General surgery Flashcards
COCP Rules for surgery
The COC should be stopped:
1) Four weeks before any major surgery (which includes operations lasting more than 30 minute), all surgery to the legs, or surgery that involves prolonged immobilization of a lower limb.
2) If emergency surgery or immobilization (such as for a leg fracture) is necessary
ASA Grading
ASA Classification (American society of anaesthesiologist) Definition Examples
ASA I A normal healthy patient
Healthy, non-smoking, no or minimal alcohol use
ASA II A patient with mild systemic disease Mild diseases only without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30 < BMI < 40), well-controlled Diabetes Mellitus/Hypertension,Mild lung disease
ASA III A patient with severe systemic disease Substantive functional limitations; One or more moderate to severe diseases. Examples include (but not limited to): poorly controlled Diabetes Mellitus/Hypertension, COPD, morbid obesity (BMI 40), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, End Stage Renal Disease (ESRD) undergoing regularly scheduled dialysis, history (>3 months) of Myocardial infarction, Cerebrovascular accidents
ASA IV A patient with severe systemic disease that is a constant threat to life Examples include (but not limited to): recent (< 3 months) of Myocardial infarction, Cerebrovascular accidents, ongoing cardiac ischaemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, ARD or ESRD not undergoing regularly scheduled dialysis
ASA V
A moribund patient who is not expected to survive without the operation Examples include (but not limited to): ruptured abdominal/thoracic aneurysm, massive trauma, intra-cranial bleed with mass effect, ischaemic bowel in the face of significant cardiac pathology or multiple organ/system dysfunction
ASA VI A declared brain-dead patient whose organs are being removed for donor purposes
What happens if excess NaCl given post op
Hyperchloraemic acidosis
Propofol use
USe
Key features
Rapid onset of anaesthesia Pain on IV injection Rapidly metabolised with little accumulation of metabolites Proven anti emetic properties Moderate myocardial depression
Widely used especially for maintaining sedation on ITU, total IV anaesthesia and for daycase surgery
Sodium thiopentone use
Key features
Extremely rapid onset of action making it the agent of choice for rapid sequence of induction
Marked myocardial depression may occur
Metabolites build up quickly
Unsuitable for maintenance infusion
Little analgesic effects
Ketamine use
Key features
May be used for induction of anaesthesia
Has moderate to strong analgesic properties
Produces little myocardial depression making it a suitable agent for anaesthesia in those who are haemodynamically unstable
May induce state of dissociative anaesthesia resulting in nightmares
Drugs which impair wound healing
Non steroidal anti inflammatory drugs
Steroids
Immunosupressive agents
Anti neoplastic drugs
How is total parenteral nutrition delivered
The definitive option in those patients in whom enteral feeding is contra indicated
Individualised prescribing and monitoring needed
Should be administered via a central vein as it is strongly phlebitic
Long term use is associated with fatty liver and deranged LFT’s
Post op VTE prophlyaxis with LMWH duration for
Hip arthrplasty
knee arthroplasty
NOF fracture
Hip arthrplasty
- 28 days
knee arthroplasty
- 14 days
NOF fracture
- Until mobile
What is suxamthonium
MOA
Use
Side effects
on-competitive (or depolarising) muscle relaxant, which works by inducing prolonged depolarisation of the skeletal muscle membrane.
- Clinically, this manifests as fasciculations (a number of un-coordinated muscle contractions/twitches) which last for a few seconds before profound paralysis occurs. P
Use
- The muscle relaxant of choice for rapid sequence induction for intubation
Side effects
Malignant hyperthermia (Rx is dantrolene)
Hyperkalaemia (normally transient)
Contraindications
Suxamethonium is contraindicated for patients with penetrating eye injuries or acute narrow angle glaucoma, as suxamethonium increases intra-ocular pressure
Elective surgery
How long before to stop food and fluids
6 hours for food
2 hours for clear fluids
Patients taking long term prednisolone - how to manage during op?
As a rule of thumb:
Minor procedure under local: no supplementation required
Moderate procedure: 50mg hydrocortisone before induction and 25mg every 8h for 24h
Major surgery: 100mg hydrocortisone before induction and 50mg every 8h for 24h, thereafter halving dose every 24h until maintenance dose reached.
Prep for colonoscopy
Patient will require laxatives the day before the colonoscopy.
Patients are required not to eat for 24 hours before the examination
Post0op complications
Day 1-2: ‘Wind’ - Pneumonia, aspiration, pulmonary embolism
Day 3-5: ‘Water’ - Urinary tract infection (especially if the patient was catheterised)
Day 5-7: ‘Wound’ - Infection at the surgical site or abscess formation
Day 5+: ‘Walking’ - Deep vein thrombosis or pulmonary embolism
Any time: Drugs, transfusion reactions, sepsis, line contamination.
What is malignant hyperthermia
Causes
Investigations
Management
Condition often seen following administration of anaesthetic agents
Characterised by HYPERPYREXIA and muscle RIGIDITY
cause by excessive release of Ca2+ from the sarcoplasmic reticulum of skeletal muscle
associated with defects in a gene on chromosome 19 encoding the ryanodine receptor, which controls Ca2+ release from the sarcoplasmic reticulum
susceptibility to malignant hyperthermia is inherited in an autosomal dominant fashion
neuroleptic malignant syndrome may have a similar aetiology
Causative agents
halothane
suxamethonium
other drugs: antipsychotics (neuroleptic malignant syndrome)
Investigations
CK raised
contracture tests with halothane and caffeine
Management
dantrolene - prevents Ca2+ release from the sarcoplasmic reticulum
