|Respiratory System: 76 y/o man with mental status changes and lethargy|
A 76 year old Caucasian man with a history of chronic obstructive pulmonary disease and smoking (1 pack per day for 40 years) presents in the emergency room with mental status changes and lethargy. The patients son noted that his father had 2 episodes of hemoptysis and had been complaining of pain in his thighs and numbness and tingling of his fingers and toes. Physical examination revealed a lethargic patient with wheezing and absent deep tendon reflexes. Laboratory examination was significant for a serum sodium level of 117 meq/l and increased urine sodium and osmolality. You fluid restrict the patient to treat the hyponatremia and the patients mental status improves. You now note that the patient has proximal muscle weakness, but strength increases over several seconds of sustained contraction.