Exam 1 Flashcards
(164 cards)
Lecture 1
-Important terminology: anesthesia, analgesia, sedation, tranquilization, neuroleptanalgesia.
-Review of Calculations: calculate anesthetic drug dosage, fluid drop rates, convert % solutions to mg/ml, and determine drug dilution amounts.
Define the following terms
anesthesia, analgesia, sedation, tranquilization, neuroleptanalgesia.
Anesthesia: total loss of sensation in a body part or in the whole body, generally induced by drug (s) that depress the activity of nervous tissue either locally, regionally, or generally (central).
Analgesia: Loss of sensitivity to pain without loss of consciousness.
Sedation: CNS depression in which an animal is awake but calm and generally uninterested in its surroundings, often interchangeable with tranquilization. If given sufficient stimulation the animal will be arouse/awaken.
Tranquilization: similar to sedation. The animal may be awake or not. Potentially indifferent to minor pain.
Neuroleptanalgesia: Hypnosis and analgesia produced by the combination of a neuroleptic drug (e.g., tranquilazer) and an anelgesic drug.
Anelgesia = loss of feeling
Awareness = consciousness
Agonist: a drug that produces an effect by interacting with an specific receptor site ex: opioid agonist morphine.
Antagonist: a drug that cunteracts the effects of another drug ex: opioid antagonist naloxone.
What are the five phases of anesthesia?
- Preanesthetic
- Induction
- Maintenance
- Recovery
- Postanesthetic period.
What is the difference between dose and dosage?
Dose: quantity of drug to be delivered at a particular time. It is expressed in mg, ml and calculated from the dosage rate.
Dosage: the amount of drug per unit of body weight.
Which is the only distinguishable microdrip set size after the bag has been opened?
The 60 drop.
What are some useful formulas for IV drop calculations?
drip rate = ml required/time * drops/1ml
concentration in mg/ml = mg of drug/ml of IV fluids.
ml per hour = volume to be infused in ml/length of infusion in hr
ml per minute = volume to be infused in ml/ length of infusion in hr * 60 (min/hr).
Lecture 2
What are the five W’s of performing a patient evaluation (pre-anesthetic)?
- Who should perform it: the veterinarian in charge of the patient should perform the evaluation
- What does it include: Start with the signalment. History (include previous anesthetic events)
-If patient is ill, find out what symptoms are present, the severity and how long it has been going on.
-What about recent medications, vaccinations?
-Physical exam (PE). Including BCS and BW
-Blood and urine samples
-Temperament/mentation, level of pain and stress
-Advanced diagnostics if indicated: ECG, BP, radiographs, and U/S, echo, endocrine testing, etc. - Where
- When
- Why
Is ECG a routine screening?
-For Patients with a history of cardiovascular disease
-Geriatric patients
-Underlying disease that may lead to arrhythmias: Hypekalemia, GDV, Splenomegaly, traumatic myocarditis.
AliceCor Heart monitor is an FDA approved iPhone case that produces an ECG
-Telemedicine consults with boarded cardiologists.
Physical exam, how do you use your stethoscope and fingers?
What do you evaluate with stethoscope?
Why should you palpate the trachea?
-Auscultate for murmur while palpating for femoral pulse simultaneously.
-Rate, quality, rythm
Respiratory rate: describe what you hear or don’t hear. “no presence of cracking, wheezing,..etc.
Mucus membranes, Capillary refill time. 2 seconds or less is normal. A CRT <1 sec is indicative of hyperdynamic state and vasodilation (bright red mucous membranes). It can be associated with systematic inflammation, heat stroke, distributive shocks, and hyperthermia.
What are some of the physical findings in dehydration? by percentage
<5 not detectable
5-6% subtle loss os skin elasticity
6-8% Defined prolonged CRT, eyes possibly sunken, dry mm possilbe.
10-12% tented skin stands in place, definite prolongation of CRT, eyes sunken, signs of shock.
12-15% definite signs of shock (tachycardia, cool extremities, rapid and weak pulses). Death imminent.
What are some other important part of PE and why?
-Integument: infection, tick, fleas
IV and epidurals should not be placed through infected skin. Surgery may be canceled.
Lymph nodes: maybe inflammation indication. FNA
GI tract, abdominal palpation, gut sounds. Pregnant, enlarged prostate,
Genitourinary tract: check for descended testicles
CNS: want to know about balance, seizures, aggression to select proper anesthetics.
What kind of lab work should be done before surgery?
Does extensive labwork pre-sx improve the outcome? NO
Depends on the physical exam and history of the patient.
-Young (<5 years old) healthy patient having an elective surgery with no abnormal history = PVC/TS/GLUCOSE/BUN (Big 4 or QATS).
-Older patients elective or non-elective, history of recent illness, etc. = CBC/CHEMISTRY profile/UA (minimum database).
-If break in preventative =4Dx
-+/- T4, ECG, blood pressure, thoracic radiographs, liver function, coagulation profile, etc.
Where is the pre-anesthetic evaluation performed?
When should it be performed?
Why should a pre-anesthetic evaluation be done in all patients?
-Clinic, but also done during farm calls
-Find a quiet area can better auscultate heart and lungs
-Within the day before the surgery or up to one week prior.
-Emergency cases done immediately
Questions to ask the owner:
-When was the patient last fed, pregnant, any drug or toxin exposure?
