The Effects of helium/oxygen mixture (heliox) before and after extubation in long-term mechanically ventilated very low birth weight infants.
OBJECTIVE
Our goal was to evaluate the effects of a helium/oxygen mixture (heliox) on pulmonary mechanics and gas exchange in preterm infants during both conventional and noninvasive ventilation.


METHODS
Ten preterm infants, ventilated from birth, were enrolled. Resistive work of breathing, pulmonary compliance, static compliance, respiratory rate, minute ventilation, ventilatory support, and gas exchange were measured before and during treatment. One hour after heliox therapy, subjects who showed a decrease of peak inspiratory pressure of >20% of the initial value were extubated and shifted to nasal bilevel positive airway pressure with heliox for the following 3 hours. Pulmonary mechanics and ventilatory parameters were measured during air/oxygen ventilation and again 10 minutes and 1 hour after starting heliox. Transcutaneous pressure of O(2) and CO(2), oxygen saturation, and respiratory rate were recorded continuously. Arterial blood gases were measured immediately before and 1 hour after initiating bilevel positive airway pressure. To maintain oxygen saturation at >92% during the bilevel positive airway pressure phase, the mean fraction of inspired oxygen was increased from 0.34 to 0.36.


RESULTS
Mean peak inspiratory pressure decreased from 21.4 to 17.4 cmH(2)O, work of breathing decreased from 0.46 to 0.22 joule/L, and transcutaneous pressure of CO(2) decreased from 52.3 to 49.1 mmHg. Mean transcutaneous pressure of O(2) improved from 42.8 to 46.7 mmHg, and minute ventilation improved from 332 to 478 mL/kg per minute. No significant differences were observed in mean airway pressure, respiratory rate, oxygen saturation, pulmonary compliance, and static compliance. Eight infants were extubated. One of them needed to be reintubated after 5 hours.


CONCLUSIONS
Our data show that mechanical ventilation with heliox reduces resistive work of breathing and ventilatory support requirements and improves gas exchange in preterm infants.
Migliori
Claudio
C
Department of Neonatology and Neonatal Intensive Care, Spedali Civili Hospital, p.le Spedali Civili, 25123 Brescia, Italy. claudio.migliori@tin.it
Gancia
Paolo
P
Garzoli
Elena
E
Spinoni
Vania
V
Chirico
Gaetano
G
D001785:Blood Gas Monitoring, Transcutaneous; D045422:Continuous Positive Airway Pressure; D005260:Female; D006371:Helium / Q000008:administration & dosage*; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D008134:Long-Term Care; D008176:Lung Volume Measurements; D008297:Male; D010100:Oxygen / Q000008:administration & dosage*; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012127:Respiratory Distress Syndrome, Newborn / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology*; D015300:Ventilator Weaning
D006371:Helium; C038949:heliox; D010100:Oxygen