Surgery 1 Flashcards
(33 cards)
Pre-operative Assessment
Assess cardiorespiratory system, exercise tolerance, existing illnesses, drugs and allergies.
Identify risk factors – unstable neck (e.g. is arthritis – may complicate intubation), history of MI, diabetes, asthma, hypertension, rheumatic fever, epilepsy or jaundice.
Any specific risks – is the patient pregnant and have there been any previous anaesthetic complications e.g. nausea or DVT?
Pre-operative Investigations - Bloods
- General bloods – all patients should have FBC, Us and Es and blood glucose.
- Crossmatching – e.g. group and save for mastectomy or cholecystectomy, crossmatch 2 units for Caesarean section, 4 units for a gastrectomy or 6 units for aortic aneurysm surgery.
- Specific bloods – e.g. LFTs in jaundice, malignancy or alcohol abuse, amylase in acute abdominal pain, drug levels if patient is on digoxin or lithium, clotting studies in liver or renal disease, DIC, massive blood loss or if on valproate, warfarin or heparin. In addition HIV and HBsAg antigens in high risk patients and sickle test in those from Africa, West Indies or Med.
Pre-operative Investigations - Other Tests
- CXR – if known cardiorespiratory disease, pathology or symptoms, possible mets or >65 years.
- ECG – if >55 years, poor exercise tolerance, history of MI, hypertension or rheumatic fever.
- Echo – may be performed if there is any suspicion of poor left ventricular function.
- Pulmonary Function tests – in patients with known respiratory disease or in obese patients.
- Lateral cervical spine x-ray – if history of RA, ankylosing spondylitis or Down’s syndrome.
- MRSA screen – colonisation is not a contraindication for surgery but the patient may be put last on the list to minimise the risk of transmission to others and given vancomycin.
ASA Classification
- Class I – the patient is normally healthy.
- Class II – the patient has a mild systemic disease.
- Class III – the patient has a severe systemic disease that limits activity but is not incapacitating.
- Class IV – patient has an incapacitating systemic disease which poses a constant threat to life.
- Class V – the patient is moribund – not expected to survive 24 hours even with the operation.
Pre-op - Antibiotics
Tetracycline and neomycin may increase the neuromuscular blockade.
Pre-op - Anticoagulants
Avoid epidural, spinal and regional blocks.
Aspirin should be continued unless there is a major risk of bleeding and discuss clopidogrel with a cardiologist or neurologist.
Pre-op - Anticonvulsants
Give as usual pre-op.
Post-op give IV or via the NG tube until oral intake is possible. Give usual valproate dose IV and give a slow dose of IV phenytoin and monitor ECG.
Pre-op - Beta Blockers
Continue up to and including day of surgery to prevent a labile cardio response.
Pre-op - Contraceptive Steroids and HRT
Stop 4 weeks before major or leg surgery and ensure adequate alternative contraception is used.
Restart contraceptive steroids 2 weeks after surgery.
Pre-op - Digoxin
Continue up to and including the day of surgery – check for toxicity with ECG and levels and do plasma K+ and Ca+ (suxamethonium can increase K+ and cause arrhythmias).
Pre-op - Diuretics
Beware of hypokalaemia, dehydration (especially as nil by mouth) and do Us + Es (also check bicarbonate).
Pre-op - Levodopa
Can cause possible arrhythmias when patients are under general anaesthetic.
Pre-op - Lithium
Get expert help – it may potentiate neuromuscular blockade and cause arrhythmias.
Pre-op - MAOI
Interactions can cause hypotensive or hypertensive crisis.
Pre-op - Tricyclics
These can enhance adrenaline and cause arrhythmias
Pre-operative Preparation
- Fast the patient – keep them nil by mouth >2 hours for clear fluids and >6 hours for solids.
- Check - does the patients require any bowel or skin preparations or prophylactic antibiotics.
- DVT prophylaxis – as indicated e.g. graduated compression stockings and 5000U heparin SC 2 hours pre-op and then every 8-12 hours SC for 7 days or until ambulant or 20mg enoxaparin.
