Comprehensive Veterinary Nursing, Wound Care, Toxicology, and Clinical Procedures Study Guide

Wound Healing Phases and Mechanics

  • Inflammatory Phase (0−3 days0-3\,\text{days}):

    • Lag phase comprises inflammation and debridement together.
    • Vasoconstriction occurs initially to reduce bleeding.
    • Platelet aggregation and clot formation occurs (blood clot formation occurs in the first 6 hours6\,\text{hours}).
    • Vasodilation follows.
    • Neutrophils remove bacteria and debris.
    • Macrophages clean wound and release growth factors.
    • Clinical signs: Redness, heat, swelling, pain.

  • Debridement Phase (1−6 days1-6\,\text{days}):

    • Neutrophils and macrophages remove dead tissue.
    • Wound becomes cleaner.
    • Growth factors stimulate repair.
    • Prepare wound for tissue repair.

  • Repair/Proliferative Phase (3−5 days3-5\,\text{days}, can be up to 20 days20\,\text{days}):

    • Granulation:
      • Fibroblasts produce collagen.
      • New capillaries develop (angiogenesis).
      • Granulation tissue fills wound (formation of granulation bed begins).
    • Epithelialization:
      • Epithelial cells migrate across wound surface.
    • Contraction:
      • Myofibroblasts pull wound edges together.

  • Maturation/Remodeling Phase (Weeks to years):

    • Collagen reorganizes.
    • Scar tissue forms.
    • Tensile strength increases.
    • Maximum strength: About 80%80\% of original tissue strength.

Wound Closure Intentions and Classification

  • General Rule: Both primary and delayed wound closure heal through first intention, appositional closing.

  • Primary Wound Closure (First Intention / Appositional Healing):

    • Indications: Fresh, clean, sharply incised wounds with minimal tissue trauma and minimal contamination.
    • Time Window: Performed rapidly after injury, strictly within the 6−8 hour6-8\,\text{hour} "golden period".

  • Delayed Primary Wound Closure:

    • Indications: Mildly contaminated or minimally traumatized wounds requiring initial cleansing and débridement.
    • Time Window: Closure performed 1−3 days1-3\,\text{days} post-injury (after the 6−8 hour6-8\,\text{hour} golden period).
    • Key Requirement: Closed BEFORE the appearance of granulation tissue in the wound bed.

  • Second Intention Healing:

    • Description: Wound is allowed to heal naturally without surgical closure.
    • Example: Cat bite abscess, can include surgical or mechanical debridement.

  • Third Intention Healing (Secondary Closure):

    • Description: Surgical closure executed at least 3−5 days3-5\,\text{days} post-injury.
    • Key Requirement: Closed AFTER a healthy bed of granulation tissue has fully formed.

Host Factors Affecting Wound Healing

  • Local Factors:

    • Infection
    • Foreign bodies
    • Excess motion
    • Poor blood supply
    • Edema
    • Necrotic tissue

  • Systemic Factors:

    • Age
    • Poor nutrition
    • Diabetes mellitus
    • Obesity
    • Shock
    • Immunosuppression
    • Corticosteroid therapy
    • Anemia

Wound Treatment, Lavage, and Drainage

  • General Treatment Rules:

    • No added antibiotics, soaps, detergents, antiseptics, due to cellular toxicity.
    • Must use isotonic crystalloids like Normosol-R or 0.9%0.9\% NaCl.

  • Initial Steps:

    1. Control hemorrhage
    2. Clip hair widely
    3. Protect wound during clipping
    4. Lavage with sterile saline
    5. Debride necrotic tissue
    6. Culture if needed
    7. Bandage or close wound

  • Lavage Parameters:

    • 7−8 psi7-8\,\text{psi} ideal pressure.
    • 35-mL35\text{-mL} syringe + 18-gauge18\text{-gauge} needle commonly used.

