Anaesthesia (01-22) Flashcards
a state in which there is lack of sensation
anaesthesia
a state of unconsciousness produced by anaesthetic agents, with absence of pain sensation over the entire body
general anaesthesia
lack of sensation caused by interrupting the sensory nerve conduction of any region of the body
regional anaesthesia
this is an insensibility to pain without loss of consciousness
analgesia
a state of reduced anxiety
anxiolysis
this is a state of reduced irritability or excitement
sedation
this is a state of stupor or unconsciousness
narcosis
this is an artificially induced state of passivity
hypnosis
a male pig can be castrated without anaesthesia up to this age
7 days
a male calf can be castrated without anaesthesia up to this age
2 months (7 days with rubber ring)
a male lamb can be castrated without anaesthesia up to this age
7 days
this feature of an ideal anaesthetic means the drug does what it is meant to do
efficacy
this feature of an ideal anaesthetic means the drug does the same thing on every occasion and in every animal
predictability
this feature of an ideal anaesthetic means that the ease of administration is desirable
convenience
a balanced anaesthesia should have this triad of functions
narcosis, analgesia, muscle relaxation
name the 5 phases of anaesthesia
- pre-operative period
- Pre-anaesthetic medication
- induction
- maintenance
- recovery
in this phase of anaesthesia: animals are examined, drugs/fluids given to control pre-existing medical conditions, anaesthetic equipment prepared for use
pre-operative period
in this phase of anaesthesia: drugs are used to sedate the animal to make it less anxious, relieve pain, and decrease drug doses required for subsequent events
pre-anaesthetic medication (premedication)
in this phase of anaesthesia: the animal is rendered unconscious with agents
induction
in this phase of anaesthesia: unconsciousness is maintained
maintenance
in this phase of anaesthesia: drug administration ceases and the animal is allowed to regain consciousness
recovery
what is the moral/ethical reason for anaesthesia
prevent suffering caused by stress and/or pain
what is technical/practical reasons for anaesthesia?
prevent patient moving during surgery, reduce human risk
what are 6 features of an ideal anaesthetic?
- safety
- efficacy
- predictability
- convenience
- cost
- legality
this is a concept where different agents are used to produce each element of the anaesthetic triad instead of just 1 drug for all elements
balanced anaesthesia
name 4 risk factors identified for small mammal death rates under anaesthesia
- recovery period
- increased operative time
- unfamiliarity with anaesthetic technique
- intubation/fluid administration for cats
name the breed(s) associated with the specific consideration
airway problems
brachycephalics
name the breed(s) associated with the specific consideration
high incidence of von Willebrand’s disease
Dobermann
name the ASA classification based on the patient’s physical status
normal, healthy animal
ASA I
name the ASA classification based on the patient’s physical status
mild systemic disease or impairment
ASA II
name the ASA classification based on the patient’s physical status
elderly dog but otherwise healthy
ASA II
name the ASA classification based on the patient’s physical status
more severe systemic disease which is well compensated/ controlled by treatment
ASA III
name the ASA classification based on the patient’s physical status
dog with heart murmur which is bright, lively, and active
ASA III
name the ASA classification based on the patient’s physical status
severe systemic disease which is not compensated
ASA IV
name the ASA classification based on the patient’s physical status
dog with heart murmur which is showing signs of cardiac failure and pulmonary oedema
ASA IV
name the ASA classification based on the patient’s physical status
Moribund, unlikely to survive 24 hours
ASA V
name the ASA classification
added to any classification if the anaesthetic is an emergency
E
food withdrawl period before anaesthesia?
dog/cats
4-6 h
food withdrawl period before anaesthesia?
horses
6-12 h
food withdrawl period before anaesthesia?
cattle
18-24 hours
name some physical factors to help prevent hypothermia during surgery (5)
increase temp of environment, BAIR hugger, no cold table, heat incoming fluids, insulate animals (foil/bubble wrap)
name some anaesthetic factors to help prevent hypothermia during surgery (5)
- short-acting anaesthetics
- anaesthetic depth not too deep
- adequate but not excessive ventilation
- rebreating systems
- HME exchangers
name some surgical factors to help prevent hypothermia during surgery (4)
minimize surgical time,
small incision size,
technique,
avoid unnecessary wetting/clipping of non-surgical area
3 features of a good environment for recovery period from anaesthesia
warm, comfortable, quiet (but observed)
when to extubate a dog
swallowing
when to extubate a cat
before swallowing
name the gas in the canister
black with white shoulder OR white
oxygen
name the gas in the canister
blue
nitrous oxide
name the gas in the canister
grey with white & black shoulder
medical air
name the part of the anaesthetic machine
reduces high cylinder pressure to useable pressure; keeps outlet pressure constant
presure regulator
name the part of the anaesthetic machine
fine regulation of fresh gas flow; tapered graduated tube with needle valve at base
flowmeters
name the part of the anaesthetic machine
locks the vaporiser to machine, O rings prevent leakage
backbar
name the part of the anaesthetic machine
allows a ventilator to be attached to the anaesthetic machine
mini schraeder connectors
name the anaesthetic machine safety feature
prevents wrong cylinder to be attached to hanger
pin index valves
name the anaesthetic machine safety feature
helps cylinders make good contact and prevents fires
bodok seal
these are methods used to remove environmental contaminants from the immediate surroundings of the staff to ensure exposure limits are not exceeded
scavenging
name the type of scavenging
fan draws waste anaesthetic gases to the outside of the building where it mixes with the air outside
active scavenging
which has a greater affect on resistance in a breathing system?
hose length or hose diameter
diameter
how to overcome most problems associated with resistance and reduce the work of breathing
intermittent positive pressure ventilation (IPPV)
high or low?
gas flow requirement in rebreathing systems
low
high or low?
gas flow requirement in non-rebreathing systems
high
high or low?
volatile agent required in rebreathing systems
low
high or low?
volatile agent required in non-rebreathing systems
high
high or low?
pollution risk in rebreathing systems
low
high or low?
pollution risk in non-rebreathing systems
high
high or low?
resistance to respiration in rebreathing systems
high
high or low?
resistance to respiration in non-rebreathing systems
low
conserved or lost?
expired heat and moisture in rebreathing systems
conserved
conserved or lost?
expired heat and moisture in non-rebreathing systems
lost
cheap or expensive?
rebreathing system
expensive
cheap or expensive?
non-rebreathing system
cheap
soda lime required?
in rebreathing system
yes
soda lime required?
in non-rebreathing system
no
slow or fast?
change in inspired anaesthetic agent in rebreathing systems
slow
slow or fast?
change in inspired anaesthetic agent in non-rebreathing systems
fast
what is minimum fresh gas flow calculated based on for rebreathing systems
based on metabolic O2 consumption
how is minimum fresh gas flow calculated for non-rebreathing systems
respiratory minute volume x X
name 2 types of rebreathing systems
circle system; to and fro system
name some effects of increased respiratory resistence
- hypoventilation
- increased work breathing
- positive end expiratory pressure (PEEP)
- hypoxia
name 4 types of non-breathing systems
- Magill
- Lack
- T-piece
- Modified T-pieces
- Bain
what rebreathing system is being described?
inspiratory and expiratory limbs connected to endotracheal tube connector with a Y connector
circle system
what rebreathing system is being described?
fresh gas inflow situated next to endotracheal tube connector, metal gauze screen at patient end of canister, APL valve between canister and patient
to and fro system
what non-rebreathing system is being described?
