system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 65-year-old man is brought to the emergency department because of a 3-day history of increasing shortness of breath and chest pain. He has had a productive cough with foul-smelling sputum for 1 week. He has gastritis as well as advanced Parkinson disease and currently lives in an assisted-living community. He smoked one pack of cigarettes daily for 40 years but quit 5 years ago. He has a 30-year history of alcohol abuse but has not consumed any alcohol in the past 5 years. His temperature is 39.3°C (102.7°F), he is tachycardic and tachypneic and his oxygen saturation is 77% on room air. Auscultation of the lung shows rales and decreased breath sounds over the right upper lung field. Examination shows a resting tremor. Laboratory studies show:
Hematocrit 38%
Leukocyte count 17,000/mm3
Platelet count 210,000/mm3
Lactic acid 4.1 mmol/L (N=0.5–1.5)
A x-ray of the chest shows infiltrates in the right upper lobe. Which of the following is the most significant predisposing factor for this patient's respiratory symptoms?"
assistant
Parkinson disease
"