Odds & Ends

Suture Material Characteristics

  • Surgeon's Choice

    • Type of procedure determines which suture materials are suitable.

    • Familiarity with characteristics of available suture materials is essential.

    • Recommendation to maintain a notebook or card file listing:

    • Surgery packs

    • Suture materials

    • Special equipment

    • Patient position and preparation instructions for different procedures.

Types of Suture Material

Absorbable Sutures

  • Defined as sutures that are broken down and reabsorbed by the body.

  • Lose tensile strength within 60 days.

  • Ideal for tissues that heal rapidly.

    • Common procedures using absorbable sutures include:

    • Ovariohysterectomy (OHE)

    • Castration

    • Gastrotomy

    • Cystotomy

Characteristics of Absorbable Sutures

  • Chromic Gut

    • Also known as catgut.

    • Made from collagen fibers from sheep gut; treated with chromic salts to delay resorption.

    • Broken down by phagocytosis, may lose tensile strength rapidly in inflamed tissue.

  • Dexon

    • Composed of polyglycolic acid.

    • A multifilament synthetic suture, broken down by enzymatic hydrolysis.

    • Provides good handling and knot security but not recommended for hollow organs or infected tissue.

  • Vicryl

    • Made of polyglactin 910.

    • Similar properties to Dexon; used in similar applications.

  • PDS

    • Composed of polydioxone.

    • A synthetic monofilament, retains tensile strength for 3 to 6 weeks.

    • Features "memory," which can make it harder to handle.

  • Maxon

    • Made from polyglyconate.

    • Similar characteristics to PDS.

  • Monocryl

    • Composed of polyglecaprone.

    • A synthetic monofilament that is reabsorbed more rapidly than PDS or Maxon.

    • Excellent handling characteristics.

  • Biosyn

    • Made of glycomer 631, characterized by rapid absorption.

Non-Absorbable Sutures

  • Defined as sutures that maintain tensile strength over time.

  • Used in tissues subjected to repeated stress and in slower healing conditions, such as orthopedics.

Characteristics of Non-Absorbable Sutures

  • Silk

    • Natural multifilament suture with excellent handling and knot security.

    • Has wicking properties, may harbor bacteria, and inflammatory reactions can lead to strength loss in 6 months.

  • Stainless Steel

    • Can be either monofilament or multifilament.

    • Biologically inert, no wicking properties, making it ideal for infected tissue.

    • However, it is poor in terms of handling.

  • Nylon

    • Synthetic suture that can be monofilament or multifilament.

    • Does not provoke tissue reaction, allowing for internal use; however, it loses tensile strength over time.

    • Often used for skin sutures due to its toughness.

  • Prolene

    • A synthetic monofilament, retaining tensile strength like nylon.

  • Novafil

    • Composed of polybutester, synthetic monofilament with elastic properties.

    • Useful for repairing ligaments.

  • Braunamid/Supramid

    • Polymerized caprolactam, synthetic, coated multifilament offering high tensile strength with minimal tissue reaction.

    • Only recommended for skin sutures due to wicking potential.

Suture Size

  • Smaller sizes include 3-0, 2-0, 0, 1, 2.

  • Oversized suture material does NOT increase wound strength but could lead to overtightening.

  • Smaller sutures tend to provide better knot security.

Suture Packaging

  • Most sutures are sterilized within their packaging.

    • Common sterilization methods include:

    • Gamma irradiation

    • Ethylene oxide

    • Always check expiration date before use.

  • Cassette Packaging

    • Sterilized suture encased in a cassette with preservatives to maintain sterility.

    • Only pull the necessary amount needed for a procedure while adhering to aseptic techniques.

  • Some sutures can withstand autoclaving up to 3 times, such as nylon, polypropylene, and stainless steel.

Suture Alternatives

  • Staples

    • Rapid application using a dispenser.

    • Made of non-reactive stainless steel.

  • Surgical Glue

    • Can be used standalone (e.g., onychectomy) or in conjunction with subcuticular sutures.

    • Requires hemostasis to ensure effective adhesion.

Suture Needles

  • Selecting the Correct Needle

    • Size: must reach both sides of the incision.

    • Shape: commonly half-circle or 3/8 circle.

