Pathophysiology
Imaging & Tests
Risk Factors
Treatment
100
When listening to the lungs of your first pulmonary embolism patient, you are surprised that they are clear to auscultation and percussion. You go home and research, what do you learn?
In a PE, there is no fluid leakage into the alveoli or airway constictions that would cause abnormal lung sounds. Instead, there is decreased perfusion to the area due to decreased blood flow, which would not cause abnormal findings on this exam.
100
In our case, Jennifer has elevated chloride on her BMP. Explain why a pulmonary embolism can lead to an increased serum chloride.
Normally, chloride enters red blood cells as bicarbonate exits in order to keep negative charges balanced. In a patient who is hypocapnic, or has a relatively low CO2 like Jennifer, there is less bicarbonate inside cells, which leads to less chloride entering cells. This leads to increased chloride in the serum.
100
A 45-year-old male with a history of smoking, obesity, and hypertension undergoes surgery for an elective knee replacement. He is at increased risk for pulmonary embolism (PE) primarily due to:
Decreased activity and prolonged bed-rest throughout recovery
100
When researching the triage protocol likely followed by the ED when treating Jennifer, you find that there is one major source of discussion surrounding treating postpartum women with PE. What is the topic being discussed and why?
Anticoagulation and thrombolytics, because it has been shown to reduce risk of PE in postpartum women, but it has also shown to have significantly increased risk of major bleeding in postpartum women compared with the general population.
200
A 30-year-old woman presents with sudden-onset dyspnea, pleuritic chest pain, and tachycardia. On physical exam, her lungs are clear to auscultation, but she is noted to have tachycardia (heart rate 120 bpm), hypotension (BP 90/60 mmHg), and a mild fever. Which of the physical exam findings is most suggestive of a pulmonary embolism? (3)
Tachycardia, hypotension, lungs clear to auscultation, Tachycardia and hypotension, along with clear lung fields, can be signs of a pulmonary embolism, as PE can cause right ventricular strain and reduced cardiac output. In the absence of findings such as wheezing or crackles, the combination of tachycardia and hypotension in a patient with acute chest pain and dyspnea should raise suspicion for PE.
200
A 45-year-old woman presents with sudden onset of shortness of breath, pleuritic chest pain, and tachycardia. She has a history of prolonged bed rest following hip surgery. What is the most appropriate initial diagnostic test for pulmonary embolism (PE) in this patient?
D-dimer, D-dimer is a sensitive but nonspecific test for thrombotic events like pulmonary embolism. It is often used as an initial screening tool, especially in patients with a low or moderate clinical suspicion for PE. If the D-dimer is normal, PE is unlikely, and further imaging may be avoided. If the D-dimer is elevated, additional testing such as a CTPA may be needed to confirm the diagnosis.
200
A 32-year-old pregnant woman presents with sudden shortness of breath and chest pain. She is in her third trimester and has no significant past medical history. What mechanism is most likely contributing to her increased risk for pulmonary embolism?
Hypercoagulability due to high circulating clotting factors. These are commonly elevated in pregnant patients in order to decrease risk of bleeding during childbirth and general hormonal changes in pregnancy
200
The triage protocols differ for a stable versus unstable patient presenting to the ED with dyspnea. How do the supplemental O2 protocols specifically differ when treating an unstable versus stable patient?
In stable patients without any signs of respiratory distress, give supplemental O2 via nasal cannula at 2L/min. For unstable patients, give supplemental oxygen via nonrebreather at 50-60L/min.
300
A hypoxic patient presents to the ED with V/Q mismatch. Explain what two compensation mechanisms you expect to see in vitals, and why the body is reacting with these mechanisms.
Tachycardia and tachypnea
The patient will be tachycardic because their heart beats faster in an attempt to increase cardiac output in order to maintain oxygen perfusion to the body. The patient will also be tachypneic, because chemoreceptors will sense low oxygen and stimulate an increase in the respiratory rate in an attempt to increase gas exchange. Therefore, you would expect to see high HR and high RR on physical exam.
300
A Hampton hump is a common chest X-ray finding for patients with an acute PE. Explain what a Hampton hump is, and why Jennifer’s X-ray did not have one.
A Hampton hump is a wedge-shaped pulmonary infarction on the lateral wall of the lungs. In Jennifer’s case, her clot was lodged in the pulmonary arteries close to the right ventricle (we saw decreased pulmonary artery filling). Since the lungs receive blood from the pulmonary trunk and the bronchial arteries, Jennifer would not have a hampton hump because her lunsg are still able to receive blood from the bronchial arteries.
300
A 60-year-old woman with a family history of cardiac disease presents to your clinic with shortness of breath, chest pain, and a history of recent weight loss. She has been diagnosed with a malignancy, and her laboratory tests show elevated D-dimer levels. What is most likely contributing to her increased risk of pulmonary embolism?
