biochemical disturbances

Last reviewed 01/2018

Biochemical disturbances in adult pyloric stenosis may be summarised as follows:

  • the patient is dehydrated and the haematocrit level is raised
  • the urine is scanty, concentrated, initially alkaline, but later acid; its chloride content is reduced or absent
  • serum chloride is lowered because of the vomitus losses
  • serum sodium and potassium are lowered as a result of the kidney exchanging sodium ions and some potassium ions for hydrogen ions lost in the vomitus
  • the plasma bicarbonate is raised
  • the urea level is raised because of dehydration
  • the result of all these changes is the development of a hypochloraemic alkalosis