Case 9: Thoracic Aortic Dissection

Question 1

What is the Debakey Classification System?

Answer 1

Question 2

How would you perform acute normovolemic hemodilution

Answer 2

• Ensure patient is a good candidate for ANH
• Collect 1-2 units of his blood while simultaneously replacing with warmed crystalloid
• In setting of CAD i would only allow hct to be reduced to around 27%
• Following cessation of significant blood loss, re infuse autologous blood in reverse order of collection recognizing the first unit contains highest concentration of coagulation factors and platelets.

Question 3

PFT results consistent with increased risk of post operative mechanical ventilation

1.

2.

3.

Answer 3

1. FEV1 <2L total
2. Maximum breathing capacity <50% predicted
3. Maximal mid expiratory flow <50% predicted

Question 4

You are appropriately concerned about the potential for massive blood loss. Recognizing this risk, what would you do?

Answer 4

1. Place atleast 2 large bore IVs in addition to CVC
2. Ensure rapid transfusing and warming devices in room
3. Have blood products in the room
4. Plan to utilize intraoperative cell salvage

Question 5

When would you agree to employ acute normovolemic hemodilution?

Answer 5

1. As long as hematocrit is >33%, hemoglobin >11
2. No significant renal or pulmonary disease
3. Agree to this strategy because avoiding exposure to allogenic blood transfusion reduces risk of infection, transfusion reactions, and red cell alloimunization

Question 6

What monitors would you need for this case?

Answer 6

1. Standard ASA
2. 5 lead EKG to monitor cardiac ischemia
   - upper and lower arterial lines to fascilitate ABG sampling and rapid treatment of hemodynamic instability (Cross clamp)
3. large bore central line to administer vasoactive drugs, rapid transfusion
4. Pulmonary artery catheter to assess fluid status and cardiac function
5. TEE to help confirm extent and severity of aortic disease
6. core temp
7. SSEP, MEP
8. Foley