Introduction to Anesthesia Flashcards
indications for anesthesia
- to perform certain procedures that animal may not tolerate
- most animals in zoo/wildlife medicine (safety)
- most surgical procedures (general anesthesia)
classification of anesthetic techniques
- local anesthesia
- regional anesthesia
- general anesthesia
goals of anesthesia
- ensure adequate analgesia
- ensure the patient is in the optimal state for the procedure to be performed
- ensure patient safety and survival
anesthesia definition
the loss of sensation of a particular body part or the whole body generally induced by drugs that depress the activity of the nervous system either peripherally or centrally
general anesthesia
- state of unconsciousness produced by controlled, reversible drug administration that causes inhibiton of the CNS which results in the absence of pain sensation, muscle relaxation
- overall aim to produce unconsciousness, immobility, amnesia, muscle relaxation, and analgesia
general anesthesia techniques
- induction by administrating injectable anesthetic agents
- combo of both injectable and inhalant agents to produce general anesthesia
- maintained with inhalant anesthetics, injectable anesthesia, or a combo
balanced anesthesia
- state of surgical anesthesia acheived by use of two or more drugs or anesthetic techniques, each of which contributes its own pharmacological effects
- allows for a lighter plane of anesthesia while resulting in more stable CV and pulmonary function
providing safe anesthesia includes:
- selecting appropriate drugs for each patient and the procedure
- assessing the physical status of each patient
- having a working familiarity of anesthetic drugs and their potential side effects
preanesthetic assessment of the patient:
- history
- evaluation of patient’s physical status
- metabolic and endocrine
-
physical exam
- CV, respiratory, nervous systems
ASA Physical Status Classification (ASA-PSC)
- classifies a patient based on simple descriptors of their current health status
- six categories, only five applicable to vet med
- emergency: ‘E’ is added
ASA Physical Status 1
a normal healthy patient
ex. neutering
ASA Physical Status 2
a patient with mild systemic disease
ex. minor fractures, slight dehydration
ASA Physical Status 3
a patient with severe systemic disease
ex. chronic heart disease, anemia
ASA Physical Status 4
a patient with severe systemic disease that is a constant threat to life
ex. ruptured UB, closed pyometra
ASA Physical Status 5
a moribund patient who is not expected to survive wihtout the operation
ex. severe shock
reviewing medical record
- any historical anesthetic complications
- endotracheal tube size
- previous drugs administered and how they were tolerated
examination of patient’s history
- animal’s behavior at home
- previous or concurrent disease state(s)
- fasting
physical exam
- change in body temp from normal
- auscultation of thorax
- pulse rate and quality
- respiration rate, effort, noise, and abnormal breathing patterns
- note age, temperament and size of patient
what is the basic bloodwork every patient should have regardless of age?
hematocrit
plasma protein concentration
withholding times for food and water
- both species and patient dependent
- ruminant species are fasted for longer periods of time than small animal species
- condition of patient will help determine duration of fasting
goal in an emergent situation
improve the overall status of the patient so that they can better handle the cardiopulmonary and respiratory depressant effects of anesthetics
