Indirect arterial pressure measurement differed from direct readings by a mean of 3.13 mm Hg for systolic and 6.70 mm Hg for diastolic disappearance, making systolic pressure a more accurate guide.
Observational (n=30)
Blinded observer
Summary: Direct and indirect arterial pressures were compared in 30 patients by one observer in a “blind” manner. Arterial pressures were raised and/or lowered in six patients. Two cuff sizes were used (22.5× 12.5 cm and 27.5 × 11.00 cm) and skin fold thickness and arm circumference were noted. Differences as great as 25 mm Hg were noted between directly measured and indirectly measured diastolic pressure, and disappearance of Korotkov sounds was found to be more accurate than muffling as a criterion of diastolic pressure. Systolic pressure was measured much more accurately than the diastolic and was recommended as the pressure to be used as a guide to diagnosis and treatment of hypertension. No significant difference in accuracy was noted between the two cuffs. Mean difference between direct and indirect readings were systolic—3.13mm Hg diastolic muffling 17.92 mm Hg and diastolic disappearance 6.70 mm Hg. Direct pressure recording was found to be simple and painless to the patient and its more frequent use is advocated especially where there is any suspicion as to accuracy of indirect pressure.
Breit et al. (Tue,) conducted a observational in Hospitalised patients (n=30). Direct arterial pressure measurement vs. Indirect arterial pressure measurement was evaluated on Mean difference between direct and indirect arterial pressure readings. Indirect arterial pressure measurement differed from direct readings by a mean of 3.13 mm Hg for systolic and 6.70 mm Hg for diastolic disappearance, making systolic pressure a more accurate guide.