Nociceptive Pain Types of Pain

Practitioners should utilize pain assessment tools, expectation for length of pain control required, and the patient’s individual pain history to help guide decisions in pain management while con- tinuing to reassess the patient for pain control and monitoring of side effects after initiation of pain medications.

9.4.1 World Health Organization

Pain Ladder The World Health Organization WHO created a three-step pain ladder as a basic approach to pain management in children with cancer Fig. 9.2 . A fourth step has also been developed for cancer pain not responding to pharmacotherapy alone and therefore requiring adjunct therapies such as interventional anesthesia. Morphine is the opioid used in the algorithm due to its ease of administration, tolerability, wide availability and well-understood side effects Sirkia et al. 1997 . Substitution with a different opioid is acceptable. The ladder is based on four major principles: 1. By the ladder: a stepwise approach should be taken on the escalation of analgesics depend- ing on the severity of symptoms. 2. By the clock: scheduled analgesics should be given for steady state blood concentrations with appropriate as-needed PRN dosing. 3. By the mouth: the least invasive route of admin- istration should be used that is convenient and cost-effective with effective pain control. Table 9.1 General analgesic principles a 1. Assess pain. Pain is a subjective feeling ask the patient or use a developmentally appropriate pain assessment scale – see Sect. 9.2 a Determine previous pain history and management, current medications, allergies b Explore contributing factors e.g. disease course, anxiety, age, development, temperament 2. In opioid-naïve patients, start with short-acting opioids to control acute, moderate to severe pain. Do not use long-acting opioids to control acute pain 3. When titrating or changing opiate dose, start by calculating the previous day’s total opioid requirement in oral morphine equivalents OME a Since all opioids produce analgesia by the same mechanism, they will produce similar degrees of analgesia if provided in equianalgesic doses see Sect. 9.4.5 4. Determine if dose is adequate for pain control, and increase as needed see Sect. 9.4.2 5. Choose opioid that will be used and dose adjust for incomplete cross-tolerance if necessary see Sect. 9.4.5 a Typically, the only reasons to change from one opioid to another are side effects or renal failure b When rotating, decrease dose by 25–50 to correct for incomplete cross-tolerance 6. Determine route that opioid will be given. IM administration is rarely, if ever, indicated a Rectal = oral = sublingual dosing and SC = IM = IV dosing 7. Determine a dosing schedule a Use only short-acting prn doses until a sense is gained as to how much opioid is needed b Once stable daily needs are determined and need for pain medication is expected to persist, consider giving 66–75 of daily OME as a long-acting opioid see Sect. 9.4.3 c For patient-controlled analgesia PCA dosing see Sect. 9.4.6 8. Determine breakthrough dose for acute pain not controlled by the long-acting medication see Sect. 9.4.4 a Use same opioid for short- and long-acting when possible b Give 10–15 of total daily long-acting dose as breakthrough dose q3h prn 9. Manage side effects as they arise see Sect. 9.4.7 a Constipation is typically treated prophylactically 10. Determine whether co-analgesicsadjuvants andor non-pharmacologic treatments would be benefi cial see Sects. 9.5 and 9.6 IM intramuscular, SC subcutaneous, IV intravenous, prn as needed a Level of evidence 1C for all recommendations per Guyatt et al. 2006 ; see Preface 9 Pain