-Greater chance of safe anesthetic episode and/or more successful outcome.
-Formulate assessment of the patient’s overall organ function and preoperative risk.
-Provide client with valuable information for decision/risk.
Document the conversation prior to anesthesia
What are the five categories of ASA Physical Status Scale?
Which categories are more likely to suffer complications?
- A normal healthy patient
- A patient with mild systemic disease
- Patient with severe systemic disease
- Patient with severe systemic disease that is a constant threat to life
- Moribund patient that is not expected to survive without operation.
3-5 categories 4 times > complications than 1-2
Add E for emergency
What is the physical status of a patient?
When should the ASA be assigned?
How is an emergency defined?
-Presence or absence of disease
Determined by history, PE, laboratory and other diagnostics.
-Severity of pain present
-Levels of stress
-Overall efficiency and function of organs
-ASA after PE and labwork and diagnostics.
-Emergency: as existing when delay in treatment would lead to a significant increase in the threat to life or body part.
Why is ASA Physical status important?
-Used to assess the anesthetic risk of a case and select appropriate drugs.
-Physical status effects the pharmacokinetics and pharmacodynamics and aids in the selection of drugs, techniques for the patient.
Organs/systems we’re concerned with? = cardiovascular, pulmonary.
-Can also be used from a legal standpoint, retrospective.
What are often more important factors to considered in predict operative risk than increased ASA classification?
-Age, obesity
-Severity of operation
-anesthesia providers skill, staff
-Medicine, blood, implants
-Competence of surgical team, etc.
Increased cardiopulmonary emergencies during surgery*
Is age a disease? obesity?
What are other considerations for dosing drugs selection?
-No but it is an important independent risk factor regarding morbidity and mortality. Predictor of preoperative outcome.
-Obesity decreases CV function, at risk for hypoventilation.
-SA vs. LA
-Species variation in PK & PD
-Size of patient: smaller animals require a higher dose per unit of BW
-Obesity: volume of distribution for drugs changes
-Poor body condition, starvation
-Age: how does it change metabolic rate?
What are some of the effects of age when selecting anesthetic drug dosages?
How does fever affect metabolic rate?
-Neonate or pediatric: decrease dose
-Juvenile to early adulthood: Increase dose
-Geriatric: decrease dose
Fever: increases metabolic rate. 1 degree = 7% increase.
Hyperthyroidism: increases metabolic rate
Hypothyroidism: decreases MR.
Leukemia: can increase MR
Long-term pain: increases MR
Shock: lowers MR
Conditions for specific breeds or species
- Pigs: Malignant hyperthermia. Stress triggered, genetic.
- Quater horses: Hyperkalemic Periodic Paralysis, which causes episodes of tremors, myotonia, weakness, or paralysis in association with elevated serum potassium
- Rabbits: Malignant hyperthermia?
- Herding breeds: ABCB1/MDR1 (multidrug resistent gene mutation)
- Doberman Pinschers: Von Willebrand’s disease. Bleeding disorder. Do a buccal mucosal bleeding before emergency surgery. Avoid Acepromazine tranquilizer.
- Miniature Schnauzers: Sick sinus syndrome. Heart rate and rhythm condition, abnormal. Careful with atropine bc it can induce initial sinus bradycardia. Glycopyrrolate safer.
- Boxers: Arrythmogenic Right Ventricular Cardiomyopathy. Adult onset cardiac muscle disease. Caution with Acepromazine
- Pugs: Brachycephalic syndrome
What substances can either induce or inhibit microsomal enzymes?
Inducers
-Diazepam: maximal enzyme level after 5 days
-Diphenhydramine
-Hyperthyroidism
-Pentobarbital
-Phenobarbital
-Phenylbutazone
-Rifampin
-Progesterones
-Strogen
-Griseofulvin
-Prednisone
Inhibitors
-Chloramphenicol
-Cimetidine
-Cyclophosphamide
-Erythromycin
-Ketoconazole
-Morphine
-Organophasphates
-Quinidine
-Tetracycline
-Verapamil
Why is it important to ask owner about any current medications, including natural supplements?
They could cause problems during pre-anesthesia
What are the recommendations for the owner for patient preparation?
-Fasting and water: species and age dependent
Canine and feline: 6-12 hours. Water: access up to time of premed
Small ruminant: 12-18 hrs. Water: 8-12 hrs
Equine: 4-12 hrs. Up to premed
Cattle: 18-24 hrs. 12-18
Swine 12-24 hrs.
Rodents and rabbits: not necessary
Bird: 4-6 hrs
Birds <200g: not necessary
Neonate: not necessary.
Patients are fasted prior to anesthesia for the following reasons:
-Decrease food and fluid in stomach
-Decrease risk of aspiration
-Distended stomach or rumen impairs ventilation and could lead to hypoxemia and hypercapnia.
-In horses, a full stomach could rapture at induction
Why is it nor necessary for neonates, small birds, and some mammals to be fastened?
What about water deprivation?
They are prone to hypoglycemia within a few hours of starvation
Increased metabolic rate in birds and small mammals.
Some animals can not vomit, horses and rabbits
Water
-Renal insufficiency
-Febrile
-Diabetes
-Hot environment
Gastroesophageal reflux incidence in dogs decreased with small amount of canned food 3hrs prior to surgery.