Blood Chemistry of Normal Full-term Infants in the First 48 Hours of Life.

The subjects of the study were normal infants born in hospital of healthy mothers by normal delivery. The cord was clamped at once after birth. In a subsequent paper the effects of various abnormalities of birth are examined. Sodium and potassium were estimated by flame photometer in a dilution of 10 micro litres (,lI.) in 5 ml. water; chloride by iodometric titration using silver iodate; calcium by adapting Wilkinson's EDTA titration method (1957) for 201l. serum; totalprotein by biuret using Natelson's (1957) technique; urea by a urease method modified from Archer and Robb (1925); sugar by a modification of Nelson-Somogy's (Natelson) using 10 V..; inorganic phosphorus by an adaptation of Natelson's method; and lactic acid by adapting Barker and Summerson's (1941) method using 10 ,ul. serum. Haematocrit was estimated by using thin even bore heparinized capillary tubes. Cell potassium was estimated by taking 10 V.I. whole freshly mixed blood in 5 ml. water, centrifuging, and estimating in the flame photometer. The blood was taken from a heel using the technique described by Wilkinson (1960), but first covering the skin with sterile petroleum jelly and collecting in plastic tubing with a sealed end and a diagonally cut top containing 10 pul. of a heparin solution. Blood for sugar, phosphorus, and lactic acid was collected separately in a small tube containing fluoride and oxalate. A total of about 1 ml. was collected at 1, 2, 3 ,5, 7, 9, 11, 19, 24, 36, and 48 hours after birth. Cord blood was collected at birth from the umbilical vein. All estimations were performed in duplicate. The results are shown in detail in a Ph.D. thesis by one of us (P.T.A.) accepted by the University of London (1962) and are here summarized. Standard deviations have been calculated on the unjustified assumption of a normal distribution in all cases. Results