A 64-year-old man is evaluated in the hospital 24 hours after sustaining a pelvic fracture in a motor vehicle collision. Medical history includes chronic obstructive pulmonary disease. The patient has been receiving pain medications, blood transfusion, and prophylactic heparin. For the past 2 hours, he reports increasing shortness of breath. Temperature is 36.9 C (98.4 F), blood pressure is 130/74 mm Hg, pulse is 112/min, and respirations are 24/min. Oxygen saturation is 87% on room air; it increases to 95% with 3 L oxygen. The patient is mildly disoriented. Pupils are small bilaterally. Lung sounds are clear bilaterally, and heart sounds are regular and without murmur or gallop. The abdomen is soft and nontender. The patient can move all 4 extremities, which are warm and pink. Petechiae are noted on the anterior chest and axillary areas. Chest x-ray is unremarkable. ECG shows sinus tachycardia but is otherwise normal. Laboratory results, including arterial blood gas analysis on room air, are as follows: What is the best next step in management?

Question

A 64-year-old man is evaluated in the hospital 24 hours after sustaining a pelvic fracture in a motor vehicle collision.  Medical history includes chronic obstructive pulmonary disease.  The patient has been receiving pain medications, blood transfusion, and prophylactic heparin.  For the past 2 hours, he reports increasing shortness of breath.  Temperature is 36.9 C (98.4 F), blood pressure is 130/74 mm Hg, pulse is 112/min, and respirations are 24/min.  Oxygen saturation is 87% on room air; it increases to 95% with 3 L oxygen.  The patient is mildly disoriented.  Pupils are small bilaterally.  Lung sounds are clear bilaterally, and heart sounds are regular and without murmur or gallop.  The abdomen is soft and nontender.  The patient can move all 4 extremities, which are warm and pink.  Petechiae are noted on the anterior chest and axillary areas.  Chest x-ray is unremarkable.  ECG shows sinus tachycardia but is otherwise normal.  Laboratory results, including arterial blood gas analysis on room air, are as follows:  What is the best next step in management?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d211_51ac_bc81_c7d7b274fca4_MD0003_00 This patient has worsening respiratory status (eg, dyspnea, tachypnea leading to acute respiratory alkalosis, hypoxemia), neurologic dysfunction (eg, disorientation), and a petechial rash 24 hours after sustaining a pelvic fracture. This presentation is most concerning for fat embolism syndrome (FES), in which fracture of a bone (eg, pelvis, femur) containing abundant marrow releases fat and hematopoietic cells into the venous circulation. FES can result in the following: Microvascular occlusion in the pulmonary capillaries, resulting in respiratory distress Microvascular occlusion in the systemic circulation (eg, brain, dermal capillaries), resulting in neurologic dysfunction and, in up to half of cases, a petechial rash Degradation of embolized fat into proinflammatory intermediaries, resulting in a systemic inflammatory response (eg, tachycardia, leukocytosis) Nonspecific findings (eg, anemia, thrombocytopenia, lipiduria) may or may not be present. FES is a clinical diagnosis, and management is supportive. Supplemental oxygen is given to correct hypoxemia. Systemic corticosteroids are not given routinely but may be considered in life-threatening cases. Although death can occur, it is rare, and most patients make a full recovery, often within a few days. Intubation and mechanical ventilation may be necessary for severe FES cases that progress to respiratory failure or obtundation with inability to protect the airway. However, they are not indicated in this patient with mild disorientation (vs obtundation), clear lungs, and improved oxygen saturation of 95% on 3L oxygen, which would likely be reflected in increased PaO₂ if arterial blood gases were obtained on supplemental oxygen rather than on room air (Choice B). ₂ (Choice A) Chronic obstructive pulmonary disease exacerbations can cause tachypnea and hypoxemia and are treated with bronchodilators (eg, albuterol) and systemic glucocorticoids (eg, prednisone). This patient's pelvic fracture, clear lung sounds, and petechial rash make FES more likely. (Choice C) This patient is likely receiving opioid pain medications (eg, small pupils noted on examination). Opioid toxicity (treated with opioid discontinuation and naloxone) can depress central respiratory drive, decrease respiratory rate, and result in hypoxemia. However, bradypnea and hypercarbia would also be expected. (Choice E) Transthoracic echocardiography (TTE) may be performed when there is suspicion for blunt chest trauma (eg, chest wall bruising, pulmonary contusion on chest x-ray), especially with blunt cardiac injury (eg, ECG abnormalities). TTE is sometimes used as a rapid test for pulmonary embolism (PE) in hemodynamically unstable patients in whom thrombolytic therapy is being considered. However, this patient is not hypotensive, PE typically presents within days (not 24 hours) of an inciting event (eg, trauma, surgery, immobilization), and a petechial rash and neurologic dysfunction are not characteristic. Educational objective: Fracture of a bone containing abundant marrow (eg, pelvis) can release fat into the venous circulation, resulting in fat embolism syndrome. Diagnosis is made based on clinical signs (eg, respiratory distress, neurologic dysfunction, petechial rash), and management is supportive (eg, supplemental oxygen). References: Fat embolism and fat embolism syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/30958807) Fat embolism syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/23724388)

A 64-Year-Old Man Is Evaluated in the Hospital 24 Hours