Burn pathophysiology and management skill that are mandatory

Burns pathology and management

1. 1

2. I. Definition
A burn injury is a coagulative damage or
destruction of skin and/or its contents by
*Thermal
*Chemical
*Electrical
*Radiation energies or combinations
2

3. II. EPIDEMIOLOGY
Incidence varies greatly b/n cultures
Uk (popn. 65 million)
175,000 burned pts/yr seek health care
13,000/yr need hospital admission
~ 1000 have severe burns requiring fluid resuscitation.
 Half of them are <16yrs of age
USA
1.1million burned pts/yr seek health care .
45,000 require hospitalization
4500 death
Nearly ½ are smoking related due to substance abuse.
3

4. Ethiopian situation
1.A community-based study showed highest
incidence in children < 5
Scald burn (59 %)
Flame (34 %)
Home (81 %)
2.A hospital-based study
Scald 61.1 %
11.5 % died
4

5. III .ETIOLOGY
Flame 33%
Scald 30%
Contact15%
Flash 10%
Electrical5%
Friction1%
Radiation1%
At great risks are
♦ The very young
♦The very old
♦ Those whose ability to
protect themselves is
impaired.
*Epilepsy
*Alcohol
*Drug abuse
5

6. Etio …cont’d
A.SCALD BURNS
●Scalds from hot water are most common cause of burn
●Depth is proportional to
T
o,
Duration of contact
Thickness of skin.
eg. Water at 60
o
c for 3 sec &at 69
o
c for 1sec cause
deep dermal or full-thickness burn
● Immersion scalds are always deep, severe burns
6

7. Etio …cont’d
B. FLAME BURNS
●House fires
●Smoking related fires
●Improper use of flammable liquids
●Automobile accidents
●Ignition of clothing from stoves or space heaters
●Fall into open fire
7

8. Etio …cont’d
C.FLASH BURNS
●Explosion of natural gas ,gasoline
& other flammable liquids cause intense heat for a
brief time
● Depth depends on the amount and type of fuel
●Clothing, unless it ignites, is protective against
flash burns
●May be associated with thermal damage to the
upper airway
8

9. Etio …cont’d
D.CONTACT BURNS
●Result from contact with hot metals,
plastic, glass or hot coals
●Limited in extent & very deep
9

10. Etio …cont’d
E.CHEMICAL BURNS
●Caused by strong acids or alkalis
●Cause progressive damage until they are
inactivated by rxn c
­
the body tissue or diluted c
­

water
●Acid burns may be more self-limiting than alkali
burns
●Chemical burns should be considered deep
dermal or full-thickness until proven otherwise
10

11. F. ELECTRICAL BURNS
●May be low-voltage or high-voltage
●3 mechanisms of injury :
i. Electrical current injury
ii. Electrothermal burns from arcing current
iii. Flame burn caused by ignition of clothes
●Deep destruction of muscles ,nerves & vessels –
myoglobinuria ATN
●The entry &exit wound is only the tip of the
iceberg
11

12. IV.PATHOPHYSIOLOGY OF BURN
Burn wound is 3 dimensional mass of damaged
tissue.
Zone of hyperemia  at its margin
the usual inflammatory response of healthy tissue
to non-lethal injury.
Zone of coagulation at its center
irreversible vessel coagulation & no capillary blood
flow
Zone of stasis :sluggish capillary blood flow
12

13. Pathophy …contd
The Burn Syndrome
Following a major burn injury a myriad of physiologic
changes occur that together comprise the clinical
scenario of the burn patient.
Burn shock

Metabolic response
Immune response
Effect on vital organs
13

14. Pathophy …contd
1.Fluid and Electrolyte Imbalance (burn
shock) 
 
microvascular changes induced
by *Direct thermal injury and
*Release of chemical mediators of
inflammation
Systemic intravascular losses of water,
sodium, albumin and red blood cells.
 
