burn

Objectives Describe epidemiology of burn injury Discuss causes of burn Classify burn injury Discuss Pathophysiology of burn Assessment of burn patient Describe treatment plans for burn

patient by using ATLS principles Discuss complications of burn

Thursday, April 20, 2023 BURN 2

Introduction

Burn Tissue injury

○ thermal ( heat, cold)○ electrical○ Radiation○ chemical

coagulative necrosis



Epidemiology 1% of the world population each year

USA ~ 2.4 million burn injuries/ yr & 10,000 death/yr

UK ~ 250,000 patients treated with burns & 700 deaths/yr. In Kenya 5,000 deaths/yr

TZ(MNH) 10% of admission in pediatric surgical ward

??BMC


epid……

AgeScald - < 5 year of ageflame, electrical & chemical burn - adult

Sexdomestic burn - females occupational - males

RaceNo race predilection exists in burn injuries


Risks factors

Diseases e.g. epilepsy, diabetes Children< 5years; Elderly > 75 years Cold weather Occupational – electricians/industrial Alcoholism ??Low socioeconomic status

High morbidity and mortalityemotional & psychological



AnatomySkin

The epidermis derived from

ectoderm it can regenerate.

The dermis from mesoderm cannot re-generate,


AETIOLOGYThermal injuries

Scald Flame Flash Contact

Chemical injuriesElectrical injuriesRadiation injuriesCold injuries


classificationtype /cause

body site

degree

size/extent

severity


Class.. - typeThermal burn

○ Scald○ Flame burn○ Contact burn○ Flash

Electrical burnChemical burnRadiation burnCold burn

Class..

site Facial burn Head & neck Trunk Limbs Perineal burn

depth Superficial

burn○ Epidemal○ Dermal

Deep burn○ Dermal○ Full thickness

Mixed burn



degree of tissue injury First degree burn

Second degree burn• 2nd Degree Superficial (superficial Dermal)• 2nd Degree Deep (deep Dermal)

Third degree burn

Fourth degree burn

Class..


Size/Extent Total body surface area (TBSA) burned

severity of burn• Minor burn

• Moderate burn

• Major burn

Class..


PATHOPHYSIOLOGYBurn injuries result in:-

local response

systemic response


LOCAL RESPONSE Inflammation Jackson zones (1947)

coagulation /necrosis

Stasis/ischaemia hyperemia

Pathophysiology……


SYSTEMIC RESPONSE:-Significant burn massive release of

inflammatory mediators, both in the wound and other sites.

Pathophysiology……

Follow burn injury , neutrophils ,monocytes & platelets migrate into burn wound

Capillary permeability locally & in distinct organs.

↓ Plasma oncotic pressure ↑ Interstitial oncotic pressure due to

increased capillary permeability protein loss edema in burned & un-burned tissues



Biochemical … ↓ tissue perfusion tissue hypoxia

anaerobic resp

Pyruvate ↑ lactic acid

metabolic acidosis

alter cellular enzymes activity

Biochemical…..

Thursday, April 20, 2023 20BURN

↓ATP↓ Na+Ka+-ATPase

↑↑Na+ intracellular & ↑↑K+ extracellular

cellular swelling hyperkalemia

↓ ECF vol.

Cell death by necrosis or apoptosis


CVS ♥ ↓Myocardial contractility TNF♥ ↓ CO due to loss of intravascular vol, ↑

viscocity & ↓cardiac contractility.These changes, coupled with fluid loss from

the burn wounds systemic hypotension & end organ

hypotension MOD MOF


Respiratory Inflammatory mediators

→bronchoconstriction, → ARDS

Pulmonary dysfunction Inhalation injury Aspiration Shock Circumferential thoracic eschar


GIT mucosal atrophy changes in the digestive absorption intestinal permeability

Thromboxane A2 prominent mesenteric vasoconstriction ↓gut blood flow compromise gut mucosal intergrity & ↓ immune fxn

Stress (Curling’s) ulcer ( stomach & duodenum).

Acute pseudo-obstruction of the colon (Adynamic ileus)

Acute dilatation of the stomach & colon. Acalculous cholecystitis


Renal Changes BV &↓ CO RBF GFR

ATN ARF


CNS Changes CNS dysfunction in up to 14% of burn

patientsDelirium, disorientation

Hypoxia smoke inhalation, pulmonary edema, pneumonia


Haematological Haemoconcentration Anaemia

Destruction of RBC Continual loss of RBC for 1 wk

Mild thrombocytopenia (sequestration) early, followed by thrombocytosis (2-4x > normal) by end of the 1st week

Persistant thrombocytopenia associated with poor prognosis suspect sepsis

DIC with generalized bleeding can occur

shock, sepsis, hypoxia, reperfusion injury


Immunological

Innate immunity Skin

Cellular Immune Function lymphocyte function

Humoral Immune Function

IgG & IgA


Metabolic

Ebb phase

Flow phase

Catabolic phaseAnabolic [recovery phase]


Ebb phaseOccurs during the 1st 24 hours

hypothermia CO & O2 consumption


Catabolic PhaseOccurs after 24 hours of burn injury Mediated through release of catabolic

hormones [ eg, catecholamines, glucocorticoids, glucagon ] and other chemical mediators e.g. cytokines, lipid mediators.

