Lecture 14 10/29/24 Flashcards
(38 cards)
What are the steps to ligating during the skin incision?
-prepare for bleeding
-identify the vessels
-use hemostatic forceps, encircling ligature, or electrocautery to stop bleeding
When is hemorrhage/uncontrolled bleeding likely to occur?
-ovarian pedicle during OVH
-vaginal artery during dystocia
-after removal of emasculators
-any large superficial artery or vein wounds
What are the first steps to managing hemorrhage?
-identify the origin of the bleeding
-clamp and ligate the bleeding vessel(s)
-reassess continuation of procedure and any changes needed to prevent further hemorrhage
What are the characteristics of pressure/tamponade?
-gentle pressure on the bleeding structures
-use a 4x4 gauze
-hold for 2 to 3 minutes
-pay careful attention when removing gauze and look for continued bleeding
What are the characteristics of packing?
-done for profuse bleeding
-re-intervention necessary to remove gauzes used for packing
How is the amount of blood loss assessed?
measure volume collected in suction apparatus
-count soaked 4x4 gauzes; each holds approx. 10 mL
-count soaked lap. sponges; each holds approx. 100 mL
What are the characteristics of topical vasoconstrictors?
-used for management of diffuse inaccessible bleeding
-often used in sinus surgeries
-used soaked on gauzes
-may induce severe CV effects if absorbed systemically
What are the characteristics of tourniquet use?
-broad, tight bandage
-applied proximal to bleeding on the limbs
-prevents arterial and venous blood flow
-increases visibility but makes vessel ID more difficult
What are the three groups of hemostatic agents?
-mechanical hemostatic agents
-active hemostatic agents
-hemostatic sealants
What are the characteristics of cellulose-based products?
-mechanical agent
-mesh applied on top of oozing structure
-becomes saturated with blood
-forms a gelatinous mass
-acts as a scaffold for the formation of blood clot
What are the characteristics of gelatin sponges?
-mechanical agent
-porcine gelatin
-absorbs up to 40x its own weight
-adheres to tissue and induces tamponade effect
-does not actively promote platelet aggregation
-absorbable but can form a nidus of infection if contamination occurs
What are the characteristics of collagen?
-mechanical agent
-derived from bovine collagen
-microfillar collagen
-binds with the bleeding surface
-acts as a mechanical obstruction to bleeding
-does not swell; good for use around spine
-absorbed in 14 days
What are the characteristics of polysaccharide spheres?
-mechanical agent
-derived starch
-hydrophilic/absorbs water contained in blood
-concentrates the solid components of blood
-stimulates platelet response
-rapidly metabolized
-swells up to 500%
What are the characteristics of beeswax?
-mechanical agent
-used for bleeding in bone
-physical barrier applied in the foramen from where bleeding originates
What are the characteristics of zeolite-based agents?
-mechanical agent
-microporous aluminosilicate minerals
-absorbant
-absorbs water and forms an exothermic reaction
-external use only
What are the characteristics of thrombin?
-active agent
-factor II of the coagulation cascade
-actively converts fibrinogen to fibrin to create a clot
-exogenous origin can lead to antibody development and coagulopathy; do not use in consecutive surgeries
What are the characteristics of fibrin?
-hemostatic sealant
-direct apposition of fibrin in surgical site
-completely independent from coagulation cascade
-rare in vet med
Which actions should be taken once hemorrhage is identified?
-communicate with anesthesiologist
-animal will become hypotensive and need fluids immediately to restore blood volume
What are the characteristics of an animal’s ability to handle blood loss?
-awake animals can tolerate acute blood loss up to 25% of blood volume
-anesthetized animals are less tolerant; blood replacement should be considered for any loss greater than 10% of blood volume
How can surgeons be prepared for hemorrhage?
-collect blood from donors prior to risky procedures
-acquire blood from blood banks
Which aspects of the patient should be monitored to reassess how the patient is doing following hemorrhage?
-heart rate
-mucous membranes
-PCV and TP
What are the potential causes of hemoperitoneum?
-mesenteric bleeding from ligature failure
-non-recognition of active bleeder while under anesthesia
What can help to prevent a patient from developing post-operative hemorrhage?
-baseline hematology +/- coagulation profile prior to operation
-effective hemostasis
-monitoring of surgical blood loss
-post-op monitoring of vital signs
-post-op monitoring of PCV and TP
What should be done when a patient is suspected to have post-op hemorrhage?
-administration of volume of resuscitation +/- blood transfusion
-medical imaging (ultrasound or CT) to identify origin of bleeding
-second surgical procedure for unstable patients
-continued close monitoring and support for stable patients
