A 60-year-old man complains of shortness of breath 2 days after a cholecystectomy. He denies fever, chills, sputum production, and pleuritic chest pain. On physical examination, temperature is 37.2°C (99°F), pulse is 75, respiratory rate is 20, and blood pressure is 120/70. There are diminished breath sounds and dullness over the left base. Trachea is shifted to the left side. A chest x-ray shows a retrocardiac opacity that silhouettes the left diaphragm. Which of the following is the most likely anatomical problem in this patient?A) Postoperative pneumonia
Postoperative atelectasis or volume loss is a very common complication of surgery. General anesthesia and surgical manipulation lead to atelectasis by causing diaphragmatic immobilization. Atelectasis is usually basilar. On physical examination, shift of the trachea to the affected side suggests volume loss. On chest x-ray in this patient, loss of the left hemidiaphragm, increased density, and shift of the hilum downward would all suggest left lower lobe collapse. Atelectasis needs to be distinguished from acute consolidation of pneumonia, in which case fever, chills, and purulent sputum are more pronounced and consolidation is present without volume loss. Volume loss would not be a feature of a space-occupying mass, bronchospasm, or pneumothorax. Tension pneumothorax would push the trachea to the opposite side and would usually be associated with unilateral hyperresonance.