Pre-operative assessment Flashcards
What questions is it important to ask about in an anaesthetic history?
What 2 types of reactions to anaesthetic drugs do you need to ask about?
What 3 medical conditions do you need to ask about?
Anyone in family or personal history had bad reaction to anaesthetics?
Any post op nausea or vomiting?
Anaphylaxis
Difficult or failed intubation
Malignant hyperthermia
Suxamethonium apnoea
Acute porphyrias, myasthenia gravis, neuromuscular disease, GORD or hiatus hernia,
How do you work out a patients pre-operative cardiac risk? What level is a risk to post-op cardiac event?
METS - over 4 indicated by inability to climb 2 flights of stairs is at risk of post op cardiac event
What does an anaesthetist need to know about angina pre op?
Is it stable or unstable, unstable need to know functional impair, exacerbating or relieving factors, frequency
What does an anaesthetist need to know about MI pre op?
When STEMI or NSTEMI How was MI treated - PCI, thrombolysis, CABG, stents How many vessels were involved Has functional capacity changed
What does the level of cardiac impairment effect in management of a patient?
BP control- inotropes
Level of monitoring in op - arterial lines and CVL
Post op care - HDU or ICU
What heart disease is spinal anaesthesia contraindicated in?
Severe aortic stenosis
What is dual antiplatelet therapy?
Aspirin and P2Y12 inhibitor
Difference between a STEMI and an NSTEMI in terms of anatomy?
STEMI is full thickness infarction whereas NSTEMI is subendocardial MI/partial thickness
Why do drug eluting cardiac stents need DAPT? How long do they need it for? Why is this an issue for anaesthetists?
DES will undergo stenosis without taking DAPT for the initial 6-12 months that the artery is recovering around the stent
Issue as you dont want to stop DAPT in this time period and risk stenosis of the vessel, can you prolong surgery? if not you need fine tuned management plan
Difference between anticoagulants and antiplatelets?
Anticoagulants are heparins, direct thrombin inhibitors, Factor Xa inhibitors and Vitamin K antagonists
Antiplatelets are COX inhibitors, ADP/P2Y12 inhibitors, phosphodiesterase inhibitors, glycoprotein 2a3b inhibitors
Example of a LMWH anticoagulant?
Enoxaparin
Example of a direct thrombin inhibitor anticoagulant?
Dabigatran
2 examples of a direct factor Xa inhibitor?
Rivaroxaban and Apixaban
Example of a vitamin K antagonist?
Warfarin
Example of a COX inhibitor?
Aspirin
Example of a P2y12 inhibitor?
Clopidogrel
Example of a phosphodiesterase inhibitor?
Dipyridamole
Example of a glycoprotein 2a3b inhibitor?
abciximab
How long pre op does aspirin need to be stopped?
Doesnt
How long does clopidogrel need to be stopped pre op?
7 days
How long does warfarin need to be stopped for pre-op? goal INR?
4-5 days (goals INR at 1.4)
How long before op do Dabigatran, Rivaroxaban and Apixaban need to be stopped?
18-96 hours
How long since your last dose of Enoxaparin can you administer neuraxial anaesthesia?
12 hours or more
what can you assess about a patient that would increase their risk of post operative pulmonary complications?
COPD Smoking Age Myasthenia gravis Anatomical abnormalities like kyphosis Nutritional status Sleep apnoea
What happens in a patient with reactive airways?
They get bronchospasm and can’t be ventilated so need a period in ICU
How do you work out pack years as a smoker?
number of packs a day x years as a smoker
How long after stopping smoking does it take to clear carbon monoxide out of your system?
12-24 hours
How long after stopping smoking does your upper airway reactivity improve?
2-10 days
How many months after stopping smoking does your post operative complications reduce?
5-6 months
What occurs in diabetics that may make intubation difficult?
Stiff joint syndrome causing glycosylation of collagen effecting the TMJ and atlanto-occipital joints
Why do diabetics tend to experience a longer hospital stay?
Prone to infection and anastomoses break down
What HbA1c level pre op leads to a delayed elective surgery?
Over 69 mmol/L
How is insulin given to a patient with diabetes pre operatively whilst fasting? If they are receiving this pre-op how does their insulin regime alter post op?
Variable rate IV insulin infusion
Need a 30-60 minute overlap to prevent DKA
What should blood glucose levels be intra-operatively for a diabetic patient?
6-10mmol/L
What does GORD lead to in surgery?
Aspiration pneumonitis
9 situations that can increase your risk of GORD during surgery?
