Quiz Answers with Rationale

1) The most common cause of a pulmonary embolism (PE) is the result of a blood clot from a deep vein traveling to the lungs, where it becomes lodged in the pulmonary arteries.

A. True

B. False

Rationale: Question 1 is true. PE’s are most often caused by the embolization of a deep vein thrombosis.

2) Which of the following are less common causes of pulmonary embolisms (Select all the apply.)

A. Air

B. Blebs

C. Amniotic Fluid

D. Lipids

E. Foreign Bodies

Rationale: Air, Amniotic Fluid, Lipids and Foreign bodies (often pieces of medical devices) can all become logged in the pulmonary arteries if they accidentally enter the bloodstream. Blebs, while associated with lung injury, are not mobile and have no way of entering the vasculature or causing occlusion of the pulmonary arteries.

3) When a pulmonary embolism occurs, which of the following are the results?

A. The patient will become bradycardic

B. The patient will have an increase of PO2 noted on their arterial blood gas

C. Ventilation-perfusion mismatch and decrease in surfactant production by the alveoli

E. Nothing, patients usually show no clinical signs/symptoms.

Rationale: When a PE occurs, the patient will have a VP mismatch due to the loss of blood flow to the affected area(s) of the lungs. The loss of blood flow also results in a decrease in surfactant production, leading to further lung injury and possibly atelectasis. Patients generally become tachycardic, not bradycardic, as a compensatory mechanism. Arterial blood gasses will show a decrease in PO2 from the lack of air exchange in the affected lung tissue. Patients quickly become symptomatic and show multiple signs/symptoms, including shortness of breath and chest pain.

4) The Triad of Virchow includes all of the following EXCEPT?

A. Venous Stasis

B. Hypercoagulability

C. Hypokalemia

D. Endothelial Injury

Rationale: The Triad of Virchow describes the three elements believed to be risk factors leading to venous thrombus formation. Virchows Triad includes Venous Stasis (immobilization, heart failure, obesity, prolonged leg dependency, age), Hypercoagulability (inherited coagulation disorders, malignancy, hormone replacement, oral contraceptives, pregnancy, smoking), and Endothelial Injury (trauma, infection, diabetes, caustic intravenous infusions). Hypokalemia has no effect on the formation of DVTs or PEs.

5) Signs and symptoms of a pulmonary embolism include which of the following? (Select all that apply.)

A. Pleuritic chest pain

B. Cheyne Stokes breathing

C. Dyspnea

D. Night Sweats

E. Friction rub on auscultation

Rationale: Pulmonary embolisms often cause a sudden onset of sharp, pleuritic chest pain because they irritate the pleura. This irritation and inflammation will also lead to a friction rub when auscultating lung sounds. The patient also suffers from dyspnea due to the dead space and VP mismatch. Night sweats are often associated with other lung diagnoses such as lung cancer and tuberculosis. Cheyne Stokes respirations are often due to metabolic abnormalities.