Comprehensive Veterinary Surgical Asepsis, Anesthetic Planes, and Patient Monitoring

Vocabulary practice flashcards covering veterinary surgical asepsis, sterilization techniques, anesthetic stages and planes, and physiological patient monitoring equipment and parameters.

Asepsis

The absence of pathogenic microorganisms that cause infection, creating a surgically clean environment rather than a strictly sterile environment.

Sterile

The state characterized by the absence of all living microorganisms, including bacterial spores.

Surgical Conscience

The professional commitment of surgical personnel to strictly adhere to aseptic techniques, ensuring that any breaks in technique are immediately reported, addressed, and corrected regardless of whether they were observed by others.

Exogenous Route of Contamination

A route through which microorganisms enter surgical sites from external sources, specifically air, surgical supplies, the patient's skin, and the surgical team.

Endogenous Route of Contamination

A route through which microorganisms reach the surgical site from within the patient's own body, primarily through bacteremia entering via the bloodstream.

Anesthetic Duration Infection Risk Rule

The surgical principle stating that the risk of infection doubles for every $1\text{ hour}$ a patient is kept under general anesthesia.

Sterilization vs. Disinfection

Sterilization refers to the elimination or destruction of all living organisms from a material, whereas disinfection is the destruction of vegetative forms of bacteria but not their spores.

Sterile Field Boundaries (Surgical Gown)

The surgical gown is considered sterile from $2\text{ in}$ above the elbow down to the edge of the cuff and across the front of the chest down to the level of the surgical table; unsterile areas include the neckline, shoulders, top of the cuff, lower portion of the gown, and the back.

Strike-Through Contamination

Contamination that occurs when liquids soak through a surgical drape, allowing microorganisms to transport from a sterile area to an unsterile area or vice versa.

Autoclave Minimum Standard Cycle

The safe minimum standard for steam-under-pressure sterilization, requiring an exposure of $121^\circ\text{C}$ ($250^\circ\text{F}$) for $13\text{ minutes}$.

Flash Sterilization

Rapid steam sterilization performed in prevacuum sterilizers for an exposure duration of $3\text{ minutes}$.

Verify™ Integrator

A steam and ethylene oxide chemical indicator strip that provides quality control based on standard biological biological indicators ($10^5\text{ Bacillus stearothermophilus}$ for steam and $10^5\text{ Bacillus subtilis var. niger}$ for EO), rejected when the lower bar appears lighter than the upper bar.

Ethylene Oxide Sterilization

A gas sterilization method using a flammable, explosive, and toxic gas that penetrates plastic packaging at room temperature over $12\text{ hours}$, requiring quarantine in a well-ventilated area for $7\text{ days}$ or aeration in a mechanical aerator for $12\text{--}18\text{ hours}$.

Hydrogen Peroxide Gas Plasma

A low-temperature gas sterilization method that is safer for personnel and the environment than ethylene oxide, but cannot be safely used for linen, wood/paper, endoscopes, certain plastics, liquids, or long or small-diameter tubes and catheters.

Cold Sterilization

The practice of soaking instruments in disinfecting solutions such as chlorhexidine or glutaraldehyde, reserved only for minor procedures or equipment that cannot withstand heat/moisture, requiring thorough rinsing before patient contact.

Circulating Nurse

An unscrubbed member of the surgical team who opens sterile packs and acts as the runner in the operating room.

Patient Monitoring Frequency

The standard protocol requiring the veterinary anesthetist to assess and denote patient parameters on the anesthesia form at least every $5\text{ min}$.

Stage I Anesthesia

The period of voluntary movement where the patient begins losing consciousness, characterized by fear, excitement, disorientation, struggling, urination, defecation, and increased heart and respiratory rates, ending with recumbency.

Stage II Anesthesia

The excitement stage characterized by involuntary movement, irregular breathing, vocalization, struggling, paddling, dilated pupils, marked muscle tone, and intact reflexes, ending with muscle relaxation, reduced respiration, and decreased reflex activity.

Stage III, Plane 1 Anesthesia

A plane of light anesthesia not adequate for surgery, characterized by regular respiration, absent involuntary limb movement, ventral eyeball rotation, partial pupil constriction, and decreased reflex responses during which an endotracheal tube may be passed.

Stage III, Plane 2 Anesthesia

The medium surgical plane suitable for most procedures, characterized by regular shallow respirations, mildly decreased heart rate and blood pressure, relaxed muscle tone, absent pedal and swallowing reflexes, and ventromedial eye rotation.

Stage III, Plane 3 Anesthesia

A state of deep anesthesia that is excessive for most procedures, showing low heart and respiratory rates, reduced pulse strength, increased CRT, poor to absent PLR, centrally positioned eyeballs, moderately dilated pupils, and totally absent reflexes.

Stage III, Plane 4 Anesthesia

Early anesthesia overdose characterized by jerky abdominal breathing, fully dilated pupils, dry eyes, flaccid muscle tone, pale mucous membranes, prolonged CRT, and marked cardiovascular depression.

