VT 131 Intro to anesthesia and patient prep, Ketamine

Ketamine and tiletamine are in the same drug class, true of false

True

Narcosis

similar to hypnosis, but usually achieved with narcotic agents.

What are some false effects of ketamine

Schedule IV controlled drug Bradycardia Hypotension

What type of drug induces a level of calm with drowsiness?

Sedative

The California Medical Board states that a veterinarian should examine a patient within what time frame prior to a general anesthetic?

12 hours

Which patient is least likely to have special anesthetic needs? A 0.5 kg teacup Chihuahua presenting for an OHE A 95 kg Great Dane presenting for castration and preventive gastropexy A 19 year old Poodle presenting for a splenectomy A 9 year old DSH presenting for routine dental prophylaxis

A 9 year old DSH presenting for routine dental prophylaxis

What are some abnormal factors of a CBC that should immediately be reported to the veterinarian

A PCV <25% in a dog or <20% in a cat, horse, or cow A total protein < 4.0 g/dL in any species Any decrease in the platelet count Any coagulation test result outside the normal range

Define 'minimum patient database':

A compilation of pertinent information from the patient history, physical examination, and diagnostic tests

Hypnosis

A deep sleep like state, patient is rouseable

ASA V

A moribund patient, not expected to survive without the procedure

ASA I

A normal healthy patient

ASA II

A patient with mild systemic disease

ASA III

A patient with severe systemic disease

A patient in ASA class IV physical status is

A patient with severe systemic disease that is a constant threat to life

ASA IV

A patient with severe systemic disease that is a threat to life

Physical exam

A physical examination is a complete evaluation of a patient's physical condition using the assessor's hands, eyes, ears, and nose. A veterinarian uses the physical findings to arrive at a diagnosis and plan treatment. In contrast, a veterinary technician uses findings to provide effective patient care, respond to patient needs, and alert the veterinarian to changes in patient condition. Combining these two approaches allow the team to provide high-quality care. A complete physical examination should be conducted on every animal scheduled for anesthesia. The California Veterinary Medical Board states: "Within twelve (12) hours prior to the administration of a general anesthetic, the animal patient shall be given a physical examination by a licensed veterinarian appropriate for the procedure. The results of the physical examination shall be documented in the animal patient's medical records."

Frankenstein, a 4 month on intact male DLH presents for routine castration. Pre-anesthetic evaluation shows no parameters outside of normal limits. What would Frankenstein's physical status classification be?

ASA I

Sunflower, a 4-year-old intact female Golden Retriever presents for an emergency ovariohysterectomy due to acute open pyometra. What would Sunflower's physical status classification be?

ASA IV

What information is included in the patient's signalment?

Age, gender, breed

What are the desirable effects and/or uses of ketamine ?

Analgesia Sedation Anesthetic induction

How can anemia affect anesthesia

Anemia increases the risk of hypoxemia.

What are some special considerations for patients undergoing gastrointestinal procedures

Animals undergoing gastrointestinal procedures such as enterotomy, colonoscopy, or intestinal biopsy may require longer withholding times, enemas, or cathartics to minimize the amount of ingesta within the gastrointestinal tract at the time of surgery.

What is ketamine's mechanism of action ?

Antagonizing NMDA (N-methyl-D-aspartate) receptors in the brain.

How can boxers and giant breed dogs be affected by anesthesia

Boxers and giant breeds of dog are more sensitive to acepromazine than other breeds.

How can brachycephalics be affected by anesthesia

Brachycephalic animals are difficult to intubate and must be watched closely to ensure a patent airway before, during, and after any anesthetic procedure. Brachycephalic animals often require use of smaller endotracheal tubes than most other breeds.

Preinduction patient care

Before induction, ensure the following: Patient has been fasted Patient has received appropriate nursing care Patient has a fluid therapy plan (some patients are started on fluids before anesthesia) Check regarding medications or other care ordered by the veterinarian All treatments should be recorded in the medical record. A checklist of procedures may be helpful, particularly if more than one person is responsible for preanesthetic care.

Preanesthetic workup: blood chemistries

Blood Chemistries There are a variety of blood chemistry panels to assess organ health or function. Discuss abnormalities with the veterinarian prior to anesthesia.

You are going to perform anesthesia on a 2-year-old, male neutered, French bulldog, who is undergoing a neuter. How does his signalment affect his anesthesia?

