Noninvasive monitoring of vascular compromise in trauma

Many types of trauma may lead to vascular compromise unless treated effectively and promptly. In addition to direct trauma to a major vessel are the crushing injuries, fractures, and burn injuries which give rise to an ischemia-edema cycle and subsequent muscle necrosis and tissue loss. Objective adjuncts to clinical impressions, such as isotope clearance muscle blood flow or the ultrasound Doppler flowmeter are generally not suitable for continuous, uninterrupted monitoring of the degree of vascular compromise. A technique that appears promising in this respect is that of photoplethysmography. This technique uses a small LED infrared emitter/detector array. Blood volume changes in an illuminated vascular bed produce variations in the amount of reflected light sensed by the detector, which after appropriate electronic amplification results in pulsatile blood flow (if present) and its change with time being displayed on the monitor. This technique was used with 25 trauma patients with good results, avoiding unnecessary compartmental decompression in some cases. It has proved to be a simple technique that requires little or no training for interpretation, provides continuous monitoring, is noninvasive and atraumatic in nature, is portable for easy set-up, and is relatively inexpensive.