Canine & Feline Anesthesia and Anesthetic Monitoring & Problems

Anesthetic Induction

The process by which an animal loses consciousness and enters general anesthesia; goal is to take patient from consciousness to Stage III anesthesia smoothly and rapidly so that an ET tube can be placed

Anesthetic Maintenance

The process of keeping a patient in a state of general anesthesia; the period between induction and recovery

Anesthetic Protocol

A list of anesthetic agents and adjuncts prescribed for a particular patient including doses, routes, and order of administration; primary determinate of dynamics; selected by the attending veterinarian based on the minimum patient database, the patient’s physical status class, procedure to be performed, and personal preference

Anesthetic Recovery

The period between the time the anesthetic is discontinued and the time the animal is able to stand and walk without assistance

CNS Vital Centers

Areas of the brain that control cardiovascular function, respiratory function, and thermoregulation; affected by anesthesia and leads to adverse effects seen with anesthesia

Hypostatic Congestion

The pooling for blood in the dependent lung and tissues (those nearest to the floor or table)

Larynospasm

A reflex closure of the glottis in response to contact with any object or substance; will cause the glottis to forcibly close during intubation and is particularly prevalent in cats

Titration

Administration of an anesthetic agent in small increments until the desired depth of anesthesia is reached as opposed to the administration of the full calculated dose

Total IV Anesthesia (TIVA)

Induction and maintenance of anesthesia by IV injection of ultrashort-acting anesthetics with no concurrent use of inhalant agents; accomplished using repeat boluses or a CRI; acceptable for non-invasive procedures of short to moderate length

Apnea Monitor

A monitor used to alert the anesthetist when the patient has not taken a breath within a set period of time; works by detecting the change in temperature of air moving between the ET tube and breathing circuit as the patient breathes

Blood Gas Analysis

A measurement of the pH, bicarbonate level, and partial pressure of oxygen and carbon dioxide in the blood; most often tests arterial blood obtained by an intra-arterial catheter

Calculated Oxygen Content

The total volume of oxygen in the blood including both dissolved and bound forms expressed in mL/dL ; accurately measures total oxygen available to tissues

Partial Pressure of Oxygen

A measurement of the unbound oxygen molecules dissolved in the plasma expressed in mmHg; differs depending on whether arterial, capillary, or venous blood is tested

Central Venous Pressure (CVP)

Blood pressure in a large central vein; allows for the assessment of blood return to the heart and heart function and hydration status

Percent Oxygen Saturation

A measurement of the percentage of the total hemoglobin binding sites occupied by oxygen molecules

Respirometer

A monitoring device used to measure tidal volume and respiratory minute volume that is placed between the expiratory hose of rebreathing circuit and the exhalation unidirectional valve

Capnograph

A monitoring device that measures the amount of carbon dioxide that in breathed in and out by the patient; noninvasive, continuous, and practical method of monitoring carbon dioxide levels in anesthetized animals

Functional Residual Volume

The amount of air left in the lungs after expiration

Opisthotonus

A severe spasm in which the back arches and the feet and head flex dorsally; has several causes including drug reactions and brain lesions

Sequestration

The loss of blood or plasma into tissues or spaces within the body resulting in a decreased circulating blood volume

Stertor

A heavy snoring sound during inspiration often caused by partial upper airway obstruction; seen in patients with laryngospasm, laryngeal edema, and in brachycephalic dogs