Post-operative Pain and Vomiting

Question 1

Non-drug treatments of post-op pain

Answer 1

There are a range of non-drug treatments that appear to have modest beneficial effects in the management of pain. These include distraction (for children), advice on preparation for the procedure and potential resulting pain, and other psychoeducational interventions. TENS, relaxation advice, relaxation and music therapy are probably ineffective in the acute post operative pain time period The evidence for the use of acupuncture in this acute scenario is not substantiated.
Anxiety and fear may worsen the pain experience. Pre-operative education and counselling may reduce post-operative analgesic requirements.

Question 2

Dexmethasone dose to reduce post op NV

Answer 2

Dexamethasone (4 to 8 mg) prior to induction of anaesthesia is effective in the prevention of PONV. This dose is also effective against late vomiting up to 24 hours postoperatively. Adverse effects associated with corticosteroid administration have not been reported with a single dose of dexamethasone.

Question 3

Experts choice of pain meds for post-op pain

Answer 3

Paracetamol Regular, 1gm, rectal (change to oral when tolerated), QID 0800,1200,1800,2200, pain
Morphine PRN, subcut, 2.5-5mg, 3hrly, max dose 30mg/24 hrs, pain
Ondansetron Once only, IV, 4mg

Question 4

Route of administration in acute post of NV

Answer 4

Parenteral generally required in vomiting patients

Question 5

NSAIDs in post-op pain

Answer 5

Probably not the best choice if creatinine is elevated pre-operatively

Question 6

Regular paracetamon

Answer 6

Reduce her opioid requirement

Question 7

Metoclopramide 10mg intra-operatively

Answer 7

Shown to have no effect in the prevention of post-operative nausea and vomiting

Question 8

Which of drug is most likely to cause problems in someone with renal disease?

Answer 8

Pethidine - The metabolite norpethidine accumulates and may cause seizures and other CNS toxicity after less than 24 hours.

Question 9

What is the most important clinical difference between commonly used oral analgesics that might be used for post-operative pain relief (e.g. paracetamol, codeine, ibuprofen, celecoxib, tramadol)?

Answer 9

The adverse effects of these drugs are very different - leading to specific contraindications in certain patients.

Question 10

A 73 year old woman with Parkinson’s disease has a bladder repair.  Afterwards, she has a number of episodes of vomiting. Which of the following anti-emetic drugs is least likely to worsen the symptoms of her Parkinson’s disease?
Droperidol
Metoclopramide
Trifluperazine
Ondansetron

Answer 10

Ondansetron is the only agent listed that doesn’t block dopamine receptors.

Question 11

What is the most likely problem with using codeine in a CYP2D6 ‘poor metaboliser’?

Answer 11

Lack of efficacy -

Codeine is converted to morphine by CYP2D6 and has little or no analgesic activity on it’s own