Brachycephalic dogs can be difficult to intubate and need a smaller ET tube than other dogs of similar size.

Blood coagulation screens

Blood coagulation screens evaluate a patient's ability to clot normally. This is important surgery patients are at an increased risk for intra-operative and postoperative hemorrhage. A coagulation panel, including prothrombin time (PT) and activated partial thromboplastin time (APTT), should be performed on any patient that may have a preexisting coagulation disorder or animals of breeds known to be commonly affected by hereditary coagulation disorders, such as Doberman pinschers, Rottweilers, and Scottish terriers. The buccal mucosal bleeding time is an in-house screening test that can be used in any patients, including those with normal platelet counts and coagulation panels, to determine the likelihood of peri-operative bleeding. This test is commonly used to screen Doberman pinchers prior to surgery because they are frequently carriers of the genetic disorder, Von Willebrand's disease.

How can bruising and petechia be affected by anesthesia

Bruising and petechia often indicate a clotting disorder, which will increase the risk of potentially life-threatening intra-operative and postoperative bleeding.

Preanesthetic workup: buccal mucosal bleeding time

Buccal Mucosal Bleeding time (BMBT) An in-house screening test that can be used in house to determine the likelihood of perioperative bleeding. This test is commonly used to screen Doberman pinchers prior to surgery because they are frequently carriers of the genetic disorder, Von Willebrand's disease.

Preanesthetic workup: complete blood count

Complete Blood Count (CBC) The following findings may affect anesthesia and should be reported to the attending veterinarian immediately: A PCV <25% in a dog or <20% in a cat, horse, or cow A total protein < 4.0 g/dL in any species Any decrease in the platelet count Any coagulation test result outside the normal range

What are some common uses/effects of ketamine

Can be used to anesthetize cats, dogs, birds, horses, and exotics. Ketamine was previously used to help in restraint of feral or aggressive cats. Ketamine is a popular induction agent for dogs and also is utilized in a wide variety of large animals and exotics for anesthesia, sedation, pain control, and immobilization

Client communication

Clients are very bonded to their patients and frequently feel anxious about medical procedures. Our job is to communicate honestly and clearly to maximize client satisfaction. Communication is key for a successful practice! Make eye contact and speak clearly, at a level your client understands.

Client communication during discharge

Clients need clear discharge instructions communicated both verbally and in writing.

Client communication during/after the procedure

Clients should be called with a progress report

Preanesthetic workup: coagulation tests

Coagulation Tests Blood coagulation screens evaluate a patient's ability to clot normally. A coagulation panel includes prothrombin time (PT) and activated partial thromboplastin time (APTT) This may be performed on patients at high risk of having a bleeding disorder

Patient history for anesthesia

Confirm procedure to be performed Collect a history Confirm that patient was fasted as instructed Confirm vaccines and other preventative care needs Inquire about drug allergies or reactions What is patient's condition the day of the procedure? Obtaining a good patient history requires skill and care. Ask open-ended questions and avoid leading questions that can be answered "yes" or "no". When inquiring about signs of illness, ask follow-up questions about that illness to determine: The duration (how long has it been going on?) The volume or severity (how much or how severe?) The frequency (how often?) The character or appearance (what does it look like?)

How can cryptorchid patients be affected by anesthesia

Cryptorchid patient will require a different surgical prep, longer surgery time and different surgical approach compared to a patient with both testicles descended.

How can dehydration influence anesthesia

Dehydration increases the risk hypotension, poor tissue perfusion, and kidney damage.

On physical assessment prior to a neuter it is discovered that the patient is cryptorchid. How does this affect the anesthetic plan?

Different surgical preparation and longer surgery time

What drug class is ketamine

Dissociative

What are some things to check for during pre-induction patient care

During the pre-induction period the technician should ensure that the patient has been fasted and receives appropriate nursing care, fluid therapy, medication administration, and any other care ordered by the veterinarian. All treatments should be recorded in the medical record. A checklist of procedures may be helpful, particularly if more than one person is responsible for preanesthetic care.

What complication is prevented by fasting our patients prior to anesthesia?

