de Abreu Marcelo Gama, Geiger Stefan, Winkler Tilo, Ragaller Max, Pfeiffer Thomas, Leutheuser Dirk, Albrecht Detlev Michael
Clinic of Anesthesiology and Intensive Care Medicine, University Clinic Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
Intensive Care Med. 2002 Mar;28(3):318-23. doi: 10.1007/s00134-001-1204-3. Epub 2002 Feb 1.
To evaluate the performance of a new device for noninvasive measurement of nonshunted pulmonary capillary blood flow (PCBF) by partial CO2 rebreathing.
Prospective clinical trial in an intensive care unit of a university hospital.
Twenty mechanically ventilated patients with acute lung injury.
Variations in PEEP of +/-3 cmH2O.
Initially PCBF was measured invasively as cardiac output minus venous admixture (Q(VA)/Q(t)) flow, and by partial CO2 rebreathing at baseline PEEP (PEEP(b)). The PEEP was then reduced by 3 cmH2O (to PEEP(b-3)) and measurements were repeated after 30 min. PEEP was then increased by 6 cmH2O (to PEEP(b+3)), and measurements were repeated after 10, 20, and 30 min. The overall correlation coefficient between noninvasive and invasive PCBF measurements at PEEP(b) was high ( r=0.97), with close agreement between methods being observed (0.1+/-0.6 l/min, bias and precision, respectively). Accordingly, both the correlation coefficient and agreement between methods for changes in PCBF from PEEP(b-3) to PEEP(b+3) levels were satisfactory ( r=0.71; 0.2+/-0.5 l/min, bias and precision). The new device was able to detect the correct PCBF trend in 17 of 20 patients investigated and in all patients who showed invasive PCBF changes equal to or greater than 0.3 l/min ( n=12). Noninvasive PCBF changes were stable as early as 10 min after variation in PEEP, as compared to 30 min values.
The new device appears to be clinically useful for the monitoring of PCBF in patients suffering from acute lung injury. Our results suggest that titration of PEEP aimed at improving PCBF can be performed with the new device.
通过部分二氧化碳重吸入法评估一种用于无创测量非分流性肺毛细血管血流量（PCBF）的新设备的性能。
在一所大学医院的重症监护病房进行的前瞻性临床试验。
20例急性肺损伤的机械通气患者。
呼气末正压（PEEP）±3 cmH₂O的变化。
最初，PCBF通过有创测量法测量，即心输出量减去静脉混合血（Q(VA)/Q(t)）流量，并在基线PEEP（PEEP(b)）时通过部分二氧化碳重吸入法测量。然后将PEEP降低3 cmH₂O（至PEEP(b - 3)），30分钟后重复测量。随后将PEEP增加6 cmH₂O（至PEEP(b + 3)），并在10、20和30分钟后重复测量。在PEEP(b)时，无创和有创PCBF测量之间总的相关系数较高（r = 0.97），两种方法之间观察到密切一致性（分别为偏差和精密度0.1±0.6 l/min）。因此，从PEEP(b - 3)到PEEP(b + 3)水平，PCBF变化的两种方法之间的相关系数和一致性均令人满意（r = 0.71；偏差和精密度0.2±0.5 l/min）。新设备能够在20例接受研究的患者中的17例以及所有有创PCBF变化等于或大于0.3 l/min的患者（n = 12）中检测到正确的PCBF趋势。与30分钟时的值相比，PEEP变化后仅10分钟，无创PCBF变化就稳定下来。
新设备似乎在临床上可用于监测急性肺损伤患者的PCBF。我们的结果表明，使用新设备可以进行旨在改善PCBF的PEEP滴定。
