Pain & Anaesthesia Flashcards
1
Q
Bolles and Fanselow’s three behavioral responses to pain:
A
- perceptive phase
- defensive phase
- recuperative phase
2
Q
Pain responses in the recuperation phase:
A
- changes in motor patterns (limping, cringing, avoiding a limb)
- motivational changes (staying in a safe space, refraining from action, low alertness, apathy, depressive-like behaviors)
3
Q
Vocal responses to pain
A
- primary pain: screams & roars
- secondary: sighs, moans, groans, yelps
4
Q
physiological responses associated with pain:
A
- pupilary dilation
- changes in cardiac rate
- respiratory changes
- salivation
- sweating
- gastrointestinal motility
- defecation & urination
5
Q
Clinical signs which can be used to determine humane endpoints:
A
- rapid weight loss (15-20%)
- extended period of weight loss
- prolonged diarrhea
- nasal discharge
- coughing
- neoplasma accounting for 15-20% of body weight
- self-induced trauma
- severe ulceration or bleeding
- drop in body temperature > 4C
- labored breathing
- cyanosis
6
Q
Components of general anesthesia
A
- loss of consciousness (hypnosis)
- loss of sensory function (analgesia)
- relaxation of skeletal muscles
- suppression of reflex activity
7
Q
Types of local anesthesia:
A
- surface anesthesia (minor superficial interventions, e.g. catheters, skin incisions)
- local infiltration (desensitize deeper layers of tissues)
- local nerve block (desensitize limbs or tail)
- regional anesthesia (local anesthetic close to spinal cord or in the plexus supplying one of the limbs
8
Q
Most widely used local anesthetics:
A
- procaine
- lidocaine
- bupivacaine
- prilocaine
(sometimes in conjuction with epinephrine to cause local vasoconstriction and slow the absorption of the compound)
9
Q
Main advantage of local anesthesia:
A
- in general it has less influence on normal physiological functions (except for spinal or epidural anesthesia, which may result in an extensive blockade of the sympathetic nervous system, leading to systemic hypotension and tachycardia)
10
Q
Pre-anesthetic preparations
A
- measure animal weight and record food and water intake for the day
- check for any clinical signs of disease
- larger animals must be fasted to prevent regurgitation and aspiration of stomach contents
- anticholinergic agents (e.g. atropine) ma be used to reduce the volume of bronchial and salivary secretions and to block any undesirable autonomic response either drug induce or due to surgical manipulation
- sedatives or tranquilizers may be used to reduce stress and make animals easy to restrain
11
Q
Inhalational vs intravenous anesthetics
A
- easy adjustment for the depth of anesthesia
- repeated administration IV is unstable and accumulation may occur
12
Q
Features of isoflurane
A
- irritating to the airways
- suitable for all lab animals
- no biotransformation and removed by exhalation
- does not induce liver enzymes (less interference with drug metabolism)
- results in vasodilation and, consequently, hypotension and tachycardia
13
Q
What is MAC?
A
- the Minimum Alveolar Concentration is the concentration of an anesthetic (as an inspired percentage concentration) at which 50% of the animals do not react to a standardized painful stimulus)
- minimum 1.5 MAC required for surgical anesthesia
14
Q
Inhalation anesthetics:
A
- isoflurane
- halothane
- methoxyflurane
- enflurane
- sevoflurane
- desflurane
- ether
- nitrous oxide
15
Q
Barbiturates
A
- long acting: phenobarbital
- short acting: thiopentone & methohexitone
- produce sleep but have no intrinsic analgesic properties
- surgical anesthesia only obtained at high doses which cause cardiovascular & respiratory depression
