What is the diagnosis and treatment plan for a 62-year-old female with a history of Rheumatoid Arthritis (RA) on chronic prednisone (Prednisone), presenting with severe sepsis secondary to Pneumonia (PNA), hypoxia, and tachycardia, with recent completion of Augmentin (Amoxicillin-Clavulanate) and azithromycin (Azithromycin) for an Upper Respiratory Infection (URI)?

Differential Diagnosis for 62 y.o. Female with Severe Sepsis

Single Most Likely Diagnosis

• Aspiration Pneumonia: The patient's presentation with shortness of breath, wheezing, cough, and hypoxia, along with bronchoscopy findings consistent with aspiration pneumonia, makes this the most likely diagnosis. The recent history of a productive cough with thin yellow sputum and the presence of multifocal hazy opacities on CXR and CT scans further support this diagnosis.

Other Likely Diagnoses

• Community-Acquired Pneumonia (CAP): The patient's symptoms, such as cough, shortness of breath, and fever, are consistent with CAP. The presence of Strep pneumoniae in blood cultures also supports this diagnosis.
• Sepsis due to RA Medications: The patient's immunosuppressed state due to chronic prednisone and multiple biologic agents increases her risk for infections, including pneumonia.
• Influenza or other Viral Pneumonia: Although the patient was treated for a URI in March, the possibility of a viral pneumonia cannot be ruled out, especially given her immunosuppressed state.

Do Not Miss Diagnoses

• Invasive Fungal Infection: The patient's immunosuppressed state and recent antibiotic use increase her risk for invasive fungal infections, such as aspergillosis or candidiasis.
• Pneumocystis jirovecii Pneumonia (PCP): Although the patient is not HIV-positive, her immunosuppressed state due to RA medications increases her risk for PCP.
• Tuberculosis (TB): The patient's symptoms, such as cough and shortness of breath, could be consistent with TB, especially given her immunosuppressed state.

Rare Diagnoses

• Cytomegalovirus (CMV) Pneumonia: The patient's immunosuppressed state increases her risk for CMV reactivation, which can cause pneumonia.
• Legionnaires' Disease: Although the patient has no recent travel history, the possibility of Legionnaires' disease cannot be ruled out, especially given her immunosuppressed state.
• Q Fever: The patient's exposure to animals (her dog) and her immunosuppressed state increase her risk for Q fever, which can cause pneumonia.