A 52-year-old homeless male patient presents via EMS to the ER, having been found unconscious on the street. The patient is responsive to pain, but lethargic and very drowsy. He cannot give an accurate history. 

Vital signs show temperature of 99.5, HR 102 and regular, BP 148/80, R 24, with pulse oximetry 92% on RA. 

The patient is not using accessory respiratory muscles, and breathing appears non-labored. 

On exam, patient’s skin is somewhat dry, and lungs demonstrate some coarse breath sounds throughout. 

During examination, patient has witnessed an episode of non-bloody, non-bilious emesis and is quickly placed onto his left side. 

CXR obtained at the time of presentation demonstrates haziness of the left upper lobe consistent with an acute infiltrate.  Labs demonstrate a WBC of 14,000, Hgb 10.2 with MCV 102, normal platelets, normal chem 7, and a blood alcohol level of 0.15. 

Based on the information provided, what is the most accurate documentation for this patient’s primary diagnosis? Click the best answer.