You are a doctor on call and are asked to attend a 66-year-old woman who has become acutely short of breath. Seven days ago, she underwent hemiarthroplasty for a fractured femur and her recovery has been slow. When you attend to her, you note that the patient has already received an oxygen mask and feels comfortable. But she still complains of chest pain on deep inspiration and finds it difficult to talk in complete sentences. She has no cardiovascular disease but is overweight. Examination Respiratory rate: 35 breaths/min.; BP: 100/80 mmHg; Pulse rate: 120 bpm.
Oxygen saturation: 35% She is afebrile. Abdominal examination is unremarkable. Complete blood (hemoglobin, platelets, WBCs), electrolytes (Sodium, Potassium), Urea, creatinine, and pH are within normal range. Partial pressure of CO2 (pCO2): 3.8 kPa (Normal range: 4.7-5.9 kPa). Partial pressure of O2 (pO2): 6.6 kPa (Normal range:…
