Efficacy of nasal intermittent positive pressure ventilation in treating apnea of prematurity. Randomised controlled trial of nasal ventilation in acute ventilatory failure due to chronic obstructive airways disease.
The efficacy of nasal intermittent positive pressure ventilation (NIPPV) in treating apnea of prematurity was evaluated. Apneic preterm infants were randomly assigned to receive either NIPPV or continuous positive airway pressure (NCPAP) for 4 hr when they failed to respond to conservative therapy. The amount of reduction in apneic spells and bradycardia in the two groups after treatment was compared. Thirty-four infants (18 with NIPPV, 16 with NCPAP) were enrolled. Their birth weights ranged from 590-1,880 g (mean, 1,021 g) and gestational ages from 25-32 weeks (mean, 27.6 weeks). The baseline characteristics were comparable in the two groups. Frequency of apnea and bradycardia was reduced during both forms of treatments. However, the infants receiving NIPPV had a greater reduction of apneic spells (P = 0.02) and a tendency to greater decrease in bradycardia (P = 0.09) than those receiving NCPAP. We conclude that NIPPV is more effective than NCPAP in reducing apnea in preterm infants. NIPPV may reduce bradycardia; however, this needs to be validated by a larger number of observations. Acute exacerbations of chronic obstructive airways disease (COAD) are a common cause of admission to hospital, and have a high mortality. Nasal intermittent positive pressure ventilation (NIPPV) has been used successfully in patients with respiratory failure due to neuromuscular and skeletal disorders, but the outcome of treatment in patients with COAD is less well known. We carried out a prospective randomised controlled trial of conventional treatment versus conventional treatment plus NIPPV, in 60 patients with acute ventilatory failure due to exacerbations of COAD. For the NIPPV group there was a rise in pH, compared with a fall in the controls (mean difference of change between the groups 0.046 [95% CI 0.06-0.02, p < 0.001]), and a larger fall in PaCO2 (mean difference in change between the groups 1.2 kPa [95% CI 0.45 to 2.03, p < 0.01]). Median visual analogue scores over the first 3 days of admission showed less breathlessness in the NIPPV group (2.3 cm [range 0.1-5.5]) than in the control group (4.5 cm [range 0.9-8.8]) (p < 0.025). Survival rates at 30 days were compared for intention-to-treat and efficacy populations. In the efficacy mortality comparison, mortality in the NIPPV group was reduced: 1/26 vs 9/30 (relative risk = 0.13, CI = 0.02-0.95, p = 0.014). This effect was less in the intention-to-treat analysis: 3/30 vs 9/30 (relative risk = 0.33, CI = 0.10-1.11, p = 0.106). In patients with acute ventilatory failure due to COAD who received NIPPV there was a significant rise in pH, a reduction in PaCO2 and breathlessness, and reduced mortality.
Implications for practice: NIPPV may be a useful method of augmenting the beneficial effects of NCPAP in preterm infants with apnea that is frequent or severe. Its use appears to reduce the frequency of apneas more effectively than NCPAP. Additional safety and efficacy data are required before recommending NIPPV as standard therapy for apnea.
Implications for research: Future trials with sufficient power should assess the efficacy (reduction in failure of therapy) and safety (GI complications) of NIPPV. Outcomes should be assessed throughout the entire period during which the infant requires assisted ventilation. The recent ability to synchronise NIPPV with an infant's spontaneous respirations is a promising development requiring further assessment.