Our interest in the effect of the knee-chest position on sick neonates was stimulated by two clinical observations. First, babies are routinely positioned with the knees flexed to the chest for lumbar puncture, and sick babies frequently do not tolerate the procedure well. Second, we had observed that knee-chest positioning was often associated with an increase in blood pressure (BP). To further define the effects of the knee-chest position, we studied continuous transcutaneous oxygen tension (tcPo2) and mean BP responses associated with this position in a group of sick neonates.
Patients and Methods.—Fourteen sick babies, ranging in birth weight from 900 to 2,900 g each (mean, 1,949 g) and in gestational age from 25 to 44 weeks (mean, 33.4 weeks), were studied at 1 to 14 days of age (mean, 2.8 days) (Table). All patients had either umbilical, radial, or posterior tibial artery catheters in place.