3-6 VT reservoir bag on inspiratory limb and corrugated hose ending at an expiratory valve
magill system
what non-rebreathing system is being described?
reservoir bag on inspiratory limb connects to an outer inspiratory limb which surrounds an inner expiratory tube that ends at an expiratory valve positioned at the machine connector
Lack system (coaxial Magill)
what non-rebreathing system is being described?
bag on inspiratory limb, inspiratory & expiratory limbs are separate and run parallel to one another
Parallel Lack System
what non-rebreathing system is being described?
reservoir bag on expiratory limb; inspiratory hose connects to the endotracheal tube connector and open ended expiratory limb at a T shaped connector
Ayres’ T-piece
what non-rebreathing system is being described?
respiratory bag on the expiratory limb; outer expiratory tube and inner inspiratory tube, +/- expiratory valve
Coaxial Bain system
what non-rebreathing system is being described?
has a T-piece with closed ended bag on expiratory limb and a pediatric low resistance valve
Parallel Bain System
what type of breathing system is N2O NOT recommended with
rebreathing systems
this is an agent that affects mood
tranquiliser
this is an agent that reduces anxiety
anxiolytic
this is an agent that causes drowsiness
sedative
this is an agent that depresses the CNS and induces sleep at higher doses
hypnotic
this is an agent that reduces aggression and agitation
neuroleptic
name the 4 major groups of tranquilizer/sedative drugs
- phenothiazines
- butyrophenones
- Alpha2-agonists
- Benzodiazepines
this group of drugs block alpha1 receptors, block histamine/muscarinic receptors, block 5-HT, tranquilize, sedate, and anxiolytic, but have no analgesic properties
phenothiazines
this group of drugs have sedative action, potent antiemetic properties but have unpleasent side effects, hallucinations, agitation, etc in people
butyrophenones
this group of drugs have a primarily anxiolytic action, anticonvulant properties, muscle relaxation and mechanism of action is via potentiation of GABA mediated inhibition
benzodiazepines
these agents have no intrinsic efficacy but bind to the receptor and prevent interaction between benzodiazepines and the receptor
benzodiazepine antagonists
these agents act on the GABA receptor, bind with high affinity, close the chloride channel causing the neuron to become vulnerable to excitation
benzodiazepine inverse agonists
name the 3 main classes of alpha2-agonists
- imidazoles
- oxazolines
- phenylethylamines
name 2 purposes of pre-anaesthetic medication
- reduce dose of other anaesthetic agents
- relief of anxiety and apprehension
general anesthesia is described as a triad of these 3 things
- unconsciousness
- muscle relaxation
- analgesia
this is an agent which produces dose dependent CNS depression & will produce unconsciousness at adequate doses
- varying degrees of analgesia and muscle relaxation
general anaesthetic
name the two types of general naesthetic agents
- injectable
- inhalational
name the 4 receptors that anaesthetic agents may interact with to produce general anaesthesia
- GABA(A)
- NMDA
- Glycine
- Nicotinic acetylcholine
as a general rule, injectable anaesthetics act here
within the brain
as a general rule, halogenated volatile inhalational anaesthetics act predominately here
within the spinal cord
name 5 ways injectable anaesthetics can be administered
- IV
- IM
- Intraosseous
- intraperitoneal
- SQ
name at least 5 properties of an ideal injectable anaesthetic agent
- Rapid onset and recovery
- No excitation or emergence phenomena
- Analgesic properties
- No pain on injection
- Safe following extravascular or intra-arterial injection
- Minimal cardiovascular and respiratory depression
- No histamine release
- No toxic effects or interactions with other agents
- High lipid solubility
- No accumulation
- Water soluble formulation
- Long shelf life at room temperature 13. Inexpensive
name 5 advantages of injectable anaesthetic agents
- little equipment needed
- easy to administer
- induction of anaesthesia can be rapid and smooth
- potentially relatively cheap
- no environmental pollution
name 5 disadvantages of injectable anaesthetic agents
- once administered, retrieval is impossible
- body mass of patient must be known
- high doses often required when used as a sole anaesthetic agent (therefore side effects)
- possibly less well tolerated by debilitated animals
- abuse potential of some drugs and risks of inadvertent self administration
a drug injected, or absorbed, into a vein must do these 5 things for uptake for general anesthesia
- travel in blood to R side of heart
- traverse the lungs
- travel through left side of heart
- travel in arterial blood to effect site
- cross blood brain barrier to interact with appropriate receptors
what is the primary role of drug metabolism
create a molecule which is more water soluble and more easily excreted by the kidney
what receptor does propofol interact with for general anaesthesia
GABA(A) agonist
name 2 adverse side effects of propofol
- dose dependent CVS depression (hypotension)
- dose dependent respiratory depression (apnea +/- cyanosis)
care must be taken with repeated doses or prolonged use of propofol in what species (bc they lack enzymes required to conjugate glucornides and have problems metabolizing triglycerides)
cats
name the general anaesthetic
licensed for IV use in cats and dogs (off-license in rabbits, birds, reptiles, small mammals);
smooth & rapid induction of anaesthesia;
generally smooth recovery from anaesthesia
propofol
name the general anaesthetic
licensed for IV use in cats & dogs (off-license in rabbits, birds, reptiles, small mammals);
smooth and rapid induction of anaesthesia;
occossional poor quality of recovery from anaesthesia;
can be used repeatedly or as an infusion
alfaxalone
what receptor does alfaxalone interact with for general anaesthesia
GABA(A) agonist
name 2 adverse side effects of alfaxalone
- dose dependent CVS depression (hypotension)
- dose dependent respiratory depression (hypoventilation +/- apnea)
name the general anaesthetic
licensed for use in cats, dogs, horses, cattle, pigs, and primates;
delayed anaesthetic induction;
possible poor quality anaesthetic recovery;
maintains cranial nerve reflexes under anaesthesia;
schedule 2 controlled drug
ketamine
name 2 adverse side effects of ketamine
- sympathomimetic actions on CVS
- irregular breathing pattern
name the 2 types of clinically important barbiturates
- thiopental (short acting)
- pentobarbital (longer acting)
name the general anaesthetic
no longer licensed for vet use (only used in equine anaesthesia as rapidly acting top-up agent to cease movement while under GA)
thiopental
name 2 adverse side effects of tihiopental
- CV depression (hypotension)
- dose dependent respiratory depression (apnea)
name the general anaesthetic
licensed only for euthanasia; concentrated and non-sterile preparations; should NOT be used for anaesthesia
(longer acting barbiturate)
pentobarbital
name the general anaesthetic
not licensed for vet med, rarely used BUT used occassionaly bc minimal CV and resp depression;
quality of anaesthetic induction may be poor;
results in decrease in adrenal gland function & cortisol production (appropriate stress response to anaesthesia & surgery cannot be mounted)
etomidate
name 5 factors that the choice of injectable anaesthetic agent for induction of anaesthesia may depend on
- species and temperament of animal
