Simple measurements to place umbilical catheters using surface anatomy.

OBJECTIVE: To use external anatomical landmarks to determine a new method for the estimation of appropriate insertion length of umbilical catheters, suitable for newborn infants of varying birth weight (BW) and gestational age. STUDY DESIGN: Neonates who had umbilical venous (UVC) or arterial (UAC) catheters placed soon after birth were included in the study. Catheters were placed using formulas derived by Shukla (1986) and/or Wright (2007), and adjusted to appropriate positions confirmed radiologically: UAC tip between T6-T10 vertebral bodies and UVC at the level of the diaphragm±0.5 cms. Final catheter length was compared with the length estimated by Shukla/Wright formulas and to four additional morphometric measurements: umbilicus to nipple (UN), umbilicus to midpoint of inter-mammary distance, umbilicus to xiphoid process and umbilicus to symphysis pubis (USp). RESULT: Of 216 infants, 32 were excluded; UVC was placed in 170 infants and UAC in 125 infants. Among the morphometric measurements, UN-1 cm ( UN distance minus 1 cm) provided the best estimate of accurate insertion length of UVC, (r=0.984, P<0.001) and estimated correct insertion length of 94% of UVCs compared with 57% accuracy with Shukla formula for all BW categories (P<0.001). Morphometric measurement UN-1+2 USp (UN distance minus 1 cm plus twice the distance from umbilicus to symphysis pubis) showed significantly better correlation with appropriate insertion length of UAC (r=0.985, P<0.001) and estimated correct insertion length of 92% of UACs in all infants as compared with 57% accuracy with Shukla formula (P<0.001), and the correct insertion length in 94% of very low BW infants as compared with 68% accuracy with Wright formula (P<0.001). CONCLUSION: Simple and intuitive morphometric measurements UN and USp provide more accurate estimates of appropriate insertion lengths for umbilical catheters in infants with all BWs than commonly used BW-based formulas.

Weight gain in exclusively breastfed preterm infants.

The weight gain of 355 preterm low birth weight infants, who were exclusively breastfed by their own mothers after discharge from the special care nursery, was analysed prospectively over the first 24 weeks of infancy. Preterm infants with birth weights of 1000-1500 g significantly doubled their birth weight by 10 weeks of age and tripled it by 18 weeks, with a growth velocity of 20-30 g/day up to 20 weeks of age. Preterm infants with birth weights of 1501-2000 g doubled their birth weight by 12 weeks of age and tripled it by 16 weeks, with a growth velocity of 30 g/day up to 11 weeks and 20 g/day after the 12th week. Preterm infants born at 32 weeks gestational age had a period of growth delay up to 3 weeks of age followed by a brisk catch-up phase, whereas infants born at 34 and 36 weeks gestational age had a shorter period of growth delay of 2 weeks followed by a similar catch up phase. The weights attained were comparable to intra-uterine growth rates.