65 year old african american patient is brought to the ER with fever and shortness of breath for last 2 days. He is a chronic smoker for last 25 years and has been occassionally consuming alcohol. He gives history of heroin abuse. On chest auscultation he has diffuse rhonchis and decreased breath sounds at the right base. His BP is 88/30 mm Hg, P 120/min, Oxygen saturation of 86 %, and has a Temperature of 102.5 F. Chest X Ray is suggestive of bilateral lower lobe patches. His saturation continues to drop in the ER. He is appropriately managed with IV antibiotics and mechanical ventilation. On third day of hospitalization in the ICU, he appears to be confused. His ABG is given as PaO2 = 92, PCO2 = 50, HCO3 = 12, and SaO2 94 %. His other investigations are as follows:
Hb 13.8, Hct = 45, TLC 14500, Neutophils 70, Lymphocytes 26, Bands 2, Eosinophils 1, Basophils 1, Glucose = 240 mg%, Na = 121, K = 3.9, Cl = 100, Ca = 9.0, Mg = 2.1. What is the most likely cause of his confusion?
a) Diabetes Mellitus
b) Diabetes Insipidus
c) SIADH
d) Alcohol withdrawal
e) Ventilator associated pneumonia
f) Drug abuse
The patient mentioned above was most likely suffering from CAP. The most common bacterial pathogen for community acquired pneumonia is S.Pneumonia (alpha hemolytic, Capsulated, Gram positive diplococci).
ReplyDeleteHis Cause of confusion is Hyponatremia. For all clinical/ examination purposes, it would be sound to assume any sodium less than 120 to be having a component of SIADH.
SIADH is a casue of euvolemic hyponatremia. The serum osmolality is low, and the urine osmolality is high (>100), Urinary Na >20, Low BUN.
The Clinician should be treating any acute hyponatremia with Fluid restriction, and slow correction of sodium with hypertonic saline. Simultaneously, one should explore the causes for his acute drop in serum sodium levels.