New developments in burns management

1. New developments in burns management Dr s naidoo Moderator :Dr T luvengo

2. INTRODUCTION • Associated with high morbidity and mortality • Acc to National Injury Mortality Surveillance System 2005 :66 deaths due to burns (in tswhane) • Burns leading cause of non traffic unintentional death • Age groups 25-34 22% • 35-44 35% • 45-54 50% • 55-64 33% • 65+ 36% • Eyal et al showed between 1998 and 2005 there were 191 deaths due to burns at kalafong hospital. • Aetiology : • open flame: 30% • Paraffin stove associated: 26% • Boiling water injury:20%

3. Classification • Cause: • Flame: damage from superheated oxidized heat • Scald: damage from contact with hot liquid • Contact: damage from contact with hot or cold solid materials • Chemical :contact with noxious chemicals • Electricity: conduction of electrical current through tissue

4. Electrical • Low voltage – domestic electrocution deep burns at contact and exit sites • High voltage >1000v results in severe injury with tissue loss and renal failure due to rhabdomyolysis • Chemical • Acids cause coagulative necrosis • Alkalis cause liquefactive necrosis with deeper wounds • Irradiation exposure to high energy electromagnetic waves

5. classification • Depth • First degree: injury localised to epidermis. Painful, red, blanches to touch. Heals spontaneously. E.g. sunburn. • Second degree superficial: injury to the epidermis and superficial dermis. Red painful, blistering, blanches to touch. Usually heals from intact skin appendages with some skin discoloration. • Second degree deep: injury through the epidermis deep into dermis. Pale mottled, does not blanch to touch, painful to pin prick. Heals with scarring • Third degree : full thickness injury into subcutaneous fat. Hard leathery eschar, painless black, white or red. No visible skin appendages. Skin grafting necessary. • Fourth degree : injury to underlying muscle and bone

7. Pathophysiology Local response : Jackson's burn zones • Zone of coagulation: irreversible tissue loss due to coagulative necrosis • Zone of stasis: decreased tissue perfusion. Tissue is viable but can deteriorate to necrosis if not adequate resuscitation. • Zone hyperaemia: outermost zone with increased tissue perfusion. Tissue usually recovers in absence of severe infection or severe tissue hypo perfusion

9. Pathophysiology Systemic Response. • Associated massive release of inflammatory mediators leads to SIRS MODS and then death. Early adequate resuscitation and prevention of wound sepsis attenuates the SIRS response. • Drugs to attenuate SIRS response can favorable improve outcomes. E.g. thalidomide , tromboxane inhibitors • Increased vascular permeability and oedema • Altered haemodynamics • Decreased renal perfusion • Decreased cardiac output • Increased gut mucosal permeability • Immunosuppression • hyper metabolism

12. management • ABC’S • Primary survey • Secondary survey • Wound management • Icu • Rehabilitation

13. ABC’S ARWAY: protect airway in suspected inhalation burns. • Signs of inhalation injury: • History flame burns or injury in enclosed space • Burns to face • Nasal singing • Hoarse voice • Intubate if: hypoxic , swollen oropharynx or signs of respiratory distress • CONSIDER BRONCHOSCOPY, MUCOLYTICS, HIGH FREQUENCY OSCILLATING VENTILATION, BRONCHODILATORS BREATHING • Escharectomy if circumferential burns restrict ventilation • 100% o2 to treat carboxyhaemoglobinaemia • Analgesia titrate ivi acc to pt discomfort monitor saturation and blood pressure

14. circulation • Cool burn wound over 20 mins with cool water (ice water damages viable tissue) • Cover burn (cling wrap ,burn shield) • Escharectomy for impaired circulation (circumferential burn has inelastic tissue which can swell with fluid resuscitation and precipitate compartment syndrome) • Escharectomy : only burnt tissue is divided, not underlying fascia differentiating from fasciotomy Fluid management: • Fluid losses must be replaced to prevent shock and MODS which are main causes of death in severe burns • Burns > 15% TBSA in adult and >10% in child will require monitored resuscitation • Good vascular access: non burned tissue ,large bore catheter • Fluid monitoring: urine catheter , CVP line , arterial line , pulse oximetry • Maximum fluid loss occurs in 1st 24 hrs • Several formulas have been developed, • parklands, Brooke Evans etc. no formula has shown improved outcome over another. • Globally the parklands formula is most commonly used.(4ml/kg/%bsa burned. 50% over 1st 8hrs since time of injury and 50% over next 16hrs )

15. circulation • Pediatric fluid administration : • Most commonly used is parklands plus maintenance fluid as well • Lund and bower chart most accurate to calculate fluid requirements in children • Also varying formulas for children , but all similarly effective European survey of fluid management in burn pts showed : • use of crystalloids is dominant strategy • Colloids not used often ( especially in first 24hrs due to capillary leak) • Colloid or crystalloid: literature suggests equal efficacy • Hypertonic saline – not recommended • More than 3 decades after Baxter formulated their concepts for fluid therapy we are still lacking the answers to what fluid, how much and how to guide fluid therapy • Tradition based fluid concepts need to be revisited in the face of modern volume replacement strategies • Monitoring : (urine output ( 0.5 – 1ml/kg/hr ), cvp, cardiac index, mixed venous saturation) is more important than formulas!

