Definitions/General Overview Flashcards
What is general anesthesia?
Reversible state of unconsciousness secondary to drug effects on the central nevous system
What are the goals of anesthesia
- Produce a state of
- Unconsciousness
- amnesia
- analgesia
- muscle relaxation
What is the approach to anesthetic management?
- Preoperative patient evaluation
- Preparation of equipment
- Anesthetic protocol
- Monitoring
- Recovery
- Post-anesthesia evaluation
What is part of the preoperative evaluation for anesthesia?
- Presenting complaint
- Hx:
- includes all current mediation
- pre-existing conditions unrelated to the current problem
- Physical examination
- Laboratory data and imaging results
- Patient problems by system
- Determine ASA status
What is ASA status?
- American Society of Anesthesiologists system for evaluating patient risk for anesthesia
- ASA status from I - V with E designation for Emergency
- Describes overall health
- Higher ASA status patients have a greater risk for anesthetic complications
- May require more intensive monitoring and management
- Does not reflect the procedure being performed
- Somewhat subjective
Describe ASA classification 1
normal healthy patient
Describe ASA class 2
mild systemic disease (obesity, geriatric, cranial cruciate rupture)
Describe ASA class 3
moderate systemic disease that limits activity but not incapacitating (dehydration, heart murmur, controlled diabetes, modest anemia)
Describe ASA class 5
Moribund patient that is not expected to survive w/ or w/out the procedure (life threatening trauma, septic peritonitis w/ septic shock)
Describe ASA class 4
Patient with severe systemic disease that is a constant threat to life (renal failure, pneumothorax, CHF
Describe ASA class E
added to any classification when an emergency procedure applies
What are the goals of the Preoperative evaluation?
- Identify any problems that may increase anesthetic risk and take any possible corrective measures
- ex: treatment of hypovolemia or dehydration PRIOR to anesthesia
- Determine if any concurrent medications should be withheld prior to anesthesia
- ex: angiotensin converting enzyme inhibitors may increase the risk for intraoperative hypotension
- Always a balance between how soon should we do the procedure and how stable is the patient
What supplies and equipment is needed for anesthesia?
- Supplies for IV catheterization
- Supplies for endotracheal intubation
- Drugs
- Anesthetic machine and breathing circuit
- Monitoring equipment
- Anesthetic record
ALL should be prepared and ready before patient is brought into the room
What are the goals of pre-anesthetic medication?
- Calm the patient and aid in restraint
- Decrease doses of anesthetic induction drugs and agents used to maintain anesthesia
- decrease any dose dependent effects of the drugs used to maintain anesthesia
- Analgesia
- Minimize undesired effects of anesthetics such as:
- nausea
- Bradycardia
- Muscle rigidity
What is anesthetic induction?
- Induce a state of general anesthesia
- Intravenous anesthetic agents used for induction
- Propofol
- Ketamine
- Ketofol
- Alfaxalone
- Etomidate
- Mask or chamber induction with an inhalant anesthetic is far less common
- fractious cats
- completion of induction after IV opioids
- Facilitates endotracheal intubation
What equipment is needed for endotracheal intubation?
- Laryngoscope
- Endotracheal tube
- Lubricant
- Endotracheal tube tie to secure the tube
- Lidocaine spray for some species (cats, small ruminants, pigs)
- Guide tube if difficult intubation anticipated
