BS Periop Complications

Question 1

Describe how platelets respond to endothelial damage

Answer 1

Endothelial damage from tissue trauma, surgery etc
Exposes collagen -> activates platelets
Allows platelets to adhere to exposed collagen

Question 2

What are 3 hypercoaguable disorders that are deficiencies (decreased anti-clot factors)

Answer 2

Protein C def
Protein S def
AT3 def

Question 3

What is the final product of the clotting cascade

Answer 3

Thrombin (IIa)
Converts soluble fibrinogen -> insoluble fibrin

Question 4

What scan should you get for PE if patient has a contrast allergy

Answer 4

VQ scan

Question 5

If there is data that many TKA and some THA patients have asx DVT + PE post op, why not therapeutically AC them all?

Answer 5

Higher bleeding/hematoma complications (infection) requiring re-op

Question 6

Mechanism TXA

Answer 6

Lysine analog
Blocks plasminogen -> plasmin
Prevents clots from dissolving

Question 7

What are the current anesthesia guidelines for waiting on spinal with
LMHW
Xa inhibitors (-axabans)
Warfarin
Direct thrombin inhibitors (dabagatran)
Antiplatelets (clopidogrel)

Answer 7

LMHW - 24h
Xa inhibitors (-axabans) - 3d
Warfarin - 5d, normal INR
Direct thrombin inhibitors (dabagatran) - 5d
Antiplatelets (clopidogrel) - 7d

Question 8

What is the data on compression stockings?
Vs pneumatic compression devices

Answer 8

No value for DVT prevention, post thrombotic protection
Vs pneumatic compression decreases proximal venous thrombosis
- And non-inferior to aspirin if portable! (improve compliance)

Question 9

Mechanism:
ASA
NSAIDs
Celicoxib

Answer 9

ASA - irreversible bind COX in platatelets
NSAIDs - inhibit COX 1/2
Celicoxib - inhibit COX 2

Question 10

Mechanism + reversal for coumadin

Answer 10

Xs vit-K clotting factors carboxylation

Factors 2,7,9,10 prot C,S

Reverse with vit K PO/IV, FFP

Question 11

Mechanism heparin vs LMWH
What is the reversal agent?

Answer 11

Heparin: reversible Xa block via AT3, factors 2, 9, 11, 12

LMWH: reversible Xa block via AT3, factor 2
- Legit a shorter molecule than heparin
- Less HIT
- Decrease dose for renal dysfunction

Reverse w/ protamine sulfate

Question 12

Mechanism rivaroxaban, reversal agent

Answer 12

Blocks Xa
Andexanet = reversal

Question 13

Mechanism dabagatran + reversal agent

Answer 13

Blocks IIa (thrombin) only

Reverse = idarucizumab

Question 14

What is the current recommendation for DVT prevention in THA/TKA in:
Pts w/ prev DVT
Pts w/ bleeding risk
Pts w/ normal risk

Answer 14

Hx DVT = meds + pneumatic compression
Bleeding risk = pneumatic alone
Normal = drugs and/or pneumatic

Question 15

Diagnose: young overhead athlete, UE pain/heaviness, vein dilation and arm discoloration
Dx
Trt

Answer 15

Ax-subclav vein thrombosis
Presents like thoracic outlet syndrome
Dx: duplex > MRA > UE venogram
Trt: thrombolysis / first rib resection

Question 16

What is the pulmonary manifestation of fat embolism syndrome
Trt

Answer 16

ARDS - 50% mortality rate
Ventilate w/ PEEP
- Open lung concept - recruit alveoli

Question 17

What values indicate poor fluid resus
UOP
Lactate

Answer 17

BAD if
UOP<30cc/hr
Lactate > 2.5

Question 18

Describe presentation of neurogenic shock
Trt

Answer 18

Warm, dry hands
- Lose sympathetic tone - blood pools peripherally

Low BP
Low HR (inappropriate response)

Trt: fluids + pressors

Question 19

Malignant hyperthermia
- Mutation
- Mechanism
- Earliest sign
- Trt

Answer 19

Genetic defect transverse T tubule
- Dihydropyridine
- Ryanodine

Give anesthesia -> uncontrolled Ca release
Sustained muscle contraction
-Acidosis
- Damage muscle cells - release K (arrhythmia)

1st = unexplained rise in end tidal CO2

Trt = dantrolene = stabilizes ryanodine receptor = drops intracell Ca2+