2004 OPEN FORUM Abstracts
NASAL HIGH FREQUENCY VENTILATION AS TREATMENT FOR EXTUBATION FAILURE IN A PRETERM INFANT
Tracy, BS, RRT-NPS, Timothy Myers BS, RRT-NPS, Robert Chatburn
RRT-FARC, Ricardo Rodriguez, MD, Rainbow Babies & Children’s
Hospital / Case Western Reserve University, Cleveland, Ohio
INTRODUCTION:Nasal continuous positive airway pressure (NCPAP) is currently the neonatal standard of care for supporting and augmenting spontaneous respiration in the immediate post-extubation period. Non-Invasive positive pressure ventilation (NIPPV) is an option worth consideration. The Cochane Review (The Cochrane Library, Issue 4, 2003) concluded NIPPV superior to NCPAP in preventing extubation failure in preterm neonates. In a separate study, van der Hoeven et al (Arch Dis Child Fetal Neonatal Ed 1998) effectively treated 21 infants with moderate respiratory insufficiency with nasal high frequency ventilation (NHFV).
CASE SUMMARY: A 34 5/7 week, 1.7 kilogram infant with RDS, IUGR, DORV, (s/p balloon valvuloplasty for pulmonic stenosis) and micrognathia was intubated on DOL 1 and given Survanta. The patient was extubated to NCPAP on DOL 14 from minimal ventilator settings. Over the next month, the patient was reintubated four additional times secondary to extubation failure for significant atelectasis, and increases of FIO2 (≥ 0.60), respiratory rate and work of breathing. Chest films (CXR) demonstrated complete left side atelectasis and right-sided patchy infiltrates. After discussion with the neonatal attending, NHFV was selected as an alternative to reintubation. NHFV was initiated with the Infant Star 950 (Infrasonics San Diego, CA) at mean airway pressure 8 cmH20 (NCPAP level), frequency of 6 Hz, ∆ P = 32 cmH20 (established by adequate chest wiggle) and FIO2 = 0.60 (CPAP FIO2). After 12 hours of NHFV, the CXR showed the left hemi-thorax almost completely re-expanded with some right upper lobe collapse. NHFV support continued without attempts to wean the settings. After 81 hours of therapy, NHFV was discontinued and the infant was placed on NCPAP +6 cmH20 and an FIO2 0.28. NCPAP and FIO2 were weaned over the next two weeks and the patient was discharged from NICU without further pulmonary complications.
DISCUSSION:NHFV was chosen over NSIMV due to the (1) significant difference found in hemithorax compliance, (2) lack of dead space ventilation concerns and (3) lack of need to synchronized NSIMV with patient spontaneous efforts. The oscillations of NHFV typically attenuate upon entry to the patient interface device. Therefore; titration of the ∆ P to achieve adequate chest wiggle, regardless of numeric value, should overcome signal attenuation. Our patient’s results for NHFV therapy duration (81 hours) are comparable to those found by van der Hoeven’s (mean 40 hours, range 17 – 126 hrs). Our patient was able to sustain spontaneous minute ventilation without a need to manipulate NHFV settings (pH 7.32 – 7.36, CO2 45 – 59, mean 50 torr). Spontaneous respiratory rate steadily declined (initially 70-80 br/min, 45-50 br/min at discontinuation). CXR results demonstrated improvement after 12 hours of NHFV without any evidence of hyperinflation. While allocation of resources may prevent NIPPV as primary non-invasive mode, NHFV but should be considered an option when NCPAP or NSIMV do not maintain adequate post-extubation support.