Chronic Pain

Question 1

A 53-year-old female is undergoing an abdominal-peritoneal resection for small bowel cancer. She has a history of hypertension, type 2 diabetes mellitus and chronic back pain, and is a smoker.

What are the key aspects of her history that you would like to explore when she attends the preoperative assessment clinic?

Answer 1

• Cardiac history: duration of hypertension, agents required, and overall control. Explore whether the patient experiences chest pain, shortness of breath, ankle swelling and any other symptoms associated with ischaemic heart disease or heart failure.
• Respiratory history: smoking pack-year history (undiagnosed COPD is a possibility).
• Diabetic history: duration, control and agents including insulin. The presence of macro and microvascular complications may indicate a longstanding history and poor diabetic control.
• Chronic back pain: cause, duration, effect on activities of daily living, and treatment including non-pharmacological and medication used to control pain.
• Other comorbidities and drug/social history, allergies and previous anaesthetic history.
• Concerns and expectations of the patient during the perioperative period.

Question 2

The patient has a 10-year history of back pain that is managed by the chronic pain clinic. She currently takes regular co-codamol, ibuprofen, rescue tramadol and wears a buprenorphine patch.

What can be done preoperatively to optimise management of this patient’s pain during the perioperative period?

Answer 2

• Assessment of the patient’s pain and current management, ideally in the pain clinic, but the urgency of her surgery may preclude this.
• Determine the total dose of the above agents that the patient takes on a regular basis as this will need to be continued as a baseline perioperatively. Discuss the patient’s previous drug history as she may have tolerated some opioids better than others.
• Explore the effect of the patient’s pain on her activities of daily living as she may need extra help/a package of care in the postoperative period when recovering from major surgery.
• Document the above information and discuss with the patient’s anaesthetic and surgical team where necessary. Establish a perioperative analgesic plan that should be explained to the patient, so all questions can be answered and concerns discussed prior to surgery.

Question 3

What is your plan for pain management for this patient during the perioperative period?

Answer 3

*No right answer, ensure a multimodal approach to analgesia which includes a range of opioid-sparing techniques. Remove buprenorphine patch?

Preoperative:
* Oral paracetamol (1 g).
* Oral gabapentin (300–600 mg).
* Usual doses of codeine/tramadol, or consider conversion to modified release oral oxycodone if tolerated by the patient.
* Remove the buprenorphine patch following a discussion with the patient. Challenges faced with the presence of the patch in the perioperative period include:

• Partial antagonism, which may lead to decreased efficacy of full opioid agonists given during the perioperative period.
• Drug delivery may be unreliable due to the decreased blood supply to the area (causing a decrease), or increased heat in the area, increasing drug delivery.

Question 4

What is your plan for pain management for this patient during the perioperative period?

Continued…

Answer 4

Intraoperative:
* Intravenous paracetamol (1 g).
* Intravenous fentanyl boluses titrated to effect.
* Intravenous lidocaine 1 mg/kg bolus followed by infusion of 1 mg/kg/ hour (or according to the local protocol).
* Intravenous magnesium.
* Intravenous ketamine (0.5 mg/kg).
* Regional anaesthesia: spinal anaesthetic with appropriate dose of
diamorphine.
* Intravenous clonidine (1–2 mcg/kg).

Postoperative:
* Regular paracetamol (1 g).
* Consider NSAIDs.
* Patient-controlled analgesia with an opioid, usually morphine, but
both fentanyl and oxycodone could also be considered.
* Modified release oxycodone with immediate release oxycodone as
rescue analgesia.
* Tramadol as required.
* Local anaesthetic wound catheters/rectus sheath blocks, or an epidural.
* Anti-emetics and laxatives as required.
* Early review by the acute pain team and management of the patient on the intensive care or high dependency unit. This patient will need regular monitoring of her pain using an objective pain scoring system and consideration of increased doses or addition of other agents if her pain is not under control. The pain is likely to be exacerbated by surgical trauma, positioning, anxiety and mobility. Early physiotherapy should be encouraged.

Question 5

What are common signs of opioid withdrawal?

Answer 5

• Yawning (early sign).
• Myalgia.
• Agitation/anxiety.
• Increased sweating.
• Abdominal pain/cramps.
• Nausea/vomiting/diarrhoea.
• Insomnia.