Variation of method for measurement of brachial artery pressure significantly affects ankle-brachial pressure index values

Background: measurement of ankle brachial pressure indices (ABPI) is import ant in the assessment of patients with peripheral vascular disease. Methods : thirty-one hospitals with a vascular surgeon were selected at radom. A te lephone questionnaire was completed to assess the method used for the measu rement of ABPI. Following the survey, 14 patients with peripheral vascular disease had their ABPI measurement done by two observers, a pre-registratio n house officer and a clinical nurse practitionar. Observers were blinded t o their own and each others results. Brachial systolic pressures were obtai ned using a DINAMAP(TM) (Critikon, Tampa, U.S.A.) automated blood pressure mointor, the Korotkoff method (12cm cuff, parallel wrap) and an 8 MHz Doppl er probe (Huntleigh) and sphygmomanometer. Ankle systolic pressures were ob tained using the Doppler probe. The results were analysed using the Wilcoxo n signed rank test. Results: the survey demonstrated that at the majority of centres with vascu lar laboratories the brachial artery systolic pressures were measured using a Doppler probe. In contrast, at centres where the house officers performe d the routine measurements, over 60% used the Korotkoff method to obtain th is reading. One in four nurse practitioners used the Korotkoff method. When the ABPI values were calculated, the DINAMAP produced significantly higher median values than the Korotkoff (0.76 vs 0.72, p = 0.003) and Doppler met hods (0.79 vs 0.70, p<0.0001). The nurse had a higher median ABPI value of 0.76 compared with the doctor (0.71, p = 0.01). Conclusion: this study shows that measurement of ABPI varies in different v ascular units. The technique for ABPI measurement should be standardised.