  • Wound Drainage Systems:

    • Manage anatomical dead space: Accumulation of blood, serum, or exudate in sub-dermal dead space delays cellular healing and increases infection risk.
    • Passive Drain System: Utilizes capillary action and gravity drainage (e.g., Penrose drain).
    • Active Drain System: Utilizes closed suction continuous negative pressure vacuum system consisting of a rigid fenestrated catheter attached to an evacuated collection bulb.

Types of Wounds

  • Abrasion: Superficial skin damage.

  • Laceration: Tear with irregular edges.

  • Incision: Sharp, clean cut.

  • Puncture: Deep narrow wound with high infection risk.

  • Avulsion: Tissue torn away.

  • Decubital Ulcers (Pressure Sores):

    • Causes: Prolonged recumbency, pressure over bony prominences.
    • Common Locations: Elbows, hocks, hips.
    • Treatment: Frequent repositioning, soft bedding, bandaging, nutritional support.

  • Degloving Injury:

    • Definition: Skin and subcutaneous tissue torn from underlying structures.
    • Common Cause: Trauma, road accidents.
    • Treatment: Aggressive cleaning, debridement, bandaging, skin grafts may be needed.

  • Burns:

    • First Degree: Epidermis only; redness; painful for 2−3 days2-3\,\text{days}; epidermal layer peels.
    • Second Degree: Involves all layers of the dermis; partial thickness; blister formation with fluid collection at the epidermal-dermal junction.
    • Third Degree: Full thickness skin destruction; white or charred black/leathery; firm texture; depressed surface relative to surrounding intact skin.
    • Treatment:
      • Intravenous crystalloid and colloid fluid resuscitation.
      • Systemic antibiotic administration.
      • Aggressive high-calorie, high-protein nutritional support.
      • Intensive local wound management and debridement.

Bandages and Applications

  • Primary Layer (Contact Layer):

    • Function: Protect wound, deliver medications, absorb drainage.
    • Examples: Nonadherent pads, wet-to-dry dressings.

  • Secondary Layer:

    • Function: Padding, absorption.
    • Materials: Cast padding, rolled cotton.

  • Tertiary Layer:

    • Function: Protection, compression, secure other layers.
    • Examples: VetWrap, elastic bandage.

  • Bandage Application Steps:

    1. Prepare wound
    2. Apply primary layer
    3. Apply secondary layer
    4. Apply tertiary layer
    5. Leave toes exposed when possible
    6. Check circulation

  • Client Information and Monitoring:

    • Assess toes 3 and 4 for warmth, color, swelling.
    • Check for foul odors and chafing from cast.
    • Keep animal from chewing bandages.
    • Restrict exercise.
    • Protect bandages from moisture.
    • Instruct owners to report slipping bandages, foul smells, cold digits, or sudden pain immediately.

  • Common Types of Bandages:

    • Robert Jones: Heavy padded bandage, temporary fracture stabilization, edema reduction.
    • Modified Robert Jones: Most common bandage applied in small animal medicine; less padding, post-operative support.
    • Velpeau Sling: Forelimb immobilization.
    • Ehmer Sling: Coxofemoral luxation reduction.

Splinting Techniques

  • Spoon Splint: Distal limb injuries.

  • Lateral Splint: Long bone fractures.

  • Caudal Splint: Rear limb support.

  • Schroeder-Thomas Splint: Femoral fractures (large animals).

Toxicology and Toxic Agent Management

  • Ethylene Glycol:

    • Organ Affected: Kidneys.
    • Treatment: Fomepizole, ethanol, fluids.

  • Chocolate:

    • Causative Agent: Methylxanthine compounds, theobromine and caffeine (the more bitter the more toxic).
    • Organ Affected: Heart/CNS.
    • Clinical Signs: Hyperactivity, tachycardia, tremors, vomiting, polydipsia, polyuria, and lethargy.
    • Treatment: Emesis, activated charcoal, cardiovascular monitoring, and fluid diuresis.

