A comparison of standardized versus "usual" blood pressure measurements in hemodialysis patients

Abstract

Hypertension is very common and contributes to the high cardiovascular morbidity in patients undergoing chronic hemodialysis therapy. However, the accuracy of blood pressure measurement in this population has not been well studied. We conducted a cross-sectional study of 270 patients at seven outpatient hemodialysis units. Predialysis and postdialysis seated blood pressure readings obtained by the dialysis unit using automated blood pressure monitors were significantly higher than readings obtained by a research nurse following standard procedures for blood pressure measurement (14.3/7 mm Hg higher predialysis; P < 0.01; 13.6/4.4 mm Hg higher postdialysis; P < 0.05). In 55% of patients, the postdialysis systolic blood pressure measured in the dialysis unit was at least 10 mm Hg higher than the standard reading. Bland-Altman analyses indicated poor agreement between the two readings. This study shows a marked discrepancy between routine dialysis unit and standardized blood pressure measurements. Blood pressure is frequently overestimated by routine dialysis unit readings. In light of these findings, efforts should be made to standardize blood pressure readings in hemodialysis units based on American Heart Association recommendations for blood pressure measurement.