RESUMO
Objective:To compare the accuracy and timeliness of 3-lead electrocardiography (ECG) and pulse oximetry (POX) in neonatal heart rate (HR) monitoring after birth.Methods:This prospective study recruited 42 high-risk newborns with gestational age ≥37 weeks and birth weight >1 500 g who were born through cesarean section without resuscitation requirement in Xi'an People's Hospital (Xi'an Fourth Hospital) from October 2019 to August 2020. 3-lead ECG electrodes and POX sensors were attached to the neonates immediately after drying to continuously monitor the HR within 10 min after birth. All procedure was recorded by video camera, and data were independently analyzed by a clinician after the procedure was completed. Differences in time required to connect the devices, time to obtain a reliable HR and the interval between them, the time needed for obtaining a reliable HR after birth, the proportion of neonates with reliable HR obtained within 5 min after birth and the consistency in the reliable HR readings between the two devices were compared using Wilcoxon signed-rank test, McNemar test, Spearman's correlation coefficient, intraclass correlation coefficient or Bland-Altman bias analysis.Results:The median time required to connect POX and 3-lead ECG and to acquire a reliable HR were 13.0 s (10.0-17.0 s) vs 23.0 s (18.0-28.3 s) ( Z=-5.050, P<0.001), and 79.5 s (56.2-128.0 s) vs 11.0 s (10.0-13.3 s) ( Z=-5.646, P<0.001), respectively. The total time from the beginning of connecting the devices and birth to acquiring a reliable HR were both longer for POX than those for 3-lead ECG [92.0 s (71.3-139.0 s) vs 35.0 s (30.0-39.5 s), Z=-5.579, P<0.001; 110.5 s (85.8-153.5 s) vs 52.0 s (45.0-66.3 s), Z=-5.579, P<0.001]. Reliable HRs were obtained in 69.1% (29/42) and 2.4% (1/42) of the infants by 3-lead ECG and POX within 1 min after birth, respectively. The percentage of infants for obtaining a reliable HR detected by 3-lead ECG within 5 min after birth were more than those by POX, but with statistically significant differences only at the first 60 s, 90 s, 120 s and 150 s (all P<0.001). The median HRs obtained by 3-lead ECG and POX within 10 min after birth were 161 beats/min (147-175 beats/min) and 160 beats/min (146-176 beats/min), respectively ( r=0.966, P<0.001). The mean difference of HR detected by the two devices was 0.56 beats/min (95% CI:-4.3 to 5.4 beats/min). The intraclass correlation coefficient was 0.961, showing good internal consistency. Conclusions:Neonatal HR can be assessed accurately by 3-lead ECG within 1 min after birth, which is far earlier than that by POX. Therefore, 3-lead ECG can be an option for continuously HR monitor in neonatal resuscitation.