Anaesthetic Accidents and Emergencies Flashcards
what is the overall anaesthetic risk for dogs according to the CEPSAF enquiry?
0.17%
what is the overall anaesthetic risk for cats according to the CEPSAF enquiry?
0.24%
what is the overall anaesthetic risk for rabbits according to the CEPSAF enquiry?
1.39%
when were complications assessed during the CEPSAF enquiry?
48 hour post op period
how many anaesthetic deaths occurred within 3 hours of recovery?
50%
is risk higher with sedation or GA?
GA
what animals have increased risk of mortality associated with ET intubation?
cats but not dogs
how does the risk of death compare between inhalation or injection induction of anaesthesia?
inhalational is 6x more likely to result in death than injectional
how many anaesthetic deaths have a post mortem investigation?
10%
why is anaesthetic risk in veterinary patients still higher than human patients?
reduced comparative skill levels in veterinary patients
all humans will be monitored by a clinical anaesthetist
often much less equipment available in vet practice
what is the main nursing aim of anaesthesia?
reduce risk
what is one of the limitations of the CEPSAF enquiry?
only assessed patients for 48 hours after surgery
what is the risk of death from sedation / GA in the 2 weeks following the procedure?
0.14%
what was the risk of death from sedation / GA in the RVC study of routine procedures?
0.009%
in the RVC study what were the 4 main risk factors for sedation or anaesthetic death?
poorer health
urgent procedures
older age
long nose
how does poorer health affect anaesthetic risk?
those with ASA scores of 3-5 had a much higher risk of death
how do urgent procedures affect anaesthetic risk?
urgent procedures posed more risk to patient health
how does old age affect anaesthetic risk?
risk increases with age from 6 months
how does having a longer nose affect anaesthetic risk?
dolichocephalic breeds had 3.7x higher anaesthetic risk
why may dolichocephalic breeds be at greater risk of anaesthetic complications?
awareness of brachycephaly which means we may be hypervigilant and more cautious with anaesthetic management rather than with other patients
additional risk pathway with dolichocephalic breeds that we don’t yet understand
what can cause anaesthetic accidents?
sick patients
equipment failure
inadequate preparation
inadequate monitoring
combination of factors
what can be used to reduce the chance of anaesthetic accidents?
safety checklist
how can anaesthetic incidents be useful?
learn from mistakes
can be avoided
define complication
event that develops but is not due to human error - it would happen regardless
give 2 examples of complications
hypotension
drug reaction
define error
an avoidable event
what are the main human errors which occur in anaesthesia?
drug admin
incomplete clinical exam
inadequate knowledge of machine and protocols
failure to appropriately monitor
closed APL valve
what are some of the equipment failures and errors be due to?
human error and poor machine check
what is a key area of equipment failure?
inability to deliver an appropriate oxygen supply
what can lead to an inability to deliver an appropriate oxygen supply?
lack of oxygen in cylinder or source
disconnection of piped O2
stuck or missing one way valve
leaks in machine or breathing system
ventilator failure
how can anaesthetic safety be improved?
checklists
what are the main complications than can occur with IV catheter placement?
trauma during insertion
lack of placement (extravascular)
infection or inflammation
phlebitis
air embolism
pain or discomfort
how can you check IV catheter placement?
flush
if infection in a catheter is suspected how what should be done?
catheter removed
tip kept for culture
define phlebitis
inflammation of the vein due to blood clotting within it or the vein walls becoming damaged
how can IV catheter complications be prevented?
aseptic technique
start low down on limb and then move up
correct catheter type
good technique or adequate restraint
prevent patient interference
daily / twice daily observation and dressing change
flush
know when to ask someone else to place
what are the main drug administration errors?
decimal point incorrectly placed - correctly or incorrectly dosed
wrong drug
wrong dose or concentration
incorrect route
miscommunication - administration not recorded on hospital sheet
how can drug admin errors be avoided?
double check calculations
accurate weight
label all drugs/syringes
understand drug pharmacology and watch for excessive or underwhelming effects
check patient form before administration
record all drugs given
draw up carefully and ensure correct drug
confirm route
training of whole team
what should you do if you see/make a drug error?
tell the vet
stop administration if not all drug given
carefully monitor animal
check drug bottle / data sheet for information
contact poisons service if needed
inform owner
clinical governance meeting needed
describe vomiting
active process where gastric contents is expelled
describe regurgitation
passive process with no GI contraction
define reflux
regurgitation in an anaesthetised patient
what may predispose a patient to regurge/reflux?
