Effects of non-invasive pressure support ventilation (NI-PSV) on ventilation and respiratory effort in very low birth weight infants.
BACKGROUND
Nasal continuous positive airway pressure (NCPAP) is used to provide support to non-intubated infants, but it often fails. Pressure support ventilation (PSV) is a mode of synchronized ventilation that can supplement the spontaneous breathing effort, but it is unknown if it is effective in non-intubated very low birth weight (VLBW) infants.


OBJECTIVE
To compare the acute physiological effects of non-invasive PSV (NI-PSV) versus NCPAP on tidal volume (V(T)), minute ventilation (V(E)), gas exchange, breathing effort, and chest wall distortion in VLBW infants.


METHODS
Stable preterm infants of birth weight less 1,250 g were studied during consecutive 2 hr periods of NCPAP and NI-PSV in random sequence. VT, V(E), and thoraco-abdominal synchrony were measured using respiratory inductance plethysmography. Breathing effort was measured by esophageal manometry. Gas exchange was measured by pulse oximetry and transcutaneous PCO2.


RESULTS
Fifteen infants of birth weight (mean +/- SD) 808 +/- 201 g and 25.9 +/- 1.8 weeks gestational age were studied while on NCPAP 5.3 +/- 0.6 cm H2O and on NI-PSV with 7.9 +/- 1.3 cm H2O above NCPAP of pressure support. There were no differences in VT, V(E), PCO2 or hypoxemia episodes. Peak and minute inspiratory effort were significantly reduced in NI-PSV mode as compared to NCPAP. There was a significant reduction in indices of chest wall asynchrony in NI-PSV mode.


CONCLUSIONS
When compared to NCPAP, NI-PSV did not increase minute ventilation, but it effectively unloaded the patient's respiratory pump as indicated by a lower inspiratory effort and reduced chest wall distortion.
Ali
Nabeel
N
Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida 33101, USA.
Claure
Nelson
N
Alegria
Ximena
X
D'Ugard
Carmen
C
Organero
Roberto
R
Bancalari
Eduardo
E
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000502:physiology*; D008297:Male; D010991:Plethysmography; D011175:Positive-Pressure Respiration / Q000379:methods*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D013990:Tidal Volume