An 84 year-old male nursing home resident presents to the ER…
An 84 year-old male nursing home resident presents to the ER with fever and altered mental status. EMS reports he was last seen as “normal” by nursing home staff approximately 5 hours ago. His vitals reveal a heart rate of 120, respiratory rate of 18, BP of 82/50, MAP 54 and temperature of 102.2°F exhibiting altered mental status. Physical exam reveals an ill-appearing man with localized expiratory wheezing heard over the left lower lobe, and chest x-ray confirms a localized area of consolidation with increased interstitial markings in the left lower lobe. Lab results are significant for a white blood cell count of 24,000. Based on this patient’s presentation, he can best be diagnosed with which of the following?