Pre-op

Question 1

How long before surgery should a patient have a pre-operative assessment?

Answer 1

2-4 weeks

Question 2

What classification is used to assess a patient’s airway for potential difficulty in intubation?

Answer 2

Mallampati classification

Question 3

A general structure of pre-operative history (during pre-op assessment)

Answer 3

• HPC - why did the patient first attended ->what procedure is planned
• PMH - general one, but ask particularly about: CVS, respiratory, endocrine, renal problems
• Extra questions:
• women in reproductive age -> pregnancy?
• Afro-Caribbean origin -> sickle cell anaemia?

Past surgical history: any surgeries before?

• Past anaesthetic history: have they head anaesthetics before -> any issues -> how they were during recovery -> nausea/vomiting?
• Drug history: medication and allergies
• Family History: any adverse reations in surgery? malignant hyperpyrexia/ hypertermia?

Question 4

Why is it important, in pre-op assessment history to ask about:

• cardiovascular disease
• respiratory disease
• renal disease
• endocrine disease

Answer 4

• cardiovascular disease (include HTN and exercise tolerance) -> as the risk of acute cardiac events is increased during anaesthesia
• respiratory disease -> to plan adequate oxygenation and prevent ischaemic events in peri-operative period
• renal disease:
• surgical complications increased with renal disease-causing: biochemical imbalance, coagulopathy, anaemia
• IV contrast or blood loss may worsen renal problems -> therefore careful planning is needed
• endocrine disease (especially DM and thyroid problems) -> medication requires change in peri-operative period

Question 5

What (2) examinations should be performed in pre-op assessment?

Answer 5

• General examination -> looking at any obvious pathology in CVS, respiratory, abdominal signs
• Airway assessment -> to predict difficulties with intubation

*area of procedure could be also examined

Question 6

ASA grading - simple explanation of each score

Answer 6

ASA grade directly co-relates with a grade of post-op complications/ mortality

Question 7

The choice of pre-op investigations depends on what? (4)

Answer 7

• local guidelines
• seriousness of procedure
• age
• co-morbidities

Question 8

What blood tests could be done pre-op? And why? (5)

Answer 8

• FBC -> to identify any potential anaemia and thrombocytopaenia -> this needs to be treated before surgery to minimise cardio-vascular compromise
• U&Es -> to assess renal function; this will allow planning if iV fluids would be administrated
• LFTs -> to assess liver metabolism and synthesis -> as may require to adjust dosing
• Clotting screen -> any coagulation problems (e.g. haemophilia, warfarin use) would need to be corrected before the surgery
• Group and Save (G&S) and crossmatch -> to prepare for blood loss and eventual transfusion

Question 9

What’s the difference between G&S and crossmatch?

Answer 9

G&S -> to define patient’s ABO group and Rh status; it also screens the blood for atypical antibodies

(G&S is recommended if blood loss is not anticipated; done in case if the blood loss would be greater than expected)

Crossmatch -> patient and donor’s blood are physically mixed -> to see if any immune reaction takes place; if it does then the other blood is tried

(crossmatch is done if a blood loss is anticipated; G&S must be done first)

Question 10

What imaging is often done in pre-op assessment? (4) Justify

Answer 10

• ECG -> done in a person with underlying cardiac problems or if major surgery is planned

it allows to a) identify cardiac pathology b have a baseline picture so we can identify a new onset of post-op cardiac ischaemia)

• ECHO -> it is considered if a) murmur is identified b) HF or its signs and symptoms c) signs and symptoms of cardiac disease
• CXR -> it should not be done routinely, on everyone; do if:
• systemic resp disease and no recent (last one was done >12 months ago) CXR
• significant smoking history
• recent travel to TB endemic area
• new onset of cardio-respiratory signs
• Spirometry -> if a patient has a chronic lung condition

done to assess baseline in case if post-op complications arise

Question 11

What other tests are done pre-op? (4) justify

Answer 11

• pregnancy test -> women in reproductive age
• urinalysis -> not done pre-op routinely; only if evidence of UTI or glycosuria
• sickle- cell anaemia -> do not do routinely, only if FHx or a person is African/Afro-Carrabiean origin
• MRSA swab -> swabs from nostril + perineum + other sites -> if MRSA is identified, anti-septic body and hair-wash is given + topical ointment applied to the nostril

*it is given pre-op for elective surgery patients (even if the operation would be delayed)