species
drugs given
breed
when are the danger periods for regurgitation?
induction and recovery
what are the risk factors for GOR?
excessive or inadequate preoperative fasting
certain drugs
increased abdominal pressure
abdominal surgery
long ops
ortho
what drugs increase regurge risk?
opioids
ACP
diazepam
what effect do drugs have which increases risk of GOR?
relax cardiac sphincter
why do ortho surgeries increase the risk of GOR?
opioids given
lots of movement of the patient
what may indicate silent regurge has occurred?
vomit blood tinged fluid in recovery
appear unable to swallow
appear distressed
what can happen to a patients oesophagus if they regurge?
burns
how can the risk of GOR be reduced?
appropriate pre-op fasting times
identify at risk patients
pre-op gastroprotectants given
head up induction
rapid induction
cuffed ET tube
have suction on hand
how long should patients be starved for pre-op?
8-10 hours for dogs
6-8 hours for cats
check this
what should you do if regurgitation is seen?
head down
swab or suction pharynx
check with VS about omeprazole
record on anaesthetic record
inform vet
what may be given to patients at risk of GOR?
GI protectents e.g. omeprazole
why are patients under anaesthetic/sedation at risk of corneal ulceration?
reduction of tear formation due to drugs
trauma from external sources e.g. masks/heating equipment
what group of drugs reduces tear formation?
opioids
what is the main effect for the patient of corneal ulcers?
pain
how can occular damage be prevented in anaesthetised or sedated patients?
care with warming devices - close lower eye
careful positioning
awareness of placement of masks
avoid liquids around the face
avoid trauma
use clinitas/lubrithal
be aware of environment!
what should you do if you notice an ulcer during or following surgery?
prevent rubbing / scratching (buster collar)
inform VS
potentially start eye meds to continue at home
identify reason
inform owner
why are anaesthetised or sedated patients at more risk of hypothermia?
normally patient is vasoconstricted so core remains warm
GA leads to vasodilation and so while skin may warm up the core temperature drops
what can hypothermia under GA or sedation lead to?
increased mortality - especially in sick animals
cardiac arrhythmia
bradycardia
impaired coagulation and wound healing
what is the effect on the body of shivering?
increased oxygen demand
what cardiac arrhythmia may be seen at 30 degrees?
atrial fibrilation
what cardiac arrhythmias may be seen at 24-28 degrees?
v fib
why is bradycardia seen with hypothermia?
low temperature affects cardiac contraction
what should be done if the patient is shivering?
give O2
how does hypothermia impact anaesthesia?
prolonged duration of action of drugs
decreased renal plasma flow
decreased oxygen delivery to tissues
lower anaesthetic requirement - check depth
how can hypothermia be prevented?
MAINTAIN
insulate patient
warm from pre-med
don’t leave pre-medded animals unsupervised
use HME
care with clip and prep
use external heat sources
ensure environment warm
avoid long GA times
what are the issues with HMEs?
dead space increased
what are the issues caused by hyperthermia?
increased basal metabolic rate
increased oxygen requirement
parenchymal cell damage
by how much is basal metabolic rate increased for every degree temperature increases above normal?
13%
what is the effect of a temperature of >41 degrees?
irreversible brain damage is a potential risk
what is the effect of a temperature of >43 degrees?
death
what animals are at risk of hyperthermia?
BOAS
overweight animals
how can hyperthermia be avoided?
close observation of patient warming
never leave an animal on a heat source they cannot move from - avoid microwave/grain bags
identify at risk animals
provide cooling as needed
how should patients be cooled?
fan
wet towels
cold water lavage
what can cause respiratory failure under GA or sedation?
depression of respiratory centres in the brain
impaired movement of thorax sue to external source (e.g. sandbag/surgeon)
impaired lung movement e.g. pleural effusion
airway obstruction
narrow ET tube
what may airway obstructions be related to?
breed (BOAS)
condition (laryngeal mass)
how can respiratory obstruction be identified?
increased respiratory effort
paradoxical ventilation
no air movement around nose or mouth
maybe cyanotic MM
capnography changes
careful observation
what is paradoxical breathing?
occurs when the cheat wall or abdominal wall moves in when taking a breath and moves out when exhaling
what may apnoea and respiratory arrest be due to?
