A 78-year-old male is on a stroke rehabilitation ward, ten days following an ischemic stroke that resulted in dense right-sided hemiplegia. His past medical history is significant for hypertension and benign prostatic hyperplasia. He suddenly develops acute shortness of breath, pleuritic chest pain on his right side, and anxiety. On examination, he is tachypneic with a respiratory rate of 28 breaths/min and tachycardic with a heart rate of 115 bpm. His blood pressure is 110/70 mmHg, and his oxygen saturation is 89% on room air. Lung auscultation reveals decreased breath sounds at the right base. His right calf is mildly swollen and tender to palpation compared to the left. What is the most likely diagnosis?

A 68-year-old male, four days after a total hip replacement, develops sudden-onset shortness of breath and left-sided pleuritic chest pain. His heart rate is 110 bpm, respiratory rate is 24 breaths/min, and oxygen saturation is 92% on room air. A pleural friction rub is noted on auscultation. His chest X-ray is unremarkable. Based on the high clinical suspicion for pulmonary embolism, the emergency department physician initiates supplemental oxygen. Which of the following is the most appropriate next step to confirm the suspected diagnosis?

A 22-year-old tall, thin male presents to the emergency department with a 3-hour history of sudden-onset, sharp, right-sided chest pain that worsens with deep inspiration. He has no significant past medical history but reports smoking 10 cigarettes per day for the last 4 years. On examination, he is in mild respiratory distress with a respiratory rate of 24 breaths/minute and an oxygen saturation of 95% on room air. His trachea is midline. Auscultation reveals markedly diminished air entry on the right side, and percussion of the right hemithorax elicits hyperresonance. Which of the following is the most likely diagnosis?

A 64-year-old man, who worked as an underground coal miner for 30 years, presents to the clinic with a two-year history of progressively worsening dyspnea on exertion and a chronic, non-productive cough. He also reports an unintentional weight loss of 6 kg over the past year. He has a 10-pack-year smoking history but quit 15 years ago. On examination, his oxygen saturation is 94% on room air, and fine bibasilar crackles are heard. Pulmonary Function Tests (PFTs) show a Forced Vital Capacity (FVC) of 65% predicted, a Forced Expiratory Volume in 1 second (FEV1) of 70% predicted, and an FEV1/FVC ratio of 88%. A chest X-ray reveals diffuse, small, rounded opacities, most prominent in the upper lung zones, along with hilar lymph node calcification described as "eggshell" calcification. What is the most likely diagnosis?

A 34-year-old obese male (BMI 36 kg/m ²) is evaluated for chronic fatigue and unrefreshing sleep. His wife reports loud, disruptive snoring and has recently noticed that he frequently stops breathing for several seconds at night. He has a high score on the Epworth Sleepiness Scale, indicating significant daytime somnolence. His past medical history is significant for hypertension. A diagnosis of Obstructive Sleep Apnea is strongly suspected. What is the most appropriate next step to confirm the diagnosis?

A 28-year-old male presents to the primary care clinic with a six-month history of persistent fatigue and excessive daytime sleepiness. He states, "No matter how much I sleep, I wake up feeling like I haven't slept at all." His wife is concerned because she has witnessed him gasping for air and making choking noises during sleep, followed by loud snoring. He has a BMI of 34 kg/m ² and a neck circumference of 44 cm. His blood pressure is 145/90 mmHg. The remainder of his physical examination is unremarkable. What is the most likely diagnosis?

A 68-year-old female with a significant smoking history was recently diagnosed with squamous cell carcinoma of the lung after a biopsy of a 5 cm mass in her left lower lobe seen on CT scan. While awaiting her oncology follow-up appointment for staging, she presents to the emergency department with a new-onset, severe headache that has been worsening over the past week. This morning, she developed difficulty with coordination in her right hand and a slight facial droop on the right side. What is the most appropriate immediate diagnostic investigation for this patient?

A 22-year-old male, a known case of bronchial asthma, is brought to the emergency department with a 2-hour history of worsening shortness of breath and audible wheezing. He has been using his salbutamol inhaler every 30 minutes at home with minimal relief. On examination, he is sitting upright, leaning forward, and appears distressed. His vital signs are: heart rate 125 bpm, respiratory rate 32 breaths/min, blood pressure 130/80 mmHg, and SpO2 91% on room air. Widespread, loud expiratory wheezes are heard throughout both lung fields. Which of the following additional findings would be the strongest indication for immediate hospital admission?

A 24-year-old male, a known asthmatic for the past 5 years, presents to the primary care clinic for a follow-up. He reports that his symptoms have been worsening over the last three months. He uses his salbutamol (albuterol) inhaler 3-4 times per week for daytime wheezing and chest tightness. More concerning to him is that he has been waking up from sleep due to coughing and shortness of breath approximately twice a week, for which he also uses his salbutamol inhaler for relief. He has no other medical conditions and does not smoke. On examination, his respiratory rate is 16 breaths/minute, and oxygen saturation is 98% on room air. Auscultation reveals mild, diffuse expiratory wheezes. According to traditional asthma severity classifications, which of the following is the most accurate classification for this patient's condition before initiating controller therapy?