Newborns have significantly different respiratory patterns compared to adults, and these patterns impact how neonatal respiratory issues are monitoring and managed. A normal respiratory rate for a neonate is anywhere from 40-60 breaths per minute, and neonates have a smaller tidal volume compared to adults. 
Respiration occurring that quickly can be difficult to track with traditional monitoring devices.2 While many newborns do well on their own, respiratory distress remains a key concern in those first few hours of life.
There are a variety of ways clinicians can monitor respiratory status in neonates including measuring arterial blood gases (ABG) and using noninvasive technology like capnography.
This article discusses the importance of noninvasive monitoring in neonates, challenges associated with managing this patient population as well as new technology available to remove logistical barriers and provide accurate respiratory readings.
Respiratory Distress in Neonates
There are multiple reasons a neonate may experience respiratory distress, including:1
- Transient tachypnea of the newborn
- Respiratory distress syndrome
- Meconium aspiration syndrome
- Delayed transition
Respiratory support with oxygen, surfactant replacement, and a proper fluid and electrolyte balance are all ways to support neonates in respiratory distress.1
If clinicians are unable to quickly identify a newborn in distress, this can lead to complications such as lung disease, respiratory failure, and death.
Monitoring Neonatal Respiratory Status
Experts recommend additional monitoring beyond physical examination when evaluating respiratory status. While nasal flaring, grunting, lethargy, and other symptoms are often present, they should not be used as the only means of respiratory monitoring.1
Pulse oximetry is recommended at a minimum, but when a neonate is experiencing respiratory distress, more precise monitoring is needed. This is especially true if interventions and respiratory support are initiated to evaluate response and patient status.1
While pulse oximetry measures oxygenation, it doesn’t measure ventilation or carbon dioxide levels like capnography or ABGs can.
Monitoring respiratory status with ABGs presents unique problems in neonates. Due to their small size and the volume required for these readings, frequent ABGs can increase the need for transfusions in newborns.2 There is also an increased risk for infection with frequent ABGs.
Capnography is a noninvasive method for monitoring respiratory status and is frequently used in adults. It measures the amount of CO2 in exhaled breath (end-tidal CO2), and it is therefore used to measure patient ventilation.6 Capnography is measured as a function of time or volume, allowing for alveolar ventilation and airway dead spaces calculations.6
Current Challenges When Using Capnography in Neonates
Traditional capnography technology has certain limitations surrounding bulky monitoring, frequent need for zeroing and recalibration, as well as being impacted by changes in temperature.
Ventilatory parameters pose a major challenge when it comes to using capnography in intubated neonates, especially in very low birth weight newborns. The volume of exhaled CO2 is much lower and tidal volumes tend to be low too. These factors can limit how accurate capnography readings are.
Additionally, the rapid respiratory rates of infants pose technical challenges with traditional capnography devices.7
Combined with small airways, changes in airway dead spaces, and the risk for endotracheal tube (ETT) leaks due to uncuffed ETT use, these physiological challenges can lead to discrepancies and decreased accuracy in capnography readings.7
How MicrostreamTM Technology Addresses These Challenges
Medtronic’s MicrostreamTM technology addresses many of the common limitations associated with capnography. MicrostreamTM Advance Filter Lines are available for both intubated and non-intubated lines with intubated lines allowing for customization for the smaller sizes of premature infants.
This customization helps minimize dead space by accounting for the small size, small tidal volume, and decreased lung capacity of neonates.8 MicrostreamTM monitoring is accurate up to 150 respirations per minute and has a lightweight design which reduces additional weight on the ETT.
Other benefits of MicrostreamTM capnography monitoring for neonates include low sample size requirement of 50ml per minute, a non-invasive end tidal CO2 measurement, and breath-by-breath capabilities making it an asset for this unique patient population.9
And with smart alarm algorithms, MicrostreamTM monitoring has shown a 53% reduction in clinically insignificant nuisance alarms with no need for auto-zero or individual patient calibration required.9
Capnography is a vital resource when it comes to monitoring respiratory status and one that needs special considerations in neonates. MicrostreamTM technology also auto-adjusts for temperature.9 MicrostreamTM monitoring has been shown to reduce blood gas analyses from 21.6 to 13.8 per encounter in the pediatric intensive care unit (PICU).
This is why GE has partnered with Medtronic to integrate the most advanced MicrostreamTM technology available. The CARESCAPE™ CO2 – Microstream™ parameter and enhanced Microstream Advance Filter Lines have been validated for clinical use on all CARESCAPE Bx50 and CARESCAPE ONE monitors with v3.2 software.
- Respiratory monitoring in neonates presents unique challenges due to patient size and respiratory patterns
- While challenging, adequate respiratory monitoring is imperative to identify respiratory distress early so interventions can be performed to improve patient outcomes
- Pulse oximetry, ABGs, and capnography are all ways clinicians can monitor respiratory status and interventions
- Medtronic’s MicrostreamTM capnography monitoring provides a solution for neonatal monitoring, taking into account the small size of neonates and unique breathing patterns
 Hermansen, C & Mahajan, A. (2015). Newborn respiratory distress. American Family Physician. 92(11). 994-1002.
 Molloy, E & Deakins, K. (2006). Are carbon dioxide detectors useful in neonates? Arch Dis Child Fetal Neonatal Ed. 91(4). F295-F298.
 Edwards, M et al. (2013). Respiratory distress of the term newborn infant. Pediatric Respiratory Review. 14(1):29-36.
 Schraufnagel, D & Kell, B. (2010). Respiratory distress syndrome. Breathing in America: Diseases, Progress, and Hope. 197-205.
 Reuter, S, Moser, C, & Baack, M. (2014). Respiratory distress in the newborn. Pediatrics in Review. 25(10). 417-429.
 Rowan, C et al. (2015). Implementation of continuous capnography is associated with a decreased utilization of blood gases. J Clinical Medical Research. 7(2): 71-75.
 Schmalisch, G. (2016). Current methodological and technical limitations of time and volumetric capnography in newborns. Biomedical Engineering Online. 15(1). 104.
 Medtronic. Quick Reference Guide. 2019:1-12. https://www.medtronic.com/content/dam/covidien/library/us/en/product/ca….
 Internal test data on file.
 Hawkins-Simons D. Continuous Capnography Linked to Lower Monitoring Costs. Anesthesiology News. 2012;38(3).
Microstream™ capnography technology should not be used as the sole basis for diagnosis or therapy and is intended only as an adjunct in patient assessment.
Users are advised to review and consult relevant cautions and warnings in Instructions for Use/Operator’s Manual for CARESCAPE™ patient monitors and Microstream™ capnography technology prior to use.