Pain Management in Burn Patient

1. Pain Management in Burn Patient Dr. Mohammad Amin K Mirza Saudi & Arab Board in General Surgery ( R3 ) Holy Makkah – KSA September 2005

2. Why this Topic ????? • The pain associated with burn injury and treatment is often managed poorly . • The pain associated with a major burn can be the most excruciating experience of a person's life. • The severity of burn pain is difficult to predict from wound depth, but for many patients it is extremely severe. • The pain can last for over a year after the initial injury and can cause marked psychological and functional difficulties. ( can increase the hypermetabolic state leading to impaired wound healing and increase the susceptibility to infection; and may cause delirium, depression, post traumatic stress disorder, or other psychiatric disorders)

3. important to avoid under treating burn pain

4. Pathophysiology • The immediate pain that follows a burn injury is due to the stimulation of skin nociceptors (pain sensing nerves). • Nerve endings that are completely destroyed will not transmit pain, but those that remain intact will trigger pain throughout the time and course of treatment, as will regenerating nerves - those still connected with intact afferent fibres • Nociceptors in skin stimulated by the initial thermal injury account for the immediate pain.

5. Primary hyperalgesia • A burn injury will immediately prompt an intense inflammatory response and the release of chemical mediators(e.g. bradykinin, histamine, substance P) that sensitise the active nociceptors at the site of injury. • The wound becomes sensitive to mechanical stimuli such as touch, rubbing or debridement, as well as chemical stimuli such as antiseptics or other topical applications

6. Secondary hyperalgesia • Continuous or repeated peripheral stimulation of nociceptive afferent fibres induces a significant increase in dorsal horn excitability, partly via N-methyl-D-aspartate (NMDA) receptors , leading to increased sensitivity in the surrounding unburned areas of skin. • 'wind-up' pain : is a component of post-burn hyperalgesia, and is exacerbated by the mechanical stimulation that occurs as a result of frequent dressing changes. ( Pedersen and Kehlet ) • may also be partly responsible for a patient's increased pain sensitivity observed during the course of burn management and reflected in the greater opioid requirement for dressing changes over time • opioid tolerance or increased pain sensitivity

7. Neuropathic pain

8. Causes of pain in burn patient • Wound. • Dressing • Procedures (Debridment & Grafting) • The most painful stage to be the removal of the innermost layer of gauze, which usually adheres to some degree to the wound bed. (Atchison et al ) • Debridement and topical applications then following. • The different types of burn pain include background, breakthrough, and procedure-related (incident) pain.

9. Factors increasing pain in Burn patient • Personality. • Gender. • Size • Duration of Dressing

10. Common causes of inadequate pain management • pain assessment techniques • analgesic knowledge deficits • and incomplete documentation

11. What to do ???

12. First, Control Acute Pain • Simple measures such as cooling the burn, covering the burn (e.g. with cling film), immobilising the patient and providing reassurance may provide sufficient relief in the period before pain can be formally assessed.

13. Give Intravenous Opioids if Pain is Severe • 50/50 mixture of oxygen and nitrous oxide unless hypoxia is present, in which case 100% oxygen should be used • Administration of opioids (e.g. morphine, nalbuphine) (should be administered intravenously during the initial period of burn resuscitation ) • short-acting medications such as fentanyl, alfentanil and remifentanil are more appropriate for pain relief in burn patients,

14. Morfine • Can be titrated in small doses • delayed onset of action (10 minutes) and longlasting effects (several hours) do not allow for the analgesic therapy to be adjusted easily to meet individual needs.

15. fentanyl, alfentanil and remifentanil • fast-acting medication, reaching peak effect in one minute. • rapid pain relief and its relatively short duration of action (mean half-life 90 minutes) fits well with the mean time taken to change a dressing, providing good post-procedural analgesia. • starting dose of 10mcg/kg, which is repeated every minute according to the level of pain • Combining repeated boluses with a continuous infusion of 2mcg/kg/min is effective in improving pain relief

16. tramadol or pethidine (meperidine) • have been used in burn patients; however, long-term use of pethidine is contraindicated because of the accumulation of a toxic metabolite, and experience of long-term use of methadone to treat burn pain is limited. • (normeperidine, is a cerebral irritant that can cause dysphoria, agitation, and seizures)

17. PCA Has Advantages

18. Managing opioid tolerance and dependence • can occur after just two weeks of opioid therapy • Because there is no maximum dose for full opioid agonists, tolerance is managed easily by increasing the dose • long-term opioids can lead to physical dependence • As opioid needs subside, physical dependence is easily managed by titrated opioid withdrawal. • Reverse titration (reducing the opioid dosage by 10-25% daily) is recommended

19. Tolerance and physical dependence should never be equated with addiction or psychological dependence, which are rare

20. survey of burn units did not reveal any cases of addiction in approximately 10,000 burn patients treated • When patients are prescribed opioids at doses too low or spaced too far apart, they might exhibit behaviors that resemble psychological dependence or pseudo-addiction in response to uncontrolled pain. • Opioids should not be avoided due to the fear of addiction

21. Non-Opioid Analgesics • NSAID : increased risk of excessive bleeding and gastric complications • Acetaminophen: should be considered the first-line analgesic in the management of background burn pain, and opioids should be added if it does not sufficiently control the pain ( in Children ). Dose at 10-15 mg/kg q 4 hrs {J Pain Symptom Manage, 13(1):50-55, 1997 Meyer ,Texas}

22. Local Blocks Not Suitable for Many • the burn area and the area for donor skin grafts extend beyond the area that can be covered by a single block • risk of sepsis • Wound Dressings May Reduce Pain

25. Conclusion • 1. pain assessment at regular intervals • 2. written guidelines for pain management protocols, which allow flexible doses to account for individual variation • 3. avoid polypharmacy • 4. periodically assess and discuss the patient's psychological status • 5. pay special attention to pain in burned children. Several studies have shown that burned children are undermedicated compared to adults.

26. The question as to whether pain has a detrimental effect on the healing outcome for burn patients remains largely unanswered and requires further investigation. • The avoidance of patient suffering is, however, a key objective as under-treated pain in burn patients can result in noncompliance with hospital treatment. This can disrupt care and increase the risk of post-traumatic stress disorders. • Under-treatment of pain remains a significant problem despite the wide dissemination of information and educational programs.

27. Thank you