机械通气患者ICU获得性肌无力危险因素分析

Intensive care unit-acquired weakness of mechanically ventilated patients:prevalence and risk factors

目的观察机械通气患者ICU获得性肌无力(ICU-AW)的发病情况,并探讨其相关危险因素。方法采用前瞻性队列研究方法,选择2015年5月至2016年1月首都医科大学附属复兴医院重症医学科(ICU)收治的年龄≥18周岁、机械通气时间≥24 h、预计ICU住院时间≥7 d的患者为研究对象。从患者入ICU第7天开始每日对其进行意识评估,将患者意识清醒且可以配合肌力测量日记录为T1,并用美国医学研究委员会肌力评定量表(MRC)进行肌力评分,进而将患者分为ICU-AW组(MRC评分<48分)和非ICU-AW组(MRC评分≥48分),以死亡、转出ICU或入ICU第28天作为观察终点。观察、记录并分析患者入ICU第1天至T1(T1前)的相关数据,包括代谢因素(血钠、血钾、血钙、白蛋白最低值和血糖最高值)、机械通气因素(机械通气模式和时间)、器官功能障碍因素〔脓毒症、多器官功能障碍综合征(MODS)的发生及持续时间〕、药物因素(氨基糖苷类抗菌药物、镇静药、神经肌肉阻滞药、糖皮质激素等应用与否、使用天数及累计剂量等);以及T1至观察终点的相关数据,包括机械通气时间、呼吸机相关性肺炎(VAP)发生率、28 d病死率、ICU住院时间、ICU住院费用及总住院费用等。将单因素分析中差异有统计学意义的相关因素进行多因素分析,建立Logistic回归方程,筛选可能导致ICU-AW的独立危险因素。结果研究期间共收治机械通气患者486例,根据纳入、排除标准,最终共37例患者纳入分析,其中ICU-AW组15例(ICU-AW发病率40.5%),非ICU-AW组22例。单因素分析显示,ICU-AW组与非ICU-AW组患者在年龄及T1前有创通气时间、总机械通气时间、制动时间、发生脓毒症和MODS例数及持续时间、镇静药和糖皮质激素的使用天数及累计剂量等方面差异均有统计学意义;且ICU-AW组患者T1至观察终点总机械通气时间、观察期间总体机械通气时间以及ICU住院时间均较非ICU-AW组明显延长〔h:190(110,274)比4(0,57),h:337(237,477)比78(43,170),d:20±7比14±7,均P<0.05〕,VAP发生率、28 d病死率及总住院费用均较非ICU-AW组明显升高〔26.7%(4/15)比0%(0/22),53.3%(8/15)比9.1%(2/22),万元:18.7±7.7比12.1±10.8,均P<0.05〕。多因素Logistic回归分析显示,患者入ICU后意识清醒前总机械通气时间〔优势比(OR)=1.03,95%可信区间(95%CI)为1.01~1.05,P=0.011〕及MODS持续时间(OR=1.79,95%CI为1.17~2.72,P=0.007)是机械通气患者发生ICU-AW的独立危险因素。结论ICU-AW在机械通气患者中较为常见,发病率较高;机械通气患者入ICU后意识清醒前总机械通气时间及MODS持续时间是发生ICU-AW的独立危险因素。

Objective To observe the incidence of intensive care unit-acquired weakness(ICU-AW)of mechanically ventilated patients,and to identify the relevant risk factors.Methods A prospective cohort study was conducted.The patients admitted to intensive care unit(ICU)of Fuxing Hospital,Capital Medical University,aged 18 years old or older,with the duration of mechanical ventilation≥24 hours and expected to stay in ICU for≥7 days from May 2015 to January 2016 were enrolled.From the 7th day after ICU admission,the patients were evaluated for consciousness every day.If the patient was awake and could cooperate with muscle strength measurement,the day was recorded as T1,and the patient's muscle strength was measured using the Medical Research Council scale(MRC)and recorded,then all patients were divided into two groups according to MRC score,ICU-AW group(MRC score<48)and non-ICU-AW group(MRC score≥48).The death,transfer or the 28th day of ICU admission were regarded as the end of observation.The data from the first day of ICU admission to T1(before T1),including metabolic factors(the lowest value of blood sodium,blood potassium,blood calcium,albumin,and the highest value of blood glucose),mechanical ventilation factors(mode and duration of mechanical ventilation),organ dysfunction factors[occurrence and duration of sepsis,multiple organ dysfunction syndrome(MODS)],and drug factors(whether the patients used aminoglycoside,sedative,muscle relaxant or glucocorticoids,etc.,the time of these drugs usage and the cumulative dose)of the patients were observed,recorded and analyzed,as well as the data from T1 to the end of the observation period,including the duration of mechanical ventilation,incidence of ventilator associated pneumonia(VAP),28-day mortality,the length of ICU stay,and the cost of ICU and hospitalization.The relevant factors with statistical significance in univariate analysis were enrolled in multivariate analysis,and Logistic regression equation was established to screen the independent risk factors that might lead to ICU-AW.Results 486 patients with mechanical ventilation were enrolled in this study,and 37 patients were enrolled according to the inclusion and exclusion criteria,including 15 patients with ICU-AW(with ICU-AW incidence of 40.5%)and 22 patients without ICU-AW.In the univariate analysis,ICU-AW group patients showed statistical differences in following factors as compared with the non-ICU-AW group:age,and the duration of invasive ventilation and the total duration of mechanical ventilation,braking time,sepsis,MODS and duration of them,the usage days and dosage of sedative and glucocorticoid before T1.The total duration of mechanical ventilation from T1 to the end of the observation period,total duration of mechanical ventilation during the observation period,and length of ICU stay of the ICU-AW group were significantly longer than those of the non-ICU-AW group[hours:190(110,274)vs.4(0,57),hours:337(237,477)vs.78(43,170),days:20±7 vs.14±7,all P<0.05],the incidence of VAP,28-day mortality and total hospitalization expenses were significantly higher than those of the non-ICU-AW group[26.7%(4/15)vs.0%(0/22),53.3%(8/15)vs.9.1%(2/22),10 thousands Yuan:18.7±7.7 vs.12.1±10.8,all P<0.05].Multivariate Logistic regression analysis showed that the total duration of mechanical ventilation between the patient awake and ICU admission[odds ratio(OR)=1.03,95%confidence interval(95%CI)was 1.01-1.05,P=0.011]and the duration of MODS(OR=1.79,95%CI was 1.17-2.72,P=0.007)were the independent risk factors for ICU-AW in mechanically ventilated patients.Conclusions ICU-AW is quite common in patients with mechanical ventilation and has a higher incidence.The risk factors associated with ICU-AW were the total duration of mechanical ventilation and duration of MODS.