- Underlying medical conditions
- Nature of the procedure
- Available drugs, equipment and conditions
- Personal preference and experience
name the drug
10% solution licensed for IV use in horses;
central skeletal muscle relaxant that affects spinal cord and brain stem; NOT an anesthetic, NO analgesic properties
GGE (guiaphenesin or glyceryl guiacolate ether)
name the 2 main groups of inhalational anaesthetics
- volatile
- compressed “gases”
name 4 types of volatile liquid inhalational anaesthetics
- isoflurane
- sevoflurane
- halothane
- desflurane
name 2 compressed “gases” used as inhalational anaesthetics
- nitrous oxide (N2O)
- Xenon
name 4 ways in which inhalational anaesthetics can be administered
- induction chamber
- face mask
- nasopharyngeal insufflation
- endotracheal tube
name 3 advantages inhalational anaesthetic agents
- increased fraction of oxygen in inhaled gas mixture provided
- airway protection by endotracheal tube
- rapid induction and recovery from GA & rapid change of anaestetic depth
name 3 disadvantages of inhalational anaesthetic agents
- additional equipment required for administration
- control of waste gases required to avoid personnel exposure
- toxic or harmful components may be produced by contact with soda lime or liver metabolism
name some properties of an ideal inhalational anaesthetic agent
- easily vaporized
- non-flammable & stable on storage
- no reaction with anaestetic system components
- non-irritant or pungent
- minimally metabolized
- smooth induction and recovery from anaesthesia with rapid control of anaesthetic depth
- some analgesia and muscel relaxation
- few CV and resp side effects
- no renal or hepatic toxicity
- cheap and not requiring expensive vaporiser
list the pressure gradient passing from the vaporiser to the brain (5)
- vaporiser
- anaesthetic system
- alveoli
- blood
- brain
is the speed of anaesthetic induction and recovery faster or slower for more soluble agents?
(inhalational anaesthetics)
SLOWER
this is a figure which is used to descrive the number of parts of gas in the blood compared to the alveolus
blood gas partition coefficient
what does a high blood gas partition coefficient mean for an inhalational anesthetic
the gas is very soluble in blood
name 3 things that anaesthetic uptake in blood is affected by
- solubility of agent in blood
- pulmonary blood flow
- concentration gradient (diffusion) between alveoli and blood
name 3 factors that will affect inhalational anaesthetic uptake
- inspired agent concentration
- alveolar ventilation
- uptake by blood and tissues
name 3 things that affect anaesthetic uptake in tissues
- solubility of the agent in tissues
- tissue perfusion
- concentration gradient (diffusion) between blood and tissues
name the degree of metabolism for isoflurane
0.2%
name the degree of metabolism of sevoflurane
2%
name the degree of metabolism of desflurane
0.02%
name the degree of metabolism of halothane
20%
this is defined as the minimum concentration required to prevent movement in response to a painful stimulus in 50% of the subjects tested
minimum alveolar concentration (MAC)
in order to provide clinical anaesthesia, what factor of MAC is required of an inhalational anaesthetic
1.5x MAC
name some factors that affect MAC of an inhalational agent
- species
- age
- PaO2<40mmHg; PaCO2»90mmHg
- high circulating catecholamines
- pregnancy
- hypotension <50mmHg
- hyperthyroidism
- CNS stimulants or depressants
- pregnancy
do most inhalational anaesthetic agents provide analgesia?
NO
what are the 3 desirable effects of volatile anaesthetic agents
- unconsciousness
- amnesia
- immobility
what is the main CVS effect of volatile anaesthetic agents
hypotension
what is the MAC of nitrous oxide (N2O) in dogs and cats
200%
Nitrous oxide is thought to offer analgesia by acting as an antagonist at these receptors
NMDA
name 3 situations where nitrous oxide should be avoided as an anaesthetic
- GDV
- closed pneumothorax
- vascular air emboli
this is an unpleasant sensory and emotional experience associated with actual or potential tissue damage
pain
this is an absence of pain in the presence of stimuli which would normally be painful
analgesia
name the theory
Melzack & Wall suggested that nociceptive information is modulated in the substantia gelatinosa of dorsal horn;
inhibitory neurons can be stimulated by either descending inhibitory neurons or non-nociceptive afferent input
gate control theory
this is an increased amount of pain associated with a mild noxious stimulus
hyperalgesia
this is pain provoked by a non-noxious stimulus
allodynia
this is the increase of synaptic potential with each stimulus (determined in research setting)
“wind-up”
name the 6 analgesic groups
- opioids
- NSAIDs
- Local anaesthetics
- NMDA antagonists
- Alpha-2 adrenoreceptor agonists
- other (gabapentin, tramadol)
what is the active analgesic form of morphine
Morphine-6-glucuronide
how are morphine glucuronides excreted?
in urine
what are the opioid receptors
G-protein coupled receptors
name 6 side effects of opioids
- sedation
- resp depression
- negative chronotropy
- emesis
- dysphoria
- histamine release
name the 4 mu agonist opioids
- morphine
- pethidine
- fentanyl
- methadone
what is the ‘gold standard’ analgesic
(mu agonist)
morphine
name the analgesic
this is a schedule 2 controlled drug, unlicensed for vet use;
metabolized to active analgesic;
gold standard analgesic
(mu agonist)
morphine
name the analgesic
schedule 2 controlled drug, licensed for vet use;
spasmolyic, positive chronotrope;
histamine release when administered IV
(mu agonist)
pethidine
name the analgesic
schedule 2 controlled drug, licensed for vet use;
rapid onset, 15-20min duration
(mu agonist)
fentanyl
name the analgesic
schedule 2 controlled drug, licensed for vet use;
synthetic mu agonist;
no emesis
(mu agonist)
methadone
name the analgesic
schedule 3 controlled drug, licensed for vet use;
partial mu agonist, moderate pain
buprenorphine
name the analgesic
prescription-only medication (POM), licensed for vet use;
synthetic opioid agonist/antagonist;
mild pain;
effective anti-tussive
(kappa agonist, mu antagonist)
butorphanol (torbugesic)
these reversibly interfere with action potential generation and conduction of noxious impulse;
they do not effect resting membrane potential
local anaesthetics
name the two groups that make up a local anaesthetic
- lipid-soluble hydrophobic aromatic ring (lipophilic unit)
- basic hydrophillic amide group (hydrophilic unit)
local anaesthetics linked by this group include procaine and cocaine
ester
local anaesthetics linked by this group include lidocaine and bupivicaine
amide
metabolism of esters produces these which cause allergic reactions
para-aminobenzoates (PABA)
this is the pH at which concentration of ionized and unionized forms of a local anaesthetic are equal
pKa
name 6 ways local anaesthetics can be administered
- local infiltration
- splash blocks
- specific nerve blocks
- IVRA
- extradural
- topical
distribution and duration of local anaesthetics are influenced by this
degree of protein binding
higher level protein binding results in (longer or shorter?) duration of action of local anaesthetics
longer
less potent local anaesthetic agents have a (faster or slower?) onset of action
faster
how are ester-linked local anaesthetics broken down
by plasma enterases to inactive compounds
how are amide-linked local anaesthetics metabolized
by hepatic amidases into metabolites
which fibers will be blocked first by local anaesthetics?