Tumor-induced inflammation and clotting factor activation, Cancer increases the risk of pulmonary embolism due to both direct effects, such as tumor-induced venous obstruction, and indirect effects, such as the production of pro-coagulant substances and systemic inflammation. These factors increase clotting activity, and the resulting thrombi can embolize to the lungs.
300
A 60 year old male arrives to the ED by EMS after complaining of shortness of breath. He has a history of CHF, Type II diabetes, hypertension and DVT for which he takes Metoprolol, Losartan, glargine, lispro, and aspirin. He has not been compliant with this medication. He is observed to be pale, cool, diaphoretic and tachypneic with increased work of breathing. Blood pressure is 90/50, HR 130, SPO2 89% on room air. No rales are noted upon auscultation, but significant peripheral edema is noted. Soon after arrival, he goes into cardiac arrest, but you and your team achieve ROSC. Explain what therapy you would give, the indications for it, and mechanism of action.
The patient is exhibiting signs of a pulmonary embolism. Signs of cardiogenic shock, cardiac arrest, and right heart failure are all indications for tPA administration. tPA converts plasminogen to the activates form, plasmin. Plasmin breaks down the clotting factor fibrin.
400
Draw the path air takes upon inspiration from the tr*chea into circulation. Detail what cells you would expect to find in each component
400
A 50-year-old male with a history of deep vein thrombosis (DVT) and recent hip replacement presents with sudden onset of chest pain and difficulty breathing. A computed tomography pulmonary angiography (CTPA) is performed and reveals a large pulmonary embolism. Which of the following is the most likely reason this test was chosen?
CTPA provides a non-invasive means of visualizing pulmonary vasculature,
CTPA is the most commonly used imaging modality for diagnosing pulmonary embolism because it allows for direct visualization of emboli in the pulmonary vasculature. It is non-invasive and provides detailed anatomical information, including the size and location of the embolus.
400
A 38-year-old woman with a family history of sudden death presents to the emergency department with difficulty breathing and tachycardia. She recently underwent surgery for appendicitis and is in the postoperative period. What is the most likely explanation for her risk of developing pulmonary embolism?
Surgery induced venous stasis combined with prolonged immobility, Postoperative patients are at high risk of developing pulmonary embolism due to venous stasis caused by immobility after surgery, especially abdominal surgery. This reduces blood flow in the lower extremities and increases the risk of deep vein thrombosis (DVT), which may then embolize to the lungs, causing a pulmonary embolism
400
The patient above is eventually discharged. He is prescribed a staple, long term therapy that inhibits clotting factor synthesis (hint: its not aspirin). Describe the mechanism, adverse affects, and drug interactions
Warfarin inhibits the synthesis of vitamin k dependent clotting factors (II, VII, IX, X) along with proteins C and S (which function to inactivate factors Va and VIIIa).
Side effects include bleeding, elevated liver enzymes, and risk of thrombotic skin necrosis.
Some antiplatelet, antiobiotics and antifungals can interact with warfarin to increase risk of bleeding
500
Explain the mechanism by which PE induces tachypnea, identify the anion whose presence increases in the serum, and explain how this increase occurs
Pulmonary embolism restricts blood flow to portions of the lung, preventing perfusion of alveoli. This results in a mismatch between air reaching the alveoli (ventilation) and gas diffusing into the alveolar capillaries (perfusion). This results in an accumulation of CO2, which the body attempts to excrete by hyperventilation.
Normally, RBCs convert CO2 to HCO3-, before reconverting to CO2 and excreting it in the lungs. During excretion, Cl- enters the RBC to maintain charge. In hypocapnia, this reaction occurs less and Cl- remains in the blood.
500
What chest xray findings would you normally expect to see on a patient with pulmonary embolism. Explain the underlying pathology and how it is reflected by radiography.
Nothing (sometimes you can see a Hampton hump, a wedge shaped pulmonary infarct in the lateral wall of the lung secondary to hemmorhagic ischemia).
500
A 30-year-old woman at 24 weeks of gestation presents to your clinic with complaints of increasing leg swelling, heaviness, and mild pain in her left lower extremity. She is otherwise healthy, and her blood pressure is normal. Based on her pregnancy, what is the most likely explanation for her symptoms?
Venous stasis due to compression of the pelvic veins by the uterus, During pregnancy, the enlarging uterus can compress the pelvic veins, particularly the left iliac vein, leading to venous stasis and edema in the lower extremities. Although venous thromboembolism is a risk during pregnancy, this patient’s symptoms of localized leg swelling are most likely due to venous stasis rather than deep vein thrombosis or pulmonary embolism.
500
Draw the coagulation cascade and indicate where two drugs indicated for thrombolytic therapy exert their effect
see google drive (we got the free version of jeopardy, sorry)