PBL 2: Skin deep

1. PBL 2: Skin deep Acute management of burns

2. Burns and the skin • Management of the burns patient must take into account the potential complications due to loss of the following functions of skin: • Protection from the environment (infection) • Temperature control (hypothermia) • Fluid control (dehydration and fluid replacement) • Energy control (need for increased caloric intake in larger burns)

3. First Aid Treatment for Burns From Therapeutic Guidelines Australia: • stop the burning process by cooling the burn to reduce tissue damage • reduce the production of inflammatory mediators • help reduce progression of tissue damage in the first 24 hours. • Irrigation with cool tap water for a period of at least 20 minutes is recommended (this is of little or no use if water is applied more than 3 hours after injury). • Using ice or iced water is not recommended, because of the risk of tissue damage from excessive cold, and the possible development of hypothermia, particularly in children. For extensive burns, to avoid hypothermia unburned areas should be kept warm with thermal blankets where possible. • Covering the burn with non-adherent dressings or clean sheets reduces pain, by reducing exposure to air currents and external stimuli.

4. Resuscitation • Airway • Beware of upper airway obstruction developing if hot gases inhaled • Suspect if Hx of fire in enclosed space, soot in oral/nasal cavity, singed nasal hairs or hoarse voice • Involve anaesthetists early and consider early intubation • Obstruction can develop in the first 24hrs • Breathing • Exclude life-threatening chest injuries (eg. tension pneumothorax) and constricting burns – decompress if chest burns are impairing thorax excursion • Give 100% O2 • Suspect CO poisoning from Hx, cherry red skin and carboxyhaemoglobin(COHb) level. • Circulation • Partial thickness burns >10% in a child and >15% in adults require IV fluid resuscitation. • Where possible, IV lines should be inserted through unburned skin, but if necessary put through burned skin • Calculate fluid replacement using burns calculator flow chart or a formula (eg. Parkland or Muir and Barclay)

5. Chemical burns • Severity of chemical injury is related to: • pH of the agent • Concentration of the agent – some concentrated chemicals may produce heat when diluted, leading to thermal as well as chemical injury • Length of contact time • Volume of the agent • Physical form of the agent • Acids generally produce coagulation necrosis by denaturing protein. This leads to the formation of eschar which tends to prevent further penetration of the acid. • Alkalis act both by denaturing protein and by fat saponification (liquefactive necrosis), therefore there is no barrier to further penetration and the damage may be more severe

6. Hydrofluoric acid (HF) • One of the strongest inorganic acids, used mainly in industry. Commonest exposure is to hands and fingers. • HF penetrates deeply before dissociating to free H+ and F- ions. The H+ ions are corrosive, and F- ions combine with calcium and magnesium to form both insoluble and soluble salts. • Systemic fluoride ion poisoning from severe HF burns can lead to hypocalcaemia, hypomagnesaemia, hyperkalaemia and death. • Symptoms of tissue destruction and necrosis may be delayed • Treatment • Initial treatment utilises topical calcium gluconate gel • In severe cases, calcium gluconate may need to be injected subcutaneously or intravenously.

7. Fluid replacement and maintenance • Parkland formula: 2-4 x weight (kg) x %burn (BSA) = mL Hartmann’s solution in 24 hr • Give half of this amount in first 8 hrs, and remainder over next 16hrs • NB. Must use crystalloid fluid for Parkland equation • Muir and Barclay formula: [weight(kg) x %burn] / 2 = mL colloid per unit time, where time periods are: • 4h, 4h, 4h, 6h, 6h, 12h

8. Silver sulfadiazine (Flamazine) • For use on small, superficial partial thickness burns • Well tolerated by most patients • Virtually no systemic effects and moderate eschar penetration • Painless on application • Effective against gram-positive and gram-negative organisms, including: • ß-hemolytic streptococci • Staphylococcus aureus and Staphylococcus epidermidis • Pseudomonas spp. • Proteus spp. • Klebsiella spp. • Enterobacteriaceae spp. • Escherichia coli • Candida albicans • Silver sulfadiazine often interacts with wound exudate to form a pseudomembrane over partial-thickness injuries. This pseudomembrane is often difficult and painful to remove. • Contraindications to use: • term pregnancy and in newborns (i.e., due to possible induction of kernicterus). • Allergy and irritation are unusual, although there is a potential cross-sensitivity between silver sulfadiazine and other sulfonamides. • Silver sulfadiazine is generally not recommended for outpatient care as it may become a potential source of infection after 24-48 hrs. • Acticoatis another silver-based product that has replaced silver sulfadiazine in many Australian burns units, but requires specialist application

