Pulse pressure as a function of cuff width.
Pulse pressure was investigated by indirect sphygmomanometry using two different cuff widths, standard (12 cm) versus correct (20% wider than arm diameter). Following the American Heart Association's recommendation for arterial pressure measurements, 7 cuffs of various widths (8 to 14 cm) were used as correct cuffs on 900 subjects; in only 50 was the standard cuff appropriate. Pulse pressure as a function of cuff width was significantly lower (P less than 0.001) with the standard cuff on subjects with diastolic pressure less than 90 mmHg (36.4 +/- 0.3 mmHg vs 41.8 +/- 0.3 mmHg) and above 90 mmHg (39.6 +/- 1.2 mmHg vs 43.8 +/- 1.3 mmHg). Mean systolic and diastolic arterial pressures were underestimated by 12.7 mmHg and 7.7 mmHg, respectively. These results suggest that cuff width influences data obtained by indirect sphygmomanometry, producing over- or underestimates when the ratio of arm circumference to cuff width differs from 0.38.