Anesthetics Pre-operative assessment Flashcards
American Society of Anaesthetist (ASA) score:
(6)
American Society of Anaesthetist (ASA) score:
- Normal healthy patient
- Mild systemic disease (e.g. asthma)
- Severe systemic disease
- Severe systemic disease that is a constant threat to life
- Moribund patient, not expected to survive without the operation
- Declared brain-dead patient – organ removal for donor purposes
Surgical severity score grades:
(4)
Surgical severity score:
Grade 1 – diagnostic endoscopy, laparoscopy, breast biopsy
Grade 2 – inguinal hernia, varicose veins, adenotonsillectomy, knee arthroscopy
Grade 3 – total abdominal hysterectomy, TURP, thyroidectomy
Grade 4 – total joint replacement, artery reconstruction, colonic resection, neck dissection
Other risk assessment scoring tools:
(3)
Other risk assessment scoring tools:
NELA – National Emergency Laparotomy Audit
SORT – Surgical Outcome Risk Tool
POSSUM – Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity
Key questions to ask about previous anaesthetics include:
(4)
Has the patient had any previous anaesthetics?
- If so, was that under general anaesthetic or another method? – e.g. peripheral nerve blocks, spinal, epidural and/or sedation
Did they have any problems with previous anaesthetics?
Serious anaesthetic complications:
- Malignant hyperthermia (MH) – a rare reaction to volatile anaesthetic agents and neuromuscular blocking drugs that can cause dangerously high body temperature and muscle contractions
- Suxamethonium apnoea – a deficiency in enzymes required to break down suxamethonium, resulting in prolonged paralysis of skeletal muscle
- Anaphylaxis. See the Geeky Medics guide for clinical features of anaphylaxis.
- Difficult airway
How long did they take to wake up? Was it a few hours or a few days?
- Did they require intensive treatment unit (ITU) admission post-op due to problems waking up?
- Is there any family history of problems with anaesthetics?
- Have they or their family members had any specific testing? – i.e. genetic, allergy or other testing relating to anaesthetic agents (MH or suxamethonium apnoea)
Did they experience postoperative nausea and vomiting previously?
Serious anaesthetic complications
(4)
Serious anaesthetic complications:
- Malignant hyperthermia (MH) – a rare reaction to volatile anaesthetic agents and neuromuscular blocking drugs that can cause dangerously high body temperature and muscle contractions
- Suxamethonium apnoea – a deficiency in enzymes required to break down suxamethonium, resulting in prolonged paralysis of skeletal muscle
- Anaphylaxis. See the Geeky Medics guide for clinical features of anaphylaxis.
- Difficult airway
How long did they take to wake up?
(3)
Did they require intensive treatment unit (ITU) admission post-op due to problems waking up?
Is there any family history of problems with anaesthetics?
POST-OP NAUSEA
Key allergies to ask
(2)
List all allergies and intolerances, regardless of the severity
Ask specifically about penicillin
Ask specifically about NSAIDs
Ask about medications
(3)
Ask specifically about anticoagulants, antiplatelet agents, antihypertensives and when they last took them.
Ask about any analgesics and when they last took them.
Ask about “over the counter” and herbal medications.
CAUTIONS FOR
Maxillofacial surgery (3)
Ear, Nose and Throat surgery (2)
GI surgery (3)
Gynae surgery (2)
Maxillofacial surgery
- mouth opening
- swelling
- dental problems
Ear, Nose and Throat surgery
- snoring/sleep apnoea
- hypertension (some operations require induced hypotension to reduce bleeding and improve the surgeon’s visual field)
GI surgery
- reflux/nausea/vomiting
- features suggesting bowel obstruction
- anaemia
Gynae surgery
- nausea/reflux
- anaemia
RESPIRATORY COMPLICATIONS
(4)
Asthma/COPD:
- Regular medications, compliance and degree of control
- Recent oral steroid treatment
- Exacerbating factors
- Smoking status
Obstructive sleep apnoea:
- BMI
- Observed apnoeic episodes
- Daytime somnolence
- Do they use a CPAP mask at night?
Functional status:
- Exercise tolerance
- Able to lie flat without becoming breathless?
Other:
- Recent hospital or ITU admissions
- Recent cough/cold or features suggesting current acute illness
CARDIOVASCULAR COMPLICATIONS
(5)
Hypertension:
- How is this managed and by who?
- Do they know what is normal for them at home?
- Is there evidence of end-organ damage? – e.g. reduced renal function
Acute coronary syndrome (ACS):
- Previous myocardial infarction? When? Symptoms? What treatment?
- Have they had angiogram/PCI/CABG and what vessels were implicated?
- Recent ECHO?