↑ Cardiac output ↑ Oxygen consumption ↑ Heat production [hyperthermia] ↑ BMR Hyperglycemia Proteolysis Peripheral lipolysis


Catecolamines CORTISOL

GLUCAGON

Gluconeogenesis

Peripheral Lipolysis

Proteolysis

GLUCOSEFREE FAT

ACIDSAMINO ACIDS

BURNSTRESS


Anabolic / recovery phaseCharacterized by:-

This phase continues for weeks to months after injury

Slow re-accumulation of protein and fat

ASSESSMENT OF BURN INJURY

Remember Establish cause. Associated injuries

During escape from fire. Explosions throw patient a distance causing

internal injuries. Electrical muscular spasms can cause fractures.

Burns in enclosed space suggest inhalational injury.

Pre-existing disease states, medication, allergies, lung sensitivities.

Establish tetanus immunization status.



Clinical assessment

History

Physical examination General Local Systemic


historyPatient characteristics age , occupationHistory of injury

Time of burnPlace of burnNature of injury○ Intentional○ Unintentional○ Undetermined


History…. Type of burn

ThermalChemicalElectrical RadiationCold

Mechanism of injury Associated injuries Associated inhalation injuries Associated clothing ignition Whether first aid measures was done at the site of

accident

ROS

PMHx

?? Epilepsy, DM, Psychosis

FSHx

??alcohol



General ExamBody weightShock Level of consciousness DyspnoeaIn pain Restless ± gaspingAnaemicDehydration


Physical examination

Local examination [assessment of burn wound] Examine the wound

Body region burnedExtent of burnBurn depthSeverity of burn

Systemic examinationCardiovascular systemRespiratory systemPACNS

Local exam

Body regionHead / neckUpper limbsTrunkLower limbsGenitalia / Perineal areas



Extent of burnSize of a Burn Injury

Total Body Surface Area (TBSA) Burned

Palmar MethodA quick method to evaluate scattered or localized

burnsClient’s palm = 1 % TBSA

Rule of Nines (Wallace’s)A quick method to evaluate the extent of burnsMajor body surface areas divided into multiples of

nineModified version for children and infants (Rule of

Sevens )

Lund-Browder MethodMost Accurate; based on age (growth)Can be used for the adult, children & infants


Burn depth Superficial (1st

Degree) Partial Thickness

Superficial (2nd Degree)

Deep ( 2nd Degree) Full Thickness (3rd

Degree) Deep-Full Thickness

(4th degree)


Superficial first degree burn

EpidermisWound Appearance:

Red to pink (light skin) Mild edema Dry and no blistering Pain / hypersensitivity to

touch ○ i.e. Classic sunburn

Desquamation occurs 2-3 days

Wound Healing Wound Healing

spontaneous Duration 3 to 5 days No scarring / other

complications 46


Superficial second degree burn

upper 1/3 of dermis

Wound Appearance Red to pink Wet and weeping wounds Thin-walled, fluid-filled

blisters Mild to moderate edema Extremely painful

Wound Healing In 2 weeks (spontaneous) Minimal scarring; minor

pigment discoloration may occur


Deep second degree burn deep dermis layer

Wound Appearance Mottled: Red, pink, to white

surface Moist Moderate edema Painful; usually less severe

than superficial 2nd Degree superficial.

No blisters Wound Healing May heal spontaneously 2-6

weeks If so Hypertrophic scarring /

formation of contracturesWound Management: Treatment of choice

surgical excision & skin grafting


Full thickness third degree burn

entire epidermis and dermisSubcutaneous fatWound Appearance Dry, leathery and rigid + Eschar (hard and in-

elastic) Red, white, yellow,

brown or black Severe edema Painless & insensitive to

palpation


Wound Healing No spontaneous healing; No epidermal or dermal

appendages remain, thus must heal by re-epithelialization from the wound edges.

Wound Management:Surgical excision & skin

graftingCx severe

scarring/contracture


Deep full thicknesss burnExtends beyond the skin to

include muscle, tendons & possibly bone.

Wound Appearance: Black (dry, dull and

charred) Eschar tissue: hard, in-

elastic No edema Painless & insensitive

to palpation

Deep full thickness……

Wound HealingNo spontaneous healing

Wound Management: Surgical excision & skin grafting

Frequently requires amputation if extremity involved



Severity classified as follows:-

MinorModerateMajor

Severity of burn is determined by Type of burn Depth of burn injury Total body surface (TBSA) burned Location of burn( face, hands, feet and

perineum are considered severe !! ) Patient’s Age Presences of other preexisting medical

conditions Presence of associated injuries Complications ( Inhalation , Hypothermia ,

Shock )



Minor burnCharacterized by:-

<10% in adult < 5% <10 yrs or >50 yrs < 2% full thickness No associated injuries, no complications,

no pre-morbid illness, no circumferential burns, not involving the hands, face, perineum

Minor burns needs outpatient Mnx.


