Case Discussion: Empyema and Hyponatremia, Medscape MedStudents

[Dennis]

This case offers an opportunity for you to work through the diagnostic process, determining what tests to order and which questions to ask.

A 47-Year-Old Man With Empyema and Hyponatremia
Posted on Medscape Medstudents by Robert M. Centor, MD, Professor, Department of Medicine, University of Alabama

Case Summary
A 47-year-old man presents with empyema, weakness, and low serum sodium.

History and Physical Information
The patient presents to the hospital complaining of progressive dyspnea of 10 days' duration. He has lower-extremity swelling. He reports that right-sided pleuritic chest pain started a few days prior to admission (which he blames on the fact that he chopped down a tree in his yard). He complains of a chronic cough.

His wife states that "he has not been himself" for the last month. He has had problems with weakness and difficulty walking. He has developed a productive cough, but denies fever, night sweats, or chills.

Prior Medical History
Unremarkable.

Current Medications
Aspirin.

Social History
45 pack-years of cigarettes, 1 to 2 cases of beer each week, no IV drug use, no HIV risk factors.

Review of Systems
Otherwise noncontributory.

Physical Exam
Vital Signs. Temperature 98º F, pulse 96, blood pressure 160/70, respirations 20.

General. No acute distress, appears older than stated age.

Head, Eyes, Ears, Nose, and Throat. Normal, anicteric.

Neck. Supple, no thyromegaly.

Heart. S1, S2 normal; no murmurs, rubs, or gallops.

Lungs. Decreased breath sounds in right thorax, dull to percussion 2/3 of right chest, positive egophony, left-sided crackles at the base.

Abdomen. Good bowel sounds, no masses or organomegaly.

Extremities. 2+ peripheral edema to mid-shin.

Neurologic. 3/5 proximal muscle weakness, sensation intact, deep tendon reflexes sluggish.

Laboratory Data on Admission
Complete Blood Count. H/H 11.6/34; white blood cell count 18,700, 38s/54b/4l; platelets 539,000.

Electrolyte Panel
Sodium 116
Potassium 4.1
Chloride 81
Bicarbonate 26
BUN 10
Creatinine 0.6
Glucose 92

Chest X-Ray. Large, right-sided effusion.

Thoracentesis. Cloudy, foul-smelling fluid.

Pleural Fluid Analysis. 116 nucleated cells, 60 red blood cells; total protein 500; pH 6.59.

The Problem
How do you evaluate his low serum sodium?
What are the likely causes of hyponatremia in this man?

[Dennis]

Solution to "A 47-Year-Old Man With Empyema and Hyponatremia"
Robert M. Centor, MD

[shafeedmarakar]

Da ,dennis .what about SIADH,I THNK empyema can cause SIADH, another dd.legeonella-rare possibility.machus come on.

[Dennis]

Yes, thats true Empyema can cause SIADH and should be the first thing that comes to mind.

But there is a problem - as far as i know, SIADH by definition CANNOT have peripheral edema. In the case of this patient, there is 2+ peripheral edema.

Check the following links:

Specific diagnostic criteria that define SIADH include the following:
Clinical euvolemia
Normal renal, adrenal, and thyroid function Source: eMedicine

SIADH - Definition: AVP excess associated with hyponatremia without edema or hypovolemia.
Source: UCLA Endocrinology

I'm not very sure about legionella.