Surgery - NBM Flashcards
NMB
Patients advised not to eat and drink pre- and sometimes post operatively for a defined length of time.
Why does pt have to be NBM for surgery
- 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.
Things to consider during NBM period
- Medications to stop.
- Medications to continue.
- Length of NBM period.
- Interactions with anaesthetic medications.
Medication to stop in NBM period
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
Medication to continue in NBM
- Alternative routes/formulations are available e.g. iv/pr/topical
- Know the equivalent iv/pr/po dose.
Levothyroxine (NBM)
- Long t1/2
- In prolonged NBM period give IV levo
Steroids (NBM)
Must give IV if patient is on regular prednisolone care/high dose inhalers.
Hypoglycaemic medicines (NBM)
- Withold
- Check renal function before restarting metformin
HRT/OCP (NBM)
- VTE risk
- Risk vs. Benefit
- OCP = increased DVT risk.
Carbamazepine (NBM)
- Not available as IV
- Can be given PR, if not rectal surgery.
Phenytoin (NBM)
- IV
- ECG monitoring
- Give in equivalent doses to oral
Isosorbide mononitrate (NBM)
GTN topical patch
Immunosuppressant (NBM)
- Withold, if appropriate in light of the underlying condition
- Impairs wound healing
Pethidine (NBM)
- Opioid
- Acute pain (po, s/c, i/m)
- Pre-medication or post-op pain
- Interaction with tramadol
Warfarin (NBM)
- Stop 5 days prior to major surgery.
- Restart when haemostasias has been achieved
- Consider the risks of not anticoagulating
Warfarin and bridging
- 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)
DOACs (NBM)
- Short half-lives
- Bridging is not required
- Stop 24-96 hours prior to surgery depending on bleeding risk and eGFR/ CrCl.
Aspirin (NBM)
Stop 10 days prior to surgery (10 days for platelets to regenerate).
Clopidogrel (NBM)
- Stop 10 days prior if low risk patient.
- Must consult cardio/stroke team.
Beta Blockers (NBM)
- 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.
Alternative routes of administration
- Rectal
- Parenteral
- Transdermal
- Buccal
- Gastrostromy tubes
Never crush the following:
- Enteric coated
- Modified release
- Cytotoxic
Anticoagulation and antiplatelets considerations
- Bleeding risk of surgery vs thrombosis risk.
- Indication for anticoagulant use and VTE risk.
- Bridging therapy.
- Optimum time for re-starting post-operatively.
Time to discontinue DOACs before surgery: minor or low risk procedure
- Re-introduce 6-12 hours post-op when haemostasis is secured