  • Rodenticide:

    • Organ Affected: Coagulation system.
    • Treatment: Vitamin K_1$.\n\n* Acetaminophen:\n * Organ Affected: Liver, RBCs.\n * Treatment: N-acetylcysteine.\n\n* Xylitol:\n * Description: Sugar substitute used in sugar free foods, candies, gum, and veterinary dental washes.\n * Organ Affected: Liver, pancreas.\n * Pathophysiology: Induces massive insulin release in dogs, leading to severe hypoglycemia and acute hepatotoxicity (can lead to severely low BG or liver failure).\n * Treatment: Emesis or gastric lavage, frequent food offering, IV fluid therapy with Dextrose for hypoglycemia, and hepatic monitoring.\n\n* Grapes/Raisins:\n * Organ Affected: Kidneys.\n * Pathophysiology: Causes acute renal failure in dogs.\n * Treatment: Decontamination via emesis and activated charcoal, followed by fluid diuresis for 48\,\text{hours}.\n\n* Permethrin:\n * Source: Found in K9 Advantix.\n * Clinical Signs: Muscle tremors, generalized seizures in cats.\n * Treatment: Methocarbamol (Robaxin) for muscle tremors, supportive care, and bathing after neurological signs are controlled.\n\n* Mycotoxins:\n * Source: Moldy food ingestion.\n * Clinical Signs: Mild to severe ataxia, muscle tremors, generalized convulsions.\n * Treatment: Emesis, gastric lavage, activated charcoal, anti-seizure medications, and supportive nursing care.\n\n* Onions and Garlic:\n * Toxicity: Toxic in all preparation forms.\n * Pathophysiology: Causes oxidative damage to canine and feline RBCs, resulting in hemolysis.\n * Clinical Signs: Hemolytic anemia, hemoglobinuria, pale mucous membranes, weakness, and vomiting.\n * Treatment: Emesis and activated charcoal for recent ingestions; severe cases require whole blood transfusions and fluid diuresis.\n\n* Macadamia Nut:\n * Toxicity: Toxic to dogs.\n * Clinical Signs: Muscle weakness, depression, vomiting, ataxia, tremors, hyperthermia.\n * Treatment: For recent ingestions, emesis, activated charcoal, and enemas.\n\n* Rising Bread Dough:\n * Pathophysiology: Expands in warm stomach environment and ferments producing ethanol.\n * Clinical Signs: Abdominal distension, severe abdominal pain, bloating, vomiting, incoordination, and depression.\n * Treatment: Emesis if recent, analgesia, administration of cool water via stomach tube or orally to halt dough fermentation, surgical removal if necessary, and monitoring/correcting metabolic acidosis.\n\n* Tobacco:\n * Causative Agent: Contains nicotine affecting both dogs and cats.\n * Clinical Signs: Excitation, tachypnea, salivation, emesis, diarrhea, muscle weakness, muscle twitching, depression, tachycardia, shallow respiration, collapse, coma, and cardiac arrest.\n\n* Decontamination Techniques:\n * Ocular Exposure: Eyes should be flushed repeatedly with water and saline solutions for a minimum of 20-30\,\text{minutes}. Eyes should be monitored for excessive redness, tearing, or pain.\n * Dermal Exposures: Animals should be bathed in a mild liquid dishwashing detergent. Wear proper PPE.\n * Corrosive Ingestion: Dilution with milk or water is recommended. Emesis is contraindicated.\n * Activated Charcoal Administration:\n * Absorbs toxicants, organic poisons, chemicals, or bacterial toxins within the gastrointestinal lumen and facilitates fecal excretion.\n * Indicated when ingested toxins undergo enterohepatic circulation (recycling pathway of bile acids, bilirubin, and drugs between the liver and small intestine).\n * Contraindicated with ingestion of caustic or corrosive substances.