Perioperative Care Flashcards
What are the types of surgery (surgery grade)
Grade 1 (minor) – Eg. Excision of skin lesion, draining abscesses
Grade 2 (intermediate) – Eg. Excision of varicose veins, tonsillectomy, arthroscopy
Grade 3 (major) – Eg. Hysterectomy, resection of prostate, thyroidectomy
Grade 4 (major+) – Eg. Total joint replacement, lung operation, colonic resection
Neurosurgery and cardiovascular surgery have their own gradings
What are the ASA Grades
ASA 1 – Normal healthy patients, no clinically important comorbidity and insignificant past medical history
ASA 2 – Patients with mild systemic disease
ASA 3 – Patients with severe systemic disease
ASA 4 – Patients with severe systemic disease, threatening to life
When should an ECG be done Pre Op
Should always be considered in any patient over 40 years old and should be performed in 80+ year olds – done routinely in patients with hypertension or pre-existing heart disease
When should an FBC be done Pre-op
Should always be considered in any patient over 60 years old
When should Renal function tests be done pre op
Should always be considered in any patient over 60 years old
When should Urine analysis be done Pre op
Should be considered in all patients
Pregnancy testing – in all fertile women
UTI
Undiagnosed diabetes or renal disease
Why should you ask about reflux in a Pre-op assessment?
Reflux is an important factor as patients who experience it definitely need intubation, laryngeal mask leaves too high a risk of aspiration
Give medication such as PPI or H2 receptor antagonist in an attempt to prevent reflux and the complications thereof
If a patient is found to be thrombocytopaenic pre op, what should be done?
Look for cause of thrombocytopaenia, such as myeloid conditions (leukaemia, myelodysplasia, etc.), infections or spleen issues (splenomegaly)
Patients will need coagulation testing
If a patient is found to have Neutrophilia pre op, what should be done?
May be artefactual – read blood film report to be sure, use citrate sample (green bottle) instead if platelet clumping is reported
IV immunoglobulin may improve the platelet count
If a patient is found to be thrombocytopaenic pre op, what should be done?
Suggests an ongoing infection – treat it first
If a patient is found to be Anaemic pre op, what should be done?
Patients will bleed more during surgery and will have poor wound healing, will need cross match and transfusion in emergency surgery
Try to correct anaemia before surgery if possible, try to find out what could be the cause, erythropoietin injections may be required
When to do a Group and save or cross match
For surgeries where blood loss is expected
Group and save if there is a low chance of bleeds
Cross-match if blood-loss is predicted or if patient is found to have atypical antibodies on blood testing, as this will make it harder to source blood at the time with just a G+S on record
Why will you ask about allergies Pre-op?
Allergy to egg or soya is important as this often indicates an allergy to propofol will also be present
Patients with an allergy to latex should be done first on the list (so latex spores aren’t floating around), non-latex gloves must be worn
Why is it It is important to know the patient’s alcohol history pre-op
If the patient is a heavy drinker then the liver may be damaged, leading to reduced production of clotting factors and a reduced rate of drug metabolism
What is Malignant hyperthermia
An Autosomal dominant inherited condition
Fast rise in body temperature due to severe muscle contractions when subjected to general anaesthetics – inhaled agents such as isoflurane/sevoflurane but also suxamethonium
Do not use anaesthetic gases or suxamethonium in these patients if the condition is known prior to surgery
Local anaesthetics work fine so a spinal block or epidural may be the best thing for it
Atracurium or rocuronium instead of suxamethonium (succinylcholine)
Dantrolene should be on hand to reverse this problem
Wrap the patient in a cooling blanket to reduce the temperature
What is Suxamethonium apnoea
May be inherited or acquired
Patient is unable to correctly metabolise suxamethonium and therefore it is not removed from the body at the correct rate
Patients will remain paralysed following surgery and must be given fresh frozen plasma, which contains cholinesterase enzymes, to break down the suxamethonium
Use atracurium in these patients instead
What risks are higher in a surgery if a patient has asthma?
Patient is more likely to undergo pneumothorax or form bullae during the operation
Risk of bronchospasm
What risks are higher in a surgery if a patient has impaired Renal and Liver function?
