Last Updated: 2001-07-06 9:35:38 EDT (Reuters Health)
(Reuters Health) – Synchronized nasal intermittent positive pressure ventilation has a higher success rate in extubating infants compared with nasal continuous positive airway pressure, according to results of a prospective study conducted at the Albert Einstein Medical Center in Philadelphia.

The patients included 84 neonates of no more than 34 weeks' gestational age diagnosed with respiratory distress syndrome. When pulmonary function tests indicated that the infants were ready for extubation, the patients were randomized to intermittent or continuous extubation. In both cases, positive airway pressure was delivered via nasal prongs.

Dr. Vineet Bhandari and his associates found that 94% of those receiving intermittent ventilation were extubated successfully, compared with 60% of those on continuous ventilation. After controlling for weight, successful extubation was 21 times greater in the intermittent group than in the continuous group, they report in the July issue of Pediatrics.

In an interview with Reuters Health, Dr. Bhandari suggested that a combination of three factors contributes to the improved outcomes in those receiving synchronized intermittent ventilation.

"First, I think that synchronization with the baby's breathing efforts is crucial," he said. "If the machine is trying to breathe into the baby and the baby is trying to breathe out, such asynchrony is going to generate pressure in the oral cavity, which can get into the stomach and cause problems."

He also believes that with nasal intermittent positive pressure ventilation, the mean air pressure may be higher than that achieved with continuous positive pressure alone.

The third factor, Dr. Bhandari added, is that intermittent irritation to the nose causes the infants to remember to breathe. In contrast, the children on continuous ventilation "just had too many apneic spells."

Since submission of this report, Dr. Bhandari's team has extended its research into the prevention of chronic lung disease in these patients. The group calls its new approach "surfactant insulation and synchronized nasal ventilation."

"As soon as neonates are diagnosed with respiratory distress syndrome, we intubate, give the surfactant, then extubate immediately and put them on nasal intubation," Dr. Bhandari explained. Initial results of a randomized, controlled trial have been promising, he added.

"The endotracheal tube appears to cause trauma to the lung, because of air hitting the lungs over and over again," he hypothesized. "Even though we have replaced some of the surfactant, there is still inflammation and damage going on."

"However, if we are able to remove the endotracheal tube, we can limit the damage. We have the benefit of having surfactant in place and we're ventilating the baby, but pressure is generated only in the nose and oropharynx. That way we are able to avoid the direct injury to the lung."

Pediatrics 2001;108:13-17.

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