Surgery - NBM

Question 1

NMB

Answer 1

Patients advised not to eat and drink pre- and sometimes post operatively for a defined length of time.

Question 2

Why does pt have to be NBM for surgery

Answer 2

• Hazardous to induce anaesthesia in patients with a ‘full’ stomach.
• Risk of regurgitation and subsequent pulmonary aspiration (Mendelson’s syndrome)
• This can lead to aspiration pneumonia.

Question 3

Things to consider during NBM period

Answer 3

1. Medications to stop.
2. Medications to continue.
3. Length of NBM period.
4. Interactions with anaesthetic medications.

Question 4

Medication to stop in NBM period

Answer 4

Know the t1/2 of drug.

• Long half-life = missing a few doses is minor
• Short half-life = higher risk of adverse effects e.g. withdrawal

Question 5

Medication to continue in NBM

Answer 5

• Alternative routes/formulations are available e.g. iv/pr/topical
• Know the equivalent iv/pr/po dose.

Question 6

Levothyroxine (NBM)

Answer 6

• Long t1/2
• In prolonged NBM period give IV levo

Question 7

Steroids (NBM)

Answer 7

Must give IV if patient is on regular prednisolone care/high dose inhalers.

Question 8

Hypoglycaemic medicines (NBM)

Answer 8

• Withold
• Check renal function before restarting metformin

Question 9

HRT/OCP (NBM)

Answer 9

• VTE risk
• Risk vs. Benefit
• OCP = increased DVT risk.

Question 10

Carbamazepine (NBM)

Answer 10

• Not available as IV
• Can be given PR, if not rectal surgery.

Question 11

Phenytoin (NBM)

Answer 11

• IV
• ECG monitoring
• Give in equivalent doses to oral

Question 12

Isosorbide mononitrate (NBM)

Answer 12

GTN topical patch

Question 13

Immunosuppressant (NBM)

Answer 13

• Withold, if appropriate in light of the underlying condition
• Impairs wound healing

Question 14

Pethidine (NBM)

Answer 14

• Opioid
• Acute pain (po, s/c, i/m)
• Pre-medication or post-op pain
• Interaction with tramadol

Question 15

Warfarin (NBM)

Answer 15

• Stop 5 days prior to major surgery.
• Restart when haemostasias has been achieved
• Consider the risks of not anticoagulating

Question 16

Warfarin and bridging

Answer 16

• Warfarin takes a while to come out of the system
• Whilst warfarin levels are reducing the risk of clotting increases so need to bridge
• Stop warfarin and allow the INR to stabilize
• Start LMWH (used due to shorter half-life)

Question 17

DOACs (NBM)

Answer 17

• Short half-lives
• Bridging is not required
• Stop 24-96 hours prior to surgery depending on bleeding risk and eGFR/ CrCl.

Question 18

Aspirin (NBM)

Answer 18

Stop 10 days prior to surgery (10 days for platelets to regenerate).

Question 19

Clopidogrel (NBM)

Answer 19

• Stop 10 days prior if low risk patient.
  
  • Must consult cardio/stroke team.

Question 20

Beta Blockers (NBM)

Answer 20

• Anesthesia and surgery may provoke tachycardia and high bp in HTN pts
• Beta-blockers may help to suppress these effects
• Reduce cardiovascular complications
• Usually continued peri-operatively.

Question 21

Alternative routes of administration

Answer 21

• Rectal
• Parenteral
• Transdermal
• Buccal
• Gastrostromy tubes

Question 22

Never crush the following:

Answer 22

• Enteric coated
• Modified release
• Cytotoxic

Question 23

Anticoagulation and antiplatelets considerations

Answer 23

• Bleeding risk of surgery vs thrombosis risk.
• Indication for anticoagulant use and VTE risk.
• Bridging therapy.
• Optimum time for re-starting post-operatively.

Question 24

Time to discontinue DOACs before surgery: minor or low risk procedure

Answer 24

• Re-introduce 6-12 hours post-op when haemostasis is secured

Question 25

Time to discontinue DOACs before surgery: **High risk procedure or when increased bleeding risk is not acceptable**

Answer 25

- Re-introduce 48 hours post-op.

Question 26

Fluid management inappropriate fluid therapy

Answer 26

Inappropriate fluid therapy leads to: - Increased mortality - Prolonged hospital stay

Question 27

Assessment of fluid status: indicators that pt may need fluid resuscitation

Answer 27

- Observations: - BP systolic <100mmHg - Heart rate >90bpm - Capillary refill >2s - Respiratory rate >20 breaths per min - NEWS ≥5

Question 28

Fluid resuscitation

Answer 28

Decide whether to provide - fluid bolus

Question 29

Routine maintenance in fluid status

Answer 29

Normal daily fluid requirements of 25-30ml/kg/day water with electrolytes.