Which of the following statements are true regarding the premature neonate?

A. A 15% to 20% right-to-left shunt occurs across the foramen ovale and patent ductus arteriosus

C. Fluid requirements are higher than in a full-term baby.

E. They are more at risk for infection than the full-term infant.

DISCUSSION: The newborn infant has a relatively elevated pulmonary artery pressure and shunts a significant amount of unoxygenated blood through the foramen ovale and patent ductus arteriosus. The normal PaO 2 below the ductus, as measured through an umbilical artery catheter, would be between 60 and 80 mm. Hg. Surfactant levels do not approach normal until after the 34th week of gestation, when enzyme levels in the surfactant pathway mature. Amniocentesis is performed to measure the lethicin-to-sphingomyelin ratio (L:S ratio) and determine whether maturation has occurred. Fluid requirements in the premature infant are between 140 and 150 ml. per kg. per day in comparison with those of the normal neonate in whom 80 ml. per kg. per day would be adequate. Increased insensible losses and the need for overhead warmers play a role in this increase. Axillary or skin probe temperature monitoring is more accurate than the rectal temperature in the neonate. The rectal temperature is not a good indicator of core body temperature until approximately 18 months of age. Premature infants lack immunoglobulin A (IgA) and have low levels of IgM, the C3b component of complement, and decreased opsonins. In addition, the leukocytes have reduced phagocytic ability, creating an increased risk of infection. Escherichia coli and beta-hemolytic streptococcus are the two most common infectious agents affecting the neonate.