Influence of age, sex, duration of symptoms and dehydration of serum electrolytes in hypertrophic pyloric stenosis.

A review was conducted of 234 consecutive patients with hypertrophic pyloric stenosis (HPS) proven at operation. The relationship of age, sex, the duration of symptoms and the clinical degree of dehydration to the severity of metabolic derangement as reflected by alterations in serum electrolytes and acid-base status, was analysed statistically. The length of history and the degree of dehydration was found to have predictive value in identifying those likely to have major metabolic disturbances. Where severe vomiting has persisted for more than 1 week, major derangements of the biochemical parameters should be anticipated; and where clinical assessment of dehydration is estimated as being greater than 5%, there is almost always some major biochemical abnormality present. Nevertheless, variation in individual cases necessitates that all patients with suspected HPS should have serum electrolytes and acid-base estimations performed.