A 76-year-old man with no past medical history has an operation for a strangulated inguinal hernia, with approximately 40 cm of small bowel resected. On the morning of his third postoperative day, he falls while getting out of bed. Immediately after the fall, the patient is responsive but confused with slurred speech. He cannot explain what happened. His blood pressure is 89/50 mm Hg, pulse is 122/min, and respirations are 24/min. Examination shows decreased bibasilar lung sounds and distended neck veins. Electrocardiogram shows new-onset right bundle branch block with nonspecific ST- and T-wave changes. Immediate resuscitation with wide-open intravenous fluids is attempted but unsuccessful. Shortly thereafter, the patient's pupils start to dilate, his pulse drops to 45/min, and he becomes unresponsive. He eventually dies despite resuscitative efforts. Which of the following is the most likely cause of this patient's death?

Question

A 76-year-old man with no past medical history has an operation for a strangulated inguinal hernia, with approximately 40 cm of small bowel resected.  On the morning of his third postoperative day, he falls while getting out of bed.  Immediately after the fall, the patient is responsive but confused with slurred speech.  He cannot explain what happened.  His blood pressure is 89/50 mm Hg, pulse is 122/min, and respirations are 24/min.  Examination shows decreased bibasilar lung sounds and distended neck veins.  Electrocardiogram shows new-onset right bundle branch block with nonspecific ST- and T-wave changes.  Immediate resuscitation with wide-open intravenous fluids is attempted but unsuccessful.  Shortly thereafter, the patient's pupils start to dilate, his pulse drops to 45/min, and he becomes unresponsive.  He eventually dies despite resuscitative efforts.  Which of the following is the most likely cause of this patient's death?

Quizplus · Accepted Answer

This patient's history and presentation are strongly suggestive of postoperative massive pulmonary embolism (PE) complicated by cardiogenic shock. Massive PE is defined as PE complicated by hypotension and/or acute right heart strain. Although dyspnea and pleuritic chest pain are common symptoms of segmental PE, syncope tends to occur only in massive PE. Jugular venous distension on physical examination and right bundle branch block (RBBB) on electrocardiogram (ECG) are signs of acute right heart strain. Because this patient has strong evidence of both right heart strain and hypotension, the diagnosis of massive PE is highly likely. The right heart strain progresses rapidly to right ventricular dysfunction, decreased return to the left side of the heart, decreased cardiac output, left heart pump failure, and resultant bradycardia. This results in cardiogenic shock and causes central nervous system effects, such as the dilated pupils and unresponsive mental status seen in this patient. Survival following massive PE is poor, with death often occurring within an hour of the onset of symptoms. If time permits, massive PE can be confirmed with CT pulmonary angiography. Although echocardiography has poor sensitivity for segmental PE, massive PE often has visible echocardiographic abnormalities that allow for rapid bedside diagnosis. In conjunction with respiratory and hemodynamic support, fibrinolysis is indicated in the treatment of massive PE. However, hemorrhagic complications are frequent, and surgery within the preceding 10 days is a relative contraindication to fibrinolytic therapy. CT pulmonary angiography (Choice A) Confusion and slurred speech always raise concern for an acute ischemic stroke. However, new-onset jugular venous distension and RBBB are indicative of right heart strain, which is commonly seen in association with PE. Moreover, blood pressure is typically elevated with ischemic stroke. This patient was likely hypoxic from the PE, causing the slurred speech and confusion. (Choice B) Hypovolemia should be considered in the setting of syncope and hypotension. However, decreased rather than increased jugular venous pressure would be expected in hypovolemia. (Choice D) The risk of myocardial infarction (MI) is increased during the postoperative period, and an MI could explain this patient's hypotension and jugular venous distension. However, the absence of significant cardiovascular risk factors and no ST elevation, T-wave inversion, or Q waves on this patient's ECG make MI less likely. (Choice E) Classic cardiovascular changes in the setting of sepsis include hypotension, decreased peripheral vascular resistance, increased cardiac output, and decreased pulmonary capillary wedge pressure. Fever and warm extremities might also be seen. However, jugular vein distension and RBBB typically do not occur. Educational objective: Massive pulmonary embolism is likely in a postoperative patient with hypotension, jugular venous distension, and new-onset right bundle branch block. References: Fibrinolysis for acute pulmonary embolism (http://www.ncbi.nlm.nih.gov/pubmed/20926501) Thrombolytic treatment (alteplase; rt-Pa) in acute massive pulmonary embolism and cardiopulmonary arrest. (http://www.ncbi.nlm.nih.gov/pubmed/24959070)

A 76-Year-Old Man with No Past Medical History Has an Operation