Surgery E2 SG PDF

Surgery E2 SG (lectures 12-20) Wound management: **Golden period: first 6-8 hours between wound contamination at injury and bacterial multiplication greater than 10^5 CFU per gram of tissue (normally “eye ball” it to access if covered in pus) Contaminated vs. infected (based on pic) with numbers...

Surgery E2 SG (lectures 12-20) Wound management: **Golden period: first 6-8 hours between wound contamination at injury and bacterial multiplication greater than 10^5 CFU per gram of tissue (normally “eye ball” it to access if covered in pus) Contaminated vs. infected (based on pic) with numbers Contaminated - normally the first few hours before increased bacterial multiplication where some microbes present Infected- bacterial numbers greater than 10^5 CFU where microbes are invading and replicating Class 1 ○ 0-6 hours old ○ Minimal contamination Class 2 ○ 6-12 hours old ○ Microbes not reached infection level Class 3 ○ > 12 hours old ○ Microbial levels greater than 10^5 = infection 6 major wounds (injury type, characteristics, and impact on healing) Abrasion ○ Superficial, bleed minimal, heal fast by reepithelialization Puncture ○ Small skin opening with deep damage ○ Extent of damage directly proportional to missile velocity Laceration ○ Created by tearing ○ Deep or superficial Avulsion ○ Tearing of tissues from attachments and creation of skin flaps ○ “Degloving”- EXTENSIVE skin loss Anatomic - skin completely torn off Physiologic- skin surface intact but separated from SQ tissue and blood supply → necrosis Thermal burn ○ Caused by heat or chemicals with HIGH risk of sepsis and infection  Decubital ulcer ○ Compression of skin and ST between bony prominence and hard surface ○ ex) pressure sore ○ Common sites: greater trochanter, lateral elbow, and lateral hock ADD PICS 4 major wound closure and if they involve 1st, 2nd, or 3rd intention healing Primary wound closure- 1st intention ○ Wound edges apposed ○ < 12 hrs in equine where close immediately Delayed primary closure w Abaxialn ○ Apposition within 3-5 days ○ BEFORE granulation tissue ○ Close after debridement in equine Healing by contraction and epithelialization- 2nd intention ○ Wound left open to heal Most of the time in equine TRY to close b/c worst case part of it dehisces ○ Eventually produces continuous epithelial surface May be ineffective or fail of ○ Cleansing or debridement might be necessary Secondary closure- 3rd intention ○ > 3-5 days apposition ○ Granulation tissue formed ○ Normally seen in SEVERE wounds ○ Debridement normally needed Lavage: reduces bacterial numbers by loosening and flushing away necrotic debris. Antibiotics I or antiseptics can aid in further reducing bacterial numbers. → SOLUTION TO POLLUTION IS DILUTION !! ** 1L fluid bag + cuff pressurized @ 300mmHg = 7-8psi ** SA 18g needle on 35 or 60ml syringe = 10-15psi LA Wound debridement? Removal of dead tissue, FBs, and microbes that delay healing Goal = fresh, clean margins for primary or delayed closure ○ Bed of granulation tissue formed EXTENT of dead tissue seen within 48hrs * Types? ○ Muscle until bleeds and contracts ○ SQ AVOID ○ Contaminated fat heavily! Antibiotics? Only for severe wounds or wounds older than 6-8hrs Antimicrobial agents (know which one given wound) Do NOT use powders (act as FBs) Caution with neosporin as harmful if inhaled ○ Prevents infection but does NOT treat (once infected = ineffective) Silver sulfadiazine = burn wounds Nitrofurazone = broad-spectrum with hydrophilic properties Gentamicin sulfate = effective against gram NEG bacteria ○ Pseudomonas spp, escherichia coli (difficult to destroy) and proteus spp. Cefazolin = effective against gram POS and some gram NEG bacteria ○ Both injectable and topical available Mafenide = severely contaminated wounds Honey = enhances wound debridement, decreases inflammation, promotes granulation tissue and epithelization, and improves wound nutrition ○ Use EARLY in wound healing but discontinue once healthy granulation bed present ○ Similar to sugar but attracts macrophages for “clean-up” Benefits of vacuum assisted wound closure Increased granulation rate Increased healing times Wound cleaning Improved blood flow Reduced edema INSERT PIC Bandaging → normally BELOW elbow and stifle (same for casts) “Breathe Stroke” in horses with counterclockwise on L limbs and clockwise on R limbs Soft padded bandage (modified robert jones) Most common Bandage layers in SA TAPE STIRRUPS FIRST on distal ⅓ of limb 1. Primary/contact layer: transfer exudate and allow breathability. Selection based on phase of wound healing, necrosis, exudate, eschar (dead skin adhered), etc ex) Telfa pad Adherent- when wound debridement required (wet to wet is only type that is still recommended. Still use dry if LARGE amount of low-viscocity exudate) Nonadherent- retains moisture and drains excess fluid Occlusive- impermeable to air, nonexudative wounds to keep moist Semi-occlusive- allows air and exudate, most common 2. Secondary/intermediate layer: decreases bacteria, extra padding ex) Splints, casting pads, cling → apply with toes-up, overlapping @ 50% when moving up, and firm/even pressure 3. Tertiary/outer layer: holds in place, protection from outer bacterial colonization ex) Vet wrap (NOT too tight in SA but tight in horses) Elastikon at end or KOOZIE!!! ~ Label on top with date, initials, reminders, and warnings ** Place cotton btw toes ** PICS Tie-Over bandage: wound in inaccessible bandaging area. Sometimes heavy string used to hold layers together. Pressure bandage: controls minor hemorrhage, edema, and excess granulation tissue over bony prominences (more convex) or pressure sores. Robert Jones bandage: immobilizes, large/thick bandage, helpful with transportation Proximal extremity bandaging? Bandage all the way UP leg, chest, and between legs (completely distally too) ○ Avoid edema build-up Spica splint: immobilization of shoulder, patient anesthetized Ehmer sling: used post hip reduction or acetabular fractures to prevent pelvic limb weight bearing. Velpeau sling: used post shoulder / forelimb procedures to prevent forelimb weight bearing. Casts for fracturing OPEN fractures do NOT cast Always radiograph post casting → must have > 50% overlap of fracture ends in EACH of 2 views Limb placed in standing position (NOT in full extension as should encourage movement) Recheck at least every 2 wks More padding = decreased immobilization Leave middle two toes exposed Always identify underlying structures ○ ex) ear bandage Most important things to look out for when checking bandage? Clean DRY! of Odor Toe temperature (not cold) ○ Nail bed cyanosis LA Wound management First = STOP the bleeding 12 hrs = primary wound closure in equine (day of) Tetanus status? ○ Not vaccinated (> 12 month) = tetanus toxoid and anti-toxin  ○ Vaccinated > 2 months = booster ○ Vaccinated < 2 months = no booster Do NOT use garden hose on wounds as creates edema Preferred suture = non-absorbable monofilament placed 5mm from cut edge ○ Ethilon (nylon) or Polypropylene ALWAYS warn owners about dehiscence!!! Wound blocks Through cut EDGE of wound PIC Synovial involvement Sterile prep AWAY from wound to avoid introduction of new bacteria ○ ex) medial laceration so sterile prep lateral aspect so fluid flows out medial end where wound already present Even the smallest of wounds require specialized attention / referral Bone sequestration Dead/infected piece of bone with bacteria present that has potential to harm blood supply ○ Body sees non-healing wound as FB Normally requires surgical removal! Cellulitis SEVERE edema associated with small wound with severe lameness Requires aggressive therapy Wound debridement (common methods) Sharp with scalpel blade = most superficial layer Mechanical with wet to dry bandage BEFORE epithelialization Autolytic moist wound healing Drainage Important to remove dead space and avoid exudate accumulation Closed with Jackson-Pratt Open with Penrose that MUST be placed ventral Pearainse Accessory carpal bone bandaging: “Figure 8” Pattern of Equine bandage complications Excessive granulation tissue formation ○ Hypoxic bandage environment ○ Do NOT bandage when excess GT as more prone to proud flesh Pressure sores Bandage bows- tendon inflammation, NOT actually bowed tendon Most important thing to remember before taking horse to Sx or euthansizing? Communication between referring veterinarian and owner AND insurance company (if insured). LA anesthesia risks Longer time under Weight, age High ASA score ATTACH CHART Hypotension Induction quality (if poor → also poor recovery) If decide to euthanize on table? Have SECOND witness in addition to owner and person repeating everything you just said to owner. Put their name and info in medical record. Equine risk factors Foals Geriatric Cardiopulmonary Increased size (Clydesdales) Broodmares with increased likelihood of colic as providing foals with increased milk Antibiotics post surgery? → ONLY if necessary (colic) and if so, within 60 mins of start of surgery Not necessary for laparoscopic procedures Surgical wound classifications 1) Clean: no infection or break in technique, sterile areas 2) Clean-contaminated: GI, vagina, oropharynx, or respiratory tracts (not sterile) entered w/o significant spillage. Minor break in technique 3) Contaminated: MAJOR break in technique with gross spillage from GI tract, traumatic