Nasal high frequency ventilation in neonates with moderate respiratory insufficiency

Abstract

Aim-To investigate the eYcacy of nasal high frequency ventilation (nHFV) in newborn infants with moderate respiratory insuYciency. Method-Twenty one preterm and term neonates were treated with nHFV for respiratory insuYciency. Criteria for starting nHFV were: deterioration on nasal CPAP expressed by a median pH of 7.24 and pCO 2 of 8.3 kPa, or increasing FIO 2 . nHFV was delivered using the Infant Star ventilator. Ventilator setting amplitude was 35 cm H 2 O; mean airway pressure 7 cm H 2 O; and frequency 10 Hz. Results-pCO 2 decreased significantly from 8.3 kPa to 7.2 kPa after nHFV was started. In five patients nHFV was discontinued after a median period of 6 1 ⁄2 hours due to CO 2 retention and high oxygen need, and endotracheal mechanical ventilation was started. Conclusions-nHFV can reduce pCO 2 in neonates with moderate respiratory insufficiency and, therefore, could be used to decrease the need for endotracheal mechanical ventilation. (Arch Dis Child Fetal Neonatal Ed 1998;79:F61-F63) Keywords: nasal high frequency ventilation; idiopathic respiratory distress syndrome Over the past two decades assisted mechanical ventilation has been used to manage respiratory insuYciency in newborn infants. However, complications such as airleaks occur in 15 to 48% of the infants who need ventilator support, 1 2 and 5 to 25% develop bronchopulmonary dysplasia (BPD).3 Both these complications contribute substantially to morbidity in preterm infants. Therefore, a less invasive approach such as nasal continuous positive airway pressure (nCPAP) is frequently used in the initial management of respiratory insuYciency.4-6 But 43 to 80% of the neonates with moderate to severe respiratory insuYciency, initially treated with nasal CPAP, will need subsequent mechanical ventilation. 7Nasal CPAP has also been used after extubation to facilitate weaning from mechanical ventilation. [8][9][10][11] However, extubation failed in 16 to 40% of cases. In both events subsequent endotracheal mechanical ventilation was needed because of CO 2 retention or increased oxygen need and apnoea of prematurity.High frequency ventilation (HFV) is a new method of mechanical ventilation based on the delivery of small tidal volumes at a supraphysiological respiratory frequency of 10 Hz. 13This technique is very eVective in eliminating carbon dioxide and is independent of dead space.We hypothesised that HFV applied on a single nasopharyngeal tube (nHFV) might reduce pCO 2 by augmenting CO 2 diVusion in the pharynx and larynx area and, therefore, decreasing the need for subsequent mechanical ventilation. To test this hypothesis we performed a non-controlled observational study and tested the eYcacy of nHFV in infants with moderate respiratory insuYciency. MethodsTwenty one newborn infants were oVered nHFV. All patients were initially treated with nasal CPAP applied via a single nasopharyngeal tube positioned at a depth of 3-4 cm. nHFV was started due to CO 2 retention (median value 8.3 kPa), acidosis (median pH value 7.24), and/or increasing oxyge...

Neonatal Noninvasive Ventilation Techniques: Do We Really Need to Intubate?

“…Short-term observational studies have suggested initial mean airway pressure set to equal the previous CPAP, frequency set at 10 Hz, amplitude adjusted to obtain visible chest-wall vibration and increased every 30 min by 4 -6 units, if necessary, to maintain clinically appropriate chest-wall vibration, transcutaneous CO 2 , or blood gas values. 80,81 Clinical responses to HFV in preterm neonates in 2 small studies have been reported. Van der Hoeven et al 79 placed 21 preterm and term infants with moderate respiratory insufficiency on nasal HFV following CPAP.…”

“…All 14 subjects were very-low-birth-weight infants (Ͻ 1,500 g) who were transitioned from CPAP to HFV via nasopharyngeal ETT, with the Infant Star ventilator in the high-frequency, flow-interrupter mode. The investigators used an approach similar to that of van der Hoeven et al, 80 for 2 hours. After 2 hours of nasal HFV, capillary blood gases were measured and the subjects were returned to their pre-study CPAP settings.…”

Nasal Ventilation Alters Mesenchymal Cell Turnover and Improves Alveolarization in Preterm Lambs

“…However, beyond 3 to 4 hours of continuous bubble nasal CPAP, Pa CO 2 rose and pH fell to unphysiologic levels, despite treating the preterm lambs with antenatal corticosteroids to accelerate lung development, exogenous surfactant to increase lung compliance, and caffeine citrate to increase respiratory drive. The only prior use of HFNV we are aware of is a small observational study in preterm neonates failing nasal CPAP reported by van der Hoeven and colleagues (28). They applied HFNV with the Infant Star 950 ventilator via a single nasopharyngeal tube in a study group that was quite diverse with respect to gestational and postnatal age.…”

Nasal High-Frequency Oscillation for Lung Carbon Dioxide Clearance in the Newborn

“…Its use also does not require synchronization of breaths as the patient can comfortably continue normal tidal breathing while on the ventilator and thus has the potential to provide superior noninvasive ventilation. Only a limited number of clinical studies have explored the use of noninvasive high-frequency ventilation but whether this strategy is able to support adequate gas exchange in neonates has not been thoroughly addressed [11,12,13]. …”