Thermal Burns PFN: SOMEML07. Terminal Learning Objective. References. Hours: 3.0 Instructor: Action: Communicate knowledge of thermal burns

Transcription

1 Thermal Burns PFN: SOMEML07 Hours: 3.0 Instructor: Slide 1 Terminal Learning Objective Action: Communicate knowledge of thermal burns Condition: Given a lecture in a classroom environment Standard: Received a minimum score of 75% on the written exam IAW course standards Slide 2 References Tintinalli s Emergency Medicine, 7 th Edition, 2010 PHTLS, 7 th Edition, 2010 Mosby Paramedic Textbook, 3 rd Edition, Chapter 23, pages Joint Theater Trauma System Clinical Practice Guidelines Slide 3 1

2 References Tactical Combat Casualty Care Guidelines Tactical Medical Emergency Protocols Tactical Trauma Protocols Slide 4 Reason Slide 5 Agenda Identify the pathophysiology of local and systemic responses to burn injury Classify burn injury according to depth, extent, and severity Identify key components in the assessment of a thermal burn casualty Identify the pathophysiology, clinical presentation, and management of toxic inhalation injury Slide 6 2

3 Agenda Identify the pathophysiology and clinical presentation of a direct inhalation injury Define the management plan of a thermal burn casualty Calculate fluid requirements and rates for a thermal burn casualty using the Parkland formula and the Rule of Ten Define the key components of burn wound care Slide 7 Agenda Identify the indications and procedural steps for an escharotomy Review Drip Calculation Homework Slide 8 Pathophysiology of Local and Systemic Responses to Burn Injury Slide 9 3

4 Pathophysiology of Thermal Injury Heat changes the molecular structure of tissue through 'denaturing' Extent of burn damage depends on: Temperature of agent Concentration of heat Duration of exposure Slide 10 Pathophysiology of Thermal Injury Ability to resist burn injury depends on: Water content of skin tissue Thickness of skin Insulating substances Peripheral circulation of skin Co morbidities? Underlying medical conditions? Slide 11 Response to Burn Injury Cellular damage is distributed over a spectrum of injury Immediate destruction Irreversible injury Reversible injury Mediated by rapid and appropriate intervention Slide 12 4

5 Jackson s Thermal Wound Theory Three 'zones' Zone of Coagulation Closest to heat source ('concentration') Nonviable tissue Zone of Stasis Area of ischemia Zone of Hyperemia Peripheral area with increased blood flow Slide 13 Local Response to Burn Injury Damaged cells initiate inflammatory response Increased blood flow to cells Release of chemical mediators; triggers: Increase in capillary permeability Fluid shift from intravascular space into damaged tissue Injury to sodium pump Sodium enters damaged cells Increases flow of vascular fluid into wound Slide 14 Systemic Response to Burn Injury Small burn Local events occur at the site Large burn Greater release of mediators and damage to sodium pumps Widespread capillary leak Significant fluid shift from intravascular to extravascular space Multi system involvement Slide 15 5

6 Emergent Phase Pain response Burn Shock Catecholamine release Tachycardia, tachypnea, mild hypertension, and anxiety Fluid Shift Phase Systemic capillary leak Shift of fluid from intravascular to extravascular space Hypovolemia and massive edema Reaches peak in 8 to 12 hours Lasts up to 24 hours Slide 16 Burn Shock Resolution Phase hours post burn Capillary integrity reestablished Progression to normal function Hypermetabolic Phase Lasts for days to weeks Incredible increase in nutrient requirements Slide 17 Systemic Response to Burn Injury Cardiovascular response Increased capillary permeability/damaged pumps Electrolyte and conduction abnormalities Decreased intravascular volume Decreased cardiac output Burn shock Slide 18 6

7 Systemic Response to Burn Injury Renal response Decreased renal perfusion Hemolysis and rabdomyolysis Increased hemoglobin and myoglobin levels Gastrointestinal response Decreased splanchnic perfusion Adynamic ileus; vomiting and aspiration; stress uclers Translocation of gut flora Slide 19 Systemic Response to Burn Injury Pulmonary response Hyperventilation to meet increased needs Inhalation injury Upper airway edema Pulmonary tissue damage Respiratory distress Obstruction Bronchoconstriction Pulmonary edema Circumferential burns Slide 20 Systemic Response to Burn Injury Immune response Altered immunity Eventual depressed inflammatory response Emotional response Pain Isolation, fear, and altered self image Slide 21 7

