To measure changes in physiologic parameters in extremely low birthweight (ELBW) infants on high-flow nasal cannula compared to nasal continuous positive airway pressure (nCPAP).
After informed consent is obtained, eligible infants who are stable on nCPAP therapy of 5-7 cm H20 achieved with a ventilator, an underwater "bubble" system, or a variable-flow device will be enrolled. All subjects will have physiologic data and electrical impedance tomography collected at: 1. Baseline nCPAP for 15 minutes 2. Upon transition to high flow nasal cannula at 8 LPM for 6 hours. Data collection is obtained after infant is calm for 15 minutes at the beginning and end of this 6 hour period 3. Then upon return to baseline NCPAP for a final 15 minutes of data collection.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
80
8 liters per minute of blended oxygen through Fisher Paykel Optiflow Jr 2 nasal prongs.
Nasal continuous positive airway pressure of 5-7 cm/H20 delivered using Ventilator or bubble cpap device through short nasal prongs or a nasal face mask.
Sharp Mary Birch Hospital for Women & Newborns
San Diego, California, United States
Percent of Unventilated Lung as Assessed by Electrical Impedance Tomography
Atelectasis will be calculated using the percentage of the lung fields that are not engaged in tidal volume.(VT) In Period 1 (nCPAP Baseline), infants on nCPAP at 5-7 cmH₂O in the supine position underwent up to 15 minutes of quiet-breathing EIT recording. In Period 2 (30 min on HFNC), infants were transitioned to HFNC at 8 L/min, and if tolerated, up to 15 minutes of EIT were collected at \~30 minutes. In Period 3 (6 hr on HFNC or earlier if failure), infants who tolerated HFNC underwent EIT at 6 hours; those meeting failure criteria returned immediately to nCPAP and were analyzed as Period 3 without a 6-hour EIT. In Period 4 (60 min after return to nCPAP), infants resumed nCPAP and up to 15 minutes of EIT were obtained about 60 minutes later. In period 4 one participant had missing primary outcome data and were analyzed as Period 4 without a 60 min return to nCPAP EIT measurement.
Time frame: Primary outcome was measured during each study period: baseline on nCPAP, 30 minutes after starting HFNC, at 6 hours on HFNC or earlier if failure, and 60 minutes after returning to nCPAP.
Geometric Center of Ventilation (CoV) - Ventral Dorsal
Spatial center of tidal volume distribution in the thorax during ventilation
Time frame: This secondary outcome was measured during each study period: baseline on nCPAP, 30 minutes after starting HFNC, at 6 hours on HFNC or earlier if failure, and 60 minutes after returning to nCPAP.
End-expiratory Lung Impedance
End-expiratory lung impedance was measured using electrical impedance tomography (EIT) to assess changes in end-expiratory lung volume. EELI reflects the sum of impedance values across all ventilated lung pixels at the end of expiration and provides an estimate of lung aeration. Values were derived from artifact-free tidal breaths captured during quiet breathing using the neonatal EIT belt and LuMon EIT system.
Time frame: This secondary outcome was measured during each study period: baseline on nCPAP, 30 minutes after starting HFNC, at 6 hours on HFNC or earlier if failure, and 60 minutes after returning to nCPAP.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Relative Tidal Stetch
Measurement of how much stretch the lung tissue undergoes during inspiration relative to baseline impedance
Time frame: This secondary outcome was measured during each study period: baseline on nCPAP, 30 minutes after starting HFNC, at 6 hours on HFNC or earlier if failure, and 60 minutes after returning to nCPAP.
Oxygenation Ratio
Values \<+3 → poor oxygenation relative to ventilation (inefficient V/Q matching) Values 4-6 → moderate efficiency Values \>6 → good oxygenation efficiency relative to ventilation
Time frame: Study Period 1 through 4