- Write up pre-meds, book pre, intra or post-operative xrays or frozen sections and book physio.
- If required – catheterise and insert a Ryle’s (nasogastric) tube to reduces organ bulk.
Consent and Capacity
- For consent to be valid – it can be given at any time (earlier is better), the proposed investigation or treatment must be clearly understood by the patient (including risks, benefits, additional procedures, alternative courses of action and their consequences), it must be given voluntarily, sought by the doctor performing procedure and the patient must have capacity (time and decision dependant).
- Capacity – patient must be able to understand, believe, retain and weigh the necessary information.
Consent - Special Circumstances
- Consent in children – those <16 years can give consent provided they understand what it involves – this is known as Gillick competence (although it is still good practice to involve the parents in the decision if the child is willing). For those <18 years and refusing life-saving treatment the law is less clear – talk to the parents, seniors and in some cases the duty judge.
- Consent in the incapacitated – no-one including parents, relatives or members of the healthcare team can give consent on behalf of a patient. Proceeding in the patients best interest is decided by the clinician overseeing their care.
Classification and Risk of Wound Infections
- Clean - incising uninfected skin without opening a viscous = <2%
- Clean - contaminated - intraoperative breach of a viscous that is not the colon = 8-10%
- Contaminated - breach of a viscous + spillage or opening of the colon = 12-20%
- Dirty - the site is already contaminated by pus or faeces = 25%
Prophylactic Antibiotics
Given to counter the risk of wound infection which occurs in 20% of elective GI surgery and 60% of emergency surgery.
Also given when there is infection elsewhere and a systemic infection would have severe consequences e.g. when a patient has a prosthetic joint or valve.
They are given 15-60 mins prior to the procedure so the skin concentration is maximised and may be given as a single dose, 3 doses or more.
Sepsis may lead to haemorrhage and wound dehiscence
Common Antibiotic Regimes
- Biliary surgery – 1 dose of 1.5g Cefuroxime IV and Metronidazole.
- Appendectomy – if uncomplicated a surgery a single dose of 1.5g Cefuroxime IV is effective.
- Colorectal surgery – 1-3 doses 1.5g Cefuroxime IV TDS and 500mg Metronidazole IV TDS. If there is heavy soiling during the surgery you can also give 1-3 doses 4.5g Tazocin IV TDS.
- Vascular surgery – 1.2g Co-amoxiclav or 1.5g Cefuroxime IV with 500mg Metronidazole.
- MRSA – an increasing concern and may warrant prophylactic treatment – Vancomycin.
Bowel Preparations
There are clear benefits of using a bowel preparation when visualisation of the lumen is required e.g. colonoscopy.
However the intended benefit for elective open procedures of minimising post-operative infection may be outweighed by the complications – liquefying bowel contents which are spilled during surgery, electrolyte loss leading to hyponatraemia and seizures, a higher rate of post-operative anastomosis leakage, increased risk of perforation and dehydration.
- Right sided operations – give a low residue diet for a few days and clear fluids the day before the op.
- Left sided and rectal operations – laxatives and an enema are usually used pre-operatively.
- Example regime – 1 sachet of Picolax at 8am and another 6-8 hours later on the day before surgery.
Surgical Drains
- Most are inserted to drain the area of surgery under suction or negative pressure and are removed when stop draining. They are used to protect against collection, haematoma and seroma formation.
- The second type of drains are used to protect sites where leakage may occur in the post-operative period e.g. at bowel anastomoses. They form a tract and are usually removed after around 1 week.
- The third type of drains e.g. Ballovac collect red blood cells from the operation site which can be autotransfused within 6 hours protecting from the hazards of allotransfusion – used in orthopaedics.
Types of Sutures
Can be broadly divided into absorbable or non-absorbable, synthetic or natural and monofilament, twisted or braided.
Monofilament sutures can be slippery but minimise infection and produce less reaction (natural fibres produce a vigorous reaction).
Braided and twisted sutures produce secure knots but may allow infection to occur between strands.
3.0 or 4.0 are smaller and used on the skin.