This process is maximum in the 1
st
8 hrs.
14

15. Pathophy…contd
2.
 
Metabolic Disturbances  

Due to neuro-endocrine mediator response (catecholamines are
the major hormones)
Metabolic changes :
Increase gluconeogenesis
Increased glycogenolysis
Increased proteolysis
This is evidenced by
Increased resting oxygen consumption (hypermetabolism)
An excessive nitrogen loss (catabolism),
A pronounced weight loss (malnutrition)
15

16. Pathophy …contd
3. 

Bacterial Contamination of Tissues 
 
 

Patients with a major thermal injury are unable to mount an
adequate immunologic defense
1.Decrease cell-mediated immunity
2.Decrease humoral immunity
3.Decrease neutrophil activity (chemotaxis, IC killing)
increasing the risks for septic shock
16

17. Pathophy …contd
4.
 
Complications from Vital Organs 
 
Renal insufficiency
 Hypoperfusion or
Nephron obstruction with myoglobulin and hemoglobin.
 
Pulmonary dysfunction
 Pulmonary edema ,  ARDS, or  Bronchopneumonia.
 
Gastrointestinal
Ischemia & stasis promote bacterial translocation as a mechanism
for endogenous infection.
 
 Curling ulcer,& erosive gastritis
Multi-system organ failure is a common final pathway leading to late
burn mortality.
17

18. B. Extent of burn
Estimation of BSA by
 Rules of 9 & 7
Palm of the pt as 1%
Lund & Browder charts

18

19. Pathophy …contd
Factors Affecting Systemic Response to Burn Wounds
Extent of the burn: systemic effects are proportional to the
percentage of the BSA.
Age of patient: prognosis for very young and elderly patients
is worse
 

Depth: systemic response is greater in large, deep burns
 

Delay in resuscitation: established burn shock is difficult to
treat
19

20. V.BURN SEVERITY &
CLASSIFICATOION
THERMAL INJURY – CLASSIFICATION .
In the classification of burn injuries, the following should be considered and
documented:
Causative agents - etiology
Extent of body surface involved
Depth of injury
Associated injuries
Co-morbid conditions – age, pre-existing diseases
A.CLASSIFICATION BY CAUSATIVE AGENTS
Thermal injury – directly related to heat and duration of contact
Flame burn / contact burn / Scald
Chemical injury
Electrical injury
Radiation injury
20

21. Classification of Burn Injuries 


Major Burns


Moderate Burns


Minor
Burns
♦ 2
O
burn >25 % in
adults & > 20 %
in children
♦3
0
burn > 10 %
♦ Deep burns of the
head, hands, feet,
and perineum.
♦ Inhalation injury.
♦ Chemical or high-
voltage electrical
burn.
♦ 2
O
burn 15-25%(adult)
10-20%(children)
♦ 3
0
burn <10 %

♦ Superficial partial-
thickness burns of the
head, hands, feet or
perineum.
♦ Suspected child abuse.
♦Concomitant trauma.
♦ Significant pre-existing
disease.
♦ 2
O
burn <15% in
adult & <10% in
children
♦ 3
0
burn <2%
♦ Nothing involving
the head, feet hands
or perineum.
21

22. C. Classification by Depth of burn
Is proportional to
 T
o
of causal agent
 Length of contact time
 Burning material
22

23. Classification
Morphology Clinical FeaturesHealing Time
First Degree
( epidermal
burn)
Involves only
epidermis
Red painful.
Sunburn is a 1st
0
Burn
3 to 7 days
Heal by
regeneration
Second
degree
(Superficial dermal
burns) ,SPTB
Involves outer
portion of dermis
Pink / red, blister,
weeping,
moist ,painful
7 to 10 days
heal with little or no
scarring
Second
degree
Deep partial
thickness burns
Extends to deep
dermis.
Appendages may
be intact
Pink/white/ dry
insensitive
May heal in 21day
hypertrophic
scarring
Rx is skin grafting
Third degree
full-thickness
burns
Full thickness skin
loss extends to fat
Leathery
Charred /black
insensitive
Requires grafting
23

24. Depth of Burn (Degree)
1
st

0
Burn
2
nd

0
Burn
Deep Dermal Burn
3
rd 0
Burn
24

25. D. Respiratory injury
Smoke or thermal damage to respiratory tree occurs in 30%
3 types :

Carbon monoxide poisoning  Intoxication /hypoxemia
Thermal injury
 Mostly to the upper airway – supraglottic
Chemical injury (Smoke poisoning)
 Mostly to the lower airway - subglottic
25

