Survival of low birthweight infants in central Queensland.

The survival of low birthweight infants < or = 2000 g born in the central Queensland area during the years 1979 to 1991 was examined. Five hundred and sixty such infants were either delivered at one of the two Rockhampton obstetric units (Rockhampton Base Hospital and the Mater Misericordiae Hospital) or retrieved from outlying central Queensland areas. Both hospitals had intensive care nurseries capable of ventilation and infants were transferred to tertiary centres only for cardiac or surgical treatment. The study involved all liveborn infants, including those with lethal malformations and all deaths up to the time of discharge. Survival rates were as follows: < or = 500 g 0%, 501 < or = 750 g 30%, 751 < or = 1000 g 51%, 1001 < or = 1500 g 79%, 1501 < or = 2000 g 93%. The survival of Aboriginal infants and outborn infants were found to be essentially the same as the overall group.

Abnormalities of surfactant in children with recurrent cyanotic episodes.

The mechanism of recurrent cyanotic episodes in infants and children is not known, but a deficiency of surfactant is a possible cause. We have measured the amount of surfactant collected by bronchoalveolar lavage from two children with recurrent cyanotic episodes and from two controls with anatomical airway obstructions. We also assessed the physical properties of the surfactant by changing the surface area (A) of a monolayer and measuring its surface tension (gamma). The cases had lower amounts of surfactant extracted, which could explain some of the abnormalities of the gamma/A loops. However, the finding that the cases had reversed loops (ie, the surface tension is higher during monolayer compression than during expansion) shows that there is also a qualitative abnormality. These features suggest a possible diagnostic test if not a mechanism for this disorder.