A 72-year-old woman is found to be severely short of breath at her skilled nursing facility. The patient was recently hospitalized for vertebral osteomyelitis and discharged 2 weeks ago to complete a 6-week course of piperacillin-tazobactam via a peripherally inserted central venous catheter. Her dyspnea began only with exertion but is now also present at rest. Medical history includes coronary artery disease with ischemic cardiomyopathy, chronic obstructive pulmonary disease, and chronic kidney disease. She has had 2 hospitalizations for heart failure over the last year; noninvasive positive-pressure ventilation was required. Paramedics observe the patient to be obtunded with agonal respirations and rales throughout the bilateral lung fields. Oxygen saturation is 72% on room air. She is intubated and transferred to the emergency department. On arrival, the patient is minimally responsive to stimuli. Temperature is 36.7 C (98 F) , blood pressure is 115/65 mm Hg, and pulse is 110/min and regular. The patient's oxygen saturation is 88% on 100% inspired oxygen. BMI is 19 kg/m². The trachea is midline. On physical examination, rales are heard on the right side and markedly decreased breath sounds on the left side of the chest. S3 is heard. There is 2+ bilateral peripheral edema. A chest x-ray reveals the following: After the intervention is performed, the patient's oxygenation improves. She is transferred to the medical intensive care unit and treated with diuretics and bronchodilators. Two days later, her ventilation requirements have improved to 50% inspired oxygen and 5 cm of positive end-expiratory pressure. The patient's respirations suddenly become dys-synchronous with the ventilator, and her oxygen saturation drops to 85%. Tidal volume spontaneously decreases from 350 to 200 mL. Temperature is 37.2 C (99 F) , blood pressure is 125/60 mm Hg, pulse is 110/min, and respirations are 25/min. Physical examination shows that the trachea is midline and the endotracheal tube is in place. No jugular venous distension is present. Breath sounds are markedly decreased on the right side. A portable chest x-ray reveals the following:
Which of the following is the best next step in management of this patient?

Question

A 72-year-old woman is found to be severely short of breath at her skilled nursing facility. The patient was recently hospitalized for vertebral osteomyelitis and discharged 2 weeks ago to complete a 6-week course of piperacillin-tazobactam via a peripherally inserted central venous catheter. Her dyspnea began only with exertion but is now also present at rest. Medical history includes coronary artery disease with ischemic cardiomyopathy, chronic obstructive pulmonary disease, and chronic kidney disease. She has had 2 hospitalizations for heart failure over the last year; noninvasive positive-pressure ventilation was required. Paramedics observe the patient to be obtunded with agonal respirations and rales throughout the bilateral lung fields. Oxygen saturation is 72% on room air. She is intubated and transferred to the emergency department. On arrival, the patient is minimally responsive to stimuli. Temperature is 36.7 C (98 F) , blood pressure is 115/65 mm Hg, and pulse is 110/min and regular. The patient's oxygen saturation is 88% on 100% inspired oxygen. BMI is 19 kg/m². The trachea is midline. On physical examination, rales are heard on the right side and markedly decreased breath sounds on the left side of the chest. S3 is heard. There is 2+ bilateral peripheral edema. A chest x-ray reveals the following:

After the intervention is performed, the patient's oxygenation improves. She is transferred to the medical intensive care unit and treated with diuretics and bronchodilators. Two days later, her ventilation requirements have improved to 50% inspired oxygen and 5 cm of positive end-expiratory pressure. The patient's respirations suddenly become dys-synchronous with the ventilator, and her oxygen saturation drops to 85%. Tidal volume spontaneously decreases from 350 to 200 mL. Temperature is 37.2 C (99 F) , blood pressure is 125/60 mm Hg, pulse is 110/min, and respirations are 25/min. Physical examination shows that the trachea is midline and the endotracheal tube is in place. No jugular venous distension is present. Breath sounds are markedly decreased on the right side. A portable chest x-ray reveals the following:

Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: Positive-pressure ventilation allows for improved oxygenation in patients with an alveolar-filling process (eg, pulmonary edema, pneumonia); however, it also poses the risk of pulmonary barotrauma, leading to alveolar rupture and subsequent air leakage into undesired parts of the body (eg, subcutaneous tissue, mediastinum, pleural space). This patient has developed a potentially serious complication of pulmonary barotrauma, a large pneumothorax. A large pneumothorax can quickly lead to tension physiology, resulting in compression of mediastinal structures and marked hypotension; however, the normal blood pressure and absence of jugular venous distension and tracheal deviation in this patient suggest that a tension pneumothorax has not yet developed. Patients with a large pneumothorax often demonstrate tachycardia, tachypnea, hypoxemia, and decreased or absent breath sounds on the affected side. In patients on mechanical ventilation, measured tidal volume markedly decreases due to an increase in airway resistance. Bedside ultrasound has become the diagnostic test of choice for pneumothorax in the critical care setting, but if performed, chest x-ray demonstrates a pleural line with an absence of distal lung markings. Management involves placement of a chest tube, which allows for definitive management of the pneumothorax with suction. chest x-ray (Choice A) Decreasing sedation is appropriate when attempting to wean a patient off the ventilator but is not appropriate in this patient. Sedation typically allows for optimal respiratory synchrony with the ventilator; decreasing sedation in a hypoxemic patient who is intubated and mechanically ventilated typically results in worsening hypoxemia. (Choice B) Temporarily disconnecting the ventilator and providing bag ventilation with long expiration time is the appropriate treatment for auto-positive end-expiratory pressure (auto-PEEP), a condition caused by insufficient duration of the expiratory phase resulting in accumulated air pressure in the lungs. However, large pneumothorax requires decompression of the pleural space (eg, chest tube). (Choice C) Increasing the PEEP is likely to cause further barotrauma and increased air pressure in the pleural space, resulting in worsening of the pneumothorax. (Choice D) Needle decompression is appropriate emergency treatment of a tension pneumothorax in a patient in whom cardiac arrest is imminent. However, needle decompression must always be followed by chest tube placement for definitive management; therefore, placement of a chest tube is more appropriate in this patient who has not yet developed tension physiology. Educational objective: Pulmonary barotrauma is a risk of mechanical ventilation and can lead to pneumothorax. Placement of a chest tube is the preferred initial treatment of a large pneumothorax in a patient who has not developed tension physiology. References: Pneumothorax: an update. (http://www.ncbi.nlm.nih.gov/pubmed/17621614)

A 72-Year-Old Woman Is Found to Be Severely Short of Breath