Kr. Braun et al., Severe pulmonary hemorrhage in the premature newborn infant: Analysis of presurfactant and surfactant eras, BIOL NEONAT, 75(1), 1999, pp. 18-30
We undertook a case-control study of premature infants who developed clinic
ally significant, severe pulmonary hemorrhage (PH) in the presurfactant and
surfactant eras to learn more about the cause of severe PH and whether the
pathogenesis of severe PH has changed with the advent of surfactant therap
y. Severe PH was defined as an acute onset of severe endotracheal bleeding
with an acute drop in hematocrit and the development of multilobar infiltra
tes on chest radiograph. Eleven premature infants from the presurfactant er
a population and 17 premature infants from the surfactant era population me
t the criteria for severe PH, all with gestational ages <32 weeks and birth
weights <1,500 g (very low birth weight infants). These were each matched
by gestational age, date of birth, birth order (for twins), and birth weigh
t to 2 controls. The incidence of severe PH in infants of gestational age <
32 weeks was similar in the two eras (1.8% in the presurfactant era and 3.0
% in the surfactant era). Severe PH was not associated with maternal charac
teristics such as drug use or prenatal care, pregnancy complications, evide
nce of intrauterine anoxia, hyaline membrane disease, frequency of endotrac
heal suctioning, or patent ductus arteriosus. Premature infants suffering f
rom severe PH in the presurfactant era required more delivery room resuscit
ation and had more severe early respiratory disease during the first 12 h o
f life as compared with their controls. However, these differences were not
present in the group from the surfactant era. Infants with severe PH were
more likely to have birth weights below the third percentile for gestation
(severe intrauterine growth restriction). The proportion of infants receivi
ng surfactant, and the number of surfactant doses used, did not differ betw
een severe-PH infants and their controls in the surfactant era group. We co
nclude that severe intrauterine growth restriction represents a risk factor
for severe PH in very low birth weight infants. The introduction of surfac
tant therapy has not altered the incidence of severe PH, even though it has
apparently helped remove the severity of early lung disease as a risk fact
or. The physiological basis of severe PH requires further investigation.