Korotkoff sounds in neonates, infants, and toddlers.

Korotkoff sounds (KSs) are the clinical norm for noninvasively estimating systemic arterial blood pressure (BP) in children and adults. Their existence and reliability in children <3 years old was unknown. This study addressed the presence and accuracy of KSs in children <3 years. Measurements of the first KS (K1), K4, and K5 (the commonly used sounds) were compared with invasive measurements of systolic and diastolic BP in > or =3 inflations/subject. Subjects were prospectively divided by age <1 (n = 20), 1 to 12 (n = 29), and 13 to 36 months (n = 17). KSs were audible with low frequency in subjects <1 month old and they were excluded from further analysis. In 143 inflations, K1 was audible in 125, K4 in 104, and K5 in 114; the frequency of audible KSs increased with subject age. Reliability of KSs as a surrogate for measured systolic and diastolic BP was assessed using paired t tests. K1 was not significantly different for the entire group or any subgroup. K4 was significantly different in all age groups. K5 was significantly different in only subjects <6 months. In conclusion, K1, K4, and K5 are routinely audible and K1 and K5 provide a reliable estimate of systolic and diastolic BP in children age 1 to 36 months.

Assessment of the validation of blood pressure monitors: a statistical reappraisal.

Protocols to determine the accuracy of noninvasive blood pressure monitors have been published by the Association for the Advancement of Medical Instrumentation, the British Hypertension Society, and the European Society of Hypertension (ESH). We compared the statistical basis for each of these protocols. Although the Association for the Advancement of Medical Instrumentation and British Hypertension Society protocols require a minimum of 85 participants, the ESH protocol requires only 33 participants. The reduced sample size results in a reduction in statistical power from 98 to 70%, which brings into question the applicability of the ESH (International) protocol.