Post Operative complciations of CT surgery

Question 1

Increased Risk Stratification – Patient-Related Variables

6

Answer 1

1. Genetic factors
2. Older patients
3. Females/smaller body mass index
4. Known coagulopathies (Von Willebrand’s dz, uremia)
5. Comorbidities (Diabetes, hepatic and renal dysfunction, PVD, infection, hypersplenism, ITP, preoperative anemia)
6. Advanced cardiac disease (shock, poor ventricular function)

Question 2

Increased Risk Stratification – Preop Medications

7

Answer 2

1. High dose aspirin
2. Clopidogrel/prasugrel
3. Emergency surgery after llb/llla inhibitors
4. Low-molecular-weight heparin within 18 hours
5. Fondaparinux within 48 hours
6. Incomplete reversal of INR off warfarin
7. Direct thrombin inhibitors, Thrombolytic therapy

Question 3

Increased Risk Stratification – Procedure-Related Variables

Answer 3

1. Complex operations (valve-CABG, thoracic aortic surgery, esp. deep hypothermic circulatory arrest cases)
2. Urgent/emergent operations
3. Reoperations
4. Use of bilateral ITA grafting
5. Long durations of CPB time (qualitative and quantitative platelet defects, coagulation factor depletion, increased fibrinolysis)

Question 4

What do you give in a post op CT surgery patient if their fibrinogen is low?

Answer 4

We give cryo

you can also give FFP

Question 5

Management of Postoperative Bleeding

8

Answer 5

1. Ensure chest tubes remain patent
2. Warm patient to normothermia
3. Control hypertension, agitation, and shivering
4. Support/optimize hemodynamics, oxygen-carrying capacity, tissue perfusion
5. Consider use of 10 cm PEEP with caution
6. TTE/TEE if concerned about tamponade
7. Urgent exploration for significant ongoing bleeding or tamponade
8. Emergency exploration for exsanguinating hemorrhage/tamponade/near arrest

Question 6

Return to the OR for surgical exploration should be considered when:

2 scenerios

Answer 6

Acute onset of rapid bleeding (>300mL/h) after minimal blood loss

> 400mL/h for 1 hour
300mL/h for 2-3 hours
200mL/h for 4 hours

Question 7

Management of Coagulopathic Bleeding

1. if PTT elevated?
2. if hematocrit < 26%
3. Other options? 3
4. if platelet dysfunction from uremia, aspirin
5. for severe coagulopathy?

Answer 7

1. Protamine 25mg IV x two doses
2. Packed red cells
3. • Platelets (1 -2 “five or six packs”)
   • Fresh Frozen Plasma, 2-4 units
   • Cryoprecipitate, 6-10 units
4. Desmopressin (DDAVP) 0.3 ug/kg IV
5. Recombinant factor VIIa 60 ug/kg

Question 8

PTT > 1.5 x nl?

ACT > 130 sec?

Answer 8

Protamine (consider FFP)

Question 9

Platelet count <100,000

Platelet dysfunction?

Answer 9

Platelets (consider desmopression)

Question 10

INR greater than 1.5

Answer 10

FFP

Question 11

Fibrinogen less than 100?

Answer 11

Cryo

Question 12

Elevated FSP or D dimer

?

Answer 12

Lytics

Question 13

Why do we transfuse packed RBCs?

Answer 13

Increase oxygen-carrying capacity and avoid end-organ ischemia and dysfunction

Question 14

Minimum Hematocrit to maintain tissue oxygenation
?
Healthy pt?
stable post op pt?
bleeding post op pt?

Answer 14

1. Healthy patients: 18 – 21%
2. Stable postoperative patient: 22 – 24%
3. Bleeding postoperative patient: 26% keep up with bleeding

Question 15

One unit of RBCs typically raises the Hct of a 70kg male __%?

Answer 15

3

Question 16

Indications for post op PLT transfusion:

2

Answer 16

1. In setting of excessive bleeding, give platelets when count is less 100,000/uL
2. When platelet dysfunction is likely (preop meds, uremia, post CPB) and bleeding persists, platelets should be given even if plt count > 100,00/uL
   (Platelets are not indicated in nonbleeding patient unless count drops to <20-30,000/uL)

Question 17

PLT: Each 6-pack unit should increase the platelet count ~ ?

Answer 17

7000 – 10,000/uL

Question 18

FFP Contains what?

Answer 18

all clotting factors at normal concentrations with a slight reduction in factors V and VIII

Question 19

Only ___% of the normal level of most clotting factors is required to provide hemostasis ( INR >1.5 before clinically significant factor deficiency exists)

Answer 19

30

Question 20

1. Single unit ~ ___mL total volume
2. Typical “dose” 2-4 units (4 units increase level of clotting factors by ~___%)?
3. Contains what? which is useful in ATIII-deficient patients

Answer 20

1. 250
2. 10
3. ATIII (antithrombin III)

Question 21

Cryprecipitate:
Provides what?
5

Answer 21

1. Provides concentrated levels of
   - factor one (fibrinogen) and
   - factor VIII:C,
   - von Willebrand’s factor,
   - factor XIII (fibrin-stabilizing factor) and
   - fibronectin (tissue integrin involved in wound healing.)