8 Systemic Complications Hypovolemia Shock Multi organ dysfunction Renal failure Electrolyte abnormalities Respiratory compromise Hypothermia Infection Decreased mobility Depression Slide 22 Burn Injury Classifications Slide 23 Classification of Burn Injury Classified according to depth Superficial burn Partial thickness burn Full thickness burn Slide 24 8

9 Superficial Burn (1 st Degree) Painful, red, dry; blanches with pressure Prolonged exposure to low intensity heat or short duration flash Heals in 2 to 3 days Slide 25 Superficial Partial Thickness Burn (2 nd Degree) Injury extends into the dermis Red, wet, and painful Blisters Generally heals without scarring within 14 days Slide 26 Deep Partial Thickness Burn (2 nd Degree) Involves basal layer of dermis Dark red to yellowish white Less moist Less painful Wound infection risk Heals within 3 to 4 weeks Slide 27 9

10 Full Thickness Burn (3 rd Degree) Through all three layers 'Pearly' white, charred, or 'leathery' Eschar often present Insensate Vessel thrombosis Infection, sepsis, and severe scarring Evac consideration: will need grafting! Slide 28 Burn Depth Slide 29 Depth of Burn Injury? Slide 30 10

11 Depth of Burn Injury? Slide 31 Depth of Burn Injury? Slide 32 Extent of Burn Injury Percent Total Body Surface Area (% TBSA) Includes partial and full thickness burns Three common methods of estimation Rule of Nines Rule of Palms Lund and Browder Chart Slide 33 11

12 Rule of Nines Expedient tool to measure extent of burn Divides TBSA into regions that are multiples of 9 Rough estimate Slide 34 Rule of Palms Uses patient s palm as comparison guide Patient s palm is equal to 1% of TBSA Works for adult, child, or infant Slide 35 Lund and Browder Chart Assigns numerics to smaller anatomic areas Best used for pediatric patients in clinical environment Extremely accurate method Slide 36 12

13 Assessment of a Thermal Burn Casualty Slide 37 Thermal Burn Assessment Scene survey! Trauma Patient Assessment (TPA)! Slide 38 Thermal Burn Assessment Consider: Source of burning agent Enclosed space? LOC Explosion? Major Traumatic Injuries? Tetanus status Slide 39 13

14 Thermal Burn Assessment Approximate extent of injury Burn depth % TBSA Specific at risk body areas affected Circumferential ('ringing') burns Inhalation injury Slide 40 Pathophysiology, Clinical Presentation, and Management of Toxic Inhalation Injury Slide 41 Inhalation Injury Slide 42 14

15 Inhalation Injury Accounts for ½ of all fire related deaths Amplified in enclosed space(s) Two categories: Toxic inhalation Direct injury Supraglottic injury Infraglottic injury Early recognition is crucial Slide 43 Toxic Inhalation Physical irritant Smoke Systemic poisoning Synthetic resin combustion Releases toxic gases Carbon monoxide, cyanide, and hydrogen sulfide Diffuse across alveolar capillary membrane Interfere with oxygen delivery or consumption Slide 44 Carbon Monoxide Colorless/odorless/tasteless in pure form Product(s) of incomplete combustion of carbon fuels Hemoglobin has a 250x greater affinity for CO over oxygen Carboxyhemoglobin carries less oxygen and holds onto oxygen more tightly Slide 45 15

16 Pathophysiology COHb mediated hypoxia Interferes with cellular respiration Cascade of inflammatory events Brain ischemic reperfusion injury CO binds to myoglobin causing myocardial impairment Slide 46 Clinical Manifestations Nonspecific Frontal headache Dizziness Nausea CNS and cardiac (most sensitive to CO) Syncope, ataxia, and coma Chest pain, dyspnea, and myocardial ischemia Delayed neurologic S/Sx Slide 47 Diagnostic Testing COHb level A very specific lab test; usually Hospital Pulse oximetry misinterprets COHb as oxyhemoglobin = false normal reading Co oximeter or breath sampling Also very specific testing Slide 48 16

17 Diagnostic Testing Glucose level HCG Cardiac monitoring/12 lead ECG Neuro exam and mini mental status exam Neuroimaging CT, MRI, and SPECT Where is the closest CT scanner? Slide 49 Venous Blood Sample Slide 50 Management Half life of CO 4 to 5 hours at room air 60 to 90 minutes on 100% oxygen 15 to 25 minutes on hyperbaric oxygen Treatment Airway and ventilatory support 100% oxygen x 4 hours Hyperbaric oxygen if warranted by symptoms Where is the closest chamber? Slide 51 17

