论文部分内容阅读
目的研究慢性阻塞性肺疾病(COPD)患者机械通气时对外源性呼气末正压的生理学反应规律,揭示反应个体化特点。方法随机选取2005年1月至2006年6月由急诊室收入我院呼吸科重症监护室的 COPD 急性加重期患者15例,仰卧位经口气管插管后接 Evita 4呼吸机(德国Draeger 公司),采用容量控制通气对受试者序贯给予相当于内源性呼气末正压水平20%、40%、60%、80%、100%、120%的外源性呼气末正压,每次给予外源性呼气末正压后均测量气道阻力、呼吸系统顺应性、气道平台压、总呼气末正压水平。根据施加外源性呼气末正压后患者气道平台压的变化,将15例患者分为正常反应组(11例),反常反应组(4例),对两组间各参数进行比较。结果 15例患者当外源性呼气末正压为80%、内源性呼气末正压为100%水平时的气道阻力分别为(18.5±2.0)cm H_2O·L~(-1)·s~(-1)(1 cm H_2O=0.098 kPa)、(18.0±2.2)cm H_2O·L~(-1)·s~(-1),与外源性呼气末正压为0时的气道阻力[(23.0±2.9)cm H_2O·L~(-1)·s~(-1)]比较差异有统计学意义(t 值分别为5.36、6.27,P 均<0.01);当外源性呼气末正压为120%内源性呼气末正压水平时,气道阻力和总呼气末正压水平分别为(17.3±2.1)cm H_2O·L~(-1)·s~(-1)、(12.7±2.2)cm H_2O,与外源性呼气末正压为0时[(23.0±2.9)cm H_2O·L~(-1)·s~(-1)、(10.0±1.1)cm H_2O]比较差异有统计学意义(t 值分别为6.79、-3.90,P 均<0.01)。正常反应组患者基础生理学参数(外源性呼气末正压为0时)内源性呼气末正压水平、气道阻力、呼吸系统顺应性、气道平台压分别为(10.0±1.0)cm H_2O、(22.8±1.9)cm H_2O·L~(-1)·s~(-1)、(39±6)mL/cm H_2O、(20±4)cm H_2O,与反常反应组[(10.0±1.4)cm H_2O、(23.1±4.1)cm H_2O·L~(-1)·s~(-1)、(42±9)ml/cm H_2O、(21±3)cm H_2O]比较差异无统计学意义(t 值分别为0.03、0.10、0.60、0.15,P 均>0.05);正常反应组患者在外源性呼气末正压分别为40%、80%、100%、120%内源性呼气末正压时,ΔP_(plat40),ΔP_(plat80),ΔP_(plat100),ΔP_(plat120)分别为(-0.020±0.970)cm H_2O、(1.6±1.0)cm H_2O、(4.0±2.9)cm H_2O、(6.4±3.3)cm H_2O,与反常反应组[(-7.500±0.920)cm H_2O、(-4.4±1.4)cm H_2O、(-3.8±1.9)cm H_2O、(-1.6±1.2)cm H_2O]比较差异有统计学意义(t 值分别为-9.64、-5.90、-3.80、-3.92,P 均<0.01)。结论提示部分无自主呼吸的被动机械通气患者应用外源性呼气末正压是有益的,可以使患者气道平台压显著下降。
Objective To study the physiological response to exogenous positive end-expiratory pressure during mechanical ventilation in patients with chronic obstructive pulmonary disease (COPD) and to reveal the individual characteristics of the response. Methods Fifteen patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) admitted to the Department of Respiratory Care and Intensive Care Unit of our hospital from January 2005 to June 2006 were enrolled in this study. Supine tracheal intubation followed by Evita 4 ventilator (Draeger Company, Germany) , The volume of controlled ventilation was used to consecutively give exogenous positive end-expiratory pressure equivalent to 20%, 40%, 60%, 80%, 100% and 120% of endogenous positive end-expiratory pressure in subjects, Airway resistance, respiratory compliance, airway plateau pressure, and total expiratory pressure were measured after each exogenous CPAP. According to the changes of airway pressure in patients with exogenous positive end expiratory pressure, 15 patients were divided into normal reaction group (n = 11) and abnormal reaction group (n = 4). The parameters of the two groups were compared. Results The airway resistance of the 15 patients with exogenous positive end expiratory pressure of 80% and endogenous positive end expiratory pressure of 100% were (18.5 ± 2.0) cm H 2 O · L -1 · S -1 (1 cm H 2 O = 0.098 kPa) and (18.0 ± 2.2) cm H 2 O · L -1 s -1, respectively. When the positive end-expiratory pressure was 0 (23.0 ± 2.9) cm H 2 O · L -1 · s -1] (t = 5.36, 6.27, respectively, P <0.01) Positive end-expiratory pressure was 120% endogenous positive end-expiratory pressure, and the mean airway resistance and total positive end expiratory pressure were (17.3 ± 2.1) cm H 2 O · L -1 · s ~ (-1) and (12.7 ± 2.2) cm H_2O, respectively. Compared with exogenous positive end expiratory pressure of 0 [(23.0 ± 2.9) cm H_2O · L -1 s -1, 10.0 ± 1.1) cm H_2O] (t = 6.79, -3.90, P <0.01 respectively). The basal physiological parameters (exogenous positive end expiratory pressure of 0) in patients with normal reaction group were (10.0 ± 1.0), positive end-expiratory pressure, airway resistance, respiratory compliance and airway pressure respectively (22.8 ± 1.9) cm H 2 O · L -1 s -1, 39 ± 6 mL / cm H 2 O and 20 ± 4 cm H 2 O, respectively, compared with those in the abnormal reaction group [(10.0 ± 1.4 cm H 2 O, (23.1 ± 4.1) cm H 2 O · L -1 · s -1, (42 ± 9) ml / cm H 2 O, (21 ± 3) cm H 2 O] (T = 0.03,0.10,0.60,0.15, P> 0.05). In the normal group, the exogenous positive end expiratory pressure was 40%, 80%, 100% and 120% respectively The values of ΔP_ (plat40), ΔP_ (plat80), ΔP_ (plat100) and ΔP_ (plat120) were -0.020 ± 0.970 cm H_2O, 1.6 ± 1.0 cm H_2O, 4.0 ± 2.9 cm cm H_2O, (6.4 ± 3.3) cm H_2O and (-7.500 ± 0.920) cm H_2O, (-4.4 ± 1.4) cm H_2O, (-3.8 ± 1.9) cm H_2O and (-1.6 ± 1.2) cm H_2O ] Were statistically significant difference (t values were -9.64, -5.90, -3.80, -3.92, P <0.01). The conclusion suggests that exogenous positive end expiratory pressure may be beneficial in some patients with passive ventilation without spontaneous breathing, which can decrease the airway pressure significantly.