Question 22

Both factors _____ are essential for proper platelet aggregation and adherence to endothelium
Especially beneficial for patients with von Willebrand’s disease or hypofibrinogenemia

Answer 22

I and VIII

Question 23

Recombinant Factor VII (rFVIIa)

Used successfully in arresting bleeding in patients with severe uncontrollable coagulopathy

Combines with tissue factor at the site of vessel injury and to the surface of activated platelets, activating factor X

What does this result in?

Answer 23

Results in thrombin generation, platelet activation and an explosive “thrombin burst” that promotes localized hemostasis at the site of tissue injury

Systemic thrombosis may occur – beware!

Question 24

Causes of Low Cardiac Output Syndrome

8

Answer 24

1. Decreased preload
2. Decreased contractility
3. Tachy-Bradyarrythmias
4. Increased Afterload
5. Diastolic dysfunction
6. Sepsis
7. Anaphylaxis
8. Protamine Reactions

Question 25

Treatment Approach to low cardiac output syndrome? | 5

Answer 25

1. Look for non-cardiac causes 2. Treat ischemia or coronary spasm 3. Optimize preload PCWP or LA pressure 18-20mmhg 4. Optimize heart rate Pace if necessary to a HR around 90 bpm 5. Control Arrhythmias

Question 26

Low cardiac output syndrome 1. Assess Cardiac output and start inotropic support if cardiac index is? 2. Calculate SVR and start vasodilator if SVR over ? 3. If BP is low with a low SVR? - marginal CO? - satisfactory CO? 4. What if these two fail? 5. Transfuse to keep HCT greater than?

Answer 26

1. less than 2.0 2. 1500 3. - Norepinephrine if marginal cardiac output - Phenylephrine (neo) if satisfactory cardiac output 4. Vasopressin if the first two fail 5. 26% Surgeon specific. Be sure to check what the threshold is for transfusion in your particular service

Question 27

Actions of dopamine: 1. At 3-5mcg/kg/min? 2. 5-10mcg/kg/min? 3. >10mcg/kg/min

Answer 27

1. renal vasodilator 2. vasodilator/inotropy 3. vasoconstrictor

Question 28

Actions of dobutmaine? | 5-20mcg/kg/min

Answer 28

Vasodilator > Inotropy

Question 29

Actions of Milrinone? | 0.25- 0.75mg/kg/min

Answer 29

Vasodilator > Inotropy

Question 30

actions of Epinephrine 1-20mcg/min? >20?

Answer 30

inotropy/vasodilator | vasocontrictor

Question 31

actions of Norepinephrine? 1-2 mcg/min >2mg/min

Answer 31

inotropy | vasoconstrictor

Question 32

actions of Isoproterenol? | 1-10 mcg/min

Answer 32

chronotropy >inotropy

Question 33

What is the definition of acute renal failure?

Answer 33

Defined as a 50% increase in the serum creatinine concentration above baseline

Question 34

Risk Factors for Acute Renal Failure: | 6

Answer 34

1. Pre-operative Cardiac performance 2. Advanced atherosclerotic vascular disease 3. Reduction in creatinine clearance pre-op 4. Increase CPB time 5. Presence of perioperative hemodynamic instability 6. Use of radiocontrast agents immediately before surgery

Question 35

1. When should you use Continuous Renal Replacement Therapy: 2. What is CVVH? 3. CVVHD 4. CVVHDF:

Answer 35

1. Utilized with hemodynamic instability 2. : Continuous venovenous hemofiltration 3. : Continuous venous venous hemodialysis 4. Continuous venous venous hemodiafiltration

Question 36

Risk factors for the development of mediastinitis include the following? 10

Answer 36

1. Pedicled bilateral internal mammary artery (BITA) grafts. - This risk is even higher among patients with diabetes, thus rendering many surgeons reluctant in using BITA grafting in this subgroup of patients. 2. Emergency surgery 3. External cardiac compression (conventional cardiopulmonary resuscitation) 4. Obesity (>20% of ideal body weight) 5. Postoperative shock, especially when multiple blood transfusions are required 6. Prolonged bypass and operating room time. 7. Reoperation 8. Reexploration following initial surgery 9. Sternal wound dehiscence 10. Surgical technical factors (eg, excessive use of electrocautery, bone wax, paramedian sternotomy)

Question 37

Arogatroban in HIT until PLT are? and INR is?

Answer 37

1. over 100,000 | 2. 4

Question 38

HIT: Do not start Coumadin until PLT are?

Answer 38

Over 100k