CURRENT THERAPEUTIC APPROACHES AND GAPS
A treatment regime should ideally fulfil a certain number of criteria, in order to be an optimal post-operative pain treatment. These include:
- Fast onset of action
- Sustained pain relief
- Appropriate dosage
- Follows individual course of pain
- Risk of errors should be low
- Less personnel-intensive
- No restriction of mobility
When selecting the most appropriate post-operative pain management for a patient, the performance of the various currently available treatment options with regard to these criteria should be taken into account.
|Versatility*1||Invasive (risk of infection etc.)2|
|Improved pain control and patient satisfaction1||Impairment to mobility2|
|Safety1||Equipment problems (kinked tubing etc.)2|
*i.e. can be programmed to account for individual needs and responses and can be rapidly adjusted and titrated
PCA allows patients to relieve pain through self-administered predetermined doses of analgesic medication. PCA can be used with different analgesics and administration routes, but IV PCA with an opioid is the most widely used. PCA can be initiated with a loading dose and a lockout interval, during which no additional medication can be self-administered, used or given with an additional continuous background infusion. PCA leads to better patient satisfaction and pain relief, less sedation and fewer post-operative complications.
PCA can be used for systemic and regional pain management in post-operative pain management.
|Convenient3||Slow onset of action*3|
|Non-invasive3||Highly dependent on patient compliance3|
|Lack of need for specialist training3||Increased possibility of drug-drug and drug-nutrient interactions3|
|Attenuation of the stress reponse4||Potential for serious complications5|
|Reduced incidence of various post-operative disorders4||Risk of errors (misplacement of catheter etc.)6|
|Leads to improved gastrointestinal function4||Risk of inadequate anaesthesia or analgesia3|
Peripheral Nerve Block
|Better post-operative pain control*7||Risk of catheter dislodgement or obstruction9|
|Reduces the need for opioids8||Risk of long-term and/or permanent nerve injury9|
Nerve blocks are commonly used in regional analgesia. In nerve blocks, local anaesthetics (e.g. bupivacaine, ropivacaine, levobupivacaine) block voltage-dependent sodium channels and thereby inhibit the initiation and transmission of pain.
Nerve blocks inhibit pain in the specific area that is operated on, making them suitable for post-operative pain management.
Nerve blocks are applied as a single injection or as a continuous infusion via catheters near the nerve. Peripheral nerve blocks are applied using ultrasound guidance or peripheral nerve stimulation. Wound infiltration is usually performed at the end of surgery. A catheter placed in the wound can allow continuous wound infiltration.
|Few fluctuations in drug concentration10||Greater amount of additional analgesia required*12, 13|
|Less expensive equipment**11||Higher number of non-responders**14|
*when compared to patients given the same hourly dose via automated bolus or PCA
**when compared to PCA
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2 Palmer PP and Miller RD. Current and developing methods of patient-controlled analgesia. Anesthesiology Clin. 2010; 28: 587-99.
3 Hughes J, Pain Management: From Basics to Clinical Practice. 1st ed. London, UK: Elsevier. 2008: p38-9.
4 Nimmo SM. Benefi t and outcome after epidural analgesia. Contin Educ Anaesth Crit Care Pain. 2004; 4: 44-47.
5 Moen V et al. Severe neurological complications after central neuraxial blockades in Sweden 1990-1999. Anesthesiology. 2004;101:950-9.
6 Hermanides J et al. Failed epidural: causes and management. Brit J Anaesth. 2012;109:144-54.
7 Ilfeld BM. Continuous peripheral nerve blocks: a review of published evidence. Anesth Analg. 2011;113: 904-25.
8 Harmer M and Davies KA. The effect of education, assessment and a standardised prescription on postoperative pain management. Anesthesia. 1998; 53: 424-30.
9 Chelly JE et al. Continuous peripheral nerve blocks in acute pain management. British Journal of Anaesthesia. 2010;105: i86-i96.
10 Alon E et al. Post-operative epidural versus patient-controlled analgesia. Minerva Anestesiol. 2003;69:443-6.
11 van de Vyver M et al. Patient-controlled epidural analgesia versus continuous infusion for labour analgesia: a meta-analysis. British Journal of Anaesthesia. 2002;89:459-65.
12 Taboada M et al. Comparison of continuous infusion versus automated bolus for postoperative patient-controlled analgesia with popliteal sciatic nerve catheters. Anesthesiology. 2009;110:150-4.
13 Hernández-Garcia D et al. Cost-effectiveness analysis of patient-controlled analgesia compared to continuous elastomeric pump infusion of tramadol and metamizole (Article in Spanish). Rev Esp Anestesiol Reanim. 2007;54:213-20.
14 Stamer UM et al. Postoperative analgesia with tramadol and metamizol continual infusion versus patient controlled analgesia (article in German). Anaesthesist. 2003;52:33-41.