    • Point types include:

    • Taper

    • Blunt taper

    • Cutting edge, or curved cutting

    • Reverse cutting edge

    • Taper cut

    • Micro-point spatula curved

Needle Point Diagram

  • Taper point

  • Blunt taper point

  • Cutting edge or curved cutting

  • Reverse cutting edge

  • Taper cut

  • Micro-point spatula curved

Scalpel Blades

Small Animal Scalpel Blades

  • Handle: #3 Bard Parker

  • Blade types:

    • #10

    • #15

    • #11

    • #12

Large Animal Scalpel Blades

  • Handle: #4 Bard Parker

  • Blade types:

    • #18

    • #22-24

Electrosurgery

General Overview

  • Coagulation: achieved through electrocautery.

  • Cutting: supplied by electroscalpel.

  • Safety Precautions:

    • Ground plate must be correctly positioned, and gel used for optimal contact.

    • Be aware of sparks; they can ignite oxygen or alcohol.

    • If any electrical shock occurs, inspect the glove for perforation.

Types of Electrosurgery

  • Monopolar Electrosurgery

    • Most common method for cutting or cautery.

    • Tissues must be blotted dry for effective hemostasis.

  • Bipolar Electrosurgery

    • Instrument resembles thumb forceps, with current passing between sides through tissue grasped.

    • Preferred for delicate tissue work (e.g., ophthalmic, neurosurgery).

Cleaning Electrosurgery Probes

  • Probes should be wiped with alcohol or hydrogen peroxide followed by gauze for cleanliness.

  • Clean in an ultrasonic cleaner if needed; refer to manufacturer's guidelines before autoclaving.

  • Store probes in cases to protect against damage.

Laser Surgery

General Overview

  • Used for both cutting and coagulation.

  • Safety Considerations:

    • Fire hazards exist; avoid oxygen or alcohol exposure during the procedure.

    • Protect the patient’s eyes with wet gauze during the procedure and ensure all personnel wear protective goggles.

Advantages of Laser Surgery

  • Provides precise incisions.

  • Results in effective hemostasis.

  • Promotes rapid healing.

  • Less postoperative pain for patients.

Positive Pressure Ventilation

  • Defined as any ventilation support mechanism that pushes gas into the patient by increasing pressure in the breathing circuit.

  • Manual Ventilation: can be achieved through bagging or sighing the patient.

  • Intermittent Mandatory Ventilation: a method where the anesthetist manually regulates respiration.

  • Mechanical Ventilation: replaces the reservoir bag with a ventilator for controlled respiration.

Mechanical Ventilation

Indications for Use

  • May be necessary for:

    • Horses

    • Cattle/Ruminants

    • Patients with head trauma

    • Patients suffering lung disease

    • Procedures involving the chest cavity

    • Extended surgical operations

Guidelines for Ventilation

  • Recommended respiratory rate (RR) is 6-12 breaths per minute.

  • Pressure settings of 25-40 cm H2O for large animals, 15-20 cm H2O for small animals.

  • Exhalation duration should be twice that of inhalation (e.g., inhale for 1 second, exhale for 2 seconds).

  • Adequate ventilation can usually prevent spontaneous ventilation; if issues arise, neuromuscular blocking agents may be required.

Neuromuscular Blocking Agents

Applications

  • Utilized for mechanical ventilation, orthopedic procedures, ophthalmic surgeries, and cesarian sections.

Important Considerations

  • NO anesthetic or analgesic activity; only to be used in conjunction with general anesthesia, appropriate analgesia, and ventilatory support.

  • Blocks skeletal muscle while not affecting cardiac or smooth muscle.

  • Watch for reflex alterations involving skeletal muscles (such as palpebral response and muscle tone); monitor for corneal drying and the possibility of hypothermia.

Types of Neuromuscular Blocking Agents

  • Non-depolarizing agents

    • Examples: Atracurium, which is reversible with edrophonium.

  • Depolarizing agents

    • Example: Succinyl choline; short-acting and not reversible.

    • Administered IV as a slow injection.

Recovery and Monitoring

  • During recovery, reverse neuromuscular agents must be implemented.

  • Avoid abrupt discontinuation of ventilation.

  • Gradually reduce ventilation rate to 4 breaths/minute, then to 2 breaths/minute.

  • Continue to provide oxygen until the patient is capable of maintaining spontaneous ventilation.

Potential Complications of Mechanical Ventilation

  • Respiratory Rate Too High: risk of respiratory alkalosis.

  • Pressure Too High: can lead to ruptured alveoli or pneumothorax.

  • Maintaining elevated pressure may compromise cardiac output; allow sufficient time for exhalation.

  • Increased anesthetic depth may occur during extensive ventilation processes.