Recovery from anaesthesia Flashcards
When do a majority of anaesthesia deaths occur?
60% occur in the recovery period with nearly half of these dying within 3 hours of disconnection.
What is the fatality rates in healthy dogs?
0.17%
What is the fatality rates for healthy cats?
0.24%
What is the fatality rates for healthy rabits?
1.39%
What is the fatality rate for horses?
0.9%
Name 7 risk factors for recovery?
- ASA category
- Breed
- Age
- Weight
- Duration of anaesthesia
- Drugs given
- Temperature
Which breed of horse has more problems in recovery?
heavy breeds and draft horses.
What age of animals struggle with recovery?
Geriatrics and paedeatrics
What do we mean by the ‘drugs given’?
These are the drugs given at pre-meds. if there is a traumatic induction, this will influence the recovery.
What do we have to monitor in terms of temperature and recovery?
If the animal is cold, it is not going to recover very well.
What sort of breeds will have problems with extubating?
Bulldogs and bracycephalic breeds.
When do you extubate cats in relation to dogs and why?
Extubate cats earlier than dogs because they have a more sensitive larynx. There is a risk of laryngospasm at extubation.
Name 8 things that should be present in the recovery room?
- Oxygen and delivery system
- anaesthesia induction drugs and analgesics
- fluid therapy equipment
- crash box/ trolley (for CPR)
- suction
- Monitoring equipment and warming devices
- protective clothing and gloves
- bedding
What is recommended in terms of recordning things for animals?
Keep all of the records on the same piece of paper.
If Nitrous oxide, how long do you leave the animal on pure oxygen for following surgery and why?
10 mins because of the dangerous of nitrous oxide. It also exacerbates hypoxia
What do you do to the reservoir bag at the end of surgery and why?
‘Dump’ the reservoir bag and fill up with fresh gas as this artificailly speeds up recovery by increasing the concentration gradient.
Why is it good practice to leave animals connected for a long time following surgery?
Because this means the more iso is scavenged so not in the air around you therefore this is good practice.
When might cuff not be fully deflated during recovery?
During dental/oral procedures so as to prevent blood, mucus/ debris (teeth) being inhaled.
What do you do in these cases e.g. post-dental/ oral procedures?
can check the oropharynx with laryngoscope..
When is the ET tube removed in most species?
When the gag reflex is returned.
How is the gag reflex indicated?
Attempts to swallow and tongue movements.
Is it best to extubate on inspiration or expiration?
expiration
In what situation might the palpebral reflex not return?
If NMBD blockers have been used.
In which dogs do you leave the tube in longer for?
Brachycephalic obstructive airway syndrome dogs.
What tubing to horses have to have during anaesthesia and why?
Nasal tubes because horses are obligate nose breathers.
When do you extubate cats?
Just before the gag reflex has returned e.g. when there is palpebral reflex is back, and tongue movement.
What should you do with cats following extubation?
Keep the head and neck extended and the tongue pulled foward.
What are 6 signs of airway obstruction?
- increased respiratory noise and effort
- abdominal effort, nares flaring
- ‘air hunger’ posture - head and neck extended
- cyanosis
- reslessness and agitation
- agonal breathing
What 4 things should you do if you suspect airway obstruction?
- call for help!
- Open mouth, use laryngoscope
- Pull tongue foward and suction blood/mucus
- re-intubate if possible (might need to give drugs to do this)
At what point would you supplement an animal with oxygen in recovery?
SPo2 is <93%
How could you increase oxygen delivery?
Oxygen cages/ incubators/ buster collar with clingfilm
In first stage of recovery, what should be monitored and how often?
Rate and quality of pulse every 5 minutes.
Name 5 other things you can monitor?
ECG, CRT, temp, Blood pressure, mucus membrane colour
What temperature do we want the animal to be at following surgery?
normothermic
Name a good example of warming dogs in recovery on fluids?
Warm the IV fluids and flushing solution
Give 4 reasons an animal could be restless/vocal when in recovery?
- in pain
- Dysphoric (depression, anxiety, disorientation)
- Emerging from the anaesthesia
- uncomfortable e.g. fall bladder, needs to defecate
If in doubt as to why the animal is restless/vocal, what should you do?
Give the animal an analgesic and re-assess.
When do most issues that manifest themselves in recovery occur in the horse?
When something goes wrong during maintenance.
Name 4 things in the horse which might have gone wrong in maintenance but manifest themselves in recovery?
- hypotension
- Hypoxaemia
- hypercapnia
- poor positioning
What happens to lungs of horses when in surgery?
If horses are on their backs for a prolonged period of time, the bottom part of their lungs are being perfused, whereas the top part of their lungs are being ventilated. There is a mismatch which could lead to hypoxaemia.
What are the two things that cause post-op myopathy?
It is caused by malpositioning and hypotension during surgery
When does post-op myopathy manifest itself?
When the horse wakes up.
Name 6 signs of post-op myopathy?
- mild lameness and inability to stand
- Hard, swollen and painful muscles
- extreme distress
- sweating
- difficult breathing
- restlessness
What are the two causes of post-op neuropathy?
- hypotension also
2. Pressure on a nerve
What is another sign of myopathy?
Weeing brown urine e.g. damage to the kidneys
What is another onset that can come on during post-operative recovery in horses?
Spinal cord malacia e.g. softening of the biological tissues.
What kind of horses does spinal cord malacia occur in?
Young, brassy, heavy horses
How does spinal cord malacia occur?
Something happens to the blood flow to the spinal cord during surgery
What is the outcome of spinal cord malacia in horses?
The only option is euthanasia as they will not recover.
When do eye problems tend to occur in horses?
When the horse is in lateral recumbency - need to administer lubrication because surgery always reduces tear production.
What are the three most common issues in horses during the recovery phase?
- myopathy
- neuropathy
- self-inflicted traumas
How can you reduce self-inflicted trauma during post-op recovery? 4 things?
- calm recovery e.g. sedation
- analgesia
- padded box
- head and tail ropes
How can you stop horses from getting up?
Sit on their necks and hold their heads up
What is it called when you tie their tail to the box to guide the horse up?
tail gaiting
How can you detect an upper airway obstruction in horses on recovery? 5 things
- stridor or stertor following extubation
- nostril flaring on inspiration
- abdominal respiratory effort
- exaggerated thoracic excursion
- absence of airflow at the nostrils
Where does obstruction tend to occur in horses?
In the nasal passages or at the level of the pharynx
What is common in horses in the recovery phase to do with the nares?
Nasal oedema - everything seems to drain and then the oedema goes - short-lived.
what could you do to reduce the effects of nasal oedema?
use nasopharyngeal tubes or phenylephrine (reduces congestion)
What other type of obstruction is common other than upper airway obstruction?
Laryngeal obstruction
What two things might cause laryngeal obstruction?
- dorsal displacement of the soft palate
2. Epiglottic retroversion
What two methods can be used to alleviate symptoms of a dorsal soft palate displacement?
- be prepared to re-intubate
2. Emergency tracheastomy
What are the 3 signs of pulomonary oedema in horses follwing surgery?
pinkish, frothy discharge at the nares following re-intubation, exaggerated respiratory efforts and cyanosis.
How do horses get pulmonary oedema?
Related to changes of venous return and an influx of fluid into the alveoli as a result of excessive negative pressures within the thorax.
What are the 3 ways to treat pulmonary oedema?
- remove obstruction
- provide oxygen
- frusemide and dexamethasone.
What other presentation can be a problem in horses post-operatively?
Colic
What should you make sure on recovery -4 things?
- no pain
- no obstructions
- full bladder not a problem
- secure jugular catheter in palce
