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.
Guidance on antihypertensives and antiarrhythmics
(3)
Angiotensinogen converting enzyme (ACE) inhibitors should be withheld on the morning of major surgery. If unsure, contact the anaesthetic team.
Beta-blockers should be continued as per the patient’s normal prescription unless otherwise instructed.
Patients on digoxin will need an ECG and blood tests to exclude hypokalaemia.
Guidance on Anticonvulsants before surgery
(1)
Patients should continue their normal anticonvulsant therapies unless otherwise indicated.
Guidance for diabetic medications before surgery
(3)
Diabetic medications
Oral hypoglycaemic agents such as metformin should be omitted on the day of surgery.
It is important the surgical and anaesthetic teams are aware of diabetic patients listed for surgery as they will need to be first on the operative list to minimise the starvation period.
Diabetic patients that will be missing more than one meal due to fasting and operative time should be considered for insulin-dextrose sliding scale therapy during the perioperative period.
Guidance regarding steroid medications before surgery (1)
Patients who take more than 5mg prednisolone daily will need supplementary steroids during the perioperative period.
Guidance regarding hormonal therapies before surgery (2)
NICE state that: advise patients to consider stopping oestrogen-containing oral contraceptives or hormone replacement therapy 4 weeks before elective surgery.
Tamoxifen is used in the management of breast cancer and should only be stopped if the risk of VTE outweighs the risk of interrupting treatment.
Guidance regarding Antidepressants
(2)
If a patient is on a MAOi, it is essential that the anaesthetist responsible for the patient at the time of surgery is informed.
Patients taking lithium should have a lithium level and U&Es checked, along with TFTs before proceeding to surgery.
Guidance regarding Herbal medications before surgery
(2)
Herbal medications such as St John’s Wort and ephedra should be stopped 2 weeks before surgery.
Pre-operative medication prescription (4)
Analgesics
- Paracetamol and codeine are given for their analgesic effects during surgery.
- NSAIDs are given if there are no patient or surgical contraindications.
Antacids
- Ranitidine or omeprazole can be given to minimise stomach acid and reduce the risk of aspiration during induction.
Anxiolytics
- Anxious patients, or patients requiring procedures pre-operatively such as peripheral nerve blocks or invasive line insertions, can be given anxiolytic medications such as midazolam. This is done at the discretion of the anaesthetist.
Anti-sialagogue
- Occasionally patients will be given medication such as glycopyrrolate to reduce oral secretions prior to airway instrumentation.
Guidance on additional investigations before surgery
(7)
ECG
- An ECG should be performed in the following circumstances:
- >80 y/o
- >60y/o and surgical severity >3
- Cardiovascular or renal disease
FBC:
- If > 60y/o and surgical severity >2
- All adults with surgical severity >3
- Severe renal disease
U&Es and creatinine:
- > 60y/o and surgical severity >3
- All adults with surgical severity >4
- Renal disease
- Severe cardiovascular disease
Sickle cell test:
- Families with homozygous disease or heterozygous trait
Pregnancy test
- Should be performed in all women of reproductive age.
Baseline CXR
- Should be performed for all patients scheduled for post-op critical care admission.
Cardiopulmonary exercise testing (CPET)
- CPET is useful for assessing cardiovascular and respiratory functional capacity.
- It will be requested by the anaesthetic or surgical team for patients with chronic disease affecting their daily function who are listed for major surgery.
Guidance on hypertension before surgery
(3)
This can be difficult to assess on the day of surgery as pre-op nerves can raise blood pressure.
If a patient’s BP is greater than 180mmHg systolic or 110mmHg diastolic on the day of surgery, the operation should be postponed until hypertension is under control.
Inform the GP as BP management should be done in partnership with primary care. The patient’s BP needs to be 160/100 mmHg or lower in the community prior to the operation.
Guidance on anaemia before surgery
(2)
Anaemia (Hb <13g/dL in men AND women) necessitates further investigation.
Inform the patient’s GP and ensure they are involved in any further investigations and treatment decisions.
Summary of anaesthetics history
(6)
Previous anaesthetic history:
- When did they have an anaesthetic and what for?
- Previous problems with anaesthetics problems (malignant hyperthermia, suxamethonium apnoea, anaphylaxis, postoperative nausea and vomiting)
- Family history of anaesthetic problems
Allergies:
- What drug?
- What type of reaction?
Regular medications:
- What drug?
- When was their last dose?
- Anticoagulants, antiplatelets
Presenting complaint:
- What led them to want/need this surgery?
Past medical history:
- Respiratory assessment
- Cardiovascular assessment
- Reflux assessment
- Functional assessment
- Airway assessment
The following should be assessed:
- Mouth opening
- Jaw protrusion
- Neck movement
- Mallampati score
- Dentition
Preparation for surgery
(4)
Fasting period:
- 6hrs – food/milk
- 2 hrs – water
Peri-operative medications:
- Make a plan for their regular medications – do any need omitting or altering?
Further investigation:
- Does the patient require further investigations or treatment before their surgery (e.g. due to anaemia, hypertension or acute change in their clinical condition)?
- Does the patient meet the criteria for referral to the pre-operative anaesthetic assessment clinic?
Consent:
- Ensure the patient has consented appropriately for their operation AND anaesthetic.
Questions for patients with Gastro-oesophageal reflux (GORD):
(4)
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
- Frequency and the most recent episode
- How is it controlled?
Questions for patients Asthma/COPD (4)
Regular medications, compliance and degree of control
Recent oral steroid treatment
Exacerbating factors
Smoking status