Question 12

Investigations for day-case patients

Answer 12

• ECG – All patients >70yrs or a history of chest pain, hypertension, or a heart murmur
• LFT’s – Any alcohol intake over the expected amount
• U&E’s – All patients >60yrs, currently taking antihypertensives, history of DM or renal problems, or a urine sample >1+ protein
• Sickle cell test – If Afro Caribbean (and not previously tested)
• CXR – Any recent pneumonia, to discuss with anaesthetist
• TFTs – Patients on thyroxine or having thyroid surgery
• FBC – All patients >60yrs, or history of anaemia, any bleeding disorder, or sickle cell trait

For DM patients, perform a routine HbA1c; if >69mmol then disucss with anaesthetist regarding the need to defer the surgery

Question 13

What about fluid intake in regards to NBM before most surgeries?

Answer 13

Clear fluids up to 2 hours before

Question 14

Which medication should be stopped earliest before surgery?

Answer 14

Clopidogrel

Question 15

How long before the surgery stop HRT/OCP?

Answer 15

4 weeks before

Question 16

Contraindications to LMWH

Answer 16

• endocrine, neck surgery
• peptic ulcer disease
• previous cerebral haemorrhage

Question 17

What procedure requires phosphate enema in the morning before the operation?

Answer 17

Left hemicolectomy

Question 18

What’s RAPRIOP?

Answer 18

It is a mnemonic for pre-op management of a patient

R - reasurrance

A - advice

P- prescription

R - referral

I - investigations

O- Obs

P - patient

Question 19

Advice regarding fasting before surgery (A in RAPRIOP)

Answer 19

• Stop eating – 6 hours before
• Stop dairy products (including tea and coffee) – 6 hours before
• Stop clear fluids – 2 hours before

Question 20

Why do we need to fast before surgery?

Answer 20

It is mainly to avoid pulmonary aspiration during peri-operative period

*may cause:

• pneumonitis -> do to very acidic gastric content
• aspiration pneumonia -> due to secondary infection following pneumonitis or aspiration of an infected material

Question 21

What are 3 categories of pre-operative drug regimes (in regards to P from RAPRIOP)

Answer 21

P - prescriptions

• prescriptions to stop
• prescriptions to alter
• prescriptions to start

*some patient may require bowel preparation and blood productions

Question 22

What are (4) drugs to stop before surgery and when?

Answer 22

Memonic CHOW

C - clopidogrel -> stop 7 days before surgery (due to bleeding risk)

*Aspirin and other anticoagulants can be carried out - as minimal effect on surgical bleeding

H - hypoglycaemics -> complicated, another flashcard

O - OCP or HRT-> 4 weeks before surgery (due to DVT risk)

W - Warfarin -> stopped 5 days before the surgery and LMWH started instead

Question 23

What’s the INR target for a patient on Warfarin before surgery?

Answer 23

Need to be INR <1.5 an evening before the surgery

if INR is above the target then may need to supplement the patient with PO vitamin K

Question 24

What are drugs to alter before surgery (2)?

Answer 24

• Subcutaneous insulin -> may switch to IV variable rate infusion
• Long term steroids -> must continue (risk of Addisonian crisis if not) -> If the patient cannot take these orally, switch to IV

Question 25

Conversion rate of predniosolone (PO) to hydrocortisone (IV)

Answer 25

conversion rate is **5mg PO *prednisolone*** = **20mg IV *hydrocortisone***

Question 26

What considerations should be done pre-op for a patient on long - term steroids?

Answer 26

Surgery -\> metabolic insult and trauma -\> activation of HPA -\> production of corticosteroids If a patient is on a long- term steroid therapy -\> HPA may be suppressed = risk of acute adrenal failure **Management**: give a peri-operative stress dose of corticosteroids

Question 27

(3) drugs that we need to prescribe pre - op

Answer 27

* **LMWH** -\> complete VTE risk assessment on admission, but most of the patient will receive it unless contraindications exist * **TED stockings** -\> all patients receive below the knee TED stocking (but contraindicated in vascular surgery patients) \*also contraindicated in other instances - on different flashcard * **Prophylactic antibiotics** -\> for patients with orthopaedic, GI, vascular surgeries

Question 28

General (in simple terms) management of a patient with **T1DM** pre-surgically - considerations before surgery - NBM patient - post-op

