Anaesthesia: Recovery and Anaesthesia Emergencies Flashcards
Which period carries the highest risk of anaesthetic related morbidities and mortalities?
The recovery period
What % of anaestetic deaths occured during recovery?
43%
What is the most common anaesthetic related morbidity in smaller animals?
Hypothermia- 32% dogs, 70% cats
Why is the recovery period the most dangerous phase?
Mobidities- most anaesthetic related morbidities are identified during the recovery period- can vary from transient to severe to life changing
Several common morbidities that can occur in veterinary species
Why is the recovery phase so dangerous?
The level of physiolgical support is often greatly reduced as well as the level of monitoring
Some problems often manifest after a day so animals can deteriorate after appearing healthy
What are some common recovery problems?
Hypothermia
Emergence delirium
Hypoxaemia
Hypotension/hypertension
What are the causes of hypothermia during the recovery period?
What are the consequences of hypothermia during recovery?
How can it be prevented?
Causes: drugs, clipping, surgical spirit, open body cavity
Consequences: reduced MAC requirment, delayed recovery, shivering, prolems with wound healing
Prevention- proactive steps to reduce heat loss, heat pads, forced air blankets, flush body cavities with warmed fluids
WARNING- injudicious use of warming aids can result in hyperthermia and burns- monitor temp and don’t allow direct contact to the skin
What is emergence delirium?
How is it prevented and treated?
In people- state of disociation of consciousness, the patient is incoherent, inconsolable irritable and uncooperative
5-15 min risk of injury to animal and handlers
Occurs in animals- more obvious with social or non-prey species
Prevention/treatment- chemical sedation or physical restraint, reduce stimulation, noise and light level, ensure adequate analgesia
What are the causes of hypoxaemia during recovery?
What are the clinical signs?
What is the treatment/prevention?
Airway obstruction, inadequate ventilation, poor gas exchange
Clinical signs- cyanotic mucous membranes, tachypnoea/dyspnoea, steror/stridor, reduced level of consciousness
Treatment- ensure patient airway, ventilate, O2 brachiocephalics usually dont mind being ET tubed, additional therapy
Prevention- only extubate when the animal can protect its own airway
What is the problem with hypotension/hypertension during recovery and how is it prevented and treated?
Problem- not routinely measured during recovery, however it is likely that animals have abnormal blood pressures
Prevention/treatment- utulise fluid therapy/vasoactive drugs during and after anaesthesia
How do you generally reduce recovery problems and when is the recovery phase over?
Monitor animals
Communication
Anticipation
rapid reconition/intervention
Is it ever over?
What is common in dogs and cats during the recovery period?
Gastric reflux
Regurgitation
Aspiration
Stricture
Occurs in 1 out of 6 cats and dogs
What is the gastric reflux protocol?
Check ET tube cuff
Head down and suction of oropharynx
Check pH of regurgitate
Place stomach tube and lavage stomach and oesopagus until clear fluid comes out
Give bicarbonare and sucralfate
What can happen in cats during recovery and how is it prevented?
Tracheal tear and rupture:
Related to over inflation of ET tube cuffs
Predominatly occurs in dental cases
Prevention- consider pharyngeal packing as alternative
Blindness: related to cerebral ischaemia through hypertension or altered blood flow through mouth gags
What problems occur to horses during recovery of anaesthesia?
Colic- post anaesthetic colic- drugs that cause ilias and stress caused
Myopathy/Neuropathy- neuropahty pressure on nerves, myopathy when muscles cannot function after bad perfusion
Fracture- classic horse
What problems occur in ruminants and pigs during recovery from anaesthesia?
Ruminants- regurgitate and aspirate, bloat
Pigs- respiratory obstruction- vomit and regurgitate, hypothermia/sunburn
Describe how to plan for emergency critical care of a patient
Stabilisation:
Planning and preparation- IV access, fluids, oxygen, emergency drugs
Teamwork
Don’t Panic
Assessment of patient:
Airways, breathing, circulation
What are the presenting problems- prioritise most life threatening
Basic diagnostic test:
PCV/TP, electrolytes, glucose, T-fast, A-fast (ultrasound of thorax and abdominal for fluid check)
IV access:
may need to provide analgesia first- don’t increase stress
Fluid therapy:
Bolus technique, 10-20ml/kg over 10 mins
Analgesia
Oxygen
What are some potential complications associated with anaesthesia in a critical patient?
Cardiovascular- primary CV disease, shock hypovolaemia
Respiratory- primary respiratory disease, hypoventilation
Neuological- altered mentation (consciousness), seizures
Pain- can make assessment difficult
Temperature
What are the options for analgesia in a critical patient?
NO PLAN
NSAIDs
Opioids
Paracetamol
Local anaesthetics
Alpha 2 agonists
NMDA antagonists
Ketamine- doesn’t effect CV much
Why might you sedate a critical patient and what drugs would you use?
Sedation for minor procedures such as diagnostic imaging or to provide oxygen
KAABO
Ketamine
Alpha 2 agonitsts
Acepromazine- CV effects
Benzodiazepine- CV effects
Opioids
Benzo/opioids has minimal effects on the CV
When would anaesthesia be used in a critical patient?
For complex procedures
To secure airway
Mechanical Ventilation
Pain not controlled with sedation
What drugs would be used for induction and maintenance of a critical patient?
Induction- propofol, alfaxalone, ketamine, benzodiazepines
Maintenance- isoflurane, sevoflurane, propofol, alfaxalone
Use what you’re comfortable with
What vital parameters are monitored and what should they be?
HR- dog 50-100, cat 80-169
Pulse quality
MM colour/CRT- pink, <2secs
Temperature- >37
Depth of sedation- pupil position, palpebral response, jaw tone
Blood pressure- >60
Pulse oximetry- >90
Capnography- <60
ECG- arrythmias
What adjucnts are available to aid anaesthesia and analgesia in a critical patient?
Blood pressure support- fluids, positive inotropes- increase contractility, vasopressors- vasocontstriction
Fluids- colloids, blood products, glucose, electrolytes
Anti-arrythmias- GCV
Antibiotics
Anti-seizure mediation
Stabilisation of limbs- bandages, splints