1. small or large?
2. unmyelinated or myelinate?
3. C-fibers or Ad fibers?
4. Pain sensation or touch?
- small
- myelinated
- Ad fibers
- pain sensation
name 3 CNS effects of local anaesthetics
- tremors
- convulsions
- respiratory depression
name 2 CV effects of local anaesthetics
- reduced myocardial contractility
- vasodilation
name 3 unwanted effects of local anaesthetics
- reduces epithelial repair
- tissue irritation
- allergic reactions
name 4 amide-linked local anaesthetics
- lidocaine
- bupivicaine
- mepivicaine
- proxymetacaine
name the local anaesthetic
adrenaline in prep prolongs action duration;
class 1B anti-arrhythmic;
infusion lowers MAC
(amide-linked)
lidocaine
name the local anaesthetic
long acting (8h);
cardiac toxicity (no IV admin.)
(amide-linked)
bupivicaine
name the local anaesthetic
equivalent potency to lidocaine;
less vasodilation than lidocaine;
less irritant to tissues;
expensive;
no preservative
(amide-linked)
mepivicaine
name the local anaesthetic
used for conjunctival sac anaesthesia, but toxic to corneal epithelium;
rapid onset (10s);
10-20 min duration
(amide-linked)
proxymetacaine
name the local anaesthetic
short duration
causes vasoconstriction
PABA reactions
added to penicillin to reduce pain on injection
(ester-linked)
procaine
name the local anaesthetic
eutectic mix of local anaesthetic;
topical anaesthesia of skin;
used to facilitate venipuncture
EMLA
name the NSAID
contraindicated in cats;
vet licensed prep is available;
overdose causes liver failure;
analgesic, antipyretic and mild anti-inflamm. properties;
little ulcerogenic potential, no effect on platelets or bleeding time
paracetamol
name the NSAID
block excitatory amino acid (EAA) receptors, reducing modulation and CNS activity;
analgesia is produced at low doses, progressing to dissociative anaesthesia at higher doses
NMDA antagonists
name the general anaesthetic
cyclohexane derivative;
chemical restraint/dissociative anaesthesia;
somatic analgesia;
inhibits central sensitization
ketamine
name the NSAID
no vet license;
atypical synthetic opioid-like substance which reduces nociceptive transmission by binding at mu receptors;
also inhibits re-uptake of serotonin and noradrenaline in the CNS
tramadol
name the NSAID
no vet license;
stabilizes electrical nerve activity and has been used as an analgesic, esp. for neuropathic pain
gabapentin
name the NSAID
provides good visceral analgesia, along with profound sedation
Alpha-2 agonists
name 5 advantages of local anaesthesia
- true analgesia
- only local disturbance of function
- limited systemic effects
- relatively inexpensive
- minimal equipment needed
name 5 disadvantages of local anaesthetics
- rare complications
- systemic toxicity
- allergic reaction
- neurological injury
- technique failure
name 5 potential side effects of local anaesthesia
- infection
- coagulopathy
- raised intracranial pressure
- pruritus
- hypotension
name the 6 main ways local anaesthetics may be used
- Topical
- Local Infiltration
- Conduction blockade (nerve block)
- Intra-articular
- Intravenous regional anaesthesia (IVRA)
- Neuraxial anaesthesia
name 4 uses of topical local anaesthetics
- laryngeal
- corneal
- cutaneous
- wound margins
name 4 uses of local infiltration anaesthetics
- line block
- inverted L block
- intradermal
- ring block
name the local infiltration anaesthetic technique
local anaesthetic solution is infiltrated in a linear fashion under the proposed incision site;
used for minor lumpectomies (small animal) & abdominal surgery (ruminants)
line block
what are inverted L blocks used for in cattle
laparotomy
name the local infiltration anaesthetic technique
Local anaesthetic injected through the skin as a transcutaneous “bleb” to facilitate passage of vascular catheters or large paravertebral or spinal needles
intradermal
name the local infiltration anaesthetic technique
local anaesthetic solution is infiltrated on the circumference of an appendage in an attempt to block afferent sensory activity (distal limb and teat analgesia in cattle)
ring block
what nerve is blocked in cattle for dehorning
cornual
what 2 nerves are blocked in goats for dehorning
cornual branches of:
1. zygomatic-temporal n.
2. intratrochlear n.
name the 4 nerves that can be blocked for dentistry
- mental
- mandibular
- infraorbital
- maxillary
what does blocking the infraorbital nerve anaesthetize/provide analgesia for?
- upper lip and nostril
- upper incisors/gums
what does blocking the mental nerve anaesthetize/provide analgesia for?
- lower lip
- lower incisors and gums
what nerves are blocked for paravertebral local anaethesia
T13, L1, L2
distal or proximal paravertebral nerve block?
needle is inserted vertically to skin off the cranial edge of transverse process of L1, the caudal edge of L1, and the caudal edge of L2
proximal
distal or proximal paravertebral nerve block?
needle is inserted parallel to transverse process (half given ventral, half given dorsal to it) of L1, L2, & L4
distal
what 3 things indicate a succesful paravertebral nerve block?
