150 - Comparative efficacy of humidifiers in noninvasive infant respiratory support

Poster Number: 150
Publication Number: 150.112

Stephen C. John, University of Minnesota Masonic Children's Hospital, St Paul, MN, United States; Casey D. Hokanson, University of Minnesota Medical School, Shakopee, MN, United States; Ashley Bjorklund, Hennepin Healthcare and University of Minnesota, Eden Prarie, MN, United States; Tina M. Slusher, University of Minnesota, Roseville, MN, United States

Background: Infants in respiratory distress can benefit from noninvasive treatments such as oxygen via nasal cannula, CPAP and NIPPV. Given the sensitive skin of infant nares, delivering cold, dry air at high flow rates can lead to skin breakdown and discomfort. In high resource settings, electric heated humidifiers are used to mitigate this problem. In many resource constrained settings, passive non-electric bubbling humidifiers are instead used.

Objective: In these experiments we compare the efficacy of a Fisher Paykel heated humidifier, a custom-built low cost heated humidifier and a standard passive non-electric bubbling humidifier with the control of no humidification. 
 

Design/Methods: In a hospital patient room (Temperature 22C, humidity 50%), the temperature and humidity delivered to a simulated patient lung (38C) via a BC161-10 Fisher Paykel bubble CPAP system was measured with a Fisher Paykel heated humidifier vs. a low cost custom-built heated humidifier vs. a passive bubbling humidifier vs. no humidifier. Delivered CPAP was set at 5 cm H2O and the flow rate was varied from 4 to 8 LPM  in 2 LPM increments.

Results: As the flow rate was varied from 4 - 8 LPM, the delivered relative humidity (standard deviation) with each humidifier was as follows: control 10% (3.6%), passive bubbler 44% (3.7%), custom-built humidifier 67% (1.7%), heated humidifier 91% (0.86%). The delivered temperature with the heated humidifier was 38 C (0.21C) vs. 33 C for all other set ups.Conclusion(s): There is a significant difference in the degree of relative humidification with a heated humidifier vs. a passive bubbling humidifier. The custom built low cost heated humidifier provides an intermediate degree of humidification. Through further improvement of this concept with a heated inspiratory circuit and sensor based control of the heating element, an effective yet low cost solution heating humidification could be developed.
CV_john.pdf