Clinical events in association with timing of intraventricular hemorrhage in preterm infants.

To ascertain whether any routine practices or clinical manipulations in a neonatal intensive care unit could induce intraventricular hemorrhage (IVH) in preterm infants, we performed ultrasonic monitoring of the germinal layer continuously for 48 hours in 33 extremely premature infants with respiratory distress. Intraventricular hemorrhage developed in 16 of these infants. In four infants the timing of the germinal layer hemorrhage was confirmed with ultrasonic monitoring. Three of the four cases were apparently associated with clinical events occurring at the moment of IVH: manual ventilation for improvement of hypercapnia associated with primary pulmonary hypertension of the newborn; correction of hyperkalemia, which was causing an arrhythmia, with administration of calcium gluconate and sodium bicarbonate; and administration of surfactant-TA to improve respiratory failure caused by pulmonary hemorrhage. In these three infants it appeared that one of the basic factors inducing IVH might be an increase in blood pressure with or without hypercapnia, causing cerebral reperfusion after ischemic damage of the germinal layer.