\n * Emetics:\n * Dogs: Apomorphine (Injection or conjunctival is preferred emetic), Hydrogen peroxide (1\text{ tsp}/5\text{ lbs}nottoexceednot to exceed3\text{ tablespoons}).\n * Cats: Dexmedetomidine (Dexdomitor - Dogs and cats), Xylazine.\n * Contraindications: History of seizures (epilepsy), clinical sign of vomiting, history of cardiovascular disease, exposure to corrosives or petroleum distillates, history of being debilitated, clinical sign of sedation, exhibiting signs of excessive stimulation.\n * Cathartics:\n * Enhance elimination of activated charcoal. Without cathartics, the toxicant bound by charcoal can eventually be released and reabsorbed.\n * Contraindicated if the animal has diarrhea or is dehydrated.\n * Used with activated charcoal: Sorbitol.\n * Gastric and Enterogastric Lavage:\n * Gastric Lavage: Gentle stomach pumping performed under general anesthesia. Contraindicated following caustic or petroleum distillate ingestion.\n * Enterogastric Lavage ("Through-and-Through Lavage"): An initial enema clears large fecal matter from the colon. Water is then introduced and allowed to flow through a stomach tube until the output runs completely clear.\n\n# Physical Therapy and Rehabilitation Modalities\n\n* Heat Therapy (Thermotherapy):\n * Mechanism: Introduces thermal energy to dilate local blood vessels, increase soft tissue extensibility, lower muscular spasms, and promote metabolic clearance.\n * Effects: Increased blood flow, muscle relaxation.\n * Contraindications: Acute inflammation, active bleeding.\n\n* Cold Therapy (Cryotherapy):\n * Mechanism: Extracts heat from body tissues upon contact, inducing peripheral vasoconstriction, reduced local blood flow, decreased cellular metabolism, and reduced pain signal transmission.\n * Effects: Reduces pain, decreases swelling.\n * Contraindications: Poor circulation.\n\n* Therapeutic Ultrasound:\n * Mechanism: Uses high-frequency sound waves to produce deep tissue heating (thermal effects) and micro-streaming/cavitation (non-thermal acoustic effects).\n * Uses: Tendon injuries, muscle injuries.\n * Contraindications: Growth plates, neoplasia, pregnancy.\n\n* General Contraindications to Rehabilitation: Unstable fractures, fever, active infection, severe pain.\n\n* Acupuncture Modalities:\n * Dry Needling: Standard insertion using solid stainless steel acupuncture needles.\n * Moxibustion: Application of heat through the burning of dried leaves of the *Artemisia vulgaris* (mugwort) plant over acupuncture points.\n * Aquapuncture: Injection of a liquid solution directly into an acupuncture point.\n * Electroacupuncture: Passing electrical energy/current through acupuncture points via inserted needles.\n * Implantation: Surgical insertion of specific materials directly into acupuncture points to achieve continuous, long-term stimulation. Classified as a formal surgical procedure. Materials utilized include Catgut, Stainless steel, Silver, and Gold (gold is the most common material used).\n * Low-Intensity ("Cold") Lasers: Non-invasive laser energy used to stimulate acupuncture points.\n * Acupressure: Manual stimulation of acupuncture points using physical pressure without skin penetration.\n * Needle Placement and Removal: Precise mechanical placement and withdrawal procedures.\n\n* Acupuncture Concepts and Clinical Applications:\n * Concepts: Stimulation of acupuncture points, neurologic and endorphin effects.