Pourriat J L, Baud M, Lamberto C, Fournier J L, Cupa M
Département d'Anesthésie-Réanimation, CHU Jean Verdier, Bondy, France.
J Clin Monit. 1994 Jan;10(1):26-34. doi: 10.1007/BF01651463.
Our objective is to present a methodology for the automated acquisition and storage of BP and P0.1 during a CO2 rebreathing test.
The system consists of a microcomputer with additional circuits and an automatic electronically controlled valve to occlude the inspiratory airway. Data collection and data processing are separate programs. Airway pressure and flow are digitized at a 100-Hz rate, while PETCO2 is determined and P0.1 is measured on a breath-by-breath basis. Off-line processing calculates the BP variables, generates a correlation matrix (VE/PETCO2, TTOT/PETCO2, TI/PETCO2, TE/PETCO2, [VT/TI]/PETCO2, [TI/TTOT]/PETCO2, P0.1/PETCO2), and edits graphic data. The accuracy of the volume and pressure measurements was tested by comparing known volumes provided by a syringe (n = 100) and a series of pressures controlled by a water manometer (n = 41) on the one hand, with volumes and pressures measured by the device. The accuracy of the time intervals and P0.1 was assessed by comparing in 10 healthy subjects the values measured manually on a graphic recording with those provided by the device (n = 170).
Volumes:Vmeasured = 0.99 x Vcontrolled, r = 0.99, p < 0.001. Pressures:Pmeasured = 0.97 x Pcontrolled + 0.09, r = 0.98, p < 0.001. Inspiratory time:TIautomatic = 0.91 x TIgraphic + 0.22, r = 0.93, p < 0.001. Expiratory time:TEautomatic = 0.93 x TEgraphic + 0.34, r = 0.95, p < 0.001. Occlusion pressure:P0.1automatic = 0.95 x P0.1graphic + 0.62, r = 0.94, p < 0.001. Reproducibility was assumed to be represented by the intraindividual coefficient of variation of the CO2 response. The comparison of an automatic breath-to-breath method with a graphic manual recording revealed significantly less variability with the former (VE/PETCO2: 15.2 +/- 4.5% vs 22.5 +/- 6.3%, p < 0.01; P0.1/PETCO2:8.3 +/- 4.3% vs 19.7 +/- 7.2%, p < 0.001; [VT/TI]/PETCO2:9.1 +/- 3.5% vs 14.5 +/- 5.3%, p < 0.05).
Our automated acquisition and storage of waveforms and breath-by-breath determination of BP and P0.1 provide an easy and thorough analysis of the respiratory response to CO2 and decrease the variability of the results.
我们的目的是介绍一种在二氧化碳重复呼吸试验期间自动采集和存储血压（BP）及吸气阻断压（P0.1）的方法。
该系统由一台带有附加电路的微型计算机和一个用于阻塞吸气气道的自动电控阀组成。数据收集和数据处理是独立的程序。气道压力和流量以100赫兹的速率数字化，而呼气末二氧化碳分压（PETCO2）是逐次呼吸测定的，P0.1也是逐次呼吸测量的。离线处理计算BP变量，生成相关矩阵（每分通气量/呼气末二氧化碳分压[VE/PETCO2]、总呼吸时间/呼气末二氧化碳分压[TTOT/PETCO2]、吸气时间/呼气末二氧化碳分压[TI/PETCO2]、呼气时间/呼气末二氧化碳分压[TE/PETCO2]、[潮气量/吸气时间]/呼气末二氧化碳分压[[VT/TI]/PETCO2]、[吸气时间/总呼吸时间]/呼气末二氧化碳分压[[TI/TTOT]/PETCO2]、P0.1/呼气末二氧化碳分压[P0.1/PETCO2]），并编辑图形数据。一方面，通过将由注射器提供的已知容积（n = 100）和由水检压计控制的一系列压力（n = 41）与该设备测量的容积和压力进行比较，测试容积和压力测量的准确性。通过在10名健康受试者中比较图形记录上手动测量的值与该设备提供的值（n = 170），评估时间间隔和P0.1的准确性。
容积：测量值V = 0.99×控制值V，r = 0.99，p < 0.001。压力：测量值P = 0.97×控制值P + 0.09，r = 0.98，p < 0.001。吸气时间：自动测量的吸气时间TI = 0.91×图形记录的吸气时间TI + 0.22，r = 0.93，p < 0.001。呼气时间：自动测量的呼气时间TE = 0.93×图形记录的呼气时间TE + 0.34，r = 0.95，p < 0.001。阻断压：自动测量的P0.1 = 0.95×图形记录的P0.1 + 0.62，r = 0.94，p < 0.001。重复性被认为由二氧化碳反应的个体内变异系数表示。自动逐次呼吸法与图形手动记录法的比较显示，前者的变异性显著更小（VE/PETCO2：15.2±4.5%对22.5±6.3%，p < 0.01；P0.1/PETCO2：8.3±4.3%对19.7±7.2%，p < 0.001；[VT/TI]/PETCO2：9.1±3.5%对14.5±5.3%，p < 0.05）。
我们对波形的自动采集和存储以及对BP和P0.1的逐次呼吸测定为二氧化碳呼吸反应提供了一种简便且全面的分析方法，并降低了结果的变异性。
