Validation of a new noninvasive method to measure blood pressure and assess baroreflex sensitivity in preterm infants during sleep.
OBJECTIVE
Accuracy and precision of a noninvasive device for continuously measuring blood pressure (BP) (Finometer, FMS, The Netherlands) during sleep was assessed in preterm infants.


METHODS
Absolute BP beat-to-beat values, interbeat changes, measurement precision, and baroreflex sensitivity were compared with BP measurements from intraarterial catheters.


METHODS
Ten preterm infants (gestational age 27-36 weeks; birth weight 964-2620 gm) were studied in the neonatal intensive care unit.


RESULTS
The 2 modes of BP measurement were compared in 2-minute epochs (n = 10-12/infant). Mean arterial pressure, systolic arterial pressure, and diastolic arterial pressure were analyzed beat to beat, and baroreflex sensitivity was assessed using spontaneous sequence analysis. Mean differences for absolute BP (mm Hg) were as follows: mean arterial pressure, 3 (limits of agreement, -1 to 8); systolic arterial pressure, -4 (-8 to 1); and diastolic arterial pressure, 7 (4 to 10). Mean differences and limits of agreement for interbeat changes were essentially 0 for mean arterial pressure, systolic arterial pressure, and diastolic arterial pressure. Precision (+/- 95% confidence intervals, mm Hg) for the Finometer were mean arterial pressure +/- 7, systolic arterial pressure +/- 8, and diastolic arterial pressure +/- 6. Precision was greater for the arterial catheter (mean arterial pressure +/- 3, systolic arterial pressure +/- 4, and diastolic arterial pressure +/- 4). Baroreflex sensitivity calculated from the Finometer BP was (mean +/- SEM, ms/mm Hg) 1.74 +/- 0.23 and, from the catheter system, BP was 1.56 +/- 0.21 (p value NS).


CONCLUSIONS
The Finometer provides accurate measurements of beat-to-beat BP and baroreflex sensitivity. The ability to continuously measure BP and baroreflex sensitivity during sleep in infants may provide vital clues into pathologic conditions associated with impaired autonomic control during sleep.
Yiallourou
Stephanie R
SR
Ritchie Centre for Baby Health Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
Walker
Adrian M
AM
Horne
Rosemary S C
RS
D017704:Baroreflex / Q000502:physiology*; D015924:Blood Pressure Monitors; D002408:Catheters, Indwelling; D004867:Equipment Design; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007363:Intensive Care Units, Neonatal; D008297:Male; D017286:Polysomnography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*