Anaesthesia for Sicker Patients Flashcards
Describe ASA 1 patients
Normal and healthy
Non-brachycephalic
Normal BCS
No underlying disease, presenting for an elective procedure
Describe ASA 2 patients
Patient with mild systemic disease - compensating well
Includes brachycephalic and obese patients
Mild anaemia
Dehydration - 4-6%/mild
Describe ASA 3 patients
A patient with severe systemic disease - not fully compensating
Moderate anaemia
Brachy breed with GI/resp signs
Moderate dehydration
Very young/neonatal (<12 weeks)
Describe ASA 4 patients
A patient with severe systemic disease that is a constant threat to life
Severe anaemia
Severe cardiac diseases/arrhythmias/murmurs
Severe dehydration
SIRS
Describe ASA 5 patients
A moribund patient who is not expected to survive without the procedure
GDV
Intracranial haemorrhage
Decompensated shock
What is the main focus with ASA 2-4 patients
Not emergencies or going to die imminently so focus is on stabilisation
If an ASA 2-4 patient has cardiovascular disease, what are the main considerations before anaesthesia
If you are able to get a diagnosis of what the specific disease is - blood, ECG, radiographs
Check for anaemia
Consider the effects of poor cardiac output and perfusion on other organs
What can be done to stabilise the patient first
How may the disease affect what drugs we use
Inhalation agents depress the CV system
How to stabilise an ASA 2-4 patient with renal disease
IVFT - Hartmann’s
Anti-emetics
If anaemic - give blood transfusion on severe cases
How to assess if renal disease is pre-renal or post-renal azotaemia
Urinalysis
Post-renal the potassium levels can be elevated => potentially fatal arrhythmias
Why is maintaining blood pressure and cardiac output so important in ASA 2-4 patients with renal disease
Kidneys are very susceptible to ischaemic injury
Name the main consideration regarding drugs when dealing with an ASA 2-4 patient with renal disease
NSAIDs are contraindicated
Reduce doses of any drugs renal excreted
What is an important consideration of an ASA 2-4 patient with oesophageal obstruction or megaoesophagus
High risk of regurgitation and aspiration
Need to monitor carefully after sedation - risk of regurg
Raise head when intubation, use a cuffed ET tube
Avoid alpha-2 as can cause emesis
What drug class is contraindicated in animals with V+ D+
NSAIDs
What are some important considerations in ASA 2-4 patients with severe liver dysfunction
Reduced metabolism of most drugs => prolonged effect
Albumin may be low => more free drug => use lower doses
May be hypoglycaemic or hypotensive
Increased risk of infection
What are some important considerations in ASA 2-4 patients with diabetes insipidus
Lack of ADH/kidney response to ADH
Severe PUPD - likely dehydrated and hypovolaemic
Can have hypernatremia due to dehydration
