A 58-year-old woman comes to the emergency department due to cramping mid-abdominal pain. Imaging shows a small bowel obstruction. Vital signs and laboratory studies, including complete blood count and comprehensive metabolic panel, are within normal limits. The patient is admitted to the hospital for nonsurgical management. Oral intake is withheld to promote bowel rest, and an isotonic saline infusion is administered for hydration. She has no vomiting or diarrhea and after 2 days the abdominal pain improves. Total administration of sodium chloride infusion was approximately 6 L. Which of the following changes have most likely occurred in this patient since the onset of her hospitalization?

Question

A 58-year-old woman comes to the emergency department due to cramping mid-abdominal pain.  Imaging shows a small bowel obstruction.  Vital signs and laboratory studies, including complete blood count and comprehensive metabolic panel, are within normal limits.  The patient is admitted to the hospital for nonsurgical management.  Oral intake is withheld to promote bowel rest, and an isotonic saline infusion is administered for hydration.  She has no vomiting or diarrhea and after 2 days the abdominal pain improves.  Total administration of sodium chloride infusion was approximately 6 L.  Which of the following changes have most likely occurred in this patient since the onset of her hospitalization?

Quizplus · Accepted Answer

Eductional Objective: The infusion of excessive normal saline (sodium chloride) is a common cause of nonanion gap metabolic acidosis. The excess intravascular chloride (Cl-) causes intracellular shifting of bicarbonate (HCO₃-), reducing serum HCO₃- and decreasing blood pH.

A 58-Year-Old Woman Comes to the Emergency Department Due to Cramping