test 6 left heart bypass

Question 1

LEFT HEART BYPASS

Answer 1

 Basically, a shunt around the aneurysm/ dissection
 Used on DESCENDING LEGIONS
 Heart pumps blood to the lungs (bypass left side)
 Lungs oxygenate
 Venous cannula places in LA/ L. Pulmonary veins
 Risk of air embolism
 Move tip of cannula – impair drainage
 Could cannulate Apex of LV
 Great flow
 Risk of LV injury
 Arterial cannula placed in descending aorta
 If the patient needs volume – Anesthesia must give
 Heart pumps blood to the vessels proximal to the clamp (usually the head vessels)
 ECC pumps distal to clamp
 2/3 of CO to lower body
 Arterial pressure
 Monitored at radial or brachial artery (upper body)
 Monitored at femoral artery (lower body)

Question 2

ECC Circuit for left heart bypass

Answer 2

 Tubing
 Centrifugal pump
 No Reservoir
 No H/E
 No Bubble Trap
 Excluding those help minimize the heparinization
required.

Question 3

Proximal arterial pressure: high
Distal arterial pressure: low
Pulmonary wedge pressure: low

Answer 3

Volume, Increase Pump Flow

Question 4

Proximal arterial pressure: high
Distal arterial pressure: low
Pulmonary wedge pressure: high

Answer 4

Increase Pump Flow

Question 5

Proximal arterial pressure: high
Distal arterial pressure: high
Pulmonary wedge pressure: low

Answer 5

Volume; Vasodilator

Question 6

Proximal arterial pressure: high
Distal arterial pressure: high
Pulmonary wedge pressure: high

Answer 6

Vasodilator; diuretic; maintain pump flow, hold volume in pump reservoir (if used)

Question 7

Proximal arterial pressure: low
Distal arterial pressure: low
Pulmonary wedge pressure: low

Answer 7

Volume; look for partial occlusion of arterial outflow cannula (if reservoir in use)

Question 8

Proximal arterial pressure: low
Distal arterial pressure: low
Pulmonary wedge pressure: high

Answer 8

Increase pump flow; inotrope

Question 9

Proximal arterial pressure: low
Distal arterial pressure: high
Pulmonary wedge pressure: low

Answer 9

Decrease pump flow; inotrope; diuretic

Question 10

Proximal arterial pressure: low
Distal arterial pressure: high
Pulmonary wedge pressure: low

Answer 10

Decrease pump flow; may need volume