BCA BCA Thoracic & Vascular Anesthesia 1

Question 1

During one-lung ventilation (OLV), the MOST common cause of hypoxemia is:

Accepted Answer

Hypoxic pulmonary vasoconstriction failure in the non-ventilated lung

Answer

Impaired hypoxic pulmonary vasoconstriction (HPV) in the non-ventilated (collapsed) lung allows continued blood flow without gas exchange, creating a large intrapulmonary shunt.

Question 2

A double-lumen endotracheal tube (DLT) is placed for left lung surgery. Correct positioning is confirmed by:

Accepted Answer

Clinical auscultation and fiberoptic bronchoscopy

Answer

Fiberoptic bronchoscopy combined with clinical auscultation is the gold standard for confirming correct DLT position and ensuring adequate lung isolation.

Question 3

During thoracic aortic cross-clamping, the MOST critical consequence of prolonged clamp time is:

Accepted Answer

Spinal cord ischemia leading to paraplegia

Answer

Aortic cross-clamping interrupts blood flow to the anterior spinal artery (artery of Adamkiewicz), causing ischemic myelopathy and potential permanent paraplegia.

Question 4

Cerebrospinal fluid (CSF) drainage during thoracic aortic aneurysm repair is used to:

Accepted Answer

Increase spinal cord perfusion pressure by lowering CSF pressure

Answer

Draining CSF reduces intrathecal pressure, thereby increasing spinal cord perfusion pressure (SCPP = MAP − CSF pressure) and protecting the spinal cord from ischemia.

Question 5

Which volatile anesthetic MOST inhibits hypoxic pulmonary vasoconstriction (HPV)?

Accepted Answer

All volatiles inhibit HPV equally at equipotent doses

Answer

At equipotent doses (1 MAC), all currently used volatile anesthetics produce similar degrees of HPV inhibition; the clinical significance at typical doses is modest.

(BCA) Board of Certification in Anesthesiology Practice Test

(BCA) Board of Certification in Anesthesiology Practice Test

BCA BCA Thoracic & Vascular Anesthesia 1