- scoliosis (spine curved with concavity to unblocked side)
- heat
- absence of response to pin-pricking
name 4 nerve blocks for the eye
- retrobulbar
- Peterson (only cattle)
- Auricopalpebral
- Supraorbital
what does an auricopalpebral block anaesthetize
motor fibers to the eyelids
what does a supraorbital nerve block anaesthetize?
forehead and middle portion of upper eyelid
what is intra-articular local anaesthesia used for?
prior to & following joint surgery or arthrocopy (horses)
name 2 uses of intravenous regional anaesthesia (IVRA) in large animals
- digit amputatuon (cattle)
- distal limb surgery (horses)
what technique of local anaesthesia involves applying a tourniquet (slowly so veins are occluded before arteries) before injection
IVRA (intravenous regional anaesthesia)
what technique of local anaesthesia is the hanging drop technique used for?
extradural anaesthesia
name the neuraxial local anaesthesia technique
site for injection ID’d by ‘pump-handling’ the tail to reveal first intercoccygeal space as most mobile in this part of the axis, injection is given just cranial to this;
abolishes Ferguson’s reflex
sacrococcygeal extradural
what does lumbosacral extradural anaesthesia anesthetize?
both hind limbs & abdomen
where should you give lumbosacral extradural anaesthesia
in palpable depression just caudal to L7
what does RUMM conduction blockade in small animals anaesthetize?
below the elbow (radius, ulnar, musculocutaneous, and median nerves)
what does brachial plexus conduction blockade in small animals anaesthetize?
from mid humerus (5-6 nerves blocked)
what does femoral & sciatic conduction blockade in small animals anaesthetize?
from stifle (main nerves to hind limbs)
name the term
an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage
pain
name the term
an absence of pain in the presence of stimuli which would normally be painful
analgesia
name 4 reasons for analgesia
- ethical
- logical
- professional
- clinical
name 3 undesirable things prevented by effective peri-operative anti-nociception
- central sensitization
- nociception: sypatho-adrenal outflow
- reflex movement
name 5 things that must be taken into consideration with pain assessment
- species
- severity of pain
- somatic v visceral pain
- location
- level of consciousness
name 4 benefits of effective pre-operative pain management
- facilitates prep & exam of animals
- reduces risk of personal injury
- reduces induction problems
- smoothes induction in horses
clinical strategy for optimizing an animal’s peri-operative comfort
administration of analgesia before painful stimulus;
to prevent central sensitization
pre-emptive analgesia
clinical strategy for optimizing an animal’s peri-operative comfort
maintain post-op anti-inflammatory drugs until the wound has almost healed
prolonged post-operative pain therapy
clinical strategy for optimizing an animal’s peri-operative comfort
Infusing drugs like ketamine and short acting opioids during anaesthesia (which have less depressant effects); central sensitization is blocked, intra-operative analgesia is improved; anaesthetics can be used at minimal doses
Partial Intravenous Anaesthesia (PIVA)
name 3 important advantages if partial intravenous anaesthesia (PIVA)
- reduces dose of inhalation anaesthetic required (less physiological depression)
- intra-operative analgesia is improved
- central sensitization is blocked
clinical strategy for optimizing an animal’s peri-operative comfort
combining sub-analgesic doses of drugs from different classes to provide total analgesia resulting from additive or synergistic drug effects;
also reduces likelihood of adverse drug effects arising from the use of high doses of a single drug class
polymodal pain therapy (PMPT)
this is analgesia resulting from additive or preferably synergistic drug effects ;
involves premedication, intraoperative analgesia, and postoperative analgesia
multimodal analgesia (polymodal analgesia)
this is the process by which water is drawn across a semipermeable membrane in response to the presence of osmotically active particles
osmosis
this is the theoretical pressure that would be needed to prevent osmosis
osmotic pressure
name 4 osmotically active particles
Na+, Cl-, K+, glucose
what is normal plasma osmolarity
280-320 mOsm/L
this is a measure of the effective osmolarity and predicts the effect of the solution on cell volume at equilibrium
tonicity
what is the tonicity of the fluid?
<280 mOsm/L
increased cell volume
hypotonic
what is the tonicity of the fluid?
280-300 mOsm/L
= cell volume
isotonic
what is the tonicity of the fluid?
> 300 mOsm/L
decr. cell volume
Hypertonic
aka colloid osmotic pressure (COP);
the part of osmotic pressure which is contributed by the large molecules (proteins) - albumin
oncotic pressure
this is a gel-like layer covering the luminal surface of vascular endothelial cells ;
acts as a macromolecular sieve;
controls vascular permeability and microvascular tone
endothelial glycocalix
name 4 factors compromising the function of the endothelial glycocalix
- hyperglycemia
- ischemia
- inflammatory mediators
- hypervolemia
name the type of fluid loss causing these consequences
- Solute is lost from the ECF
- ECF becomes hypotonic relative to ICF
- water moves from ECF to ICF
hypertonic fluid loss
name the type of fluid loss causing these consequences
- water is lost from the ECF
- ECF becomes hypertonic relative to ICF
- water moves from ICF to ECF
hypotonic fluid loss
name the type of fluid loss causing these consequences
- no change in osmolarity
- no fluid shifts
- hypovolemia
isotonic fluid loss
name the type of fluid loss causing these consequences
- reduced oncotic pressure
- hypovolemia
protein-rich fluid
name the 3 types of fluids
- crystalloids
- colloids
- blood products
name the 3 main uses of crystalloid fluids
- replacement
- maintenance
- special situations
name 4 types of crystalloid fluids used for replacement
- saline (NaCl 0.9%)
- Hartmann’s solution
- lactated ringer’s solution
- Plasma-Lyte
name the crystalloid fluid
no buffer;
acidifying fluid leads to hyperchloemic metabolic acidosis;
no K+, can lead to hypokalemia if not supplemented;
used for short term vomiting, hypochloremia, hyponatremia, hypercalcium, etc
saline - NaCl 0.9%
name the crystalloid fluid
balanced (similar electrolyte composition as plasma);
buffered (lactate), alkalizing effect;
used for fluid resuscitation and perioperative fluid therapy;
also diarrhea, renal failure, DKA
Hartmann’s solution
name the crystalloid fluid
similar to Hartmann’s solution but uses acetate as a buffer (instead of lactate) and has magnesium
Plasma-Lyte
list 3 options for using crystalloid fluids for maintenance
- 5% dextrose
- 0.18% saline & 4% glucose
- alternate btwn 1 bag Hartmann’s then 2 bags 5% dextrose
