.7 percent during decreasing PEEP (NS). Both in mechanically ventilated and spontaneously breathing subjects, the difference between methods was significant for VT and VT/TI. The difference in VT was -2.2 +/- 0.2 percent during mechanical ventilation, -1.1 +/- 0.5 percent in spontaneously breathing COPD patients, and 2.9 +/- 0.4 percent in healthy volunteers (NS between groups).
The RIP is sufficiently accurate for the measurement of PEEP-induced changes in EELV during controlled mechanical ventilation. The accuracy of tidal volume measurement is similar during mechanical ventilation and spontaneous breathing. The calibration of the RIP is stable enough for bedside monitoring of changes in lung volumes.
评估呼吸感应体积描记法在机械通气期间测量呼气末正压（PEEP）引起的呼气末肺容积变化的准确性，以及在控制机械通气和自主呼吸期间测量通气的准确性和稳定性。
使用标准方法对两种方法进行开放比较。将呼吸流速仪（用于机械通气患者）或肺活量计（用于自主呼吸受试者）用作参考方法。
三级医疗中心；多学科重症监护病房和代谢研究单位。
6名机械通气、瘫痪的心脏直视手术后患者、6名自主呼吸的慢性阻塞性肺疾病（COPD）患者和8名健康志愿者。
在控制机械通气期间，将PEEP从零逐步增加和降低至12 cm H₂O；对机械通气和自主呼吸受试者重复进行呼吸感应体积描记法（RIP）校准的验证。
RIP在体外的基线漂移为10 ml/150分钟，在通气模型中为20 ml/150分钟。在机械通气患者中，150分钟后校准的平均误差在±5%以内。在将PEEP逐步增加至12 cm H₂O的过程中，使用RIP测量的呼气末肺容积（EELV）变化为849±136 ml，使用呼吸流速仪（PT）测量的为809±125 ml；在PEEP逐步降低的过程中，分别为845±124 ml和922±122 ml（无显著差异[NS]）。在增加和降低PEEP期间，两种方法在测量EELV变化方面的平均差异分别为-6.6±3.5%和6.6±6.7%（无显著差异）。在机械通气和自主呼吸受试者中，两种方法在潮气量（VT）和VT/吸气时间（TI）方面的差异均具有统计学意义。在机械通气期间，VT差异为-2.2±0.2%；在自主呼吸的COPD患者中为-1.1±0.5%；在健康志愿者中为2.9±0.4%（组间无显著差异）。
RIP在控制机械通气期间测量PEEP引起的EELV变化足够准确。在机械通气和自主呼吸期间，潮气量测量的准确性相似。RIP的校准足够稳定，可用于床边监测肺容积变化。