Heart failure:
- Exercise tolerance
- Breathless when lying flat? (this is important as they will probably need to lie flat for their operation)
- Peripheral oedema
Valve disease:
- Syncopal episodes
- Surgical treatment
Atrial fibrillation:
- Anticoagulation
- Associated complications
MILD CARDIOVASCULAR DISEASE (3)
SEVERE CARDIOVASCULAR DISEASE (4)
MILD CARDIOVASCULAR DISEASE (3)
- Mild angina, not limiting ordinary activity
- MI > 1 month ago
- Compensated heart failure
SEVERE CARDIOVASCULAR DISEASE (4)
- Severe/unstable angina limiting activity
- MI < 1 month ago
- Decompensated heart failure
- Severe valvular disease
DIABETES HISTORY (3)
How is it controlled? Diet, oral medication or insulin?
How often do they check their capillary blood glucose and what’s normal for them?
Do they still have hypo-awareness?
RENAL HISTORY
(3)
Key questions to ask about renal disease:
- Type of renal disease and cause (if known)
- Fluid restriction
- Dialysis schedule
NEUROLOGICAL HISTORY (4)
Key questions to ask about neurological disease:
- Previous stroke or TIA?
- Residual symptoms – specifically swallowing, communication, mobility
- Epilepsy – seizure type, most recent seizure, medication
- Dementia/delirium – exacerbating factors, alleviating factors (e.g. family presence)
GASTROINTESTINAL COMPLICATIONS
(3)
Gastro-oesophageal reflux (GORD):
- A history of GORD can potentially affect how the patient’s airway is managed. Significant reflux would require rapid sequence induction and intubation to reduce the risk of stomach contents contaminating the airway.
- Triggers – e.g. food, lying supine
- Associated symptoms – discomfort, acid into throat/mouth
- Frequency and the most recent episode
- How is it controlled?
Alcohol use
- Quantify amount
- Features suggesting dependence and risk of withdrawal
Nausea and vomiting
MSK HISTORY
(3)
Musculoskeletal - Conditions affecting the cervical spine as this may make airway access difficult:
- Rheumatoid arthritis
- Ankylosing spondylitis
- Osteoarthritis
General mobility and assistance with walking/self-care as this will guide post-operative recovery requirements
GYNAECOLOGICAL HISTORY
(3)
For women of reproductive age, could they be pregnant?
When was their last menstrual period?
Do you take birth control?
FASTING PERIODS
(3)
Fasting periods:
- WATER – up to 2 hours before induction of anaesthetic
- FOOD/MILK-CONTAINING DRINKS – up to 6 hours before induction of anaesthetic
- ***Chewing gum up to 2 hours before induction ***
AIRWAY ASSESSMENT (3)
Wilson’s score
- Score <5 suggests easy laryngoscopy
- Score 5-8 suggests potentially difficult laryngoscopy
- Score 8-10 indicates a risk of severe difficulty in laryngoscopy
Mallampati score
- The Mallampati score is used to predict the ease of endotracheal intubation.
- The test comprises a visual assessment of the distance from the tongue base to the roof of the mouth, and therefore the amount of space in which there is to work.
Dentition
- Ask about any caps or crowns a patient might have and whether they have any loose or wobbly teeth.
Guidance for Warfarin
(4)
For minor superficial surgery (e.g. ophthalmic or minor dental procedures) warfarin may not need to be omitted (however guidelines vary, so always consult local guidance).
For all other surgical interventions, the last dose of warfarin should be given 6 days before the procedure.
For emergency surgery or surgery where warfarin was not omitted, check INR and consider reversal with Vitamin K or other agents according to procedure and timeframe. This needs to be discussed with the surgical and anaesthetic team involved in the case.
“Bridging therapies” refers to the use of alternative anticoagulation therapy, such as short-acting low molecular weight heparin (LMWH), during the pre- and immediately postoperative period. Your hospital trust will have a protocol on this.
Guidance for heparin
Unfractionated heparin (2)
LMWH (2)
Unfractionated heparin is short-acting and normally given via IV infusion. It must be stopped 4 hours before neuraxial block with evidence of a normal APTT.
LMWH is longer acting and administered subcutaneously.
Following “prophylactic dose LMWH”, a neuraxial block cannot be performed for 12 hours.
Following “treatment dose LMWH”, this is increased to 24 hours.
Guidance for Novel oral anticoagulants (NOACs)
(3)
Rivaroxaban clearance is dependent on dose and renal function:
Prophylactic dose with creatinine clearance >30ml/min – 18 hours before neuraxial block.
Treatment dose with creatinine clearance >30ml/min – 48 hours before neuraxial block
Dabigatran and Apixaban – wait 48 hours before neuraxial block
Guidance for antiplatelet therapy before surgery
(2)
Aspirin, dipyridamole and NSAIDs can be continued as per patient’s usual prescription unless there are confounding factors such as deteriorating renal function.
Clopidogrel causes irreversible platelet inhibition and therefore should be stopped 7 days before surgery and/or neuraxial intervention.