Patients with reduced eGFR will excrete drugs at a slower rate, meaning they will stay in the system for longer
Patient at risk of overdose or of staying asleep for longer than expected
Caution use of radiocontrast for imaging assisted procedures in patients with low eGFR
Patients with reduced liver function will not metabolise drugs as easily
May not work as quickly
May wear off more slowly
May increase risk of toxic levels
Patients with reduced liver function may also have reduced clotting factors
Liver responsible for factors 1, 2, 5, 7, 8, 9, 10 and 11
Some patients may have a history of waking up sooner than expected in surgery due to hypermetabolism – take this into account
What changes should be made pre-op for diabettic patients
HbA1c should be targeted at <60mmol/mol (<7.5%) for surgery – ideal values
<48mmol/mol (<6.5%) is generally the target for diabetics in everyday life
HbA1c must be at least below 69mmol/mol (8.5%) – this is the highest acceptable value
Patients going for elective surgery should have their HbA1c assessed and reduced if necessary in primary care
This will reduce the risk of complications and reduce the time taken to heal
Diabetic patients should have eGFR taken to look for any diabetic nephropathy
Patients missing more than one meal will need to be given a variable rate IV insulin infusion (sliding scale) during the operation
0.45% NaCl and 5% glucose with 0.15-0.3% Kcl (depending on potassium levels)
Target blood glucose for elective surgery is 6-12mmol/L
4-12mmol/L is the acceptable range
Patient should be done first on the list if possible
How can you assess an airway for intubation?
LEMON assessment for difficult airways
Look at the external airway, is there anything that may obstruct entry?
e.g. Obesity, micrognathia (small jaw), evidence of previous surgery, trauma or irradiation, facial hair (large beard hard to mask ventilate), dental abnormalities (including large teeth and poor hygiene), high arched palate, thick or short neck
Evaluate 3, 3, 2 rule – 3 fingers should fit in the jaw vertically, 3 fingers from the mentum (front of chin) to the hyoid bone, 2 fingers from the hyoid to the thyroid cartilage notch
Mallampati score – used to predict the ease of endotracheal intubation
Visual assessment of the distance from the tongue base to the roof of the mouth, indicating the amount of available space to work in
An increasing score indicates increasing difficulty of intubation
Cormack-Lehane scale is more accurate and describes what is seen on laryngoscopy during intubation
Obstruction – soft tissue swellings, burns, broken necks, trauma to face or neck, foreign bodies lodged in the airway, excessive soft tissue and obesity
Neck mobility – preferably, neck should be able to be extended during laryngoscopy
What Blood thinners and anti-clot agents
will you stop pre-op?
Clopidogrel – antiplatelet agent (inhibit ADP receptors)
Stop 1 week before surgery
May not need to be stopped – depends on patient risk of clot and how soon after a throboembolic event or MI
Aspirin – antiplatelet agent (blocks thromboxane A2 formation)
Stop 1 week before surgery
May not need to be stopped – depends on patient risk of clot
Restart following surgery at surgeon’s discretion
Warfarin – inhibits vitamin K dependent synthesis of clotting factors 2, 7, 9 and 10
Stop 1 week before surgery, cover with dalteparin prophylactic dose (5000 units daily) to prevent thromboembolic events during this week
May not stop if surgery has low bleed risk and risk of thromboembolism is very high
What Respiratory medicine will you stop pre-op?
Inhalers should be taken all the way up to the day of surgery, taken on the morning of the day of surgery
What Blood pressure medication will you stop pre-op?
Ace inhibitors and ARBs eg. ramipril, lisinopril, losartan, candesartan
Not taken on the day of surgery and continue following procedure
Calcium channel blockers eg. amlodipine, nifedipine, diltiazem
Not taken on the day of surgery and continue following procedure
Beta blockers eg. atenolol, bisoprolol, propranolol
Taken on day of surgery and continued following procedure
Sudden cessation can lead to rebound angina/infarction – may need some during op
Thiazide diuretics
Stop the day before surgery and continue when back on oral fluids
What Diabetes medications
medication will you stop pre-op?
Oral hypoglycaemics, eg. Metformin
Omit dose on day of surgery to prevent issues caused by possible changes in renal function
Insulin if necessary while undergoing surgery – Variable rate IV insulin infusion (VRIII)
Insulin until patient can take substances orally again following surgery
Insulin
Omit short acting but continue long acting on day of surgery
Insulin (VRIII) if necessary during surgery and usual dosing following surgery