17. Primary /secondary survey Assess extent of burn: • Erythema should not be considered • Lund and Browder chart: most accurate method ,it compensates for variation in body shape with age. Useful in children • Wallace rule of nines: good quick assessment, not accurate in kids • Palmar surface: area of palm and fingers =0.8% TBSA • Burn card method • Using gauze on the wound

18. Rule of nines

24. Assessing burn depth • Gold standard is clinical assessment by the doctor who is going to treat pt. 60-70% accuracy • Biopsy and histology : disadvantages are invasive, early biopsies inaccurate due to wound progression, experienced pathologist required • Laser Doppler techniques: • Assesses perfusion-90-97% accurate. disadvantages are ambient light problems, high cost, wound infection and topical substances affect readings. • Video microscopy_ :90-97% accurate. disadvantages are skin contact so risk for infection. Pt compliance necessary so problematic in kids and restless pts

27. Wound management • The major change in burn wound management over the past 40 years has been the more rapid removal of devitalized tissue and earlier wound closure. • After the initial resuscitation , the major cause for mortality and morbidity is wound infection • Without topical antimicrobial agents the wound becomes colonized with gram pos organisms within 48hrs.most common gram pos : beta hemolytic streptococcus and staphylococcus. • Gram negative organisms appear after 3-21days. Pseudomonas , proteus and acinetobacter baumani are the most common organisms • Eschar will become infected unless it’s removed by re - epithealization process or surgical excision • Systemic antibiotics only if systemic infection. • Showering better than bathing- less wound cross contamination • Dressing wound must be done under sterile conditions • Blister removal controversial-recommendation is to aspirate blister and leave skin intact • Wound swab useful to dx bacteria but can’t differentiate between colonisation and wound infection, tissue culture is superior (quantifies bacteria) • PCT, CRP, WCC, NEUTROPHILS ,TEMP useful markers to monitor sepsis • Delayed burn surgery associated with increased infection

28. Wound management • Superficial and small burns heal within 2 weeks • Large deep dermal burns heal within 2-3 weeks • Any burn not healed after 3weeks needs grafting • Open dressings: inexpensive but increased heat and fluid loss , though decrease incidence of pseudomonas • Closed dressings :reduce heat and moisture loss, less painful, but higher incidence of pseudomonas • Wound surface drying impedes ability of epithelial cells to migrate across the wound • Moist wound healing: • Increased activity of growth factors • Increased activity of surface proteolytic enzymes • Improved oxygen and nutrient delivery

29. Wound management • Early excision and grafting associated with better outcomes • Grafting should be done within 1st week • Humby knife or dermatome with mesher • Versa jet new technology : good outcomes. useful in paediatrics and difficult access areas. Hydro surgery using pressurised saline • Donor sites used 3x with 10day intervals • Graft maximum 20% at a time • Pt must be able to tolerate stress of theatre • Large variety of topical wound treatments • Future- icu surgery

35. Topical agents • Silver sulfadiazine- effective 24hrs ,water soluble, low toxicity, most commonly used. • Pov-iodine :short half life ,inactivated by wound exudates ,did not improve healing times • Mupirocin: broad spectrum antimicrobial but not effective against pseudomonas • Chlorhexidine:effective against pseudomonas but difficult to apply • Mafenide: broad spectrum and good penetration. Causes electrolyte imbalance and painful application • Acriflavin: good antiseptic. Can be cytotoxic, irritate skin , stain skin • Acticoat; anti bacterial + anti fungal , 5 day application. Treatment choice with good outcomes • Melladerm: local honey based products , antibacterial , promotes moist wound healing ,very promising results

36. Skin substitutes • allograft : cadaver skin for temporary cover. Tissue lasts 3 weeks before rejection. Expensive needs special preservation , disease transfer • Xenografts (pig skin) : temporary coverage, less expensive than allograft, more readily available, sloughs easily • Human amnion : for temporary wound closure, superficial wounds and excised wounds, poor screening for viruses so not recommended. • Synthetic coverings • Opsite : provides moisture barrier, accumulation of exudates. • Biobrane :2layer membrane with outer silicone membrane to prevent bacterial invasion.accumalation of exudates but otherwise good product. inexpensive long shelve life • Transcyte: similar to biobrane, can stimulate wound healing • Integra: provides complete wound closure, leaves a dermal equivalent, sporadic take rates

37. Icu considerations • No place for prophylactic antibiotics • Stress ulcer prevention • Tight glucose control • Recombinant factor 7 decreases bleeding • Early enteral nutrition superior to parenteral feeding . Curreri formula ( 25kcal x weight) +(40 kcal x %TBSA burned) • Immunonutrition: glutamine , arginine , omega fatty acids • B blockers to attenuate hyper metabolism • Icu monitoring • Dvt prophylaxis-clexane • Anabolic steroids-controversial. Oxandrolone attenuates post burn catabolism • Address myoglobinaemia

40. references • Sabistons textbook of surgery 18th ed • Burns journal 2006-2008 • Burnsurgery.com