Management of severe burns

Transcription

1 Management of severe burns

2 Who gets admitted to the ICU? Large % surface area burns >25% adults >15% children/elderly Inhalational or airway burns Multi-trauma Co-morbidities

3 Burns centres Regional referral National Burns Centre >30% Prolonged ventilation >15% child/elderly Chemical Electrical

4 BURN=TRAUMA ultimate distracting injury RX as trauma EMST approach EMSB Burn specific care

5 Fundamentals of burn care Accurate burn assessment Early aggressive resuscitation Aggressive wound management and escharotomy Support of the patient until the wound is covered

6 LD50 is increasing Burn Size (%TBSA) Year

7 Basic First Aid STOP THE BURNING PROCESS COOL-running tap water, 20 minutes not of value >3 hours post burn minimise hypothermia COVER

8 What are the key determinants of burn severity? Depth Size Other very important factors Age Co-morbidities First aid Inhalation injury Other injuries

9 Burn depth

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11 How do you assess burn area? Rule of 1 s Rule of 9 s Charts Only count dermal and full thickness burns

12 Wallace Rule of nine s

13 Lund & Browder chart

14 Paediatric burns assessment

15 Resuscitation Goals Minimise burn shock Maintain perfusion without fluid overload Fluids Adults >20% Paeds >10% Delay in fluid resus Inc mortality

16 Burn Shock The burn wound is a 3-dimensional mass of damaged tissue Loss of fluid/electrolytes and proteins into interstitium WCC release of vasoactive substrances Microthrombi

17 Burn Shock

18 How do we see this clinically?? Hypovolaemia Reduced UO,BP High Hct Oedema Low CO Lactate Other end organ injury Major burns non burnt tissue becomes oedematous

19 Fluid resuscitation- the formulae Modified Parkland formula 4 ml/kg/%tbsa burned/first 24 hours 50% over first 8 hours from injury 50% over next 16 hours MANY others e.g Brooke uses 2ml/kg/%SA Galveston & Shriners calc SA Military I:O ratio Required in adult >20% kid>10%

20 Fluid Therapy in burns- Monitoring response Invasive BP, pulse rate and pressure, cap refill Urine output Adults UO 0.5ml/kg/hr Kids <30kg 1ml/kg/hr Lactate Haematocrit Na- useful >24hr

21 Must not set and forget The minute by minute, hour by hour titration of volume to effect Resuscitation endpoints: BP, urine, capillary refill, lactate, Hb, sodium ScvO2, PiCCO, echocardiography Avoid boluses if possible

22 Enteral Which fluid? First 24 hours Buffered isotonic crystalloid Plasmalyte (WARMED!) Colloid- NOT synthetic! 4% albumin Cochrane review 2011 no reduction mortality?after 24hr?12hr Transfuse RBC as needed Significant blood loss when debriding

23 FLUID CREEP Oedema Local Ischaemia Conversion of zone of stasis Generalised Airway Pulmonary Gut Limbs Jackson burn wound model Zone coagulation Zone stasis Zone hyperaemia

24 Complications of fluid resuscitation Limb ischaemia/ compartment syndrome Abdominal compartment syndrome Gut oedema Abdominal wall burns Very poor outcome especially if laparostomy is required May occur within 24 hours

25 Abdominal compartment syndrome

26 Airway Major burns Swelling 1-3hr post injury and continues normal tissue swell Intubate early Avoid suxamethonium >24hr post injury Beware cuff leak Secure- screw or wire

27 Guide only Assessment VERY hard size and weight of patient 100kg 55% burn = 22L in 24hr 85kg 43% =14.6L Doesn t take into account depth of burn Delayed resuscitation Tends to underestimate fluid requirements Pre-existing dehydration, other injuries, electrical etc.

28 Maxillary screw Not in children Wire cutters to remove

29 Inhalational injury Doubles the mortality rate Mortality trends don t follow recent improvements in cutaneous burns Injury Above larynx-heat Below larynx- chemical Systemic toxicity

30 Inhalational injury Supplemental O 2 (humidified) 100% if CO inhalation suspected Decreases half life from 2.5 hours to 40 mins Early intubation prior to swelling Bronchoscopy Lung protective ventilation Advanced ventilation- ECMO, oscillator

31 Exam question Outline the pathophysiology and clinical features of a smoke inhalation injury in a patient with major burns

