Mayrovitz Harvey N, Sims Nancy, Taylor Martha C
College of Medical Sciences, Nova Southeastern University, 3200 S. University Drive, Ft. Lauderdale, FL 33328, USA.
Ostomy Wound Manage. 2002 Jun;48(6):34-8, 40-2.
Pressure ulcers occur over the sacrum but are rare over the gluteus maximus. This predilection is partly explained by pressure concentration effects, but other factors may be involved. The authors hypothesized that if resting sacral skin blood flow was greater than in surrounding tissues, a decrease or stoppage of blood flow during loading might represent increased risk because relative tissue deficits would be greater. Because information on sacral skin blood flow is scarce yet important to the plausibility of this hypothesis, the objective was to determine if actual sacral skin resting blood flow is, in fact, different than flow in other nearby posterior areas. Thus, skin blood flow was measured with laser Doppler imaging in 15-cm2 areas overlying the sacrum in 30 subjects (15 male) and compared to skin blood flow in other posterior sites (gluteus maximus and lower back) and to remote sites (hand and fingers). Results showed that average sacral skin blood flow (59.1 +/- 1.4 arbitrary profusion units) was significantly (P < 0.001) greater than other posterior sites (48.7 +/- 2.5 a.u.) and was significantly (P < 0.01) greater in females (63.0 +/- 1.6 vs. 55.2 +/- 1.8). These findings provide the first systematic characterization of resting sacral skin blood flow. The data are consistent with the tentative hypothesis, but more direct evidence of a linkage is clearly needed. Large spatial variability in skin blood flow (40%) suggests that comparisons of skin blood flow among sites are best done with laser Doppler imaging in contrast to standard laser Doppler monitoring.
压疮多发生于骶骨部位，而在臀大肌部位则较为罕见。这种偏好部分可由压力集中效应来解释，但可能还涉及其他因素。作者推测，如果静息状态下骶部皮肤血流大于周围组织，那么在负荷过程中血流减少或停止可能意味着风险增加，因为相对的组织缺血会更严重。由于关于骶部皮肤血流的信息稀缺，但对该假设的合理性很重要，所以目的是确定实际的骶部皮肤静息血流是否实际上与其他附近后部区域的血流不同。因此，在30名受试者（15名男性）的骶骨上方15平方厘米区域用激光多普勒成像测量皮肤血流，并与其他后部部位（臀大肌和下背部）以及远处部位（手部和手指）的皮肤血流进行比较。结果显示，骶部皮肤平均血流（59.1±1.4任意灌注单位）显著高于其他后部部位（48.7±2.5任意灌注单位）（P<0.001），且女性的骶部皮肤血流显著高于男性（63.0±1.6对比55.2±1.8）（P<0.01）。这些发现首次对静息状态下的骶部皮肤血流进行了系统描述。这些数据与初步假设一致，但显然还需要更直接的证据来证明两者之间的联系。皮肤血流存在较大的空间变异性（40%），这表明与标准激光多普勒监测相比，用激光多普勒成像来比较不同部位的皮肤血流是最好的方法。
