471 - Heart rate and saturation trends over first 15 minutes of life in spontaneously breathing high-risk neonates compared to apneic neonates requiring bag mask ventilation

Publication Number: 1453.471

Emily Ahn, New York-Presbyterian Komansky Children’s Hospital, New York, NY, United States; Jackline Cypriane, Kilimanjaro Christian Medical Centre, Moshi, Kilimanjaro, Tanzania; Ester Frank. Ngowi, Kilimanjaro christian medical centre, Moshi, Kilimanjaro, Tanzania; Aisa M. Shayo, KCMC University, Moshi, Kilimanjaro, Kilimanjaro, Tanzania; Jeffrey M. Perlman, Weill Cornell Medicine, New York, NY, United States

Background: There is limited data regarding cardiorespiratory changes immediately post-delivery in high-risk neonates, particularly in the low resource setting. Current technology facilitates timely detection of both heart rate (HR) and pulse oximetry (PO), which may enhance understanding of transitional circulation.

Objective: Describe the transitional changes of HR and saturation values (SV) immediately after birth in high-risk neonates who are spontaneously breathing as compared to apneic neonates requiring bag mask ventilation (BMV).

Design/Methods: This is a physiologic study utilizing continuous PO (Rad-G, Masimo) and dry electrode ECG (NeoBeat, Laerdal) recordings for subsequent analysis. Data were obtained following delivery of high-risk pregnancies (e.g. prematurity, pre-eclampsia) in a referral hospital in Tanzania. DR interventions included stabilization (dry/stimulate) and/or resuscitation (BMV with a self-inflating bag and oxygen). CPAP or intubation in the DR was not available. Data were analyzed with paired and unpaired t-tests.

Results: Simultaneous recordings were obtained from 20 spontaneously breathing neonates (birth weight (BW) 2.4±0.8 kg, gestational age (GA) 35.7±2.7 wks) and 16 apneic neonates requiring BMV (BW 2.5±1.3 kg, GA 34.9±3.9 wks, Fig 1). For those spontaneously breathing, initial SV was 86.8±6.6% and at 15 minutes 94.6±8.5% which reflected an increase of 11.0±4.5% (p < 0.001). The initial HR was 173.7±12.6 bpm and at 15 minutes 151.5±19.4 bpm which reflected a decrease of 15.9±15.5 bpm (p=0.01, Fig 2). For neonates requiring PPV, initial SV was 49.1±31.3 and at 15 minutes 90.9±12.2 which reflected an increase of 45.0 ± 26.5 (p=0.004). The initial HR was 100.1±37.6 bpm and at 15 minutes 165.6±23.3 bpm which reflected an increase of 55.1±31.9 bpm (p=0.001, Fig 3). The apneic neonates had lower initial SV than breathing neonates (p=0.05) and achieved SV >80% by 5 minutes, the NRP target goal. Apneic neonates also had a lower initial HR (P < 0.05); no difference between group HRs were seen by 4 minutes. The NeoBeat detected a HR within 20.7±18.2 seconds from placement.

Conclusion(s): Spontaneously breathing neonates had higher initial HRs and SV than those with apnea. The lower HR and SV in the apneic neonates corrected quickly with effective BMV. The initial high HR (mean 173) in spontaneously breathing neonates coupled with early SV >85% was unanticipated and may be indicative of a rapid decrease in pulmonary vascular resistance. In both groups, the HRs stabilized around 155 bpm (Fig 2,3). The early detection of a readily visualized HR facilitates the ability to judge effective ventilation.

Flow diagram of study population broken down by level of stabilization/resuscitation needed: neonates spontaneously breathing (n = 20), neonates receiving oxygen only (n = 27), and neonates receiving BMV (n = 16).
Figure 1.jpeg

Box and whisker plot of oxygen saturation (A) and heart rate (B) recordings over the first 15 minutes of life in spontaneously breathing neonates.
Figure 2.jpegData represented as medians (line), interquartile range (grey shaded box), range (whiskers), outliers (dots), and means (X). Means represented by X. Number of patients represented as N on the x-axis.

Box and whisker plot of oxygen saturation (A) and heart rate (B) recordings over the first 15 minutes of life in neonates requiring bag mask ventilation.
Figure 3.jpegData represented as medians (line), interquartile range (grey shaded box), range (whiskers), outliers (dots) and mean (X). Number of patients represented as N on the x-axis.