Among patients requiring resuscitation, delays in achieving a normal heart rate or normal SpO2 in the first minutes of life are associated with increased likelihood of death in the first week of life, or for development of hypoxic‐ischemic encephalopathy.4 For example, bradycardia at five minutes after birth is associated with 4.5 times greater risk of death.5 An SpO2 of 80% at five minutes is associated with 2.7 times greater risk of death.5
Consequently, guidelines for the resuscitation of neonates in the delivery room emphasize completing assessment, stabilization, and initiation of respiratory support (if required) within the “golden minute”, or first minute of life.1 In short, when it comes delivery room resuscitation, rapid recognition of need and quick delivery of care (particularly ventilation) is critical.
Despite the urgency to rapidly evaluate neonatal status, traditional means of neonatal evaluation (manual heart rate, chest excursions, reflex irritability, muscle tone and color) may be inaccurate, suffer from poor inter-rater reliability, and/or be difficult to interpret.6 Consequently, objective heart rate monitoring (either via SpO2 or EKG) is now recommended as the primary parameter to guide identification of, and decision making in, neonatal patients requiring resuscitation, as it provides an objective insight into the ability of the patient to perform spontaneous respirations.1
The Neonatal Resuscitation Program (NRP), which was developed jointly by the American Academy of Pediatrics and American Heart Association, developed guidelines and recommendation for the management of delivery room emergencies. The Neonatal Resuscitation Algorithm (Table 1) presented in the guideline utilizes SpO2 monitored heart rate as the key measure for clinical decision making. In addition to identifying patients that require escalation of care, the heart rate-based algorithm helps clinicians carefully monitor the effectiveness of interventions such as positive pressure ventilation.1 Evidence has demonstrated that an increase in heart rate to >100 BPM occurs within 73 seconds of lung aeration and gas exchange via positive pressure ventilation.7
In this environment, the reliability, speed, and accuracy of heart rate measurement is critical. 8 Overestimation of heart rate may result in a delay of treatment. Underestimation of heart rate may lead to unnecessary interventions. We’ve discussed the consequences of delayed treatment above. Likewise, the potential consequences of unnecessary interventions are well documented. Especially among premature infants, even brief periods of inappropriate respiratory support places patients at increased risk neurological or pulmonary injury, such as bronchopulmonary dysplasia and intraventricular/periventricular hemorrhage. 9-11
In the delivery room environment, clinicians relying on pulse oximetry to provide objective heart rate require rapid acquisition of a the SpO2 signal, accurate SpO2 and heart rate values, and reliable signals even during patient movement or low perfusion.12 The recent study by Khoury et al. evaluated accuracy, with respect to ECG, and reliability the Masimo Radical-7™* monitor with M-LNCS sensor and Nellcor™ Bedside SpO2 Patient Monitoring System with the Neonatal-Adult (MAXN) Nellcor™ pulse oximetry sensor in sixty newborns delivered via C-section.
The study was set up as a prospective, observational study in the delivery room. During the resuscitation/stabilization period, both oximeters were simultaneously connected to each foot (left or right side randomized). ECG heart rate was simultaneously recorded. All sensors were first applied to the newborn, before connecting the cable to the oximeter.13, 14 The endpoints included:
Nellcor™ pulse oximetry outperformed Masimo with a statistically significant shorter time to achieve a signal, better correlation with ECG, and less instances of false bradycardia.
*The Nellcor™ pulse oximetry monitoring system should not be used as the sole basis for diagnosis or therapy and is intended only as an adjunct in patient assessment.