在慢性阻塞性肺疾病急性加重患者中，低流量体外二氧化碳清除回路的二氧化碳清除率。

In vivo carbon dioxide clearance of a low-flow extracorporeal carbon dioxide removal circuit in patients with acute exacerbations of chronic obstructive pulmonary disease.

机构信息

Centre for Human & Applied Physiological Sciences (CHAPS) and School of Basic & Medical Biosciences, Faculty of Life Sciences & Medicine, King's College London, London, UK.

Department of Critical Care, Guy's and St Thomas' NHS Foundation Trust, London, UK.

出版信息

Perfusion. 2020 Jul;35(5):436-441. doi: 10.1177/0267659119896531. Epub 2020 Jan 11.

DOI:10.1177/0267659119896531

PMID:31928313

Abstract

BACKGROUND

Veno-venous extracorporeal carbon dioxide removal allows clearance of CO from the blood and is becoming popular to enhance protective mechanical ventilation and assist in the management of acute exacerbations of chronic obstructive pulmonary disease, including the prevention of intubation. The main factor determining CO transfer across a membrane lung for any given blood flow rate and venous CO content is the sweep gas flow rate. The in vivo characteristics of CO clearance using ultra-low blood flow devices in patients with acute exacerbations of chronic obstructive pulmonary disease has not been previously described.

METHODS

Patients commenced on extracorporeal carbon dioxide removal for acute exacerbations of chronic obstructive pulmonary disease recruited to a randomized controlled trial of non-invasive ventilation versus extracorporeal carbon dioxide removal had pre- and post-membrane circuit gases measured after each increment of sweep gas flow to allow calculation of the transmembrane CO clearance. This was compared with the clearance reported by the device and also corrected to inlet PCO to allow characterization of the CO clearance of the device at different sweep gas flow rates.

RESULTS

CO clearance was calculated using both the transmembrane CO whole-blood content difference and CO clearance reported by the device. The two methods demonstrated a linear relationship and agreement with a bias of 14 mL/minute (SD = ±10) and an R of 0.92. The membrane CO clearance was non-linear with nearly two thirds of total clearance achieved with sweep gas flow below 2 L/minute (VCO of 40 ± 16.7 mL/minute) and a plateau above 5 L/minute sweep gas flow (VCO 64 ± 1 2.4 mL/minute).

CONCLUSION

The extracorporeal carbon dioxide removal device used in the study provides efficient clearance of CO at low sweep flow rates which then plateaus. This has implications for how the device may be used in clinical practice, particularly during the weaning phase where the final discontinuation of the device may take longer than anticipated. (ClinicalTrials.gov: NCT02086084, registered 13 March 2014, https://clinicaltrials.gov/ct2/show/NCT02086084 ).

摘要

背景

静脉-静脉体外二氧化碳清除允许从血液中清除 CO，并越来越受欢迎，以增强保护性机械通气，并协助治疗慢性阻塞性肺疾病急性加重，包括预防插管。对于任何给定的血流速率和静脉 CO 含量，决定膜肺中 CO 转移的主要因素是吹扫气流速率。以前没有描述过在患有慢性阻塞性肺疾病急性加重的患者中使用超低血流设备进行 CO 清除的体内特征。

方法

开始进行体外 CO 清除治疗的慢性阻塞性肺疾病急性加重患者被招募到一项非侵入性通气与体外 CO 清除的随机对照试验中，在每次吹扫气流增加后测量膜前和膜后气体，以允许计算跨膜 CO 清除率。这与设备报告的清除率进行了比较，并进行了校正以适应入口 PCO，以允许在不同吹扫气流速率下对设备的 CO 清除率进行特征描述。

结果

使用跨膜 CO 全血含量差和设备报告的 CO 清除率计算 CO 清除率。这两种方法显示出线性关系和一致性，偏差为 14 mL/min（SD = ±10），R 为 0.92。膜 CO 清除率是非线性的，近三分之二的总清除率在吹扫气流低于 2 L/min（VCO 为 40 ± 16.7 mL/min）时实现，而在吹扫气流高于 5 L/min 时达到平台（VCO 为 64 ± 1 2.4 mL/min）。

结论

研究中使用的体外 CO 清除设备在低吹扫气流速率下提供高效的 CO 清除，然后达到平台。这对设备在临床实践中的使用方式有影响，特别是在脱机阶段，设备的最终停用可能比预期的要长。（ClinicalTrials.gov：NCT02086084，注册于 2014 年 3 月 13 日，https://clinicaltrials.gov/ct2/show/NCT02086084）。