what supplement is required when using cruystalloid fluids for maintenance
K+
name 3 crystalline fluids that can be used in special circumstances
- Hypertonic saline (NaCl 7.2%)
- sodium bicarbonate
- potassium chloride
name the crystalloid fluid
draws fluid into IV space by osmosis;
increases CO (by expanding plasma volume leading to sympathetic activation);
rapid onset (5min) but short duration (30-60min);
give 3-5 mL/kg over 10 min
hypertonic saline (NaCl 7.2%)
name the crystalloid fluid
for treatment of severe metabolic acidosis;
contraindicated in respiratory acidosis, controversial in lactic acidosis;
respiratory function must be adequate to eliminate excess CO2
Sodium Bicarbonate
name the crystalloid fluid
used for potassium supplementation;
mix thoroughly with NaCl or Hartmann’s;
maintenence requirements 20 mmol/day;
max safe rate: 0.5mmol/kg/h
potassium chloride
name 4 types of colloid fluids
- HES
- gelatins
- dextrans
- human albumin 20%
name the type of colloid fluid
synthetic;
manufactured in different molecular weights;
dose: 5mL/kg bolus repeated up to 4x
HES (hydroxyethyl starches)
name the type of colloid fluid
natural, derived from bovine collagen;
risk of anaphylaxis;
rapid but transient volume expansion;
dose: 5 mL/kg bolus repeated up to 4x
gelatins
name the type of colloid fluid
glucose polymers;
marked temporary volume expansion;
risk of coagulopathy and anaphylaxis;
risk of renal failure in presence of hypovolemia and pre-existing renal disease
Dextrans
name the type of colloid fluid
natural, monodisperse, hyperoncotic;
high risk hypersensitivity reactions;
for treatment of severe hypoalbuminemia
human albumin 20%
name 5 Blood products that may be used for fluid therapy
- whole blood
- packed red blood cells
- fresh frozen plasma (FFP)
- frozen plasma
- cryoprecipitate
name the blood product for fluid therapy
contains RBCs, EBCs, platelets, proteins, clotting factors;
indicated in acute blood loss;
should be administered < 6h of collection;
may be refridgerated up to 28 days but protein degradation occurs after 12-24h
whole blood
how much is 1 unit of canine whole blood
250 mL
how much is 1 unit of feline whole blood
45-60 mL
name the blood product for fluid therapy
PCV is high (60-90%);
needs resuspension in 0.9% NaCl;
for normovolemic anemia and whole blood loss (with crystalloids)
packed red blood cells (PRBCs)
name the blood product for fluid therapy
contains clotting factors and other plasma proteins;
must be frozen within 6h of collection;
can be stored up to a year at -18C;
for coagulopathies or hypoproteinemia;
dose: 10-30 mL/kg over 4h
fresh frozen plasma (FFP)
name the blood product for fluid therapy
contains vitK-dependent factors (II, VII, IX, X);
used for rodenticide toxicity
frozen plasma
name the blood product for fluid therapy
contains vWF, fibrinogen and clotting factors VIII and XIII;
used for von Willebrand’s disease and hemophilia A
cryoprecipitate
name 5 possible routes of fluid administration
- intravenous
- intraosseous
- intraperitoneal
- subcutaneous
- oral
what is the fast and reliable route of choice for fluid administration
intravenous
name the 3 common veins used in cats and dogs for intravenous fluid administration
- cephalic
- saphenous
- jugular
name 3 places where fluids can be administered intraosseously
- proximal humerus
- tibial tuberosity
- wing of ileum
what is a risk of intraperitoneal fluid administration
organ penetration
what kind of fluids can be administered intraperitonealy or subcutaneously?
isotonic only
how long does it take subcutaneous fluids to reach extracellular space
6-8h
what is the maximum volume of fluids that can be administered subcutaneously
10 mL/kg
what method of fluid administration is often used in farm animals
oral
name 5 goals of fluid therapy
- supply normal maintenance requirements
- replace pre-existing fluid losses
- replace ongoing fluid losses
- optimize intravascular volume
- treat electrolyte derangements
what is the ultimate goal of fluid therapy
support normal homeostasis and cellular metabolic function to produce optimal outcomes
name the term
this is fluid loss from all compartments
dehydration
name the term
this is specifically fluid loss from intravascular compartment
hypovolemia
name the percentage of dehydration based on the clinical signs
Hx suggests increased losses or decr. intake but can’t be detected on clinical exam
<5%
name the percentage of dehydration based on the clinical signs
tacky, dry mucuous membranes, normal-mild loss of skin turgor, eyes still moist
5-7%
name the percentage of dehydration based on the clinical signs
dry oral mm, eyes dull and sunken, consideral loss of skin turgor, weak rapid pulse, reduced urine output, increased CRT
8-10%
name the percentage of dehydration based on the clinical signs
very dry mm, eyes dull and retracted, zero skin turgor, no urine production, weak thready pulses;
may be recumbent, reduced level of consciousness
> 10-12%
name the percentage of dehydration based on the clinical signs
very dry mm, eyes dull and retracted, zero skin turgor, no urine production, weak thready pulses;
may be recumbent, reduced level of consciousness;
very prolonged CRT, moribund
> 12-15%
what is the recommended fluid rate for animals under anaesthesia
5 mL/kg/h (3-10 mL/kg/h)
name 4 types of fluid therapy strategies for the hemodynamically unstable patient
- goal directed fluid therapy
- fluid challenge
- hypotensive resuscitation
- transfusion therapy
name the fluid therapy strategy for the hemodynamicall unstable patient
the titration of fluid therapy to achieve specific endpoints;
aimed at optimization of cardiovascular dynamics;
associated with improved clinical outcomes
goal-directed fluid therapy
name the fluid therapy strategy for the hemodynamicall unstable patient
the administration of a bolus to assess the fluid responsiveness;
used in hemodynamically unstable animals;
minimizes risk of volume overload
fluid challenge
what is the estimated blood volume of dogs
80-90 mL/kg
what is the estimated blood volume of cats
60 mL/kg
what is the estimated blood volume of horses
80 mL/kg
name the fluid therapy strategy for the hemodynamicall unstable patient
the restoration of lower than normal blood pressure;
aims at facilitating hemorrhage control and reducing the risk of bleeding while ensuring blood flow to vital organs;
temporary solution until surgical hemostatic control
hypotensive resuscitation
why should we monitor anaesthesia?
to recognise trends early to resolve problems before they become life-threatening
what is the mortality rate of dogs under anaesthesia
0.17%
what is the mortality rate of cats under anaesthesia?
0.24%
how often should variables be recorded on a written anaesthetic record?
