top of the ladder…
The case.
It’s 9 o’clock at night. You are asked to review a 45 year old male on the ward for uncontrolled pain. He has a history of Crohn’s disease and is 24 hours post-laparotomy for small bowel resection & stoma formation. He is nil by mouth…
His current pain regime includes;
- Paracetamol 1g q6h
- Morphine PCA [2mg with 5min lockout] – 280mg used in prior 24 hours.
- Ketamine infusion [8mg/hr]
- Tramadol 100mg IV q6h
- Ketorolac 10mg IM q6h
- Bilateral surgically placed pre-peritoneal catheters with ropivocaine infusions (the left one ‘fell out’ 2 hours ago)….
On examination he is tachycardia and a little clammy. He has diffuse tenderness across the abdomen (L>>R) with percussion tenderness to the LLQ.
[DDET What are your thoughts ??]
Here are mine….
- Essentially he has reached the limit of his ‘conventional’ ward based analgesic therapy.
- Is there an element of opiate induced hyperalgesia?!
- Is there a post-operative surgical issue complicating the clinical picture?!
- Next line therapy gets complicated & requires further monitoring or invasive techniques…
[/DDET]
[DDET What can we offer this guy…?]
This patient represents a challenge. He has had multi-modal analgesia, but what do we do when we’ve reached the top of our analgesic ladder ?
- Lignocaine infusion
- Redo regional block (transversus abdominis plane [TAP] catheter)
- Thoracic epidural (requires trip to OT)
- Others [Dexmedetomidine]
[/DDET]
[DDET A more thorough look…]
Lignocaine Infusion.
Perioperative intravenous lidocaine infusion for postoperative pain control: a meta-analysis of randomized controlled trials.
Can J Anaesth. 2011 Jan;58(1):22-37
Methods.
- 29 studies with 1754 patients.
- IV lignocaine versus placebo (or other comparator).
Results.
- IV lignocaine lead to a statistically significant improvement (6 hours post-op) in pain at rest, with cough & with movement
- Reduced opiate requirement by ~8mg morphine.
- Other benefits included;
- Improved time to flatus/faeces
- Improvement in nausea & vomiting
- Trend towards improved hospital length of stay (though not statistically significant).
- Largest benefits seen in those having abdominal surgery.
- Little data adverse reactions.
Similar data and results are found in…
Meta-analysis of intravenous lidocaine and postoperative recovery after abdominal surgery.
Surgery 2008; 95(11): 1331-1338
- Small numbers – 8 RCTs & only 161 patients.
- Post operative abdominal-surgical patients.
- Loading dose 1.5-2mg/kg followed by an infusion of 1.5-3mg/kg/hour.
Difficult to extrapolate data to ED patients, but then there is this...
Effectiveness of intravenous lidocaine versus intravenous morphine for patients with renal colic in the emergency department.
Soleimanpour et al. BMC Urology 2012, 12:13
- Randomized double-blinded trial
- IV lignocaine (1.5mg/kg) vs Morphine (0.1mg/kg) in 240 ED patients with suspected renal colic.
- Statistically significant reduction in pain scores in lignocaine groups over morphine group.
- VAS10: Lig (1.83 ± 1.59) vs morph (2.89 ± 2.07) p=0.0001
- VAS30: Lig (1.13 ± 1.15) vs morph (2.23 ± 1.57) p=0.0001
- Similar side-effect rates.
Transversus abdominis plane (TAP) catheter.
- A peripheral nerve block designed to anesthetize the nerves supplying the anterior abdominal wall (T6 to L1)
- Local anesthetic is then injected between the internal oblique and transverse abdominis muscles just deep the fascial plane between (the plane through which the sensory nerves pass).
Axial schematic taken from www.anesthesia-analgesia.org
Ultrasound image of LA in TAP space. Taken from pie.med.utoronto.ca
httpv://www.youtube.com/watch?v=ab8Dvjauk_U
- Strong evidence of benefit in patients following abdominal surgery.
Thoracic Epidural.
- Speaks for itself.
- Requires consultation with Anaesthetics and Surgical specialties.
- Facility dependent.
Dexmedetomidine.
- Lots of evidence as a post-operative adjuvant analgesic.
- Paediatric tonsillectomy, labour etc…
- Usually requires monitored setting (likely HDU)
- A concise summary can be found in the following paper…
Current role of dexmedetomidine in clinical anesthesia and intensive care.
Anesth Essays Res 2011;5:128-3
[/DDET]
[DDET What happened to our patient ??]
Recall; he was in agony & maxed out on his IV ward-based analgesics. He had received his subcutaneous heparin 2 hours earlier (for DVT prophylaxis) so the thoracic epidural option was out of the question (at least until 2-3am). A surgical review is arranged to consider the idea of a post-operative complication & in the meantime (at the advice of the on-call Anaesthetist) you give a test dose of IV lignocaine (“to see if the subsequent infusion will be worthwhile”). He receives 80mg of IV lignocaine (~1mg/kg) and his pain practically dissolves at the end of the needle.
He is reviewed over the night, and the infusion is avoided as he remains comfortable.
Unfortunately, his pain escalates over the next day with ongoing abdominal tenderness & guarding. A CT shows intraperitoneal fluid. He is taken back to theatre and found to have faecal soiling from a small bowel leak.
Important points:
- Know the basics. Opiates plus all the necessary adjuncts.
- Know a few trick shots and how to access them in your facility.
- There is usually a reason for escalating pain, so think of the underlying pathology whilst simultaneously treating the symptoms.
[/DDET]