Esophageal reflux and aspiration

Examples of how patient signalment affects anesthesia

Examples of how signalment affects anesthesia: Boxers and giant breeds of dog are more sensitive to acepromazine than other breeds. Brachycephalics are difficult to intubate and must be watched closely to ensure a patent airway before, during, and after any anesthetic procedure. Sighthounds are sensitive to barbiturates because of their relative lack of body fat compared with other breeds. Neonates and pediatric patients are less capable of metabolizing injectable drugs because the necessary liver metabolic pathways are not fully developed. Geriatric patients may be unable to tolerate normal doses of some drugs because of poor hepatic or renal function.

Fasting protocols

Fasting recommendations are shorter than they used to be as prolonged fasting is detrimental to our patient's health. According to the 2020 AAHA Anesthesia and Monitoring Guidelines for Dogs and Cats the recommended fasting times are 4-6 hours prior to anesthesia for healthy adults. Water is not withheld unless there is a history/risk of regurgitation

Preanesthetic workup: fecal and ELISA tests

Fecal tests to check for ova and parasites Fecal float Direct smear +/- centrifugation float and sediment ELISA Tests Heartworm test Rickettsial FeLV/FIV test on cats

Anesthesia

General Anesthesia is a reversible, controlled state of unconsciousness characterized by lack of sensation, immobility and muscle relaxation.

How can geriatrics be affected by anesthesia

Geriatric patients may be unable to tolerate normal doses of some drugs because of poor hepatic or renal function.

What routes can you give ketamine

IV, IM, SQ, PO

When should client communication take place for anesthesia

Ideally communication takes place: Prior to the procedure After the procedure is completed At discharge At the start of the day, clients should be informed when they will receive communications.

Which of the following is a benefit of clear, honest, and timely communication with clients?

Improved client satisfaction

Anesthesia protocol selection

In all jurisdictions in the United States and Canada, the veterinarian is the only health care provider legally allowed to prescribe anesthetic drugs for animals. In many hospitals the veterinarian establishes one or two standard anesthetic protocols for patients of ASA class I and II, with which the technician will quickly become familiar. Each patient must be evaluated individually, based on the minimum patient database, and changes must be made to the standard protocol when necessary. When choosing the anesthetic protocol, the factors such as facilities and equipment, familiarity with the agent, the nature of the procedure, costs, and urgency are considered. Identify risk factors based on history, physical exam and laboratory tests Determine patient's ASA risk assessment Avoid or reduce the dose of drugs that worsen a specific risk factor Include drugs that may counteract the risk factor Select a protocol that will provide Minimum patient stress Proper anesthesia Adequate analgesia

What are some effects of ketamine

Ketamine causes a very quick response via IV or IM routes and can cause cats to lose their righting reflex within 90 seconds. Using ketamine IV tends to have a quicker rate of induction and recovery while using a lower dose. Using ketamine IM must be properly monitored and made sure the correct dose is given or it may cause overdose and death. Using ketamine IM can also cause excitement and seizures. Ketamine shouldn't be repeatedly used as the drug can accumulate in the tissues and may cause seizures during recovery. Dogs typically recover from ketamine quicker than cats due to differences in metabolism and excretion. Ketamine may also cause tissue irritation and some animals may show transitory pain after an IM injection. Ketamine also increases in respiratory tract secretions and salivation. Ketamine may also cause erratic or bizarre behavior during recovery.

Analgesia

Lack of pain sensation

What does the term 'analgesia' mean?

Lack of pain sensation

Preanesthetic workup: miscellaneous tests

Miscellaneous Tests Depending on patient need, existing illness, the geographic location of the practice, and other factors, other diagnostic tests may be routinely performed before anesthesia. For example, most veterinary practices in areas where heartworm disease is endemic require a heartworm test for all dogs and in some cases cats before any anesthetic procedure.

Is ketamine reversible?

No

How can neonates be affected by anesthesia

Neonates (up to 2 weeks of age) or pediatric patients (2 to 8 weeks of age) are less capable of metabolizing injectable drugs than are adult animals because the necessary liver metabolic pathways are not fully developed.

What patient status classifications can have normal anesthetic protocols

PS1 and PS2

What patient status classification require individually tailored protocols and pre surgical stabilization

PS3 to PS5

What should a physical assessment include

Patient Identification Body Weight and BCS score Assessment of Hydration Level of Consciousness Evidence of pain Temperature, pulse rate, respiratory rate (TPR) Gait Temperament/activity level Coat and Skin Lymph nodes Eyes, ears, nose, throat, teeth Cardiovascular - Note heart rate and rhythm, palpate pulses while auscultating Mucous membranes and CRT Respiratory - Respiratory rate and character Abdominal palpation

What are some true effects of ketamine

Provides analgesia Tachycardia increases intracranial pressure

How can respiratory or cardiovascular system abnormalities be affected by anesthesia

Respiratory or cardiovascular system abnormalities increase the risk of anesthetic complications and death.