Pregnancy Hiatus hernia Diabetes Opioids Alcohol Obesity Gastric outlet obstruction Pain and anxiety Bowel obstruction
What methods can be put in place to minimise the risk of aspiration under anaesthesia?
Fasting Positioning of patient upright Use of different anaesthesia methods - spinal NG tube to suction out contents Quick induction anaesthesia
How many hours before a procedure are you unrestricted by food or liquid intake? can have a small meal? can have breast milk? can only have fluids? NBM?
8 hours 6 hours 4 hours 2 hours clear liquid From 2 hours to procedure
What does atlantoaxial instability increase your risk of?
Acute subluxation and spinal cord compression
What joint issue can cause difficulties for airway management by anaesthetists?
TMJ
When can MSK issues become a problem for anaesthetists?
Contractures - IV access TMJ - airway management Difficult positioning Dry eyes - corneal abrasions immunosuppression - proper aseptic technique
What is ankylosing spondylitis and what joints does it primarily effect? What is usually needed for intubation?
Fibrosis and ossification of sacroiliac joints and spine as well as some extra articular disease
Usually need a fibreoptic intubation method through the nose
What is ASA grade?
An assessment tool used by anaesthetists to assess functional capacity of a patient to undergo surgery
What are some examples of minor surgeries performed?
Skin lesion excision
Breast abscess drainage
What are some examples of Intermediate surgeries that are performed?
hernia repair
varicose vein excising
tonsillectomy
knee arthroplasty
What are some examples of major surgeries that are performed?
GI TAH Thyroidectomy Total joint replacement Thoracic surgery Vascular surgery
What are the ASA grades? What ASA grades used for day surgery?
ASA 1 - fit and healthy (day case) ASA 2 - mild systemic illness (day case) ASA 3 - severe systemic illness ASA 4 - severe systemic illness with constant threat to life ASA 5 - Expected to die ASA 6 - brain dead organ retrieval
ASA 3 and 4 are the only groups that you consider 2 investigations for minor surgery, what are they?
Kidney function
ECG if none available from last 12 months
ASA 1 testing for intermediate surgeries?
None routinely
ASA 2, two tests you consider for intermediate surgery?
Renal function if at risk of AKI
ECG if they have CV, diabetes or renal comorb
What management and considerations are taken for an ASA grade 3 or 4 undergoing intermediate surgery?
You would do a renal function and ECG
You would consider FBC if CV or renal disease
You would consider haemostasis analysis if chronic liver disease or on anticoagulants
You would consider seeking advice from senior anaesthetist if respiratory disease
What management would an ASA 1 get for major surgery?
FBC
renal function if risk of AKI
ECG if over 65 and non available
What management would ASA 2 get for major surgery?
FBC
Renal function
ECG
What management would ASA 3 get for major surgery both compulsory and considered?
FBC
ECG
Renal function
Haemostasis considered if chronic liver disease or clotting status needed
Lung function consider senior anaesthetist review if known respiratory disease
What test would you do on women pre op?
Pregnancy test
When is an ECHO done pre op?
When there is a murmur or SOB, risk of arrhythmia
4 things that increase the risk of VTE in acute surgical or trauma patients?
Surgery longer than 90 minutes
Surgery longer than 60 minutes on pelvis or lower leg
Acute inflammatory condition or intra-abdominal condition
Expected marked reduction in mobility
When a patient first comes to hospital, how do you perform a VTE risk assess?
Thrombosis risk - 1 point then consider LMWH
Bleeding risk - 1 point then dont use LMWH unless thrombosis risk outweighs
What patient factors increase the risk of thrombosis?
Age over 65 Obesity Active cancer or cancer treatment Dehydration Known thrombophlebitis Significant medical comorbidities Personal history of VTE HRT Oestrogen contraception Pregnancy or 6 weeks post partum
What is the usual dose and form of VTE prophylaxis used for patients?
Enoxaparin 40mg SC OD
When would you only use 20mg SC OD of Enoxaparin for prophylaxis against VTE?
when their weight is under 40kg or their eGFR is under 30mls/min
When would you use 60mg SC OD of Enoxaparin for VTE prophylaxis?
When the patient is over 100kg
What non-pharmacological methods of VTE prophylaxis are there?
Anti-embolism stockings
Early mobilisation
Hydration
Intermittent pneumatic compression devices
Patient factors that increase the bleeding risk?
Active bleeding Bleeding disorders - liver disease and haemophillia Thrombocytopenia below 75 Anticoagulants being used Acute stroke Uncontrolled systolic hypertension
Admission related bleeding risk factors?
Neurosurgery, spinal or eye
High bleeding risk
Neuroaxial anaesthesia expected in next 12 hours or in the last 4 hours