\n * Clinical Indications/Applications: Pain and lameness, musculoskeletal disorders, neurologic disorders, dermatologic disorders, behavioral disorders, reproductive disorders, gastrointestinal disorders, overall improvement of quality of life.\n\n* Massage Strokes:\n * Effleurage: Light stroking, following the natural contour of the body (the most common massage stroke).\n * Petrissage (Kneading): Kneading.\n * Tapotement: Light rhythmic tapping or percussive movements applied to muscle tissue.\n * Friction: Deep circular movement.\n\n* Chiropractic Purpose:\n * Restore joint mobility.\n * Improve neurologic function.\n\n# Electrocardiography (ECG) Concepts\n\n* Electrical Conduction Pathway:\n * SA Node \rightarrowAtriaAtria\rightarrowAVNodeAV Node\rightarrowBundleofHisBundle of His\rightarrowBundleBranchesBundle Branches\rightarrowPurkinjeFibersPurkinje Fibers\rightarrow Ventricles.\n\n* ECG Waves and Intervals:\n * P Wave: Atrial depolarization.\n * PR Interval: AV conduction time.\n * QRS Complex: Ventricular depolarization.\n * T Wave: Ventricular repolarization.\n\n* Common Arrhythmias:\n * Atrial Fibrillation: No distinct P waves, irregularly irregular rhythm, common in large breed dogs.\n * Ventricular Premature Complexes (VPCs): Wide bizarre QRS.\n * Ventricular Tachycardia: Rapid ventricular rhythm.\n * Sinus Bradycardia: Slow SA node firing.\n * Sinus Tachycardia: Fast SA node firing.\n\n# Pain Management\n\n* Opioids:\n * Examples: Morphine, Hydromorphone, Fentanyl, Methadone, Buprenorphine.\n * Effects: Strong analgesia.\n\n* NSAIDs:\n * Examples: Carprofen, Meloxicam, Deracoxib, Robenacoxib.\n * Effects: Reduce inflammation and pain.\n\n* NMDA Receptor Antagonist:\n * Example: Ketamine.\n * Effects: Prevents central sensitization, wind-up pain reduction.\n\n# Triage Priorities, Emergencies, and Stabilization\n\n* Triage Priorities:\n 1. Airway\n 2. Breathing\n 3. Circulation\n 4. Disability\n 5. Exposure\n\n* Common Emergencies:\n * Small Animal: GDV, Trauma, DKA, Heat stroke, Toxin ingestion.\n * Large Animal: Colic, Dystocia, Severe lameness, Choke.\n\n* Stabilization Protocols:\n * Oxygen\n * IV access\n * Fluids\n * Pain control\n * Monitoring\n\n# Enteral and Parenteral Support\n\n* Orogastric Tube (OGT) Placement:\n 1. Measure tube to stomach\n 2. Lubricate\n 3. Pass through mouth into esophagus\n 4. Verify placement\n * Uses: Gastric decompression, Gastric lavage, Nutritional support.\n\n* Total Parenteral Nutrition (TPN):\n * Requires: Central venous catheter.\n * Provides: Protein, Dextrose, Lipids, Vitamins.\n\n# Administration Routes and Pharmacology\n\n* Oral Medication Administration:\n * Dogs/Cats: Pill orally behind tongue, follow with water or food.\n * Horses: Dose syringe, drenching.\n * Ruminants: Balling gun, drench equipment.\n\n* Catheters:\n * Peripheral IV Catheter: Most common.\n * Central Venous Catheter: TPN, CVP monitoring.\n * Urinary Catheter: Urine drainage.\n * Butterfly Catheter: Small veins.\n\n* Injection Types:\n * Intradermal (ID): Allergy testing.\n * Subcutaneous (SQ): Vaccines, fluids.\n * Intramuscular (IM): Certain medications.\n * Intravenous (IV): Immediate effect.\n * Intraosseous (IO): Emergency access.\n\n# Fluid Therapy Principles and Dehydration Assessment\n\n* Fluid Types:\n * Crystalloids: Lactated Ringer's, Normosol-R, Plasma-Lyte A.\n * Colloids: Hetastarch, Plasma.\n\n* Routes of Administration: IV, SQ, IO, Oral.\n\n* Assessing Dehydration:\n * 5\%: Mild tacky mucous membranes.\n * 6-8\%: Skin tenting.