Lecture 14 10/29/24 Flashcards
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
What is dehiscence?
opening of the surgical incision, including the skin, fascia/muscle layer, and or enterotomy/anastomosis sites
What are the risk factors for dehiscence?
-inadequate suture technique
-surgical site infection
-presence of dead space, seroma/hematoma
Which components of inadequate suture technique can result in dehiscence?
-poor knot tying technique
-improper suture material selection
-sutures too loose
-sutures too close to wound margins
-sutures not including the holding layer of tissue
-excessive tension on the wound edges
What are the common causes for dehiscence in the immediate post-op period?
-improper knot tying technique
-improper suture technique
-improper size of suture material
What are the common causes for dehiscence 3 to 5 days post-op?
-minimal healing in the wound bed
-weakening of the sutures
What are the systemic risk factors for dehiscence?
-age
-nutritional deficiencies
-hypoproteinemia
-endocrine diseases
-immunocompromised patients
What are the characteristics of evisceration?
-complete opening of the body wall
-GI tract becomes exposed
-life threatening
-can lead to secondary blood loss, sepsis, and mutilation
What is a hernia?
passage of internal organs through a wound left to heal by second intention
What is an incisional hernia?
complete rupture of the body wall with the skin remaining intact
How can forgotten instruments and gauze pads be prevented during surgery?
performing gauze and instrument counts before making an incision, before closing the body wall, and after surgery is over
What is the most likely cause of orthopedic infection?
Staphylococcus spp.
What are the treatment steps for orthopedic infection with Staph.?
-start antibiotics
-removal of implant dependent on stability and possibility
-flush/lavage synovial cavity
What can result in implant failure?
-instability of repair
-slow healing process
-fatigue of the implant
What are the characteristics of implant migration?
-smooth pins can result in infection and motion of previously repaired injury
-may require revision of the construct and removal of the implants
