Anesthetic Monitoring Flashcards

A set of 100 flashcards based on the VTT 246 Surgical Nursing lecture on Anesthetic Monitoring, covering physiological parameters, monitoring devices, and anesthesia stages.

Anesthetic Monitoring

The process of assessing cardiovascular, respiratory, and neurologic parameters in a patient under anesthesia to detect trends and make adjustments.

Veterinary Technician Anesthetist

The person whose sole responsibility during surgery is monitoring the patient to ensure safe surgical anesthesia rather than inadvertent euthanasia.

Circulating Assistant

The team member who positions the patient, attaches monitoring devices, and performs the final skin prep and paint in the surgery room.

Monere

The Latin root for the word monitor, meaning "to warn."

Monitoring Interval

The requirement that patients be monitored for the entirety of anesthesia with recordings made every $5-10\,min$.

High solubility/parturition coefficient

A property of inhalation agents that may require more frequent monitoring due to slower changes in anesthetic depth, though the transcript notes low solubility allows for quick changes.

Parameters to Monitor

Specific patient vitals including heart rate, rhythm, respiratory rate, rhythm, capillary refill time, mucous membrane color, eye position, muscle tone, reflexes, and temperature.

Treatment Parameters

Specific data that should be documented including volume of fluid administered, oxygen flow rate, anesthetic gas concentration, and other medications.

Esophageal Stethoscope

A convenient and less intrusive device used to listen to heart and respiratory rates during anesthesia.

Heart Rate Depression

The expected slowing of the heart rate under anesthesia because most anesthetic agents depress the cardiovascular system.

Large Dog Low Heart Rate Limit

The heart rate threshold of $<60\,bpm$ at which a surgeon should be notified.

Small Dog Low Heart Rate Limit

The heart rate threshold of $<80\,bpm$ at which a surgeon should be notified.

Cat Low Heart Rate Limit

The heart rate threshold of $<90\,bpm$ at which a surgeon should be notified.

Anticholinergics

A class of drugs including Atropine sulfate and glycopyrrolate administered to help maintain heart rate by blocking the vagal response.

SLURED

An acronym for the effects of anticholinergics: Salivation, Lacrimal, Urinary, Respiratory, Eye, Digestive, and Cardiac.

Salivation (SLURED)

The effect of anticholinergics involving decreased salivary secretions.

Lacrimal (SLURED)

The effect of anticholinergics involving decreased lacrimal secretions.

Urinary (SLURED)

The effect of anticholinergics involving decreased contraction of the urinary bladder and ureters.

Respiratory (SLURED)

The effect of anticholinergics involving dry respiratory secretions, bronchodilation, and increased physiologic dead space.

Eye (SLURED)

The effect of anticholinergics causing mydriasis, or pupil dilation.

Digestive System (SLURED)

The effect of anticholinergics involving decreased gastrointestinal motility.

Cardiac (SLURED)

The effect of anticholinergics involving increased heart rate and cardiac output.

Large Dog Upper Heart Rate Limit

The acceptable upper limit of $180\,beats/min$ under anesthesia.

Small Dog Upper Heart Rate Limit

The acceptable upper limit of $200\,beats/min$ under anesthesia.

Cat Upper Heart Rate Limit

The acceptable upper limit of $220\,beats/min$ under anesthesia.

Arrhythmia

An irregular heart rhythm that makes the heart inefficient at pumping blood, potentially leading to poor tissue perfusion and acidosis.

Pulse Deficit

A condition where the heart contracts but does not generate enough push to produce a palpable peripheral pulse.

Skipped Beats

A result of a single premature depolarization of the heart muscle, detectable with a stethoscope but not palpable as a pulse.

Surgical Plane Respiratory Rate

The expected rate of $8$ to $20\,breaths/min$ for a dog or cat under anesthesia.

Apnea

The total absence of breathing, observed in Stage IV of anesthesia.

Crackles and Wheezing

Auditory indicators of pulmonary airway narrowing through constriction or the presence of fluid.

