Gentle limb fixation for a faster reliable heart rate obtained with pulse oximeter at birth

Pulse oximetry is widely used to monitor heart rate (HR) and peripheral oxygen saturation during neonatal resuscitation. As HR is a key parameter guiding clinical decision-making during initial assessment and stabilization, timely and accurate HR readings are critical. However, it can take minutes to achieve a reliable reading directly after birth. This study aimed to determine whether infant limb movement and gentle fixation after pulse-oximeter application influence the time to obtain the first reliable HR.

Video recordings of neonatal resuscitations with simultaneous pulse oximetry readings were retrospectively analyzed for neonates ≥24 weeks' gestation. Neonates were categorized into three groups based on the status of the right limb during the first 10 s after sensor application: (1) movement, (2) no movement, or (3) gentle fixation by a caregiver. Time to the first reliable HR_PO was determined using a custom-developed, ECG-validated algorithm applied to the photoplethysmogram.

A total of 178 neonates were included, with a median gestational age of 30 + 4 weeks (28 + 4-33 + 6), with no significant differences between groups. Median time to achieve a reliable HR_PO was significantly shorter in the "no movement" (20.3 [16.1-34.2] s) and "fixation" (17.9 [14.9-25.4] s) groups as compared to the "movement" group (46.2 [23.5-75.1] s) (p < 0.001). The percentage of neonates who achieved a reliable HR_PO within 30 s after application was significantly higher after limb fixation (80.5%) versus no fixation (49.6%) (p < 0.001).

Pulse oximetry does not seem motion artefact resistant when the first HR is obtained. Gentle limb fixation after sensor application may facilitate more timely clinical assessment.