Moderate burn 10 - 20 % in adult 5 - 10 % <10 yrs >50 yrs High voltage, suspected inhalation, circumferential or susceptibility to

infection Admit


Major burn2nd & 3rd Degree burns >10% (BSA) in patients <10

or > 50 yrs of age2nd & 3rd Degree burns >20% BSA in pts btn 10 and

50 yrs of age2nd & 3rd Degree burns with serious threat to

functional and cosmetic impairment that involve the face, hands, feet, genitalia, perineum, and other major joints

3rd Degree burns >5% BSA

Specialized injuries such as electrical burns, including lightning and chemical burns, with serious threat of functional or cosmetic impairment


Major burn…Significant inhalation injuriesCircumferential burns of the extremities or

the chestPre-existing medical disorders that

complicate management, prolong recovery, or affect mortality

Concomitant trauma in which the burn injury poses the greatest risk of mortality


Management

aim prevent fluid and electrolyte imbalance rapid and painless healing prevent complications rehabilitation


Burn teamSurgeons –reconstructive (plastic),

General or trauma surgeon, Paediatric surgeon

NursesAnesthetist ICU team Physiotherapist Occupational therapist Social workersPsychologists PsychiatristDietitians


Criteria for admission Type of burn

Electrical Chemical Lightining

%TSBA>15% in adult >10% in children

Body site affected: face, hands, perineum, genitalia

Complications- inhalation burn Pre-existing illness – renal diseases,

Diabetes mellitus, respiratory diseases Circumferential burns of the limbs or

chest


Phases of management ATLS (Advanced Trauma Life

Support) Phase I: Primary survey phase

Phase II: Resuscitation phase

Phase III :Secondary survey phase

Phase IV: Supportive care phase

Phase V: Definitive treatment phase


Fluid Resuscitation

maintain tissue perfusion to the zone of stasis and so prevent the burn from deepening

Indication= ped 10%, adult 15%

Fluid resuscitation formula not ideal guidelines

success relies on adjusting the amount of resuscitation fluid ↔ against monitored physiological parameters

hypoperfusion VS oedema


Resuscitation cont….. Parkland formula

4mls x KgBwt x %TBSA1st 24hrscrystalloid formula For burn >50% TBSA, use 50% for

calculation (to prevent fluid overload)½ given in 1st 8 hrs & ½ next 16hrs.In children add the maintenance fluid


Resuscitation cont….

After 1st 24 hrs, colloid infusion is started at a rate of:-

0.5 ml× (%TBSA)×(Bwt in kg) and

Maintenance crystalloid (usually DNS) is continued at a rate of

1.5mlsx%TBSAxBwtEnd point to aim is a urine output of:-

0.5-1.0 ml/kg/hr in adults 1.0-1.5 ml/kg/hr in children


Resuscitation cont…..

Colloid use is controversial: ○ some units start colloid after 8

hrs( as the capillary leak begins to shut down)

○ whereas others wait until 24 hrsFFP is often used in children, albumin or synthetic high molecular

weight in adults.


Resuscitation cont… The Modified Brooke formula RL: 2 mls x % BSA x Bwt (kg)

Replacement reassessed on an hourly basis. Urine output< 0.7ml/kg/hr. If urine output is inadequate, increase infusion

by 200ml next hour

2nd. 24 hoursColloid (Albumin, Dextran 70)

(0.3-0.5ml/kg/%BSA) Dextrose to maintain urinary output


Phase III :Secondary survey phase

History Physical examination Investigations


Secondary survey cont…Baseline investigation for major burn.

Blood○ Hb○ Grp & x-match○ CoHb○ Serum glucose○ Electrolytes○ Arterial blood gases

X-rays


Phase IV: Supportive care phase Analgesics

Haematenics PPI Systemic antibiotics against ß- hemolytic

streptococcus Tetanus toxoid NGT for pts with > 20%TBSA Urethral catheterization Monitor

vital signs Input /output

Maintain body Temp Nutrition support Elevate limbs


Phase V: Definitive treatment phase (Wound care) Escharotomy

Fasciotomy skin grafting Dressing Debridement Application of autograft Splinting Contractures Mnx.


Complications

Can be classified as:-Early ComplicationsLate Complications


a. Early Complications

Fluid / Electrolyte imbalanceHypovolaemic shock Thermoregulation dysfunction Acute renal failure Inhalation injury Infections


b. Late Complications Contractures

KeloidsHypertrophic scarsMarjolin’s ulcer

‘‘Once you start studying medicine, you never get

through with it’’

Charles H. Mayo (1865-1939)


burn

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