wound, infected urine or bile. 4) Dirty: acute bacterial inflammation encountered. Must transect clean tissues to access pus. Older lacerations with retained devitalized tissues, FBs, contamination, etc. Patient stabilization pre-sx? Dehydrated? IV fluids Anemia? Blood transfusion Hypoproteinemia? Colloids (proteins like albumin that expand blood volume) Electrolyte imbalances? IV fluids +/- electrolytes ○ ex) hyperkalemia, hyponatremia, hyperchloremia Fasting for different species? Equine- overnight with water access Ruminants- 24-48 hr fast (less regurgitation b/c rumen) and 24 hr withhold water Camelids- overnight with water access Most important question for working in field? → Does what I’m doing compromise my own or patient’s safety? Methods to reduce tension when surgically closing? Undermining wound edges with scissors ○ DEEP to panniculus muscle layer to preserve subdermal plexus and cutaneous vessels ○ Bleeding likely Specific suture patterns (cruciate, vertical or horizontal mattress) Relief incisions Skin stretching Tissue expansion Allow for primary apposition ○ If not → secondary intention or reconstructed with flaps or grafts Direction of surgical incisions and why? I → manipulate skin PARALLEL to tension lines in order for wounds to heal faster, better, less dehiscence, and with less pain (aesthetic). Minimal “dog ear” formation Wound closure at long axis if minimal tensionor ATTACH PIC Surgical removal of skin tumor? Before = skin tension and elasticity should be accessed, LARGE area clipped During = excision of tumor, previous biopsy sites, and wide margins of normal tissue ○ **Benign- remove tumor + 1cm of normal tissue (length, width, dept)** ○ **Malignant- remove tumor + > 2/3cm (length, width, dept)** If deep not accessible = excise one tissue plane down ○ Do NOT need to resect cartilage, tendons, ligaments, fascia, or any collagen-dense, vascular-poor tissues as RESISTANT to neoplasia Always MARK tumor borders to prevent recurrence! Methods for recruiting skin for wound closure under tension? Pre-suture surgical incision site 24hrs before procedure to pre-stretch skin so when perform surgery and close the next day → more skin to work with Adjustable sutures ○ Use of buttons (tighten daily) or stents (cut section of IV fluid or penrose drain) ○ Walking (completely remove dead space where suture continuously placed in circular motion), subdermal (tolerates tension more compared to SQ), and external tension relieving sutures (vertical mattress pattern placed further away from skin edge) ADD PIC WALKING SUTURE willing Skin stretchers  SkinStretchers ○ AXIAL pattern flaps preferable compared to tissue expanders for large wounds Include direct cutaneous artery and vein at base of flap to allow for better perfusion compared to pedicle flaps Increased blood flow to aid in healing ex) thoracodorsal axial pattern flap Skin expanders ○ ex) inflatable tissue expanders- inflates SQ tissue with a syringe at time intervals (every 2-7 days) to stretch overlaying tissue in order for eventual skin flap creation Methods to prevent or correct “dog ears”/puckers Place sutures closer together on convex aspect and further aspect on concave aspect f ○ Unequal suture spacing with simple interrupted Outlining with elliptic incision, resecting redundant skin, and apposing skin in linear or curvilinear way Dog ear incision ○ Incise → 2 triangles where 1 excised out and the other one placed on top OR both excised and edges apposed to create linear suture line I PIC mm no Some flatten over time Dog ears more prone to happen with THICK skin Relaxing incisions: made adjacent to wound to allow closure with reduced tension of primary wound. Incisions created will be left open to heal by second intention while primary wound incision would be closed. PICS OF PLASTIES and flaps Reason behind change from ABCs to M^2ARCH^2E with initial trauma assessment ABCs- old method ○ Airway: provides a pathway for O2 to reach RBCs in lungs ○ Breathing: transport O2 to RBCs ○ Circulation: transport O2 in RBCs to tissues ○ Only relevant/useful if P does NOT have sufficient RBCs to retransport oxygen to keep cells alive ** M^2ARCH^2E **- new method ○ Massive hemorrhage and muzzle Apply lots of PRESSURE to stop bleeding (tourniquets not commonly used in vetmed) Pressure bandages used more frequently Largest aspect that leads to death ○ Airway Check for abnormal breathing sounds or face/neck/chest deformities Always restrain! Palpate trachea and throat/neck for possible obstructions Open the mouth “2-finger sweep” technique to remove any objects, vomit, blood clots, etc Removing bone trapped over lower canines? Pull tongue straight out btw lower canines