How safe is intermittent positive pressure ventilation in preterm babies ventilated from delivery to newborn intensive care unit?

OBJECTIVES: To examine whether clinically determined ventilator settings will produce acceptable arterial blood gas values on arrival, in preterm infants ventilated from delivery to the newborn intensive care unit (NICU). Further, to examine the usefulness of tidal volume and minute ventilation measurements at this time. DESIGN: A prospective observational cohort study in a tertiary level 3 NICU. PATIENTS: Twenty six preterm infants requiring intubation and mechanical ventilation at the point of delivery to the NICU. SETTING: Infants who required mechanical ventilation were monitored with a blinded Ventrak 1550 dynamic lung function monitor from the point of delivery to the NICU. A Dräger Babylog 2000 transport ventilator was set up to achieve adequate chest wall movement, and FIO(2) was adjusted to achieve preductal SaO(2) of 90-98%. Dynamic lung function monitoring data were recorded and related to the arterial blood gas taken on arrival. RESULTS: Mean gestation was 28 weeks (range 23-34) and mean birth weight was 1180 g (range 480-4200). A quarter (26% (95% confidence interval (CI) 12% to 48%)) were hypocarbic, with 20% (95% CI 7% to 39%) below 25 mm Hg, and 38% (95% CI 20% to 60%) had hyperoxia. Some (20% (95% CI 7% to 39%)) were both hypocarbic and hyperoxic. Total minute ventilation per kilogram correlated significantly with the inverse of PaCO(2) (p < 0.001). CONCLUSIONS: Clinically determining appropriate mechanical ventilation settings from the point of delivery to the NICU is difficult, and inadvertent overventilation may be common. Severe hyperoxia can occur in spite of adjustment of the FIO(2) concentration to achieve an SaO(2) range of 90-98%. Limiting minute ventilation during resuscitation may prevent hypocarbia.

Noninvasive investigation of infantile hepatic hemangioma: a case study.

A preterm infant presented with high-output cardiac failure. Color Doppler imaging of the liver revealed a large hepatic hemangioma. Pulsed-wave Doppler of the proximal aorta was used to monitor noninvasively the reduction in flow through the arteriovenous malformation in response to steroid therapy. The hemangioma resolved completely by 7 weeks of age.

A 12-year experience of retinopathy of prematurity in infants less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight.

This study reported the prevalence and severity of retinopathy of prematurity (ROP) in less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight infants over a 12-year period. Among 328 survivors of less than or equal to 28 weeks gestation, 30% had ROP, 12% had severe ROP of Stage 3 or worse, 5% had at least one blind eye and 3% were bilaterally blind. Among 201 survivors of less than or equal to 1000 g birthweight, the above abnormalities were found in 40, 16, 6 and 4% respectively. In both cohorts there was a significant increase in the prevalence of ROP and severe ROP between the period 1977-80 and 1981-84, but the lesser increase observed between the periods 1981-84 and 1985-88 was not statistically significant. The rates of ROP-induced blindness were not significantly different between the three 4-year periods. An inverse relationship was noted between the prevalence of ROP and gestational age. The results suggest a resurgence of ROP in less than or equal to 28 weeks or less than or equal to 1000 g infants, the cause of which is uncertain. In view of this trend, continued surveillance of ROP is warranted.

Perinatal factors and adverse outcome in extremely low birthweight infants.

Perinatal factors associated with death or disability at 2 years were identified in an inborn cohort of 196 live births with a birth weight of 500-999 g. Antepartum haemorrhage, multiple pregnancy, breech presentation, perinatal asphyxia, hypothermia on admission, hyaline membrane disease, persistent pulmonary hypertension, severe respiratory failure, and intraventricular haemorrhage were associated with increased mortality. Factors associated with increased survival included maternal hypertension, caesarean birth, increasing maturity or size at birth, female sex, and fetal growth retardation. Stepwise multiple discriminant function analysis showed that six factors correctly classified the outcome in 83% of infants: intraventricular haemorrhage was the most important factor followed by the presence of acidosis and hypoxia in the early neonatal period, birth weight, pre-eclamptic toxaemia, and caesarean birth. This study also showed that intraventricular haemorrhage, seizures, antepartum haemorrhage and delay in regaining birth weight were associated with increased disability among survivors.