26. Diagnosis of inhalational injury
Hx

fire in enclosed space
burn in the face, wheezing ,
air hunger, excessive sputum
P/E
soot in the mouth & pharynx ,singed
nasal hair ,hoarseness ,wheeze,
carbonaceous sputum, acrid smell of
smoke in victims clothes
Lab :bronchoscopy ,CXR ,[CO], arterial o
2
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27. VI. TREATMENT OF BURN
Morbidity and mortality are determined by
♦Extent of injury, ♦ Depth of injury
♦ Age of the patient ♦ asso. injuries
♦ Co-morbid conditions
♦ The adequacy of care at all stages, from
• Rescue • Triage
• Resuscitation • Wound care
• Rehabilitation & psychosocial recovery.
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28. TREATMENT ….contd
FIRST AID
 Remove the person from further danger.
 Remove clothing.
 Irrigate the areas with water in copious amounts
 Scald, flame for 5min.
 Chemical injuries for 20-30 min
 Start life saving measures (if indicated).
 Cover the wound with clean towel.
 Management of associated injuries
 Transport to the nearby health facility.
28

29. 29

30. Treatment …contd
Admit:
 Any burn over 15%(adults) & 10%(children)BSA.
Special areas e.g. eye, face, hands, feet, perineum.
 Inhalation injury regardless of size of burn.
 Chemical & electrical burns
 Full thickness burns where grafting is indicated
 Children & elderly pts who require additional medical
or social support.
30

31. Treatment …contd
EVALUATION AND MANAGEMENT IN THE EMERGENCY
DEPARTMENT
1. Primary survey.
ABCDEF
Airway, Breathing, Circulation
Check for life threatening injuries
2. Resuscitation
Large bore intravenous line (if burn is greater than 10% to
15% of body surface).
Start with lactated Ringer’s solution.
Airway (endotracheal tube, if indicated) - humidified oxygen
31

32. Treatment …contd
3. Secondary survey - more thorough evaluation.
▫History Nature of injury (agent and circumstances).
Time since injury.
Medical history, medication and allergies.
▫ Examination: Rapid
Check vital signs, weight
Determine extent and depth of injury.
Rule out other injuries ,examine eyes.
look for circumferential burns on chest, limbs.
Evaluate and treat inhalation injury (if indicated).
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33. ▫Collect blood samples :
Hct, x-match, electrolyte ,
BUN, glucose ,CBC
arterial blood gas analysis.
▫ Give analgesics and sedatives as indicated
▫ Give tetanus prophylaxis
▫ Calculate fluid needs and adjust infusion rate.
Treatment …contd
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34. I. Fluid Resuscitation
Prevent burn shock& maintains adequate perfusion of
blood
For burns children > 10 %TBSA
adult >15 % TBSA.
Calculate a pt’s fluid needs from the moment of burn.
Formulae serve only as a standardized base line.
Fluid therapy must be individualize.
These formulae should be used only as guidelines.
34

35. Fluid …cont

1. Parkland : 4ml x wt (Kg) x % TBSA burn
Ringer’s lactate
2. Evans  1ml x wt x %TBSA
3. Brooke  1.5ml x wt x %TBSA
4. Modified Brook  2ml x wt x % TBSA
35

36. Fluid….cont
this volume is then given at different rates
½ in  1
st
8 hrs post injury.
½ in  next 16 hrs
Next 24 hrs  give half of total
Provide the daily maintenance requirement of 2-3lt
on top of the calculated amount .
Patient monitoring during resuscitation
Clinical : PR,BP mental status, uop (30-35ml/hr)
Laboratory :Hct ( 40-45).
36

37. If burn >30% colloids can be given
*Dextrans ,*plasma
Escharotomy
In constricting full thickness burns of limbs ,digits or
chest.
▫ To maintain or improve distal circulation
▫ To aid chest wall excursion
Chest escharotomy at the anterior axillary line
extermity escharotomy
37

38. Escharotomy sites
38

39. ● Burn size is proportional to
*↑ in o
2 consumption *urine nitrogen loss,
* ipolysis, *weight loss
● If BSA burned >40%, lean body weight ↓ by 25% over the first
3 wks (in absence of adequate nutritional support.)
● Pt with major burn needs high calorie in the form of
CHO (50%)
protein (20%)
fat (30%)
● Add vitamins & minerals
Nutritional support
39