What other agents are also a class III controlled drug

Telazol

How does ketamine work?

The "mechanism of action" of this drug is it causes disruption of nerve transmission in areas of the brain and causes selective stimulation in other areas. Dissociative anesthetic inhibit NMDA or N-methyl-D-aspartate receptors in the central nervous system which can cause an exaggerated response to low-intensity pain stimulation. The inhibition of NMDA causes the analgesic effects of ketamine and other dissociative anesthetic. These drugs cause many regions of the brain to "dissociate" where the animal may seem to be awake but they are immobilized and unaware of their surroundings. Ketamines peak action occurs in only about 1 to 2 minutes after an IV injection and around 10 minutes for IM injections. Dissociates are metabolized by the liver and can be excreted in the urine so it should be cautiously used for patients with liver or kidney disease.

Preanesthetic workup: electrocardiogram

The ECG records the electrical activity of the heart and is used to diagnose arrhythmias. Recommended for patients: With heart disease With chest trauma With gastric dilatation volvulus With splenic disease With electrolyte disturbances On medications that affect heart rhythm.

Physical status classification

The patient's classification is not a direct assessment of anesthetic risk and is partially subjective. It is additional information to be used together with the history, physical exam, signalment and procedure planned. Classes PS3 to PS5 require individually tailored protocols and presurgical stabilization whereas class PS1 and PS2 patients can be anesthetized with standard protocols.

When gathering historical information about signs of illness, what is the least appropriate question to ask? The duration The severity The patients sleeping area The character or appearance

The patients sleeping area

Patient signalment

The species, breed, age, sex, and reproductive status are collectively known as the signalment. The signalment is important in planning the anesthetic procedure and follows a typical pattern. Example: "Darwin is a 2-year-old, MN, Labrador Retriever"

Selection of anesthetic protocol

The technician acting as anesthetist should not hesitate to discuss abnormal findings from the minimum database with the veterinarian. The presence of severe disease often requires an individualized protocol. If possible, sick patients should be stabilized prior to going under anesthesia.

Physical assessment

The technician performing anesthesia should also perform a physical assessment before the procedure. Here are some examples of findings that may influence patient anesthetic management: Dehydration increases the risk hypotension, poor tissue perfusion, and kidney damage. Bruising and petechia often indicate a clotting disorder. Respiratory or cardiovascular system abnormalities increase the risk of anesthetic complications and death. A cryptorchid patient will require a different surgical approach. In some jurisdictions, veterinary technicians must perform their physical assessment under the supervision of a licensed veterinarian. Consult with the state veterinary medical licensing board practice act for local laws and regulations.

Minimum database

The veterinarian and technician need to gather as much information as possible to prevent anesthetic complications. The minimum patient database consists of the following: 1. Patient history, including the patient signalment 2. Complete physical examination findings 3. Results of a preanesthetic diagnostic workup

Preanesthetic workup

The veterinarian creates the diagnostic plan for a given patient. The technician obtains samples (blood, urine, feces, or other samples) and either performs the tests in-house or submits the samples to a diagnostic laboratory.

What's the difference between a physical exam and a physical assessment

To differentiate these two approaches, the term physical examination (PE) will be used to indicate evaluation by a veterinarian for the purpose of diagnosis and treatment planning, and the term physical assessment (PA) will be used to indicate evaluation by a technician for the purpose of maximizing quality of care and influencing patient management through communication with the attending veterinarian.

Is ketamine used in combination with any other drugs? If so, which ones?

This drug is often used in combination with either Acepromazine, benzodiazepines, and alpha2-agonists. Ketamine is most commonly used with diazepam.

Preanesthetic workup: thoracic radiographs

Thoracic Radiographs Thoracic radiographs are indicated for animals with cardiac or pulmonary disease. These patients may require different drug combinations.

Which preanesthetic test is especially important for a 10-year-old, female spayed, chihuahua with a 4/6 systolic heart murmur?

