Grap Mary Jo, Munro Cindy L, Hummel Russell S, Elswick R K, McKinney Jessica L, Sessler Curtis N
The Adult Health Department of the School of Nursing.
Am J Crit Care. 2005 Jul;14(4):325-32; quiz 333.
Ventilator-associated pneumonia is a common complication of mechanical ventilation. Backrest position and time spent supine are critical risk factors for aspiration, increasing the risk for pneumonia. Empirical evidence of the effect of backrest positions on the incidence of ventilator-associated pneumonia, especially during mechanical ventilation over time, is limited.
To describe the relationship between backrest elevation and development of ventilator-associated pneumonia.
A nonexperimental, longitudinal, descriptive design was used. The Clinical Pulmonary Infection Score was used to determine ventilator-associated pneumonia. Backrest elevation was measured continuously with a transducer system. Data were obtained from laboratory results and medical records from the start of mechanical ventilation up to 7 days.
Sixty-six subjects were monitored (276 patient days). Mean backrest elevation for the entire study period was 21.7 degrees . Backrest elevations were less than 30 degrees 72% of the time and less than 10 degrees 39% of the time. The mean Clinical Pulmonary Infection Score increased but not significantly, and backrest elevation had no direct effect on mean scores. A model for predicting the Clinical Pulmonary Infection Score at day 4 included baseline score, percentage of time spent at less than 30 degrees on study day 1, and score on the Acute Physiology and Chronic Health Evaluation II, explaining 81% of the variability (F=7.31, P=.003).
Subjects spent the majority of the time at backrest elevations less than 30 degrees . Only the combination of early, low backrest elevation and severity of illness affected the incidence of ventilator-associated pneumonia.
呼吸机相关性肺炎是机械通气常见的并发症。靠背位置和仰卧时间是误吸的关键危险因素，会增加肺炎风险。关于靠背位置对呼吸机相关性肺炎发生率的影响，尤其是在机械通气过程中的长期影响，实证证据有限。
描述靠背抬高与呼吸机相关性肺炎发生之间的关系。
采用非实验性纵向描述性设计。使用临床肺部感染评分来确定呼吸机相关性肺炎。通过传感器系统连续测量靠背抬高情况。数据从机械通气开始至7天期间的实验室结果和病历中获取。
对66名受试者进行了监测（共276个患者日）。整个研究期间靠背抬高的平均度数为21.7度。72%的时间靠背抬高低于30度，39%的时间低于10度。临床肺部感染评分平均值有所增加，但无显著变化，靠背抬高对平均分无直接影响。一个预测第4天临床肺部感染评分的模型包括基线评分、研究第1天低于30度的时间百分比以及急性生理与慢性健康状况评估II的评分，该模型解释了81%的变异性（F = 7.31，P = 0.003）。
受试者大部分时间靠背抬高低于30度。只有早期低靠背抬高与疾病严重程度的综合因素影响呼吸机相关性肺炎的发生率。
