Although UGI endoscopy would demonstrate pyloric obstruction, physicians would find it difficult to differentiate accurately between HPS and pylorospasm. Endoscopic dilatation rarely has been employed as a method of treatment. Surgical repair of HPS is fairly straightforward and without many complications, yet properly preparing the infant for this procedure is vitally important. Most infants with HPS do not have complete gastric outlet and can tolerate their inherent gastric secretions. Repeated episodes of vomiting following attempts to feed the infant cause progressive dehydration and loss of hydrogen chloride from the gastric juices.
Preoperative management is directed at correcting the fluid deficient and electrolyte imbalance.
Base fluid resuscitation on infant's degree of dehydration. Adequate amounts of both chloride and potassium are necessary to correct metabolic acidosis. Unless renal insufficiency is a concern, initially add 2-4 mEq of KCL per 100 cc of IV fluid. Avoid adding hypertonic chloride or ammonium chloride. Urine output and serial electrolyte determinations are performed during resuscitation.