Thoracic radiographs

How should you prevent vomiting and minimize reflux during anesthesia

To prevent vomiting and minimize reflux during the anesthetic period, food should be withheld from most patients except for neonatal, pediatric, and some exotic patients. The use of anti-nausea/antiemetic drugs (such as Cerenia) as a premedication is becoming more common, to prevent vomiting or nausea from other medications.

There are many benefits of premedicating our patients, which of the following is NOT a benefit? To test for an allergic reaction prior to general anesthesia To calm an excited, frightened, or vicious animal To reduce the dose of inhalant needed To optimally manage pain

To test for an allergic reaction prior to general anesthesia

Preanesthetic workup: urinalysis

Urinalysis Any abnormalities in the urinalysis should be reported and investigated. Isosthenuria or hyposthenuria may indicate renal or endocrine disease. Protein in the urine may indicate hypertension or glomerular disease.

When should a physical exam take place before an anesthetic procedure

Within 12 hours prior to the procedure

Is ketamine a controlled drug? If so, what class is it in?

Yes, class III controlled

Sedation

a drug induced level of calm with drowsiness and CNS depression; ranges from mild to deep sleep-like states

Tranquilization

a drug induced level of calm without a depression in consciousness

Balanced anesthesia

anesthesia produced by smaller doses of two or more agents is safer than a larger dose of a single agent.

What type of drug is ketamine

dissociative

What does the word "anesthesia" mean?

loss of sensation

Nociceptor

the afferent nerve endings that transmit the nervous signals that produce unpleasant and painful sensations

Induction

the delivery of drug agents that produce unconsciousness

Client communication prior to the procedure

Finances Present estimate and obtain client's signature Collect deposit (veterinary practices have different policies on this) Discuss expected timeline for the day, including when communications will occur and an expected discharge time (if applicable). Confirm emergency contact information. Obtain owner's consent to the anesthesia and procedure Written consent in preferred Oral consent is legal in California, must be documented in medical record

What are some adverse effects of ketamine

Hypertension hypersalivation emesis vocalization erratic and prolonged recovery dyspnea seizures muscular tremors hypertonicity myoclonus (muscle jerks) opisthotonos (abnormal position due to muscle spasms and contractions) cardiac arrest pain with IM injections

What information is important to discuss with the owner prior to an anesthetic procedure? Finances Owner consent Emergency contact info All the above

All the above

Withholding food before anesthesia

Animals anesthetized without fasting are at an increased risk of aspiration. Esophageal reflux is common during the anesthesia from decreased lower esophageal sphincter tone. Esophageal reflux may cause irritation of the esophagus and esophagitis. This is a cause of postoperative nausea, dysphagia, vomiting, and anorexia. Regurgitation (passive process) can occur in unconscious patients, and results in the flow of stomach contents into the esophagus and mouth. If the patient is under anesthesia and does not have a swallow reflex, regurgitation leads to pulmonary aspiration, pneumonia and in some cases even immediate respiratory arrest and death.

Physical status classification

Before selecting the anesthetic protocol, the attending veterinarian should evaluate the minimum database and assign a physical status classification. The most widely accepted classification system is the one adopted by the American Society of Anesthesiologists (ASA). This classification system is used to assess the patient's overall health by assigning one of five grades: ASA I - A normal healthy patient ASA II - A patient with mild systemic disease ASA III - A patient with severe systemic disease ASA IV - A patient with a severe systemic disease that is a threat to life ASA V - A moribund patient, not expected to survive without the procedure. Patients undergoing emergency anesthesia may also be assigned an additional letter E regardless of class (e.g., ASA IIE or ASA IVE). This system can be used to guide selection of the best anesthetic protocol based on the patient's physical status.

In what patients is ketamine contraindicated

Ketamine is contraindicated in patients with hepatic disease, cats with compromised renal function or urinary obstruction, head trauma, or known seizures.

Which of the following is the reversal agent for ketamine

None

How can sighthounds be affected by anesthesia

Sighthounds such as greyhounds and salukis are sensitive to barbiturates because of their relative lack of body fat compared with other breeds.

Why would a buccal mucosal bleeding time (BMBT) test be performed prior to surgery on a Doberman Pincher?

To determine the likelihood of bleeding that day

How can an intact animal or an animal in heat be affected by anesthesia/surgical procedure

When an intact female animal is in heat, the uterus is enlarged and has a more extensive blood supply. These patients also may bleed excessively because of the effects of estrogen on the clotting cascade.