A comparison of heparinized whole blood with plasma osmolality measurements was performed on 100 sick newborns using a vapor pressure osometer. Aliquots of blood samples which had been collected into 1-ml syringes containing sodium heparin for blood gas analyses were used for osmolality determinations. There was excellent correlation between the two methods (r=0.993). A total of 85 samples agreed within 2.0 units. In 38 samples the results obtained by the two methods were identical. The maximum observed discrepancy, present in only 2 samples, was 4 mosmol. Thus, the measurement of whole blood or plasma osmolality provides comparable information. The simplicity, the small volume of the blood sample required and the rapidity of the method make the determination of whole blood osmolality particularly useful in newborns requiring intensive care.
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Oh W (1976) Disorders of fluid and electrolytes in newborn infants. Pediatr Clin North Am 23: 601–609
Bevan DR (1978) Osmometry. 1. Terminology and principles of measurement. Anaesthesia 33: 794–800
Boyd DR, Baker RS (1971) Osmometry: a new bedside aid for the management of surgical patients. Surg Clin North Am 51: 241–250
Weisberg HF (1974) Clinical diagnosis by laboratory methods (Todd and Sanford), 15th edn. Saunders, Philadelphia, pp 782–785
McSwiney RR (1978) Osmosis and osmometry. In: Williams DL, Nunn RF, Marks V (eds) Scientific foundations of clinical biochemistry, vol. 1. Heinemann, London, pp 388–395
Maffly RH (1981) The body fluids: volume composition, and physical chemistry. In: Brenner BM, Rector FC Jr (eds) The kidney, vol. 1, 2nd edn. Saunders, Philadelphia, pp 76–115
Norman ME, Assadi FK (1979) A prospective study of acute renal failure in the newborn infant. Pediatrics 63: 475–479
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Assadi, F.K. Validity of whole blood osmolality measurement in sick neonates. Pediatr Nephrol 2, 27–28 (1988). https://doi.org/10.1007/BF00870375
- Whole blood osmolality
- Plasma osmolality