The assessment of dehydration in congenital pyloric stenosis.

In a retrospective review of the records of 88 infants who underwent a Ramstedt pyloromyotomy for pyloric stenosis, biochemical and clinical measures were used to determine the most useful guide to the degree of dehydration on admission. The only measure which correlated to the dehydration was the clinical assessment (r = 0.62). Apart from indicating the presence of alkalosis and hypochloraemia, serum chloride and serum bicarbonate levels were not useful measures. While clinical measures show only a degree of linear correlation with dehydration, they do present the most useful baseline to judge fluid requirements. Biochemistry is needed to measure the electrolyte and acid base imbalance found in the condition.