18 Cyanide suspicion of cyanide toxicity in patients with severe AMS or LOC Treatment Airway management and ventilatory support 100% O2 Cyanide antidote kit Slide 52 Pathophysiology and Clinical Presentation of a Direct Inhalation Injury Slide 53 Supraglottic Inhalation Injury Upper airway is susceptible to injury from high temperatures Large Moist Vascular Risk factors Standing in the burn environment Enclosed Space? Slide 54 18

19 Supraglottic Inhalation Injury Signs & Symptoms Singed facial and/or nasal hair Black sputum (nose and/or mouth) Facial burns Hoarseness and/or dyspnea Stridor Slide 55 Probability of Upper Airway Obstruction Slide 56 Supraglottic Inhalation Injury What s wrong with this picture? Slide 57 19

20 Infraglottic Inhalation Injury Not as common as supraglottic MOIs Superheated steam Scalding liquid aspiration Explosions Risk factors Screaming Enclosed space? Slide 58 Infraglottic Inhalation Injury Signs and symptoms often delayed Wheezing, crackles, or rhonchi Cough Hypoxemia Slide 59 Management Plan of a Thermal Burn Casualty Slide 60 20

21 Goals of Burn Management Manage life threats Maintain airway patency O2/support ventilation Hypothermia prevention Fluid resuscitation Pain management Wound management Psychological and emotional support Slide 61 Thermal Burn Management: Minor Burns Local cooling Remove clothing and jewelry Analgesics Topical antibiotic ointment Bulky, sterile dressing Tetanus Slide 62 Thermal Burn Management Consider early definitive airway: Direct inhalation injury S/Sx airway obstruction Burns > 40% TBSA Consider procedural analgesia protocol/ local anesthetic for cricothyrotomy Slide 63 21

22 Thermal Burn Management Vascular access Large bore IV catheter Best site you can access IV CAN go through burned skin IO if unable to gain IV access Titrate analgesia and sedation Aggressive fluid therapy Slide 64 Additional Considerations Elevate head 30+ to minimize edema of facial burns If not contraindicated by spinal trauma Place NG tube; anticipate ileus Consider ulcer prophylaxis; H2 blocker Slide 65 Fluid Requirements and Rates for a Thermal Burn Casualty Slide 66 22

23 Fluid Resuscitation Therapy aimed at supporting patient through hypovolemic shock Volume replacement Crystalloids preferred LR is fluid of choice Hextend (up to 1000 ml) can be used Delayed or inadequate resuscitation: Suboptimal perfusion, end organ failure Slide 67 Fluid Resuscitation Casualties with severe burns, extensive soft tissue trauma, inhalation injury, or electrical injury often require increased amounts of fluid Certain patients, despite optimal resuscitation, will not recover from burn shock Slide 68 Fluid Resuscitation Parkland Formula 2 4 ml LR x pt wt (kg) x % TBSA burned = initial 24 hour fluid requirement ½ given in the first 8 hours from the time of burn ½ given over the subsequent 16 hours *These formulas are an estimate* Slide 69 23

24 Parkland Formula Demonstration 132 pound male sustained these burns 2 hours ago Slide 70 Parkland Formula Demonstration 4 ml LR x weight in kg x % BSA burn = total 24 hour fluid requirement First convert 132 pounds to kilograms 132 pounds / 2.2 = 60 kg Next determine the % BSA using the Rule of 9 s Head = 9 Anterior Torso = 18 Left arm = 9 Total = 36 % BSA burn 4 ml LR x 60 kg x 36% BSA = 8640 ml LR total fluid requirement for the first 24 hours Slide 71 Parkland Formula Demonstration Administer ½ of the total volume in the first 8 hrs 8640 ml LR / 2 = 4320 ml (first 1/2 of fluid requirements) Subtract the 2 hours since the time of the injury from the 8 hours 8 2 = 6 hours to get the first ½ in 4320 ml / 6 = 720 ml LR / hr for the first 6 hours Then administer ½ of the volume in the next 16 hrs 4320 ml LR / 16 hrs = 270 ml LR / hr for the subsequent 16 hours Slide 72 24

25 The Rule of Ten Army s new prehospital burn formula Fairly easy to remember Gives us an hourly initial flow rate Still an estimate Slide 73 The Rule of Ten Estimate %TBSA to the nearest TEN (10) % TBSA x 10 = initial fluid rate (for adult patients weighing kg) For every 10 kg above 80 kg, increase rate by 100 ml/hr Slide 74 Rule of Ten Application 132 pound male sustained these burns 2 hours ago Slide 75 25

