A 58-Year-Old Disoriented, Schizophrenic Man

Robert M. Centor, MD


July 05, 2006

This series of cases offers an opportunity for you to work through the diagnostic process, determining what tests to order and which questions to ask. A discussion link is provided below to facilitate that process.

Case Summary

A 58-year-old schizophrenic man was brought to the hospital because of strange behavior. He was disoriented and provided no history.

On the basis of the lab results presented here, your task is to identify the acid-base disturbance and postulate a coherent cause for it.

Metabolic profile:

Sodium 139 mEg/L

Potassium 4.7 mEq/L

Chloride 90 mEq/L

Bicarbonate 14 mEq/L

Blood urea nitrogen 18 mg/dL

Creatinine 1.0 mg/dL

Glucose 100 mg/dL

Arterial blood gas:

pH 7.49

pCO2 15

pO2 169 (2 L nasal O2)

HCO3 (calculated) 11

The Problem

What is the acid-base disturbance?

What is a reasonable cause of the disturbance?


Feel free to discuss this case with others. You can monitor or join in the Medscape discussion at http://www.medscape.com/px/discussions/29d55c17.