The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [337]
Methods of pain management
Using the WHO analgesic ladder
The analgesic ladder was designed as a framework for the management of chronic pain (see Figure 9.12). There are several drugs available to manage chronic pain and the analgesic ladder allows the flexibility to choose from the range according to the patient’s requirements and tolerance (Hanks et al. 2001). For acute pain management, the WHO ladder can be used as a guide in reverse, starting at step 3 for immediate postoperative pain and moving down through step 2 and then step 1 as postoperative pain improves.
Step 1: non-opioid drugs
Examples of non-opioid drugs include paracetamol, aspirin and NSAIDs that are effective for mild to moderate pain. These drugs are especially effective for musculoskeletal and visceral pain (Twycross and Wilcock 2001).
Step 2: opioids for mild to moderate pain
Examples of opioids for mild to moderate pain include codeine, dihydrocodeine, tramadol and low-dose oxycodone (steps 2 and 3). These drugs are used when adequate pain management is not achieved with the use of non-opioids and are usually used in combination formulations. It is not recommended to administer another analgesic from the same group if the drug being used is not controlling the pain. Uncontrolled pain needs to be assessed and managed with the titration of an opioid by moving up the ladder. The exception to this would be if the patient was experiencing intolerable side-effects on the weak opioid and an alternative drug might be beneficial.
In recent studies tramadol has been recognized as being efficacious in the management of chronic cancer pain of moderate severity (Davis et al. 2005). It is uncertain whether tramadol is more effective in neuropathic pain than other opioids for mild to moderate pain; one report suggests a reduction in allodynia (pain from stimuli which are not normally painful) (Sindrup and Jensen 1999, Twycross and Wilcock 2001). Nurses should be aware that circumstantial reports suggest that tramadol lowers seizure threshold, and therefore care needs to be taken in those patients who have a history of epilepsy, as well as any other medications that may contribute to the lowering of the seizure threshold, for example tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) (Twycross and Wilcock 2001). Few patients with severe pain will achieve a satisfactory level of pain control with tramadol. It is available in immediate and modified-release preparations.
Step 3: opioids for moderate to severe pain
Examples of opioids for moderate to severe pain include morphine, oxycodone, fentanyl, diamorphine, methadone, buprenorphine, hydromorphone and alfentanil.
Breakthrough analgesia
Breakthrough pain refers to a transitory exacerbation of pain experienced by the patient who has relatively stable and adequately controlled background pain (Portenoy et al. 2004). There should not be a time limit on this type of prescription because it would need to be given when and if the patient demonstrated any signs of discomfort or pain (with the exception of renal failure where dosages would need to be limited).
Rescue doses are calculated on a 4-hour equivalence; for example, if a patient was prescribed 60 mg MXL (a modified form of morphine given once a day), the equivalent rescue dose would be 10 mg of the immediate-release formulation. If several rescue doses are required within a 24-hour period, then the background analgesia (modified-release preparation) would have to be increased (McMillan 2001). However, it is important to recognize the classifications of breakthrough pain, as increasing the background dose will not always be indicated. Increasing the background preparation for pain that only occurs at certain times or is related to a specific event, such as a patient attending for radiotherapy, can result in a patient experiencing side-effects as the medication is needed for a specific time only.
Breakthrough pain