INTRAOBSERVER VARIATION IN DOPPLER ULTRASOUND ASSESSMENT OF PULMONARY-ARTERY PRESSURE

Intraobserver variation associated with the non-invasive assessment of pulmonary artery pressure (PAP), using measurement of pulmonary arter y Doppler derived systolic time intervals, was investigated. Forty pai rs of independent ultrasound examinations of the pulmonary artery were performed by a single observer in 20 preterm infants, median gestatio n 27 weeks (range 24-31 weeks). Median age at study was 17 days (range 1-47 days). Paired measurements of acceleration time (AT), ratio betw een acceleration time and right ventricular ejection time (AT:RVET), c orrected AT, and corrected AT:RVET were compared to assess intraobserv er agreement. For the corrected AT:RVET ratio, the mean percentage dif ference between observations was -0.9% (95% confidence intervals -5.0 to 3.1%). The limits of agreement for the two measurements were -26.3 to 24.5%. The coefficient of repeatability was 25.4%. Variation for ot her indices was similar. Non-invasive assessment of PAP using Doppler derived systolic time intervals is associated with considerable intrao bserver variation.