every 5 min
what 6 things should be monitored during anaesthesia
- CNS function (depth)
- Cardiovascular function
- respiratory function
- temperature
- Equipment
- General (surgeon, fluids, etc)
name the 4 stages of anaesthesia
- voluntary excitement
- involuntary excitement
- surgical anaesthesia
- overdose
what 5 things can be used to monitor anaesthesia depth
- cranial nerve reflexes
- other reflexes
- CV responses to surgery
- Resp responses to surgery
- skeletomuscular responses to surgery
this reflex is most useful and often accessible;
it is present when plane of anaesthesia is light and is usally lost at surgical plane (except in horses)
palpebral risk
name 3 things we can monitor to assess CV function during anaesthesia
- heart rate and rhythm
- pulses
- perfusion of tissues
what 3 things should be done to montor heart rate and rhythm during anaesthesia
- palpation/observation of apex beat
- auscultation
- pulse palpation
what 3 things can palpation of pulses give information on
- pulse rate
- rhythm
- quality
what two arteries are useful to palpate in small animals during anaesthesia
- metacarpal
- dorsal pedal
what 4 sites are useful in the horse to palpate a pulse
- facial
- palatine
- auricular
- dorsal metatarsal
what 3 things should you assess when palpating a pulse
- pulse pressure
- mean pressure
- character of pulse
what two things can you monitor for tissue perfusion during anaesthesia
- CRT
- mucus membrane color
name 2 reasons to “sigh” lungs frequently during anaesthesia
- helps prevent atelectasis
- allows appraisal of lung/breathing system
what 2 things can you assess using equipment to monitor CV function during anaesthesia
- ECG
- Blood Pressure
name 2 limitations of ECG monitoring
- no info about mechanical activity
- displayed HR can be incorrect
name two indirect (non-invasive) techniques of monitoring blood pressure
- Oscillometric
- Doppler
what should the width of the cuff for oscillometric blood pressure monitoring be
40% of the arm/leg circumference
name 3 limitations of oscillometric blood pressure monitoring
- affected by movements
- can over/under estimate SAP
- not continuous
name 3 limitations of Doppler technique for monitoring blood pressure
- only gives systolic pressure
- less accurate and reible than direct monitoring
- difficulty in positioning and attaching probe
what is the accurate ‘gold standard’ for blood pressure monitoring
direct (invasive) monitoring
name 5 risks of direct blood pressure monitoring
- infection
- hematoma/bleeding
- thrombus formation
- blood flow occlusion
- accidental drug injection
what does pulse-oximeter measure?
& oxygen saturation of hemoglobin (SpO2)
name 4 respiratory monitoring devices
- apnea monitors
- capnography
- pulse oximetry
- blood gas analysis
name the respiratory monitoring device
a thermistor detects warm air movements (expired gases);
gives no indication regarding accuracy;
may be misleading
apnea monitors
name the respiratory monitoring device
gives a graphical representation of continuous measurement of PCO2 throughout the resp cycle (ETCO2 estimates PaCO2);
provides info about ventilation, CO, metabolism and equipment
capnography
what does hypercapnia (ETCO2 > 45 mmHg) reflect
hypoventilation
what does hypocapnia (ETCO2 < 35 mmHg) reflect
hyperventilation
name 3 things that cause increased ETCO2
- decr. alveolar ventilation
- incr. CO2 production
- incr. inspired CO2
name 4 things that cause decreased ETCO2
- incr. alveolar ventilation
- reduced CO2 production
- incr. alveolar dead space
- sampling error
what does alveolar plateu getting lower over time on a capnogram indicate
decreasing ETCO2
what does an elevated baseline on a capnogram indicate
inspired CO2 levels increasing
angle of expiratory upstroke is reduced and it is prolonged on a capnogram;
what does this indicate?
increased resistance to exhalation
what do these features on a capnogram indicate?
shallow expiratory upstroke, low ETCO2 and short alveolar plateau
inadequate seal
this is the gold standard measurement of respiratory function
arterial blood gas analysis
this is the act of inhaling and exhaling (the act of breathing)
ventilation
this is the delivery of oxygen to tissues
oxygenation
this means high blood carbon dioxide (PaCO2)
hypercapnia
this means low blood oxygen (PaO2)
hypoxia
central or peripheral?
which chemoreceptors monitor PaCO2?
central
central or peripheral?
which chemoreceptors monitor PaO2?
peripheral
what is the cause of hypercapnia (increase in PaCO2)?
reduced ventilation
what should the fraction of inspired CO2 (FiCO2) be?
0 mmHg
what 3 things can have an effect on arterial CO2 levels (PaCO2)
- FiCO2 (fraction of inspired CO2)
- VCO2 (CO2 production by the body)
- Va (Minute Ventilation)
name 3 things that can increase VCO2 (prodiuction of CO2 by the body)
- pyrexia
- surgey
- malignant hyperthermia
name 5 things that affect minute ventilation
- anaesthesia
- positioning
- drugs (opioids)
- Hypovolemia
- Pain
name 5 consequences of hypercapnia
- tachypnea
- incr. cardiac output
- peripheral vasodilation
- narcotic
- bradydysrhythmias
how do you resolve hypercapnea
increase ventilation
name 3 consequences of hypoxia in the brain
- incr. ICP
- seizures
- death
name 3 consequences of hypoxia in the myocardium
- decr. contractility
- arrhythmias
- death
name 2 consequences of hypoxia in the kidney
- pre-renal failure
- nephrosis
name 6 causes of hypoxia
- atmospheric
- tidal
- alveolar
- hemoglobinemia
- histotoxic
- demand
name 4 ways to manage the airways during anaesthesia
- endotracheal tube
- laryngeal mask
- tracheostomy
- mask
name the method of airway management for anaesthesia
gold standard;
protect airway when cuffed;
allows mechanical ventilation;
tracheal damage;
occlusion;
tube damage
endotracheal tube
name the method of airway management for anaesthesia
may allow for mechanical ventilation;
some rated to protect airway;
very easy to place;
need to be positioned correctly;
easy to move;
laryngeal trauma?
laryngeal mask
name the method of airway management for anaesthesia
definite airway;
bypass upper airway pathology;
requires equipment;
additional morbidity;
additional aftercare needed
tracheostomy
name the method of airway management for anaesthesia
very easy to place and remove;
increases FiCO2;
no protection;
no mechanical ventilation;
no capnography
mask
name 4 things that needed for Intermittent Positive Pressure Ventilation (IPPV)
- cuffed ET tube
- appropriate breathing system
- means of delivering ventilation
- methods of suppressing ventilation
ame the 3 indications for IPPV (Intermittent Positive Pressure Ventilation)
- assist patient
- assist anaesthetist
- assist surgeon
what is the anaesthetic risk of mortality in dogs
0.17%
what is the anaesthetic risk of mortality in cats
0.24%
what is the anaesthetic risk of mortality in rabbits
1.39%
what is the anaesthetic risk of mortality in equine
1.9%
name 6 respiratory complication and emergencies that can occur during anaesthesia
- hypercapnia
- hypoxemia
- aspiration
- barotrauma
- airway obstruction
- apnea
name 4 cardiovascular complications and emergencies that can occur during anaesthesia
- hypotension
- cardiac arrhythmias
- hemorrhage
- cardiac arrest
name 4 effects of hypercapnia
- cardiac depression
- SNS stimulation
- respiratory acidosis
- CNS depression
name 3 causes of hypercapnia
- hypoventilation
- CO2 rebreathing
- Increased CO2 production
this is a low level of oxygen in the blood
hypoxemia
this is a low level of oxygen in the tissues
hypoxia
name 5 effects of hypoxemia
- cellular hypoxia
- anaerobic metabolism
- SNS stimulation
- cardiac arrhythmias
- cardaic arrest
name 4 ways to prevent/treat hypoxemia under anaesthesia
- pre-oxygenation
- increased FiO2
- lighten anaesthesia
- IPPV
name 5 causes of hypoxemia
- inadequate oxygen supply (FiO2)
- hypoventilation
- V/Q mismatch
- R to L shunt
- diffusion impairment
name 3 ways to prevent aspiration while under anaesthesia
- airway secured with leak-tested cuffed ETT
- fasting
- rapid induction
name 3 possible causes of barotrauma during anaesthesia
- mechanical ventilation with high peak inspiratory pressures
- closed APL valve
- inappropriate use of oxygen flush
name 5 causes of upper airway obstruction during anaesthesia
- soft tissue
- ETT
- blood
- vomit
- foreign body
name teo emergency treatments of upper airway obstruction during anaesthesia
- reintubation
- tracheostomy
this is total respiratory arrest and rapidly results in severe hypoxia and hypercapnia
apnea
name 4 causes of apnea during anaesthesia
- anaesthetic drug overdose
- reflex apnea
- brainstem injury
- cardiac arrest
name two consequences of hypotension during anaesthesia
- hypoperfusion
- organ dysfunction
name 5 causes of hypotension during anaesthesia
- hypovolemia
- vasodilation
- decreased contractility
- cardiac arrhythmias
- reduced venous return
if bradycardia is the cause of hypotension during anaesthesia, what is teh treatment?