and gently pull bone up from chin (possible sedation) ○ Respiration Observe and palpate chest and abdomen (take off army vest) Deep, labored breathing- lung trauma or pulmonary contusion so Shallow, rapid breathing- air, blood, or other fluid within lung spaces Irregular breathing- brain injury possible Blue gums (cyanotic) = serious issue Open pneumothorax? COVER wound Tension pneumothorax/thoracocentesis? Needle/catheter decompression over 7th to 10th intercostal spaces ○ Circulation Recheck bandages to access control of bleeding Address smaller wounds or fractures → immobilize joint above AND below (avoiding unnecessary weight) Initiate IVs if necessary Ausultate and palpate pulses (femoral and cardiac) Access mucous membranes (CRT = blood flow to tissues) Rapid HR with > 2 CRT? SHOCK or major problem ○ Head injury and hypothermia Hypothermia happens QUICK! Access consciousness and equality btw pupils  ○ Evacuate / pain management / antibiotics ○ Briefly access rest of dog for any additional wounds or trauma Compressible vs noncompressible hemorrhage Compressible- stopping bleeding via compression ○ ex) puncture wound Non-compressible- wounds that are unable to be compressed to stop the bleeding, sometimes compression will worsen the bleeding ○ ex) gunshot wound or hole in vena cava Placement of tracheotomy tube? 1) Make transverse incision through annular ligament btw 3rd & 4th or 4th & 5th cartilages → Do NOT extend incision > ½ circumference of trachea or cut into cartilaginous rings unless permanent tracheotomy (deeper cut) 2) Depress proximal cartilages with hemostat while inserting tube 3) Use encircling suture to elevate distal cartilages → Make sure tube does NOT completely fill lumen 4) Secure tube at neck by using gauze or umbilical tape (not sutures) PICS Major areas addressed in Pre-opt assessment of surgical P Patient history PE Lab data- BIG 4 (healthy animals with routine procedures) ○ PCV/hematocrit w/ blood smear, TP, BUN, and blood glucose ○ > 5-7 yrs = minimum BW with CBC, biochem, urinalysis Associated disease Patient stabilization  Surgical risk of P? Determine quality of life Some pets will NOT benefit from surgery COMMUNICATION critical!! Surgical prognosis Excellent- low potential for complications Good- some potential for complications E Fair- serious complications possible, recovery may be prolonged Poor- many complications possible (severe), prolonged recovery expected, increased likelihood of death during or post procedure Guarded- outcome highly variable or unknown —> always air on the side of caution (> 50:50 = idk but I think so…) Assign physical status based on ASA scale ATTACH CHART CDC’s classification of surgical site infections? Incisional- actual surgical incision infection ○ superficial ○ deep Organ/space- anatomic part that was manipulated during procedure infection l MUST occur within 30 days of procedure or within a yr of implant Biggest issue in humans = increased incidence of mortality ○ infected patients x2 likely to die ~ non-infected SSI: surgical site infection, endogenous microbial flora most common form —> Staphylococcus aureus and Streptococcus sp SSI importance and how to minimize? Antisepsis (preventing growth of both resident and transient microbes) with pre-opt prep to decrease likelihood of infection  Antimicrobial prophylaxis and antiseptic agents IMPOSSIBLE to sterilize skin completely without impairing natural protective function and interfering with wound healing Chlorohexidine Gluconate > Povidone Iodine Bathing the night before and shave CLOSE to time of sx Major areas addressed in patient prep? Clipping and prepping ○ 20cm on each incision side with #40 clipper blade ○ Flush male prepuce with antiseptic sln before sterile prep ○ Patient positioning warm-air circulating blankets Operative site prep and describe specific concerns for each area? Male dogs ○ Clamp prepuce to opposite sides (left hand) with sterile towel clamp and place sterile gauze over to avoid tissue trauma Towel clamps ○ tips of towel clamps considered NON-sterile when placed through skin Do NOT place soiled sponges back onto instrument table of cannot wound examine daily yr T.MY yortenaonshea BghititiYnvoive EE itiii with.EE itntegrity Ultrasound addsinfobutnotdefinitive  Hyperechoic ifSepsis Knowrightaway pastprimarydelayed healing Indintention when7days wettodrybandageforfewdays thenleaveopen in musclesuture absoyygple.sintheeateinvous skinsuture nonabsorbableverticalmattress wreversecuttingneedle Protened Delayedsecondaryhealing ProudFlesh distantertarsal Tx Footcast Sterilelube clip lavagewsaline YYetefelffnlgenecnon.at Tarsegetarsal Tarso metatarsal distal tarsaljoints inter 789782Equine