Stage IV Anesthesia

The period of anesthetic overdose characterized by cessation of respiration, circulatory collapse, and impending death, demanding immediate resuscitation.

Objectives of Surgical Anesthesia

The four clinical goals of general anesthesia ensuring that the patient does not move, is not aware, does not feel pain, and has no memory of the procedure.

Esophageal Stethoscope

A mechanical monitoring device consisting of an esophageal catheter tube, sensor, and earpieces/audio unit inserted into the esophagus to auscultate heart rate and rhythm during anesthesia.

Normal Anesthetized Heart Rates

Target heart rate ranges during anesthesia: large dogs are $50\text{--}180\text{ bpm}$, small dogs are $70\text{--}200\text{ bpm}$, and cats are $100\text{--}220\text{ bpm}$.

Capillary Refill Time (CRT)

The time it takes for blanched mucous membranes to return to their original color; a normal value is $< 2\text{ sec}$, whereas prolongation indicates low arterial blood pressure or peripheral vasoconstriction.

Mean Arterial Pressure (MAP)

The mathematically calculated average pressure throughout the cardiac cycle that serves as the best indicator of organ perfusion; normal awake values range from $85\text{--}120\text{ mm Hg}$, anesthetized patients should remain above $70\text{ mm Hg}$, and it must never drop below $60\text{ mm Hg}$.

Central Venous Pressure (CVP)

Blood pressure in the anterior vena cava measured via a jugular catheter connected to a water manometer to assess blood return, evaluate right-sided heart function, and detect overhydration during IV fluid therapy, with values $> 12\text{--}15\text{ cm }\text{H}_2\text{O}$ considered elevated.

Ultrasonic Doppler Flow Detector

A mechanical circulation monitor consisting of an electronic base unit and crystal probe that uses ultrasound gel and high-frequency sound waves to detect arterial blood flow audio.

Normal Anesthetized Respiratory Rate

The baseline breathing frequency for anesthetized animals, defined as $8\text{--}20\text{ bpm}$, where one breath equals one inhalation plus one exhalation.

Ventilating Breath Technique

The manual positive pressure ventilation procedure: 1. Close the pressure relief valve; 2. Squeeze the reservoir bag while ensuring manometer does not exceed $20\text{ cm }\text{H}_2\text{O}$ (or chest does not exceed normal excursion); 3. Open the pressure relief valve.

Pulse Oximeter

A monitoring device that applies red and infrared wavelength light to vascular tissue (such as the tongue) to measure hemoglobin oxygen saturation and heart rate.

Hemoglobin Saturation Thresholds

Pulse oximetry standards: $>95\%$ is normal on pure oxygen; $<90\text{--}95\%$ indicates hypoxemia; $<90\%$ requires therapy; and $<85\%$ for $>30\text{ seconds}$ constitutes a medical emergency.

Capnograph

An end-tidal carbon dioxide monitor that measures and records levels of $\text{CO}_2$ in inspired and expired air, closely mirroring arterial carbon dioxide ($\text{PaCO}_2$).

Mainstream vs. Sidestream Capnograph

Mainstream capnographs place the measuring sensor directly between the endotracheal tube and breathing circuit, while sidestream units draw air through sample tubing to a sensor located inside the computerized monitor.

Capnogram

A modified rectangular waveform of expired carbon dioxide showing baseline inspiration ($0\text{ mm Hg}$) and expiratory plateau ($35\text{--}45\text{ mm Hg}$), with end-tidal points reflecting arterial levels.

Malignant Hyperthermia

A genetic hypermetabolic defect most commonly observed in pigs triggered by anesthetic drugs, muscle relaxants, or restraint, characterized by muscle rigidity, red ears, hypercapnia, tachyarrhythmias, and treated using $100\%$ oxygen, cooling, and dantrolene.

Swallowing Reflex

The pharyngeal response to food or saliva, monitored via ventral neck movement; it is present in light anesthesia, absent in medium surgical anesthesia, and used clinically as the marker for endotracheal extubation upon recovery.

Laryngeal Reflex

The rapid closure of the epiglottis and vocal cords upon contact with objects to prevent tracheal aspiration, which can trigger severe laryngospasm in cats, pigs, and small ruminants during intubation.

Palpebral Reflex

The blink response elicited by lightly tapping the medial or lateral canthus or stroking upper eyelid hairs, used to evaluate anesthetic plane (lost during medium anesthesia in small animals, maintained sluggishly in horses under surgical planes).

Pedal Reflex

The withdrawal or limb flexion response elicited in small animals by squeezing, pinching, or twisting a digit or pad, indicating light anesthesia when present and medium anesthesia when absent.

Corneal Reflex

Eyeball retraction or blinking elicited by touching the cornea with sterile saline or artificial tears; useful primarily in large animals to identify excessive anesthetic depth when absent.

Jaw Tone

An indicator of muscle relaxation assessed by manually opening the patient's mouth to check resistance, which progressively decreases as anesthetic depth increases.