hemostasis Flashcards
why is hemostasis important? PATIENT CONCERNS
- Medium for bacterial growths so Increase risk of post-op infection
- Inflammation:
- Delayed healing
- Adhesion formation
- Pain
- Hemorrhage can lead to:
- Anemia
- Shock
- Death
why is hemostasis important? surgeon concerns
- Visualization:
- Iatrogenic trauma
- Inaccurate procedures
- Higher complications
- Good surgery = good visibility of target
tissue
prevention of hemostasis pre surgery
- Good history: Medications
- Good physical exam: Petechia
- Breed: Von Willebrand’s disease
- Baseline blood work: Any suspicions before surgery
check with liver disease, toxins or with history of bleeding:
Platelet Function
* Buccal mucosal bleeding time
(BMBT)
* Coagulation Factor: PT and PPT
PREVENTATIVE HEMOSTASIS surgery
- Done by experienced surgeons KNOW ANATOMY
- Ligation or coagulation of vessels before transection
- Gentle and accurate dissection
- Don’t grab or cut unless you can visualize structure
- Minimize primary hemorrhage
how to control hemorrhage
-lots of time don’t panic
-Apply pressure
* Take a breath
* Vasoconstriction
* Gather thoughts and ideas
* Assistant to scrub in
* Instruments: Suction, Gauze, Hemostats, Suture
-Don’t clamp or ligate if you can’t see, can cause damage
- Good exposure = good hemostasis
- Extend incision or retract tissue
- Pre-op management: Clip hair wide and drape wide
how much blood loss is too much + calculate
> 15-20% of total blood volume
lost need Transfusion Support.
-less than 10% okay
- 0.08-0.09 x Body weight (kg) = estimated blood volume in liters
- 80-90 ml/kg
- 30 kg dog = ~2.5 liters of blood
- Can safely lose ~250mls
- 500mls or PCV below 25% = transfusion time
pressure for hemostasis
-slows BF causes clot formation < 5 mins
-use sponges, gauze.
-dab, don’t wipe (wiping removes clots)
-good for small vessels
-large vessels need more time for clot formation so if isn’t stopping clamp vessel.
hemostasis control clamping vessel
-minimize trauma to other tissues
* Good exposure is essential
* Good hemostasis
* Enlarge incision to visualize the
vessel
forceps capable of hemostasis
- Smallest forceps capable of hemostasis
- Small vessels: Halsted mosquito and Kelly forceps
- Large tissue bundles and vessels: Crile, Ochsner, and Carmalt forceps
- Curved hemostats facilitate visualization
APPLICATION OF
HEMOSTATIC FORCEPS
-use and then drop them
what to do if pressure and clamping isn’t working?
CAUTERY
then ligatures
ELECTROSURGERY
VS.
ELECTROCAUTERY
- Electrosurgery:
- High-frequency alternating current to cut, coagulate, or ablate tissue
- More complex, larger electrosurgical units (ESU)
- Electrocautery:
- Heated metal probe to destroy tissue
- Uses a direct current to heat a metal probe that is
applied to tissue, causing thermal damage - Small, battery-operated devices
electrosurgery
-Pass electrical current through tissue leads to heat then Coagulation (hemostasis) tissue
- Small vessels
- < 1mm artery
- < 2mm vein
2 kinds: monopolar(NEED GROUND PLATE) or bipolar
MONOPOLAR ELECTROSURGERY
Ground pad
* Needs good contact
* Hair needs to be shaved
-can lead to burns if not working good
- Not recommended if:
- Close to the heart
- Close to central nervous system
-if any metal, or ECG lead
BIPOLAR ELECTROSURGERY
- Forceps type of active electrodes
- Current
- One tip > tissue between > other tip
- No ground pad required
- Minimal trauma to other tissues
LIGATURE
- The gold standard for hemostasis for
*use if > 1mm artery
*use if > 2mm vein - *Vessel with a visible lumen you want to ligature
- Tie end of the vessel off
- Sacrifice vessel
- Absorbable suture
- Monocryl
- PDS
types of ligatures
- Single ligature:
- Circumferential ligature is Gold standard
*with Square knot +2 - 4 throws in total
- Double ligation:
- Large artery/veins
Transfixation ligature:
* Prevent slippage
vascular clips
- Dissect vessel well
- Vessel diameter
- No more than 2/3 and no less than 1/3 of length of clip
- Apply several mm from cut end of vessel
- Artery and vein pair are clipped separately
- Occlude vessels up to 5 mm
- Advantages:
- Quick
- Apply in locations inaccessible to ligation
- Disadvantages:
- More frequently dislodged
- Persist in wound
- Absorbable clips are now available
- Irritating to load into applicato
HEMOSTATIC AGENTS
Gelfoam
* Porcine gelatin sponge
* Forms gel when wet
* Matrix for clot to form to
* Absorbable – 4-6 weeks
* Possible nidus for infection
- Surgicel
- Cellulose
- Similar action
