Cardiac Anesthesia

Question 1

The most accurate assessment of atherosclerosis in the ascending aorta is possible with:
A. Digital palpation
B. Transesophageal echocardiography
C. Epiaortic ultrasound
D. Transthoracic echocardiography

Answer 1

C. Although digital palpation, transthoracic echocardiography, and transesophageal echocardiography can all detect ascending aortic atheroma, epiaortic imaging has the best accuracy due to its proximity and unobstructed acoustic window for all imaging zones in the ascending aorta. Transesophageal echocardiography typically has a “blind spot” in the distal ascending aorta due to the interposition of the tracheobronchial tree between the esophagus and the ascending aorta at this level. Digital palpation of the ascending aorta can detect severe atherosclerosis or a porcelain aorta, but is unreliable to assess disease severity across all zones of the ascending aorta. Transthoracic echocardiography can image the ascending aorta but does not typically have the resolution to assess atheroma accurately throughout the ascending aorta.

Question 2

The definition by expert consensus for moderate hypothermia during cardiopulmonary bypass is:
A. 20.1 to 28C
B. 28.1 to 34C
C. 14.1 to 20C
D. 10 to 14C

Answer 2

A. Expert consensus has defined a classification of hypothermia levels during cardiopulmonary bypass based on nasopharyngeal temperature as follows:
Profound hypothermia Below 14C
Deep hypothermia 14.1 to 20C
Moderate hypothermia 20.1 to 28C
Mild hypothermia 28.1 to 34C

Question 3

The most effective neuroprotective strategy during cardiopulmonary bypass is:
A. Pulsatile perfusion
B. Embolic reduction
C. Mild hyperthermia
D. Pharmacologic adjuncts

Answer 3

B. Although pulsatile perfusion may be neuroprotective, the current evidence is not convincing to suggest that routine pulsatile perfusion during cardiopulmonary bypass is warranted. Because cerebral emboli may play a prominent role in perioperative brain injury, a multimodal approach to manage and reduce cerebral emboli during cardiopulmonary bypass has been encourage. Although mild hypothermia may be neuroprotective, mild cerebral hyperthermia has been associated with adverse neurocognitive outcomes and so has been discourage in contemporary practice. Multiple drugs including propofol, ketamine, lidocaine, and steroids have been investigated for possible neuroprotection during cardiopulmonary bypass. The evidence to support these agents for routine administration in this setting is weak.