Answer 28

Pt should be put in the morning, at the beginning of the list: ## Footnote (means they may need to be admitted a night before) A) _Before surgery_ - reduce subcutaneous insulin a night before - omit morning insulin - commence IV variable insulin infusion pump B) _if a patient is NBM_ - give dextrose infusion and check BM every 2 hours C) _Post-op_ - continue until the patient is able to eat and drink - overlap IV infusion stopping with SC insulin regimen -

Question 29

Pre-op management of pt with T2DM - if managed with diet only - if managed with oral hypoglycaemics

Answer 29

A) If T2DM patient is managed by diet and no med - nothing has to be done B) **Oral hypoglycaemics** - Metformin -\> stop on the morning before surgery - other hypoglycaemics -\> stop 24 hours before the surgery \*insulin IV variable infusion rate is then started + 5% dexterose -\> managed as T1DM patient

Question 30

(2) categories of surgeries that require bowel preparation + what to use

Answer 30

* **Left hemi-colectomy**, **sigmoid colectomy**, or **abdo-peroneal resection**: Phosphate enema on the morning of surgery * **Anterior resection**: 2 sachets of picolax (laxative) the day before or phosphate enema on the morning of surgery

Question 31

What does R on (RAPRIOP) reffers to?

Answer 31

**R** - referral - consider if ITU or HDU bed will be needed

Question 32

What does last P on RAPRIOP refer to?

Answer 32

- the patient should be fully informed and understand the plan for their care and discharge - major surgical patients -\> need a follow up appointment in the clinic, - day-case surgery -\> telephone follow-up from a nurse specialist only or may not require follow-up

Question 33

If a patient has an underlying ***valvular heart disease*** what do remember to do before the operation? (3)

Answer 33

- stop Warfarin 3 days before op -\> switch to IV Heparin - give antibiotic prophylaxis -\> to prevent endocarditis - do ECHO -\> to assess current valvular disease

Question 34

How long (if possible) to wait before the surgery after MI?

Answer 34

At least 6 months after MI

Question 35

How long an elective surgery should be deferred for after **URTI or LRTI** and why?

Answer 35

For at least 6 weeks -\> this is due to an increased risk of respiratory complications (e.g. secondary infection) if surgery under GA

Question 36

What is pre-op advice for COPD patient? (3)

Answer 36

* stop smoking at least 8 weeks before the surgery * optimise the condition with physiotherapy and exercise * be admitted a day before the surgery

Question 37

Pre-op considerations of DM person?

Answer 37

- admission 2-3 days before surgery may be needed - should be placed first on the theatre list (to minimise risk of uncontrolled BM) - **sliding scale** should be used

Question 38

What's insulin sliding scale? How to do it?

Answer 38

Sliding scale - progressive insulin dose pre-meal and nighttime * IV infusion of ***Actrapid*** (fast acting insulin) is given against the patient BM * mix with normal saline or 5% dextrose \*if patient's BM is \<15 mmol/l -\> mix with dexterose if \>15 mmol/l -\> mix with normal saline

Question 39

Minor surgery - what to advice for diabetes: - type 1

Answer 39

**Minor surgery and Diabetes Type 1:** * omit morning insulin dose + commence sliding scale * ***the sliding scale*** should be running up to the time when the patient is able to eat and drink + normal med regimen is resumed

Question 40

Minor surgery and diabetes mellitus type 2 (on tablets) if: a) scheduled for morning list b) scheduled for afternoon liest

Answer 40

A) morning list -\> omit morning tablets + monitor BM B) afternoon list -\> patient can have a nomal med regime and early breakfast Pt should be encouraged to eat and drink normally ASAP after the surgery

Question 41

Major surgery and type of diabetes - considerations: a) Type 1 b) Type 2

Answer 41

A) **_type 1_** -\> pt should be admitted a day before the surgery and started on sliding scale B) **_type 2_** -\> omit normal meds the night before; sliding scale on the day of the surgery

Question 43

What **peri- operative risks** are increased in **obesity?**

Answer 43

- peri-operative MI - arrhythmias - HF - DVT - PE

Question 44

Pt on Warfarin (not with the valvular disease) and pre-op considerations

Answer 44

- admit a day before surgery (usually warfarin is stopped 3 days before) - switch to IV heparin infusion \* heparin infusion is stopped 4 hours before the surgery \*patients taking warfarin may be **contraindicated** for **epidural**

Question 45

When to stop Aspirin and Clopidogrel before the surgery?

Answer 45

**stop 5 days before the surgery** -\> as they interfere with platelet function = risk of bleeding during or after the procedure