Respiratory Rhythm

The pattern of breathing where the inspiratory phase is about half as long as the expiratory phase.

Gasping or Labored Breathing

Symptoms indicating possible obstruction of the trachea or ET tube, or a lack of fresh gas flow.

ET Tube Patency

The state of being open or unobstructed; if lost, it may require suctioning or reintubation.

Assisted Ventilation

Also known as bagging, this practice involves manually ventilating the patient every $2$ to $5\,minutes$ to prevent atelectasis.

Atelectasis

The collapse of alveoli, often caused by shallow breathing and the weight of internal organs on the lungs in anesthetized patients.

Tissue Perfusion

The delivery of blood to the capillary bed in biological tissue, critical for removing waste and delivering oxygen and glucose.

Mucous Membranes (MM)

An indicator of tissue perfusion evaluated on the gums, conjunctiva, vulva, or prepuce.

Pale MM

A sign indicating poor tissue perfusion, anemia, or shock.

Dark-red MM

A sign indicating the patient is septic, with severe blood infection causing postcapillary venous dilation.

Cyanotic MM

A bluish color indicating that red blood cells are not carrying adequate oxygen, suggesting respiratory obstruction.

Capillary Refill Time (CRT)

The time taken for color to return to an external capillary bed after pressure; normally $2\,seconds$ or less.

Slow CRT Causes

Conditions such as low arterial blood pressure, peripheral vasoconstriction, or the use of $\alpha_2$-adrenergic agonists like medetomidine.

Pulse Strength

A general indicator of blood pressure defined by the ease or difficulty of palpating blood flowing through an artery.

Pulse Monitoring Arteries

Vessels used for palpation including the lingual, femoral, carotid, dorsal metatarsal, and digital arteries.

Mean Arterial Pressure (MAP)

A measurement of blood pressure that should be maintained above $70\,mm\,Hg$ and never fall below $60\,mm\,Hg$ during anesthesia.

Hypotension

Low blood pressure caused by hypovolemia, cardiac insufficiency, excessive vasodilation, or excessive anesthetic depth.

Monitoring Temperature Frequency

The practice of checking body temperature at least every $15\,minutes$.

Hyperthermia

An elevation in body temperature that can occur due to muscle contractions from inhalation anesthetics.

Malignant Hyperthermia

A spontaneously manifesting, dangerously high body temperature that can lead to life-threatening cerebral edema.

Hypothermia

A constant concern under general anesthesia caused by muscle relaxation, shaving/washing, room-temperature fluids, and cold gases.

Neurologic Parameters

Indicators of anesthetic depth including reflexes, muscle tone, and eye characteristics.

Reflex

An automatic reaction to a stimulus made without conscious awareness, which diminishes as anesthetic depth increases.

Auricular Reflex

An ear flick reaction to touching the pinna, used only in cats and horses, and never in canines.

Pedal Reflex

A withdrawal or toe pinch reaction used to assess depth, especially when masking a patient.

Palpebral Reflex

A blink reaction elicited by touching the medial canthus of the eye, which disappears in the surgical plane.

Laryngeal Reflex

A swallow reaction in response to matter in the pharynx, which must be lost to allow for intubation.

Corneal Reflex

A blink or globe retraction when touching the cornea, typically used to assess death during euthanasia or in large animals.

Laryngeal Spasm

A condition where the larynx closes, more common in cats if intubation is attempted before the swallow reflex is lost.

Muscle Tone

The level of tension in muscles, which usually relaxes as depth increases, except when using dissociative anesthetics.

Jaw Tone

The resistance to opening the mouth, used to assess depth; it increases as the patient becomes lighter.

Dissociative Anesthetics

Drugs like ketamine that cause muscle rigidity and may prevent changes in eye position.

Benzodiazepines

Muscle relaxants such as diazepam or zolazepam often added to dissociative anesthetics to counteract rigidity.

Eye Position (Surgical Plane)

The orientation where the eye rotates ventrally during moderate or surgical levels of anesthesia.

