12 - Hemostasis

Question 1

Hemostasis

Answer 1

• Hemostasis is an imperative component of the surgical decision making
• Better visualization of tissue planes and structures
• Minimizes surgical time
• Decreases complications

Question 2

Anatomical dissection

Answer 2

• Is the identification of tissue planes and the use of atraumatic technique
• Dissect by layers to control blood flow to extremity

Question 3

Pneumatic cuffs (tourniquets)

Answer 3

• Thigh cuff

- Ankle cuff

Question 4

Thigh cuff

Answer 4

PREFERRED
o Preferred type of hemostasis because a lot of soft tissue around the area, so less injury to the area
o General or spinal anesthesia required because it will cause pain - Cannot use a thigh cuff with sedation because patient will be very uncomfortable
o Should not exceed 500mm Hg

Question 5

Ankle cuff

Answer 5

o Generally used with all forms of anesthesia
o Higher incidence of complications (due to lack of soft tissue in this area)
o Should not exceed 250 mm Hg

Question 6

Exsanguination

Answer 6

Definition
o Draining blood from extremity before applying pneumatic cuff

Elevation of extremity before you pump up the cuff
o 45 degrees (3min.)
o 60 degrees (2min.)
o This decreases the amount of blood present in the extremity

Esmarch or ace wrap

• Wrap all the way up to the cuff
• Esmarch is large elastic band which is much wider and has much more tension

Question 7

Contraindications of cuff use

Answer 7

• Infection (when debriding, can’t see what tissue is bleeding/healthy)
• Malignancy (can possibly cause malignant particles to flow/spread through lymphatics)
• Thrombo-embolic disease (throw a clot)
• A prior endovascular procedure (stent will collapse if you use a cuff)

Question 8

Cuff inflation

Answer 8

• Proper inflation based upon systolic BP.
• Approx. 100-200mmHg above systolic  100 mmHg for ankle, 200 mmHg for thigh
• Max. times: approx. 2-3 hours (preferably 2 hours)
  o “Breathing times” 5-10 min. - stop surgery and let the tissues reperfuse

Question 9

STUDY - tourniquet

Answer 9

Studies have shown a max. tourniquet time of 1 ½ hours with a 5-10min. reperfusion interval allowed complete cellular recovery – this is IDEAL

Question 10

LOCAL physiologic changes associated with tourniquet use

Answer 10

o	pH initially  7.4 to 7.19
o	pH after 2 hrs  6.9
o	Oxygen partial pressures (45-20mm Hg)
o	Carbon dioxide (38-62 mm Hg)
o	Results in loss of integrity of muscle cell membrane

Question 11

SYSTEMIC physiologic changes associated with tourniquet use

Answer 11

o Volume overload

o Acid base disturbances

Question 12

BIlateral thigh cuffs

Answer 12

o Do NOT pump them up at the same time

o Can cause MI, cardiovascular collapse, pulmonary edema, hypertension

Question 13

Complications of cuff use

Answer 13

• Thrombosis
• Inflammation
• Paralysis
• Tissue necrosis
• Circulatory volume overload

Question 14

Vasoconstrictors

Answer 14

o Mimics natural catecholamines that bind to alpha adrenergic receptors

Question 15

Hemostasis with epinephrine

Answer 15

o Reduces vascularity locally
o Permits a higher allowable dose of local
o Increases the duration of the block (because it keeps drug in area for longer period)
o Permissible concentrations = 1:100,000 or 1:200,000

Question 16

Homeostatic agents

Answer 16

• Topical thrombin (Evithrom)
• Gelfoam
• Avitene
• Surgicel
• Floseal
• Evicel (Fibrin)
• Bone wax

Question 17

Topical thrombin (Evithrom)

Answer 17

o Protein substance of bovine origin - Reconstituted with saline 1,000-2,000units/ml
o Clots fibrinogen of blood – put on wound, hold pressure 1-2 min, check again
o 500units will clot 5ml

Question 18

Gelfoam

Answer 18

o Purified animal protein – promotes clotting via proteins as well as physical barrier
– Mechanical matrix promotes clotting, and it’s a physical compression barrier
– Always apply pressure to the area and wait a couple minutes before rechecking
o Absorbs many times its own weight in blood
o Completely absorbed 4-6 weeks – don’t need to remove from the wound

Question 19

Avitene

Answer 19

o Avitene is a microfibrillar collagen agent
o Agent that adheres to blood, works by attracting platelets
o Does not interfere w/ bone healing
o Applied with direct compression 1-5 min
o May be utilized in patients undergoing heparin and aspirin therapy

Question 20

Surgicel

Answer 20

o Comes in many different forms, is also absorbable (can leave in wound)
o Oxyidized regenerated cellulose (absorbable, fibrillar absorbable, Nu-knit absorbable)
o Hemostasis is based upon physical properties rather than chemical
– Works by binding to bleeding areas to coagulate vessels
– It’s expansion aids in compression to the area
o Promotes vasoconstriction
o Bactericidal properties – there is a small collection of blood in the wound, so it prevents infection in this case

Question 21

Floseal

Answer 21

o Newer agent – hemostatic matrix (combination of two independent hemostatic agents)
o Stops bleeding within 2 minutes, can stop a LOT of bleeding (oozing of blood, collection of blood) – you will need compression as well
o Can be utilized on abnormal surfaces
o Effective on soft tissue and bone

Question 22

Evicel (Fibrin)

Answer 22

o Injected into the area

o Human thrombin, forms a fibrin clot

Question 23

Bone wax

Answer 23

o Refined bees wax (hard to use)
o Physical barrier
o Inhibits bone healing

Question 24

Dressings

Answer 24

• Used for maintaining correction
• Used for compression to control bleeding, limit the accumulation of fluids
  o Use compression in an OPEN or a CLOSED wound when leaving the OR
  o Also keeps tissues approximated so they can heal appropriately
• Drain systems may also be incorporated within the closure/dressing when there is anticipated oozing expected