anticholinergics (to incr HR)
name some consequences of hypothermia
- MAC reduction
- recuction in metabolic rate
- impaired blood coagulation
- incr. bloof viscosity
- vasoconstriction
- hypoventilation
- arrythmogenic
name 4 ways to improve anaesthetic safety
- ID potential complications prior to anaesthesia
- preparedness and prevention
- early recognition
- prompt treatment
name 2 drugs that can cause narcosis with accidental self administration
opioids and alpha 2 agonist
name 4 consequences of extravascular administration
(anaesthesia acccident)
- no anaesthetic effect
- tissue damage
- pain
- medico-legal consequences
name the 3 ways to manage extravascular administration
(anaesthesia acccident)
- dilution
- analgesia
- record
name 5 signs of intra-carotid injection
(anaesthesia acccident)
- abnormal activity
- violent reaction
- recumbency
- seizures
- loss of consciousnes
name 3 ways to prevent and manage intraoperative awakening
(anaesthesia acccident)
- ensure IV access
- ensure top-up drugs
- monitor depth of anaesthesia
name 3 ways to prevent ocular damage during anaesthesia
- eye lubrication
- towels
- general care
name 4 effects of chronic low level personnel exposure to volatile anaesthetics
- reproductive disorders
- gestational disorders
- neoplastic disease
- psychiatric disorders
name 4 storage requirements for cylinders
(anaesthesia)
- away from heat
- vertically/horizontally in approved cages
- dry and clean
- warning prohibiting smoking
this is the sudden and often unexpected cessation of effective cardiac contractions
cardiac arrest
this is the sudden complete cessation of respiratory movements
respiratory arrest
what is the goal of CPR
O2 delivery to vital organs until return of spontaneous circulation (ROSC)
name 4 things that put an aimal at risk of cardiopulmonary arrest
- severe critical illnesses
- polytrauma
- asphyxiation
- anaesthesia
what is the ABC of basic life support
Airway
Breathing
Circulation
what is the DEF of advanced life support
Drugs
Electrical defibrillation/ECG
Follow-up
how many breaths per minute should you give during CPR
10 breaths per minute
how should a dog with small, narrow chest be positioned for CPR
right lateral
how should a dog with large-barrel chest be positioned for CPR
dorsal
where should your hands be to give chest compressions over the heart in R lateral recumbency
3rd-6th intercostal space
where should your hands be to give thoracic pump chest compressions to a dog > 15 kg
over highest point of thorax
what should the rate of compressions be for CPR
100-120 cpm
how long should each uninterrupted cycle of compressions be in CPR
2 minutes
name 4 instances to consider internal cardiac compressions in
- pneumothorax
- cardiac tamponade
- penetrating chest wounds
- intraoperative arrests
whare should you incise the chest for internal cardiac compressions
5th interspace
name 4 disadvantages of internal CPR
- complicated
- sepsis risk
- invasive
- risk tissue damage and hemorrhage
name 3 reasons why pulse oximetry, NIBP and pulse palpation are not reliable to monitor for success of CPR
- motion artifacts
- lack of sufficient arterial pulse
- poor tissue perfusion
what two things should you monitor during CPR for success
ECG and capnography
what is ECG monitoring key for during CPR
accurate rhythm diagnosis
name the 2 non-shockable CPA rhythms detected by ECG
- asystole
- pulseless electrical activity (PEA)
name the 2 shockable CPA rhythms detected by ECG
- ventricular tachycardia (VT)
- ventricular fibrillation (VF)
how long does it take for a peripheral IV injection to reach central circulation
1-2 minutes
name 2 vasopressors that can be used during advanced life support
adrenaline and vasopressin
name the drug used during advanced life support
vasopressor;
alpha1, beta1 (beta2) receptors;
0.01 mg/kg (low) - 0.1 mg/kg (high)
every 4 minutes (every other cycle of BLS)
adrenaline
name the drug used during advanced life support
vasopressor;
V1 receptor;
0.9 U/kg IV
vasopressin
when should anticholinergics (atropine) be given during advanced life support (indications)
- asystole
- PEA (pulseless electrical activity)
name the drug used during advanced life support
anticholinergic;
decr. parasympathetic tone;
single dose of 0.04 mg/kg IV;
worse outcome with higher doses;
indications: asystole or PEA
atropine
name 2 antiarrhythmic drugs that can be given during advanced life support
- amiodarone
- lidocaine
name the drug used during advanced life support
class III antiarrhythmic;
2.5-5 mg/kg IV;
refractory VF/PVT;
anaphylaxis in dogs
amiodarone
name the drug used during advanced life support
class Ib antiarrhythmic;
2 mg/kg IV slow;
refractory VF/PVT
lidocaine
name the drug used during advanced life support
to reverse opioids (be aware of analgesia);
0.04 mg/kg IV
Naloxone
what is the recommended primary treatment for VF/pulseless VT
defibrillation
name the drug used during advanced life support
to reverse benzodiazepines;
0.01 mg/kg IV
Flumazenil
name the drug used during advanced life support
to reverse alpha2 agonists;
0.1 mg/kg IV
antipamezole
fluid therapy is limited to patients with what condition during anaesthesia
hypovolemia
what is the survival to discharge rates for dogs and cats who need CPR
2-10%
name some signs of effective CPR
- CO2 detectable on capnography
- palpable pulse during cardiac compression
- improvement in mm color
- ECG changes
- return of spontaneous ventilation
- pupillary constriction
- return of cranial nerve reflexes
- lacrimation
- resturn of other neurological function
name the 3 goals of post-cardiac arrest care
- hemodynamic optimization
- respiratory optimization
- neuroprotection
