Temperature and Humidity Associated With Artificial Ventilation in the Premature Infant

Abstract

This review underscores the need for further research into current warming and humidification techniques for invasive and noninvasive neonatal ventilation. A focus on human studies and the impact of aberrant levels on infant body temperature are needed. Future research may provide management options for achieving and maintaining target temperature/humidity parameters, thus preventing the aberrant levels associated with BPD.

The Association Between Very Premature Infant Body Temperatures Over Time and Respiratory Care

“…While the impact of CPAP on infant body temperature is poorly understood (Ralphe & Dail, 2018), this study found that infants receiving CPAP were more likely to experience hypothermia than infants receiving MV. Although the effect size for this relationship was small, any increase in hypothermia risk may be clinically significant due to the associated complications of ongoing oxygen and glucose consumption (Knobel & Holditch-Davis, 2007).…”

“…However, the inspired air temperature and humidity can decrease significantly as it travels from the heated humidifier to the infant, thus becoming a risk factor for VLBW infant thermal instability (Ralphe & Dail, 2018;te Pas et al, 2010). Furthermore, incubator air temperatures have been strongly associated with inspired air temperature and humidity levels (Ralphe & Dail, 2018). Hence, if the incubator air temperature is lower than the inspired air temperature, it can cool and dry the inspired air (Preo et al, 2013;Yusuke et al, 2017); therefore, increasing infant thermal instability risk.…”

“…Because these therapies interfere with or alter the normal process of heating and humidifying inspired air, VLBW respiratory support air is typically warmed and humidified to physiologic levels (37.0 °C and 44 mg/L) to prevent complications from cold and dry gases (e.g., pulmonary epithelial damage and thermal instability) (Jiang et al, 2015; Schulze, 2007). However, the inspired air temperature and humidity can decrease significantly as it travels from the heated humidifier to the infant, thus becoming a risk factor for VLBW infant thermal instability (Ralphe & Dail, 2018; te Pas et al, 2010). Furthermore, incubator air temperatures have been strongly associated with inspired air temperature and humidity levels (Ralphe & Dail, 2018).…”

“…Furthermore, the daily nursing care (e.g., touching, stethoscopes, cleansing wipes) and respiratory care interventions (e.g., endotracheal tube (ETT) suctioning, nasal prong care) essential for VLBW infant survival can impact body temperature through direct infant contact or indirectly by disrupting incubator temperature (Mok et al, 1991). While nursing care (Mok et al, 1991) and aberrant inspired air temperature and humidity from respiratory support (Ralphe & Dail, 2018) have the potential to induce heat loss through convection, conduction, evaporation, and radiation (Guyton, 2020; Martin, Fanaroff et al, 2019), the impact of respiratory care interventions on infant thermal stability is unclear. Therefore, the purpose of this study was to examine the association between respiratory care interventions and infant body temperatures over time.…”

Humidity during high-frequency oscillatory ventilation compared to intermittent positive pressure ventilation in extremely preterm neonates: an in-vitro and in-vivo observational study.

“…2 A relatively small change (increase or decrease) in the temperature or humidity of the inspired gas may be sufficient to impair the preterm infant's pulmonary function. 3 Recommendations in this field come from adult studies, are uncertain, 4 and stipulate that humidification must be maintained between 33 and 44 mg/L of absolute humidity (AH) and 75% to 100% of relative humidity (RH). 5 Medical devices to heat and humidify the airways have been optimized for conventional intermittent positive pressure ventilation (IPPV) and can meet these humidification recommendations.…”