Eye Position (Light/Deep)

The orientation where the eye remains in a central position.

Pupillary Light Response (PLR)

The reflex where the pupil constricts in response to light, which slows as anesthetic depth increases.

Mydriasis

Pupillary dilation caused by deeper stages of anesthesia or anticholinergic drugs.

Cranial Procedures

Surgeries on the head (ophthalmic, aural, mouth) that require alternative monitoring sites like the vulva, prepuce, or tail.

Reflectance Probe

A pulse oximetry sensor that can be attached to the underside of the base of the tail.

Respiratory Compromise

A state where issues like dyspnea or abdominal pressure require the use of a ventilator.

Dorsal Recumbency

A positioning challenge where the neck in extension decreases the ability to expand the chest, causing respiratory issues.

Anesthesia Monitoring Devices

Tools such as pulse oximeters, capnographs, and BP monitors used together to provide a status of the patient.

Pulse Oximeter

A noninvasive device that estimates saturated hemoglobin ($SO_2$) and monitors pulse rate.

Saturated Hemoglobin (SO2)

A measurement of the percentage of hemoglobin bound to oxygen, with a normal range of $95\%-99\%\,SpO_2$.

Pulse Oximeter Wavelengths

The device uses red light to determine pulse rate and infrared light to determine oxygen saturation.

Pulse Oximeter Detector

The photodetector opposite the transmitter that senses light transmitted through tissue.

Pulse Oximeter Site Requirements

Criteria for sensor placement: site must be warm, motionless, nonpigmented, and hairless.

Hypoxemia Monitoring Threshold

The point at $97\%$ or below where the technician should assess the patient and equipment.

Capnometry

The measurement and evaluation of the level of $CO_2$ in the patient's exhaled breath.

End-Tidal CO2 (ETCO2)

The level of carbon dioxide at the end of an exhaled breath.

Capnograph

A device that displays the $CO_2$ levels in the form of a wave.

Capnograph Plateau

The peak height of the wave on a capnograph indicative of the $ETCO_2$ value.

Normal Expired CO2

The range of $35$ to $45\,mm\,Hg$ for both dogs and cats.

Hypocarbia

$ETCO_2$ values less than $35\,mm\,Hg$, often caused by hyperventilation, pain, hypoxia, or light anesthesia.

Doppler Monitor

An indirect blood pressure device using crystals placed over arteries to produce an auditory assessment of pulse quality.

Doppler Monitoring Sites

Common arteries used include the coccygeal, dorsal pedal, and digital arteries.

Sphygmomanometer

An instrument used in conjunction with a cuff and Doppler to measure blood pressure.

Oscillometric Device

A monitoring machine that automatically inflates and deflates a cuff to acquire blood pressure measurements.

Blood Pressure Cuff Size Rule

The cuff width should be $40\%$ of the circumference of the limb being used.

Direct Monitoring

The most accurate pressure evaluation performed by placing an arterial catheter attached to a transducer.

Aneroid Manometer

A device used in direct blood pressure monitoring to read pressure values.

Oscilloscope

A display screen that shows waveforms for pulses, systolic, diastolic, and mean arterial pressure.

Normal Systolic Pressure

The range of $90-160\,mm\,Hg$ under anesthesia.

Normal Diastolic Pressure

The range of $50-90\,mm\,Hg$ under anesthesia.

Electrocardiograph (ECG)

A device that provides continuous tracing of heart rate and rhythm to alert an anesthetist to cardiac distress.

Premature Ventricular Contraction (PVC)

An ECG finding that, if repeated, can be a sign of impending severe cardiac distress.

P Wave Changes

ECG indicators of atrial dysfunction.

T Wave Changes

ECG indicators of myocardial hypoxia or electrolyte disturbances.

Guedel's Stage III

The stage of surgical anesthesia where the patient is unconscious and immobile.

Stage IV Anesthesia

The stage characterized by apnea and cardiovascular collapse.