Effect of Backrest Elevation on Skin Integrity in the Critically Ill

描述（由申请人提供）：压疮（PUs）和呼吸机相关性肺炎（VAP）通常作为医源性并发症发生在危重患者中，导致发病率、死亡率和医疗费用增加。在机械通气患者中，预防这些并发症的策略存在冲突。降低压疮（PU）风险的建议是将患者置于小于30度的靠背位置，而降低VAP风险的干预措施是将患者置于大于30度的靠背位置。虽然有充分的证据表明，较高的靠背高度会降低VAP，但很少有经验证据表明，较高的靠背位置（30度或更大）对PU形成和组织完整性的影响。这项对危重症机械通气成人的描述性纵向研究的目的是：1)描述靠背抬高对皮肤压力和绝对力的影响；2)描述靠背抬高对组织完整性的影响。第二个目的是评估内在（患者）因素（人口统计、生理状态、支撑面、流动性）对外在因素（压力、剪切、湿度）和组织完整性的影响。来自3个成人icu的150名受试者将在24个月的时间内入组。将连续测量靠背仰角、压力和剪切力72小时。椅背高度将使用倾斜仪测量，压力和剪切将使用XSENSOR压力测绘系统测量。使用NPUAP分期系统和组织损伤测量（EPISCAN），每12小时通过皮肤观察测量组织完整性。镇静水平将通过处理脑电图（PSI）连续测量（72小时），并记录患者的运动（手腕活动记录仪）。还将获得疾病的严重程度（APACHE III）、营养状况（白蛋白前）和支持表面的类型。所有数据将由研究小组成员收集并下载到计算机中进行分析。逐步地，将使用多变量重复测量模型来描述海拔水平、皮肤压力、剪切力和组织完整性随时间的关系。这项研究将对我们理解导致危重患者组织损伤的压力水平和持续时间以及PU发展的经验基础做出重大贡献。

DESCRIPTION (provided by applicant): Both pressure ulcers (PUs) and ventilator associated pneumonia (VAP) commonly occur as iatrogenic complications in the critically ill, resulting in increased morbidity, mortality, and health care costs. In mechanically ventilated patients, strategies to prevent these complications are in conflict. Recommendations to reduce pressure ulcer (PU) risk place patients in backrest positions of less than 30 degrees while interventions to reduce VAP risk place patients in backrest positions of greater than 30 degrees. Although it is well documented that higher backrest elevations reduce VAP, there is little empirical evidence that describes the effect of these higher backrest positions (30 degrees or greater) on factors affecting PU formation and tissue integrity. The purpose of this descriptive, longitudinal study in critically ill mechanically ventilated adults is to 1) describe the effect of backrest elevation on skin pressure and sheer force and, 2) describe the effect of backrest elevation on tissue integrity. A secondary aim will evaluate the effect of intrinsic (patient) factors (demographics, physiologic status, support surface, mobility) on extrinsic factors (pressure, shear, moisture) and tissue integrity. A total of 150 subjects from 3 adult ICUs will be enrolled over a 24 month period. Backrest elevation, pressure and shear force will be measured continuously for 72 hours. Backrest elevation will be measured using an inclinometer device and pressure and shear will be measured using the XSENSOR pressure mapping system. Tissue integrity will be measured every 12 hours by skin observation using the NPUAP Staging System and a measure of tissue injury (EPISCAN). Sedation level will be continuously measured (for 72 hours) by processed EEG (PSI) and patient movement (wrist actigraphy) will be documented. Severity of illness (APACHE III), nutritional status (prealbumin) and type of support surface will also be obtained. All data will be collected by research team members and downloaded to a computer for analysis. Stepwise, multivariate repeated measures models will be used to describe the relationships among elevation levels, skin pressure, shear force and tissue integrity over time. This study will make a significant contribution to our understanding of pressure levels and duration that result in tissue injury in the critically ill and to the empirical base of PU development. PUBLIC HEALTH RELEVANCE: Pressure ulcers occur often in the critically ill. Use of elevated backrest positions are helpful to reduce pneumonia in this population but may also increase pressure ulcers. This study will evaluate use of elevated backrest position to determine its effect on tissue and skin integrity. Factors that may influence pressure ulcer risk in the population will also be explored.