Can Doppler pressure measurement replace "exclusion" arteriography in the diagnosis of occult extremity arterial trauma?

Although highly accurate, contrast arteriography is a costly, invasive, and time-consuming method to rule out occult arterial damage in injured extremities. Accordingly the authors assessed the sensitivity and specificity of Doppler-derived arterial pressure measurements in trauma victims undergoing evaluation for possible extremity arterial damage. Arterial pressure index (API) was calculated (Doppler arterial pressure distal to injury/Doppler arterial pressure in uninvolved arm), but not used in clinical decision making in 100 consecutive injured limbs in 93 trauma victims. All patients then underwent contrast arteriography. Twenty limbs had an API less than 0.90 and an abnormal arteriogram, whereas 75 had both a normal API and a normal contrast study. One limb had a significant angiographic abnormality with an API greater than 0.90; two others had API less than 0.90 but normal arteriograms. Two limbs with a normal API had false-positive arteriograms. When compared with arteriography, an API less than 0.90 had a sensitivity of 87% and a specificity of 97% for arterial disruption in this series. Sensitivity and specificity rose to 95% and 97% when API was compared with clinical outcome. In the absence of obvious signs of arterial injury, API may be a reasonable substitute for screening arteriography in the traumatized extremity, particularly if close follow-up observation can be assured.