32 Escharotomy Escharotomy NOT fasciotomy Fasciotomy for compartment syndrome- incise fascia

33 Escharotomy

34 EMSB Primary survey Resuscitation Secondary survey Investigations NG Tetanus Analgesia Documentation & Disp

35 Complications AVOID HYPOTHERMIA Cover Clean dressing SSD-discuss Heated rooms and fluids

36 Most important issue in burn care DEBRIDEMENT AND EARLY COVERAGE

37 OR Scrub down Debridement Grafting Dressing changes

38 The Function of a burn dressing Comfort Metabolic Protective IDEAL DRESSING Facilitate wound healing Acceptable appearance Promote comfort & function Cheap & easy to handle

39 Basic Principals There is NO perfect dressing different dressings achieve different things The ultimate dressing is the patient s own skin via spontaneous healing or via grafting

40 Aggressive wound care Cut off the eschar as early as possible and close the wound Improved mortality and length of stay Issues surround coverage of wounds Ideally with autograft Not usually possible with large burns. Skin substitutes Buy time until grafting or healing occurs

41 Wound care Topical agents Compresses gauze, silver containing (Acticoat) Biosynthetics Dermal replacement/biologics Barrier Waterproof and breathable

42 SSD Silver sulphadiazine Delivers silver to the wound Antiimicrobial and inflammatory Messy Forms pseudoeschar CI- pregnancy, <2/12 old

43 Nomenclature of dermal replacements Allograft = cadaver = homograft Autograft = patients own skin Increases burn area = donor site Xenograft = pig Synthetic skin substitutes Cultured epithelial autograft

44 2 layer membrane Biobrane Inner- allows nylon allows fibrovascular ingrowth Outer silastic- barrier to fluid and bacteria Uses Typically used Donor site Dressing over autograft / allograft Toxic epidermal necrolysis

45 Allograft= Cadaver Temporary skin cover Needs vascular bed Rejected 14-21/7

46 Autograft

47 Integra Bilaminar dermal replacement Silicone, collagen & glycosaminoglycans Creates a neodermis Infiltration by host fibroblasts & neovascularisation Thin split skin graft over Intolerant of wound infection Expensive

48 Skin Culture Autograft Epidermal cells are replicated But.. No dermis Fragile graft Approx 50% take Cost

49 Support until wound coverage Organ support Analgesia Background Cover procedures Temperature Nutrition

50 Prevent infection Nurse in isolation Aggressive infection surveillance Early wound care Prophylactic antibiotics No evidence unless contaminated Rectal tube Antibiotic impregnated lines

51 Infection GNB wound infection can kill in hours Vigilant Early signs Gut distension/ng asps Loss of glucose control UO tails off Inotropes whiff Low temp-consider what s normal

52 Infection Theatre for review- don t delay Antibiotics Previous micro Gram negative cover Consider other source once wounds excluded

53 Hypermetabolic response to burns BSA >25% Begins within 5/7 lasts upto 12months Ebb phase <48hr Low CO, metabolic rate, glucose intolerance Flow phase Within 5/7 Hyperdynamic and hypermetabolic Oxandrolone, Bblockers, rhgh

54 Analgesic agents Opioids Morphine, methadone, fentanyl Anaesthetic agents Ketamine, benzodiazepines Non opioids Paracetamol, Gabapentin, NSAIDs

55 Nutrition NJ tube Supplements- zinc, folate, multivits REE

56 With respect to the clinical assessment of a patient presenting with a severe burn injury sustained in a house fire: a) Outline how burns are classified. b) List three methods for estimating the total body surface area affected by a burn injury. c)other than the burn type and extent,list the other important features of the physical examination that should be noted as part of the initial clinical assessment of the patient described above.

57 55yo 60% burn some debridement and grafting Returns from OR following further debridement BP 85/50 Outline causes and Mx of his hypotension

58 Other considerations DVT prophylaxis Control of bowels Ulcer prophylaxis Eye care Family

59 Burns hot case Exam limited! If early <48hr Resus Other traumatic injuries Toxins CO ARDS ventilation Escharotomies Later Infection Oedema Nutrition

60 Anabolic agents Human Growth Hormone Accelerate donor healing Restore nitrogen balance Oxandrolone Beta- blocking agents Anti catabolic agent

61 Key points Burns=trauma Look for other injuries First aid vital Assess size and depth Fluid formulas a guide only Circumferential burns Prevent hypothermia

62 Summary The severely burned patient is a trauma patient Challenging Time and resource consuming Early aggressive resuscitation, and definitive wound care defines outcome Requires a multi-disciplinary team approach