Pre-Anesthetic Considerations Flashcards
what are the 5 components of general anesthesia?
- unconsciousness
- muscle relaxation and immobility
- amnesia
- attenuation of autonomic reflexes
- analgesia
why do patients die with anesthesia? (not LO)
- anesthetic overdose: user error!!
- cardiovascular complications: arrhythmias, circulatory failure, myocardial depression
- respiratory complications: hypoventilation, apnea, bronchoconstriction, airway obstruction, pulmonary thromboembolism
- anaphylaxis, aspiration
describe the risk factors of general anesthesia (7)
- old age: achieved 70% of life expectancy
- high ASA status
- urgent/emergent procedure: stressed out vets make mistakes
- procedure performed at night: easier to make mistakes too
- very small size patient: harder to maintain airway, keep monitors accurate
- endotracheal intubation in cats: cats have a very fragile trachea compared to dogs, easy to cause significant damage if rough with ET tube and prevent pulling or twisting of tube in airway
- pulse oximeter not used: tells what % Hb is fully saturated with O2, directly associated with O2 tissue perfusion; want 98-100% and also tells heart rate
describe the ASA classification of physical status scale
ASA I: normal health patient
ASA II: patient with mild systemic disease; generally will progress with anesthesia no worries
ASA III: patient with severe systemic disease; may try to stabilize or improve before anesthetize
ASA IV: patient with severe systemic disease that is a constant threat to life (GDV, very sick foreign body, hemoabdomen, must take to surgery now or will die)
ASA V: moribund patients not expected to survive 1 day with or without operation (probably going to die no matter what you do)
describe how to assess an anesthetic patient and assign an American Associate of Anesthesiologist (ASA) classification
describe the components and importance of patient pre-anesthetic assessment
- animal identification: correct patient, correct name/number
- signalment: species, breed, age, sex
- body weight: kilograms
- history: presenting complaint, concurrent disease, last meal (when?), concurrent medications (may need to alter timing of those concurrent meds)
- thorough physical exam!: body condition, cardiovascular, pulmonary, hepatic, renal, GI, nervous system, metabolic and endocrine, integument, musculoskeletal
- should perform a PCV/TS on ALL patients undergoing anesthesia
describe instances when specific further diagnostics are indicated prior to anesthesia
- ALL patients: PCV/TS
- CBC/chemistry/UA (minimum database):
-not needed if healthy and present with no abnormalities!! but at least recommend to CYA
-for geriatric patients: yes! will likely diagnose a problem you would have otherwise missed or find an abnormality that would make you not anesthetize - can also run:
-parasite testing
-arterial blood gas
- ECG
-echocardiogram
-radiographs
-ultrasound
-abdominal ultrasound
-coagulation profile
-blood type/crossmatch
describe the components of patient preparation for anesthesia including knowledge and appropriate fasting times (3)
- fasting: allows time for stomach to empty prior to anesthesia to decrease incidence of regurgitation/vomiting, make it easier to ventilate them, and provide a clear operative field for abdominal surgery
- healthy adult dogs and cats: 6 hours (could do 4-6 hrs)
- ruminants: 24 hours (want rumen as small as possible)
- pigs: 12 hours
- horses: 12 hours
- neonates and tiny creatures (<2kg): short fast of 1-2 hours (worried about hypoglycemia)
- resolve deficits: dehydration, electrolyte abnormalities, heart failure, anemia, and respiratory distress
- provide supportive care: temp support, pre-oxygenation, placement of monitors to obtain first readings
describe the concept of informed concent
- inform owners of risks associated with anesthesia
- obtain wishes in event of cardiopulmonary arrest (CPR or no)
- make it legal! get a signature
