ASSESSMENT OF NONINVASIVE TECHNIQUES FOR MEASURING BLOOD-PRESSURE IN PRETERM INFANTS OF BIRTH-WEIGHT LESS-THAN OR EQUAL TO 750 GRAMS

Non-invasive techniques for measuring systolic blood pressure (BP) were evaluated in 10 very preterm infants, median gestational age 24 weeks, who were all of birthweight less-than-or-equal-to 5750 g. Systolic BP measurements were attempted in all infants using a Doppler technique (Ultrasonic Doppler Flow Detector) and two oscillometers (Sentry and EME). Using each technique five separate measurements were attempted over a 10-min period. The systolic BP measurements for each device were then compared to results obtained from intra-arterial catheters which had an undamped waveform. BP measurements were possible on all 10 infants using the Doppler technique, but only in seven using the EME oscillometer and four using the Sentry oscillometer. The mean difference in measurements from those obtained using the arterial catheter were 0.27 mmHg using the Doppler technique and, in those infants in whom measurements were possible, 1.34 mmHg using the Sentry oscillometer and 1.34 mmHg using the Sentry oscillometer. We conclude that the Doppler technique provides the most useful and reliable non-invasive method of assessment of systolic BP in immature infants of birthweight less-than-or-equal-to 750 g.