depth - too light (breath hold) or too deep (suppression)
unnoticed respiratory tract obstruction
drug related (e.g. PIA, NMB)
what may cyanosis be due to?
inadequate O2 supply
very low cardiac output
if PIA is seen should a breath be given straight away?
no - if SpO2 stable allow patient to accumulate CO2 for a short time to drive ventilation
what should you do if respiratory obstruction is noted and the patient is not intubated?
inform VS/vet
straighten neck, pull tongue forwards, check mouth and pharynx
suction if needed
give O2
intubate if needed
give corticosteriods if VS requests
what should you do if respiratory obstruction is noted and the patient is intubated?
inform VS/vet
check ET tube not kinked, obstructed or too long or change ET tube
check mouth and pharynx
suction if needed
check O2 source and equipment / breathing system
give corticosteriods if VS requests
why may corticosteroids be given if the patient has a respiratory obstruction?
reduction of swelling
how may patients airway risk affect their analgesia plan?
may hold off on NSAIDs until recovered from GA incase steroids need to be given
how can you prepare for difficult intubation?
pre-oxygenate
have equipment ready to intubate
how long should patients be pre-oxygenated for?
3-5 mins
what is the purpose of pre-oxygenation?
increases length of time before patient desaturates
how can an ET tube be tested to see if change is necessary?
IPPV and check for resistance
what should you do if apnoea or cyanosis are seen?
confirm heartbeat
check anaesthetic depth
check for obstruction/obvious reason for apnoea
ensure enough O2 is being given (MV)
manually ventilate looking for chest movement
check breathing system, tube
give antagonist at VS request
turn of VA if concerned about arrest
what are the causes of CPA under anaesthesia/sedation?
preexisting CVS disease
anaesthetic overdose
hypovolaemia
electrolyte/acid base abnormalities
vagal reflex
respiratory arrest that has been undetected
what increases the chance of success with CPR?
early detection of CPA
what should you do if you suspect cardiac arrest?
get help, note time
check pulse and HR to confirm
begin compressions
check ventilation and confirm airway
turn off anaesthetic agent
ensure on 100% O2
manually ventilate
check breathing system, tube
confirm chest wall movement
what is essential following CPA?
team debrief
what are the main cell types found within the heart?
myocardial cells
self-excitatory cells
what is the role of myocardial cells?
ability to contract
what is the role of self-excitatory cells?
generate an impulse
what is automaticity?
cells that are able to generate a beat
what is the role of the SA node?
pacemaker
origin of electrical signal in heart
what areas of the heart are capable of generating a beat?
sinoatrial node
AV node
bundle of His
bundle branches / Purkinje fibres
as you move futher down the heart what is the effect on the HR generated by the excitatory cells?
speed of beat and effectiveness reduces
what HR is generated from the SA node?
60-160 bpm
what HR is generated from the AV node?
40-60 bpm
what HR is generated from the bundle of His?
40-60 bpm
what HR is generated from the Purkinje fibres?
20-40 bpm
what is an arrhythmia?
change in rhythm, rate or origin that differs from normal cardiac cycle
are all arrhythmias significant?
no - most insignificant
some not
some fatal
what happens during 1st degree AV block?
electircal signal struggles to get through AV node each time but is transmitted
how does 1st degree AV block appear on ECG?
gap between P and QRS complex is longer than gap between QRS and T
ordinarily this should be the other way around
what are the 2 types of 2nd degree AV block?
wenckebach
mobitz
what is seen on ECG with wenckebach AV block?
progressive lengthening of PR interval until the gap is so large beats start to be lost
steady prologation of gap between P and R
what is seen on ECG with mobitz AV block?
intermittent passage through AV node so PR remains constant and then one beat will be lost
no prewarning
what is the issue with 3rd degree AV block?
complete heart block
electrical signal cannot pass through AV node
how does the body manage 3rd degree AV block?
other areas of the heart generate a beat
signal is however weaker and slower
how does 3rd degree AV block appear on ECG?
odd trace
P and T waves in odd places
no order
may also be normal at times but this is luck
what is ventriculat tachycardia?
rapid heart rate caused by electrical impulses generated in the ventricles
how does ventricular tachycardia appear on ECG?
wide and bizzare
why are ventricular complexes so wide?
ventricles larger than atria
what HR is seen with VT?
> 160 bpm
what is a common arrhythmia seen with GDV?
VT
what should you do if an abnormal EGC trace is seen?
screen shot/video
print ECG
inform VS immediately