40. oRoute of administration
▫ Oral, ▫ parentral
▫ NG tube (earlier) used in TBSAB >20%
??start with in 6hrs,48hrs
●Decompression of stomach.
● Earlier paralytic ileus can be prevented.
● Mucosal integrity is preserved.
●↓Risk of bacterial translocation &
endogenous infecn.
● ↓ Catabolic response.
40

41. Curreri Formula
◘Calorie requirement /24 hrs : Kcals /day
Adult  (25 x BW)+(40 x %TBSAB)
 . 
Children  60/kg + 35% BSAB
◘ Protein requirement /24 hrs :
Adult  1g/kg + 3g%BSAB
Children  3g/kg + 1g%BSAB
41

42. Adult pts BMR+ injury &activity factor
25-30kcal/kg/d <10% TBSA burn
31-35 „ 10-14% „
36-40 „ 15-24% „
41-45 „ 25-39% „
46-50 „ 40-49% „
50 „ >50% „
42

43. BMD (butter milk diet)
*1lt of milk
*4egg
*3bannana
*50gm sugar
1ml of BMD  1Calorie
0.047gm protein
*Add vitamins (B, A,& D, C, ferrous sulphate)
43

44. Care of the burn wound
Orthodox way of mx of wound
 Daily washing
Removal of loose dead tissue .
Topical application of saline-soaked dressings until they
heal by themselves or granulation tissue appear in the
base of the wound
Protect recently healed tissues
Prevent infection and if it is established, Rx it vigorously.
Skin graft over the granulating wound after 3-8 wks after
injury.
44

45. 1. Minor burn injury - may be treated on an
outpatient basis.
2. Moderate uncomplicated burn injury -
should be hospitalized.
3.Major burn injury - should receive
specialized care such as provided by a
Burn Unit .
45

46. Principle of dressing
●Full thickness & deep dermal burns need
antimicrobial dressing.
● Superficial burns need simple dressing.
● An optimal healing envn’t can make a
difference to out come in border line depth
burns.
46

47. Dressing Mx
i. Open (exposure) methods
◘In warm climate
◘ Encourages dry crust formation.
◘ For superficial burns  Scalds
 Burns of pt’s face &neck
 Full thickness burns any where
◘ Large partial thickness burns except hands.
◘ Can be modified by Vaseline gauze
47

48. ii. Closed (occlusive dressing) method
◘ 2cm thick dressing consisting of
Paraffin gauze, cotton swabs,
bulky layer of cotton wool , crepe bandage
◘ In cold envn’t if not hyperpyrexia will occur.
◘ small burns to be Rx as out pt (especially burn on
hand).
◘ Large burns to be transported.
48

49. I. INFECTION
Predictors of infection :
●Burn size
● Age
● Inhalation injury
Site of infection in burn pts :
1.Wound infection
2. Pneumonia
3.Suppurative thromophelebitis
4. UTI

Burn Complications
49

50. Infection control
Hand washing before & after touching each pt.
Aseptic techniques for dressing & procedures
Environmental controls ,such as air filtration & balanced
ventilation.
Microbiological screening of wounds ,nose ,throat ,perineum
& axillae.
Isolation of infected pts
Early nutritional support
Eary excision of deep burns
Use of topical antimicrobials
50

51. Cxn…cont
II. Curling ulcer
III. Contracture
Prevention
●Early excision and grafting
● Splintage
● Elevation of extremity
● Early physiotherapy
● Prevention of infection
IV. Marjolin’s ulcer, Hypertrophic scar, keloid
V. Ileus & acute gastric dilation
Cxn…cont
51

52. Rehabilitation
Goals of rehabilitation:
Restore function
Prevent contractures
Return to normal activities
Best aesthetic appearance possible
Modalities and techniques:
Positioning Active range of motion/exercises
Pressure Therapy Scar Management
Splinting Activities of daily living
Vocational training Documentation
52

53. BURN PREVENTION
Significant proportion of burns can be
prevented by
♦Implementing good health & safety
regulations
♦ Educating the public
53

54. THANK U
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