TY - JOUR
T1 - Observational Study of Humidified High-Flow Nasal Cannula Compared with Nasal Continuous Positive Airway Pressure
AU - Lampland, Andrea L.
AU - Plumm, Brenda
AU - Meyers, Patricia A.
AU - Worwa, Cathy T.
AU - Mammel, Mark C
N1 - Funding Information:
Financial support for this study was provided by a grant from the Children's Hospitals and Clinics of Minnesota Foundation. The authors declare no conflicts of interest.
PY - 2009/2
Y1 - 2009/2
N2 - Objectives: To conduct an in vitro evaluation of a humidified high-flow nasal cannula (HFNC) system at different flows, cannula sizes, and air leaks and also an in vivo analysis of mean end-expiratory esophageal pressure (EEEP) from nasal continuous positive airway pressure at 6 cm H2O (NCPAP+6) versus HFNC. Study design: In the in vitro study, we measured HFNC system pressure and flow, with varying degrees of leak and with and without the use of a pressure-limiting valve. In the in vivo study, we measured EEEP in 15 newborns on NCPAP+6 and then on HFNC at 6 L/minute, with flow decreased by 1 L/minute every 30 minutes. Heart rate, respiratory rate, fraction of inspired oxygen, arterial oxygen saturation, respiratory distress syndrome score, and EEEP were recorded for each intervention. Data analysis was done using repeated-measures analysis of variance and linear regression. Results: In the in vitro study, in the absence of leaks, the pressures were limited by the pressure-limiting valve only at flows ≥ 2 L/minute. With leaks of 30% and 50%, delivered pressures were always < 3 cm H2O. In the in vivo study, respiratory rate increased from baseline (NCPAP+6) as flow decreased (P < .02). Intrapatient and interpatient coefficients of variation were always high. Conclusions: A pressure-limiting valve is necessary in a HFNC system. Although mean EEEP levels were similar in NCPAP+6 and HFNC, tachypnea developed as flow diminished. This system apparently cannot predict EEEP, because of interpatient and intrapatient variation.
AB - Objectives: To conduct an in vitro evaluation of a humidified high-flow nasal cannula (HFNC) system at different flows, cannula sizes, and air leaks and also an in vivo analysis of mean end-expiratory esophageal pressure (EEEP) from nasal continuous positive airway pressure at 6 cm H2O (NCPAP+6) versus HFNC. Study design: In the in vitro study, we measured HFNC system pressure and flow, with varying degrees of leak and with and without the use of a pressure-limiting valve. In the in vivo study, we measured EEEP in 15 newborns on NCPAP+6 and then on HFNC at 6 L/minute, with flow decreased by 1 L/minute every 30 minutes. Heart rate, respiratory rate, fraction of inspired oxygen, arterial oxygen saturation, respiratory distress syndrome score, and EEEP were recorded for each intervention. Data analysis was done using repeated-measures analysis of variance and linear regression. Results: In the in vitro study, in the absence of leaks, the pressures were limited by the pressure-limiting valve only at flows ≥ 2 L/minute. With leaks of 30% and 50%, delivered pressures were always < 3 cm H2O. In the in vivo study, respiratory rate increased from baseline (NCPAP+6) as flow decreased (P < .02). Intrapatient and interpatient coefficients of variation were always high. Conclusions: A pressure-limiting valve is necessary in a HFNC system. Although mean EEEP levels were similar in NCPAP+6 and HFNC, tachypnea developed as flow diminished. This system apparently cannot predict EEEP, because of interpatient and intrapatient variation.
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U2 - 10.1016/j.jpeds.2008.07.021
DO - 10.1016/j.jpeds.2008.07.021
M3 - Article
C2 - 18760803
AN - SCOPUS:58149513971
VL - 154
SP - 177-182.e2
JO - Journal of Pediatrics
JF - Journal of Pediatrics
SN - 0022-3476
IS - 2
ER -