\n * 10-12\%: Shock.\n\n* Fluid Overload Signs:\n * Serous nasal discharge\n * Chemosis\n * Pulmonary crackles\n * Increased respiratory effort\n * Weight gain\n\n# Respiratory, Urinary, and Critical Care Protocols\n\n* Heaves (Equine COPD/Recurrent Airway Obstruction):\n * Signs: Coughing, exercise intolerance, nasal discharge, expiratory effort.\n * Heave Line: Hypertrophied abdominal muscles.\n\n* Urinary System Nursing:\n * Normal Urine Output (Dog/Cat): 1-2\,\text{mL/kg/hr}.\n * Collection Methods:\n * Cystocentesis: Sterile sample.\n * Catheterization: Sterile collection.\n * Free Catch: Voided sample.\n * Most Common Electrolyte Abnormality in Urinary Obstruction: Hyperkalemia.\n * Consequences of Hyperkalemia: Bradycardia, arrhythmias, cardiac arrest.\n\n* CPR (RECOVER Guidelines):\n * Basic Life Support Protocol: C-A-B (1. Compressions, 2. Airway, 3. Breathing).\n * Compression Rate: 100-120/\text{minute}.\n * Ventilation Rate: 10\,\text{breaths/minute}.\n\n# Neonatal Immunity, Transfusion Medicine, and Clinical Procedures\n\n* Colostrum:\n * Provides: Immunoglobulins (IgG), Nutrients, Energy, Growth factors.\n * Absorption Window: Most absorption occurs during the first 12-24\,\text{hours}.\n\n* Blood Transfusions:\n * Canine Blood Types: DEA System (most important: DEA 1 positive, DEA 1 negative).\n * Feline Blood Types: Type A, Type B, Type AB (cats possess naturally occurring antibodies).\n * Transfusion Reaction Signs: Fever, vomiting, tachycardia, hypotension, collapse, hemolysis.\n\n* Common Blood Collection Sites:\n * Dog: Jugular (large volume), Cephalic (peripheral access), Lateral Saphenous (common restraint site).\n * Cat: Jugular (preferred large sample), Medial Saphenous/Femoral (common collection site).\n * Horse: Jugular Vein.\n * Cattle: Jugular Vein, Coccygeal Vein.\n\n* Diagnostic Sampling Techniques:\n * Fine Needle Aspirate (FNA): Cytology.\n * Skin Scraping: Parasites.\n * Ear Cytology: Otitis.\n * Tracheal Wash: Respiratory disease.\n * BAL (Bronchoalveolar Lavage): Lower airway disease.\n\n# Collection Tubes and High-Yield Exam Facts\n\n![Collection Tubes Reference Chart](https://assets.knowt.com/pdf-flow-prod/e48867b6-017c-4586-92c9-6e7079a824de-figures/0.png)\n\n* Collection Tubes:\n * EDTA: Lavender top; used for CBC.\n * Sodium Citrate: Blue top; used for Coagulation.\n * Serum: Red top; used for Chemistry.\n * SST: Tiger Top; used for Chemistry.\n * Heparin: Green top; used for Plasma chemistry.\n * Fluoride Oxalate: Gray top; used for Glucose.\n\n* High-Yield Exam Facts:\n * Hyperkalemia is the classic electrolyte abnormality with urinary obstruction.\n * P wave = atrial depolarization.\n * QRS = ventricular depolarization.\n * T wave = ventricular repolarization.\n * Inflammation \rightarrowDebridementDebridement\rightarrowRepairRepair\rightarrow Maturation.\n * Colostrum provides passive transfer of antibodies.\n * Atrial fibrillation has no identifiable P waves and an irregularly irregular rhythm.\n * Robert Jones bandage provides heavy padding and temporary fracture stabilization.\n * Ehmer sling is used after reduction of coxofemoral luxation.\n * Compression rate during CPR = 100-120/\text{min}$$.
    • Cats must be blood typed before transfusion because naturally occurring antibodies are present.
    • Jugular vein is the preferred site for large blood samples in dogs, cats, and horses.
    • Fluid overload commonly causes pulmonary crackles and increased respiratory effort.