Department of Paediatrics-Neonatology, Radboud University Nijmegen Medical Centre, Internal Postal Code 804, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
Br J Anaesth. 2012 Dec;109(6):870-8. doi: 10.1093/bja/aes297. Epub 2012 Aug 19.
Transpulmonary ultrasound dilution (TPUD) is a promising method for cardiac output (CO) measurement in severely ill neonates. The incidence of lung injury in this population is high, which might influence CO measurement using TPUD because of altered lung perfusion. We evaluated the influence of lung injury on the accuracy and precision of CO measurement using TPUD in an animal model.
In nine neonatal lambs, central venous and arterial catheters were inserted and connected to the TPUD monitor. Repeated lavages with warmed isotonic saline were performed to gradually induce lung injury. CO measurements with TPUD (COtpud) were compared with those obtained by an ultrasonic transit-time flow probe around the main pulmonary artery (COufp). An increase in oxygenation index was used as an indicator of induced lung injury during the experiment. Post-mortem lung injury was confirmed by histopathological examination.
Fifty-five sessions of three paired CO measurements were analysed. The mean COufp was 1.53 litre min(-1) (range 0.66-2.35 litre min(-1)), and the mean COtpud was 1.65 litre min(-1) (range 0.78-2.91 litre min(-1)). The mean bias (standard deviation) between the two methods was 0.13 (0.15) litre min(-1) with limits of agreement of ±0.29 litre min(-1). The overall percentage error was 19.1%. The accuracy and precision did not change significantly during progressive lung injury. Histopathological severity scores were consistent with heterogeneous lung injury. The capability to track changes in CO using TPUD was moderate to good.
The accuracy and precision of CO measurement using TPUD is not influenced in the presence of heterogeneous lung injury in an animal model.
经肺超声稀释（TPUD）是一种有前途的严重疾病新生儿心输出量（CO）测量方法。该人群的肺损伤发生率较高，这可能会影响使用 TPUD 进行 CO 测量，因为肺灌注发生改变。我们评估了在动物模型中，肺损伤对 TPUD 测量 CO 的准确性和精密度的影响。
在 9 只新生羔羊中，插入中心静脉和动脉导管，并与 TPUD 监测器连接。使用温热等渗盐水进行反复灌洗，以逐渐诱导肺损伤。将 TPUD（COtpud）测量的 CO 与围绕主肺动脉的超声渡越时间流量探头（COufp）获得的 CO 进行比较。实验过程中，氧合指数的增加被用作诱导肺损伤的指标。死后通过组织病理学检查确认肺损伤。
分析了 55 次三个配对 CO 测量的结果。平均 COufp 为 1.53 升/分钟（范围 0.66-2.35 升/分钟），平均 COtpud 为 1.65 升/分钟（范围 0.78-2.91 升/分钟）。两种方法之间的平均偏差（标准偏差）为 0.13（0.15）升/分钟，一致性界限为±0.29 升/分钟。总体百分比误差为 19.1%。随着肺损伤的进展，准确性和精密度没有明显变化。组织病理学严重程度评分与异质性肺损伤一致。使用 TPUD 跟踪 CO 变化的能力为中度至良好。
在动物模型中存在异质性肺损伤的情况下，使用 TPUD 测量 CO 的准确性和精密度不受影响。
