Nasal HFOV Versus Nasal CPAP to Reduce Post-extubation pCO2

Nasal High Frequency Oscillation Ventilation Versus Nasal Continuous Positive Airway Pressure to Reduce Post-extubation pCO2 in Very Low Birth Weight Infants: a Randomized Controlled Trial

To investigate whether nasal high frequency oscillation ventilation (nHFOV) immediately after extubation reduces the arterial partial pressure of carbon dioxide (paCO2) at 72 hours after extubation in comparison with nasal continuous positive airway pressure (nCPAP) in very low birth weight infants (VLBWs).

Randomized controlled clinical trial comparing nHFOV vs nCPAP immediately after extubation of VLBW infants.

Intervention and treatment protocol as described for the two study arms.

Definition of treatment failure (infant meets at least one criterion):

• Sustained pCO2 >80 mmHg and pH <7.20 confirmed by arterial or capillary blood gas analysis in spite of optimized non-invasive respiratory support with maximum settings as defined above.
• Fraction of inspired oxygen (FiO2) >0.6 to maintain peripheral oxygen saturation as measured by pulse oximetry (SpO2) at 90-94% in spite of optimized non-invasive respiratory support with maximum settings as defined above.
• Reintubation (study patients may be intubated at any time, due to clinical considerations, with or without reaching another criterion of "treatment failure").

Sample size:

Assuming a variability of the paCO2 as previously reported for difficult-to-wean preterm infants in our unit (Czernik C, J Matern Fetal Neonatal Med 2012) and a treatment failure rate of 22% within 72 hours after extubation, we calculated a sample size of 34 patients in each study arm to detect a difference in the paCO2 of 7 mmHg, using a two-sided significance of 0.05 and a power of 0.8.

Randomization:

Sequence generation by an independent statistician and a study nurse. Block randomization using at least two different block sizes. Allocation concealment using sequentially numbered opaque sealed envelopes.

Data monitoring:

By an independent statistician.

Inclusion Criteria:

• Gestational age <32+0 weeks
• Birth weight <1500 g
• Received mechanical ventilation via an endotracheal tube for ≥120 h
• Caffeine treatment according to unit guidelines
• paCO2 <65 mmHg with pH >7.2
• FiO2 25-40% to maintain SpO2 at 90-94%.
• Time-cycled, pressure-controlled ventilation: PIP ≤22 cm H2O, PEEP ≤6 cm H2O; Volume guarantee ventilation: Working Ppeak ≤22 cm H2O, PEEP ≤6 cm H2O; High frequency oscillation ventilation: Pmean ≤12 cm H2O, Amplitude ≤30 cm H2O
• Decision of the attending clinician to extubate

Exclusion Criteria:

• Major congenital malformation requiring surgery
• Duct-dependent congenital heart disease
• Neuromuscular disease
• Participation in another randomized controlled trial
• Death before reaching the eligibility criteria
• Hydrocortisone treatment at the time of enrolment
• Chronological age >28 days