Background Cerebral tissue oxygenation can be measured at the bedside non-invasively using near infrared spectroscopy. However normative data are lacking. Preterm infants are at significant risk of intraventricular haemorrhage and periventricular leukomalacia, with subsequent death and long-term neurological morbidities. Preterm infants have impaired cerebrovascular autoregulation, which may be involved in the pathogenesis of IVH and PVL. Near Infrared spectroscopy can be used to assess cerebral blood flow and autoregulation.
Aim (i) To determine a normal reference range for cerebral tissue oxygenation (TOI) using near infrared spectroscopy in premature infants <1500 gm. (ii) To determine changes in TOI with increasing postnatal age and correlate these with short term outcome (death or ultrasound abnormality).
Methods TOI was measured by spatially resolved spectroscopy (NIRO 200 Hamamatsu) in VLBW infants for 2 hours a day for the first 3 days of life. Cranial ultrasounds were performed day 1, day 7, and prior to discharge.
Results 35 patients were enrolled. The median gestation was 28+3 weeks and the median birth weight was 1.12 kg. TOI for day 1 was 71.51%, day 2 was 75%, day 3 was 74.98%. There was a significant increase in TOI values from day 1 to day 2 and day 1 to day 3. Three patients had > grade 3 IVH on day 7.
Conclusions Cerebral TOI increases over the first 3 days of life in VLBW infants, which may reflect increased cerebral blood flow with advancing postnatal age. There was a trend towards lower TOI values in infants with more severe IVH.