26 Rule of Ten Application Estimate burn size to the nearest TEN 36% TBSA burn = 40 % TBSA x 10 = initial fluid rate (for adult patients kg) 40 x 10 = 400 For every 10 kg above 80 kg, increase rate by 100 ml/hr N/A Estimated fluid requirements = 400 ml/hr Slide 76 Rule of Ten Application What would the fluid rate be if these same burns were sustained in a 100 kg patient? 36% = x 10 = 400 For every 10 kg above 80 kg, increase rate by 100 ml/hr Add 200 ml/hr Estimated fluid requirements = 600 ml/hr Slide 77 Fluid Resuscitation Maintain end organ perfusion Avoid under and over resuscitation Fluids must be titrated Maintain urine output ml/hr Peds: urine output at 1 ml/kg/hr (under 30 kg) Adjust rates 20% per hour as needed Assess lung fields Slide 78 26

27 Fluid Resuscitation Burn resuscitation fluid estimates are in addition to any fluids required for initial patient resuscitation Fluid resuscitation for hemorrhagic shock takes precedence over burn resuscitation Oral fluids may be acceptable in burns up to 40% TBSA if crystalloid supplies are limited Slide 79 Burn Wound Care Slide 80 Wound Care Slide 81 27

28 Wound Care What do we cover the burns with? What do we do with the blisters? When do we use topical antibiotics? When do we use systemic antibiotics? What topical antibiotic do we use on the face? Slide 82 Wound Care Cover with dry, sterile (clean) dressings Burn dressing Sheets Towels Chux Kerlex Slide 83 Wound Care Separate burned fingers and toes Avoid pillow use if ears are burned Slide 84 28

29 Field debridement only when necessary Evac 12 hours? do not apply topical antibiotics Evac 12 hours? apply antimicrobial Silvadene or Sulfamylon cream Sulfamylon wraps Silver dressings Wound Care Slide 85 Wound Care Face Bacitracin QID Ears Sulfamylon cream BID Eyelids Bacitracin ophthalmic ointment QID Eyes Erythromycin ophthalmic ointment QID Shave face and scalp Tetanus Slide 86 Systemic Antibiotics DO NOT give prophylactic systemic antibiotics for burn only patients DO give appropriate antibiotic therapy to patients with concomitant wounds If you re forced into extended management with a burn only patient, initiate systemic antibiotics if signs of infection develop Slide 87 29

30 Indications and Procedural Steps for an Escharotomy Slide 88 Thermal Burn Management Eschars Thick, leathery constriction of dead tissue Circumferential, full thickness burns Extremities Distal circulation! Chest Decreased tidal volume! Critical to restore distal circulation and adequate ventilation with escharotomy Slide 89 Escharotomy Provide procedural sedation Incise mid lateral side Incise into subcutaneous fat Extend incisions the entire length of the FTB, including joints Circulation not restored? Incise the midmedial aspect Slide 90 30

31 Escharotomy Incision Sites Dashed lines indicate preferred sites for incisions Slide 91 Midmedial Escharotomy Slide 92 Midlateral and Midmedial Escharotomies Slide 93 31

32 Circumferential Truncal Burn Escharotomy Incisions Anterior axillary line Horizontal at/below the level of xiphoid process May need to include the abdominal wall Slide 94 Burn Consult Consult the USAISR Burn Center DSN (210) Slide 95 Review Calculation Homework Slide 96 32

33 Questions? Slide 97 Terminal Learning Objective Action: Communicate knowledge of thermal burns Condition: Given a lecture in a classroom environment Standard: Received a minimum score of 75% on the written exam IAW course standards Slide 98 Reason Slide 99 33

34 Agenda Identify the pathophysiology of local and systemic responses to burn injury Classify burn injury according to depth, extent, and severity Identify key components in the assessment of a thermal burn casualty Identify the pathophysiology, clinical presentation, and management of toxic inhalation injury Slide 100 Agenda Identify the pathophysiology and clinical presentation of a direct inhalation injury Define the management plan of a thermal burn casualty Calculate fluid requirements and rates for a thermal burn casualty using the Parkland formula and the Rule of Ten Define the key components of burn wound care Slide 101 Agenda Identify the indications and procedural steps for an escharotomy Review Drip Calculation Homework Slide