Peri-Operative management Flashcards
What are the definitions of the ASA scoring system?
ASA 1: no organic, physiological, biochemical or psychiatric disturbance. Surgical pathology is localised
ASA 2: Mild/Mod systemic disruption caused by the surgical disease or pre-existing disease
ASA 3: Severe systemic disruption caused by surgical pathology or pre-existing disease
ASA 4: Severe systemic disease that is a constant threat to life
ASA 5: moribund and will not survive without surgery
What medication should be administered to a patient who is due to have surgery for a pheochromocytoma?
Alpha and beta blockers
What is the risk of over using normal saline as a resuscitation fluid?
Hypercholeraemic metabolic acidosis
What is a complication of central lines?
Pneumothorax
What is atropine?
Muscarinic antagonist
Inhibits parasympathetic activity
What are the effects of Lidocaine/Lignocaine?
- Local anaesthetic
- Less commonly used a anti arrhythmic drug
Affects Na channels in the axons of nerves
What are the features of toxicity of Lidocaine/Lignocaine?
CNS overactivity first
CNS depression later
Lidocaine initially blocks inhibitory pathways but then begins to also block activating pathways causing cardiac arrhythmias
How can higher doses of lidocaine/ligocaine be used?
Administer with adrenaline to limit systemic absorption
What is an alternative agent to lidocaine if a patient has an allergy to lidocaine?
Bupivacaine
What aesthetic agent is used in intravenous regional anaesthesia (e.g. Biers block)?
Prilocaine
It is a lot less cardiotoxic
What is the max dose of lidocaine with and without adrenaline?
Plain: 3mg/kg
With adrenaline: 7mg/kg
In which scenarios should you never use adrenaline with the LA?
Finger related surgeries
Circumcision
In which clinical situations is Bupivicaine used?
- Allergy to lidocaine
- Flail chest
- Spinal access surgery
Which anaesthetic agent is normally used to rapidly sedate an UNSTABLE patient?
Ketamine
What is the most commonly used anaesthetic agent in everyday theatre, ITU and electives?
Propofol
- has anti-emetic effedcts
- Rapid onset
- Pain on injection
- causes myocardial depression
What is a side effect of using ketamine for sedation?
Dissociative anaesthesia (nightmares while under)
What is the most commonly used muscle relaxant used in theatre and how does it work?
Suxamethonium
- Inhibits ACH and depolarises
- Rapid onset leading to paralysis
- SE of Hyperkalaemia and Malignant Hyperthermia
What is malignant hyperthermia characterised by and how is it managed?
- Hyperpyrexia
- Muscle rigidity
Managed by Dantrolene (prevents Ca2+ release from the sarcoplasmic reticulum from skeletal muscle)
When is the use of tourniquet in surgery contraindicated?
- AV fistula
- Severe PVD
- Prev vascular surgery
What tourniquet pressures are used on the upper and lower limbs?
Upper limb: SBP 250
Lower limb: SBP 350
If a patient receives a blood transfusion, they can still be a blood donor?
No
If young child who is fit and healthy is being prepared for an elective tonsillectomy, will they need any pre-operative tests and if so, which ones?
No tests required
The patient is ASA 1 and is being admitted for minor/moderate surgery as per NICE guidelines
What is the criteria for brain death testing?
- Deep coma of known aetiology
- Reversible causes excluded
- No sedation
- Normal electrolytes
What would be the recommended analgesia to use for a patient post thoracotomy/lobectomy?
Epidural analgesia
What type of block is given for a episiotomy?
Pudendal block
What type of block is done for a haemorhoidectomy?
Caudal block
What is the first line analgesia used in advanced pancreatic cancer?
NSAIDs
How is pain controlled in patients with flail chest?
Bupivicaine infiltration + O2
What is the first line medication for neuropathic pain?
- Amitriptylline (SE of hypotension)
- Pregabalin if pt hypotensive/orthostatic hypotension
What is the first line medication for diabetic neuropathy?
Duloxetine
What is the definition of massive haemorrhage?
- 50% blood loss in 3hrs
- Blood loss of 150ml/min
What are biochemical side effects of massive blood transfusions?
- Hypocalcaemia
- Hyperkalaemia
What is the name of the screen tool for malnutrition?
MUST
What are the criteria for diagnosis of malnutrition?
- BMI <18.5
- Unintentional wt loss >10% over 3-6 months
- BMI <20 AND unintentional weight loss >5% over 3-6 months
What are the metabolic consequences of referring syndrome?
- Hypophosphataemia
- Hypokalaemia
- Hypomagnesaemia
- Abnormal fluid balance
What nerve is at risk of injury during an axillary node clearance?
Long thoracic nerve
What nerve is at risk of injury during a carotid endarterectomy?
Hypoglossal nerve
What structure can most commonly be damaged during colonic resections?
Ureter
Why are beta blockers not stopped acutely prior to surgery?
May cause rebound effect causing more intra-operative complications
What dye can be used to identify the parathyroid gland intra-operatively?
Methylene blue dye IV
Stains parathyroid glands
When should clopidogrel be stopped pre-operatively?
5-7 days prior