9. Referral criteria to specialised burns unit • Burns greater than 10% of body surface area (BSA) in adults or 5% BSA or more in children • Deep partial or full thickness burns greater than 5% BSA • Burns involving face, hands, feet, perineum, flexor joint surfaces • Circumferential burns • Any inhalation injury • Burns with associated injury, major preexisting disease or suspected child abuse • Significant chemical or electrical burns

10. Pain relief • All burns, including those that appear to be full thickness, are painful. Burns cause one of the most intense and prolonged types of pain. Burn pain has both nociceptiveand neuropathic components, and changes significantly over time. • There are five major sources of pain in patients with burns: • background—at rest, in burned areas and at donor sites • breakthrough—temporary increases in pain that are part of natural fluctuations in pain levels • incident—during activities (eg movement, walking) • procedural—with procedures (eg debridement, dressings and surgical grafting) • chronic—ongoing pain after surgical treatment is finished. • Pain relief for burns patients is important and should be given early Source: Therapeutic Guidelines

11. Pain relief • While maintaining airway integrity, and managing ventilation and fluid replacement are essential, control of pain should not be delayed and should be an integral part of initial management. • There are several factors that must be considered when managing pain relief in patents with burns: • Opioid requirements may be unpredictable because of pharmacokinetic and pharmacodynamic alterations due to metabolic rate changes and fluid redistribution • Opioid resistance or tolerance occurs commonly. • Undermedication is a significant risk, and patient requests for adequate analgesia can be misinterpreted as drug-seeking behaviour. • Thermal injuries produce persistent hyperalgesia in the damaged site (primary hyperalgesia) and in surrounding unburned areas (secondary hyperalgesia). • Factors other than thermal injures, such as anxiety, ‘flashbacks’, and sleep and mood disturbances, can alter the effectiveness of analgesics.

12. Pain relief (minor burns) • Acute phase (first 24 to 48 hrs) • Oral analgesics usually sufficient for minor burns in acute phase • If paracetamol in standard doses is not sufficient for adults with pain from minor burns, give: • Morphine (2.5 to 5mg IV as initial dose, then titrated to effect) OR • Fentanyl (50 to 100 μg IV as initial dose, then titrated to effect) • Different dosages exist for children of different ages (see Therapeutic Guidelines) • Continuing pain (after 48 hrs) • Oral analgesia is usually sufficient for continuing pain relief, but additional analgesia may be required • In adults: • Oxycodone (immediate-release 5-10mg orally every 4-6 hrs) • In children: • Morphine (0.2-0.3 mg/kg orally, every 4-6hrs) • If analgesic requirements are increasing, or pain relief is not satisfactory, reassessment of the burn is recommended. In particular, infection, or a compartment syndrome in the limbs, abdomen and thorax should be excluded.

13. Pain relief (major burns) • Opioids combined with paracetamol and NSAIDs form the basis for management. These will often need to be supplemented by other agents, such as tricyclic antidepressants, anticonvulsants, or ketamine, that are used to treat neuropathic pain. Immobilisation, choice of dressings for burnt areas, and adequate control of procedure-related pain are important considerations. Pain is likely to continue as a problem for weeks or months, with analgesics required for a significant period after discharge from hospital. • In the acute phase, for adults with major burns, for initial management, use: • Morphine (2.5 to 5 mg IV, as an initial dose and then titrated to effect). • Doses may vary with age • For ongoing pain relief for adults during the acute phase, use: • Morphine (starting at 2 mg/hour IV by continuous infusion, and titrate to effect. Intermittent bolus doses of 0.05 to 0.1 mg/kg [Note 2] may be necessary for breakthrough pain (doses may vary with age, see Sensitivity to opioids) OR • Fentanyl (starting at 20 micrograms/hour IV by continuous infusion, and titrate to effect. • Intermittent bolus doses of 20 to 100 micrograms may be necessary for breakthrough pain. • Similar treatment regimes exist for management of major burn pain in children, although amounts are decreased (see Therapeutic Guidelines)

14. Paracetamol + Opioids • WHO analgesic ladder • The prototype analgesics for each step of the analgesic ladder are: • Step 1: paracetamol or non-steroidal anti-inflammatory drug (NSAID). • Step 2: codeine or dextropropoxyphene + paracetamol or NSAID. • Step 3: morphine or diamorphine + paracetamol or NSAID. • NOTE: this ladder is designed for analgesia for cancer pain, and thus is not necessarily suitable for burns patients – it just shows that paracetamol should still be prescribed at each step of the ladder

16. Burn depth and characteristics