NEONATAL SOCIETY ABSTRACTS
Effect of posture on oxygenation and respiratory function in prematurely born infants studied prior to discharge
Presented at the Neonatal Society 2002 Summer Meeting (programme).
Bhat RY, Leipala JA, Rafferty GF, Hannam S, Greenough A
Children Nationwide Neonatal Intensive Care Unit, Kings College Hospital, London, UK
Background: In the perinatal period, prone versus supine sleeping is associated with superior oxygenation and respiratory function. The limited data available suggest convalescent infants may also have better oxygenation when nursed prone, but the mechanism is uncertain.
Aim: To determine if the prone compared to the supine position is associated with better oxygenation in prematurely born infants being prepared for discharge home and whether any effect highlighted might be explained by superior respiratory function in the prone position.
Methods: Infants were studied on two successive days. On each day they were studied both supine and prone, each position maintained for three hours. The order of sleeping position was randomised between infants. Oxygen saturation (SaO2) was continuously monitored over each three-hour period, using a pulse oximeter (Datex-Ohmeda, 3740) and Flex II reusable probe. The mean SaO2 for each three-hour period was obtained using the software program SSI Download for Windows (Stowood Scientific Instruments, Oxford, UK). At the end of each three-hour period, lung volume was assessed by measurement of functional residual capacity (FRC) using helium dilution technique and compliance and resistance were measured using the single breath technique. Results are presented as means of the two days.
Patients: Sixteen (seven oxygen dependent) infants, median gestational age at birth 30 (27-32) weeks and birth weight 1.34 (1.03-1.94) kg, were studied at a median PCA of 34.5 (31.7-38) weeks.
Results: In the prone versus the supine position, the median SaO2 was higher (96%, range 94-96% versus 95%, range 94-98%) (p=0.02) as was the median FRC (25.5ml/kg, range 18.8-39.3 versus 23.5ml/kg, range 17.7-35.2) (p=0.002). There were, however, no significant differences in the compliance or resistance results with regard to position.
Conclusion: Oxygen saturation was significantly better in the prone position in these prematurely born infants being prepared for NICU discharge. Our results suggest that, this may be explained by superior lung volume in the prone position.