:Lectue(1)2021 ‫اختصاصي الجراحه التجميليه‬, ‫عالء حسين‬.

‫د‬

Burn
Demography

• 450,000 : receive medical therapy/year in USA

• 3500 death
High risk group:
pediatrics ,geriatrics ,and disabled populations
Prognosis:
Depend on :Age, total body surface area(TBSA), and presence of inhalation
injury.
• Dramatic decrease in death by:
• Prevention
• Advancement in critical care
• Early excision and grafting
Etiology

Scald burns are the most common cause of burn injury in the civilian population.
The depth of scald burn is determined by the temperature of the liquid, the
duration of exposure to the liquid, and the viscosity of the liquid (there is usually
prolonged contact with more viscous liquids). Scald bums with hot liquids will
typically heal without the need for skin grafting. Grease burns, however, tend to
result in deeper dermal burns and will occasionally require surgical management.

Flame burns, the next most common cause of bum injury, typically result from
house fires, campfires, and the burning of leaves or trash. If the patient's clothing
catches fire. burns will usually be full thickness.

Flash burns are quite common as well and typically result from ignition of
propane or gasoline. Flash bums will typically injure exposed skin (most
commonly face and extremities) and usually result in partial thickness burns.

Contact bums occur from contact with woodstoves, hot metals, plastics, or coals.
Contact bums are usually deep but limited in extent of body surface area injured.
In addition, burn injury can result from electrical and chemical agents as well.

Pathophysiology of Burn Injury

1-Local burn injury(skin damage):

A burn injury occurs when a thermal insult on the skin causes acute changes in its
composition, killing cells and denaturing proteins. Initially, burn depth is based on
two extrinsic factors: intensity of heat and duration of contact. The hotter the
source or the longer the duration of contact, the deeper the burn injury.

2-airway and lungs injury: hot gases can physically burn the upper airway causing
laryngeal oedema, and lower airway causing loss of respiratory epithelium.
Inhaled smoke particles can cause chemical alveolitis and respiratory failure.
Inhaled poisons, such as carbon monoxide, can cause metabolic poisoning. Full
thickness burn to the chest can cause mechanical blockage to the rib movement.

3-systemic and burn shock: Burns greater than 20% of total body surface area
(TBSA) cause a system-wide inflammatory response

and lead to a systemic inflammatory response syndrome, sometimes called burn

shock. As the local events become systemic, the release of inflammatory
mediators into the central circulation leads to leaky

microvasculature, vasodilation, decreased cardiac output, tissue hypoperfusion,

and ultimately, if left resuscitated, death.

4-the immune system and infection : cell mediated immunity is significantly

reduced in large burns, leaving them more susceptible to bacterial and fungal
infection.

5-changes to the intestine : shock can cause microvascular damage and ischemia
to the gut causing malabsorption.

6- danger to peripheral circulation : circumferential full thickness burn to the limb

and the leathery eschar may cause ischemia.
Initial Management(emergency treatment):

Burn patients are trauma patients and should be evaluated systematically. The
first priority must be maintenance of a patent airway, effective breathing, and
support of the systemic circulation:

1-Airway control: endotracheal intubation should be performed on patients who

have suffered severe burn, inhalation injury or an upper airway burn. Delayed
intubation may become difficult or impossible with the development of burn

edema.

2-Breathing and ventilation should be monitored .

3- Circulation: Two peripheral IV lines are usually sufficient for patients with less
than 30% burns. However, patients with larger burns or significant inhalation
injury will require central line placement.
4- Distant injuries: the next priority in evaluation is diagnosis and treatment of
concomitant life-threatening injuries, like head, neck, chest, abdomen and long
bones injuries.

5-Exposure : complete exposure to determine the extent and depth on burn

6- taking oral history of the circumstances of the injury is valuable in searching for
associated trauma, possibility of presence of inhalation injury, pre-existing
medical conditions , medications taken and allergies.

7- radiological examination of the neck , pelvis , and chest will aid in the
evaluation of possible blunt trauma.

When there is indication for admission in burn unit, then the following
guidelines should be applied.

8- fluid requirement should be calculated using Parkland formula .

Formula: 4 cc*kg*%TBSA = total fluid to be administered in the first 24

hours.50% of fluid should be given in the first 8 hours, and the other 50% of
fluid should be given in the next 16 hours. Fluid should be lactated Ringer
solution.

Sample calculation: 70-kg person with a 50% TBSA burn:

4 × 70 × 50 = 14 L of fluid
7 L in the first 8 hours
7L in the next 16 hours
The formula is only a guideline. Fluid administration should be titrated to
the urine output.
9- a Foley catheter should be inserted and urine output should be measured
hourly. Intravenous fluid should be adjusted to maintain a urine output of 30 to
50 cc's per hour in an adult and 0.5-1 cc/kg/hr. in a child.
10- Nasogastric tube: burns of over 20%-25% TBSA are associated with a paralytic
ileus. A nasogastric tube should be inserted and placed for suction to maintain
gastric decompression.
11- Analgesia and sedatives can be given as needed, but should be given
intravenously only.

12- Tetanus immunization should be determined and updated.

13- The patient must be kept warm during transfer using warm IV fluid and
adequate coverings.
14- No topical agents should be applied . The burn wounds should be covered
with clean dressing sheet.
15- Inhalational injury:
• Signs are : hoarseness , pharyngeal erythema and edema Mental status
changes. in the presence of a suspected inhalation injury, early intubation is
mandatory to prevent the development of respiratory distress. If
carboxyhemoglobin (CHgb) is elevated (>10%) , 100 percent oxygen must
be administered. The patient may need Increased resuscitation fluid .
Other investigations are: Chest x-ray and Bronchoscopy.
16: circumferential burn and the leathery eschar they produced can be a life- or
limb-threatening problem in the chest and extremities. Prior to transfer to burn
unit, escharatomies should be performed to incise the full length and depth of
the eschar.

Indication of Transfer to Burn Center

1:Second and third degree burns >10% TBSA in patients <10 or >50 years old.

2:Second and third degree burns >20% BSA in other age groups.
3:Second and third degree burns with serious threat of functional or cosmetic
impairment that involve face, hands, feet, genitalia, perineum, and major joints.

4:Third degree burns >5% BSA in any age group.

5:Electrical burns, including lightening injury.

6: Chemical burns with serious threat of functional or cosmetic impairment.

7:Inhalation injury with burn injury.

8:Circumferential burns .

9:Burn injury in patients with pre-existing medical disorders that could complicate
management, prolong recovery, or affect mortality.

10:Any burn patient with concomitant trauma.

Determination of Burn Extent

When calculating burned areas from total body surface area(TBSA), only include
those areas of partial- and full-thickness dermal injury. Superficial(1st degree) burns
involving the epidermis only are not included in the calculation.

The rule of nines is the most known method of estimating burn extent. However,
it is important to note that the proportions of infants and children are different
from those of adults. Lund and Browder charts are anther and more accurate
method of assessing burn extent.