Burn Injury : Mnemonic Approach (ATLS)

Mnemonic: BURNS

Burn depth and body surface area (BSA)

Burn degreeBurn depthFeaturesHealing
Mnemonic: Number of degrees = Number of structures involvedMnemonic: RBCS
1stSuperficial (epidermis only)Red<1 wk
2ndPartial thickness – superficial (epidermis + papillary dermis)Blister + Blanches1-3 wks
Partial thickness – deep (epidermis + reticular dermis)Compared to superficial partial thickness: Deep = Dermal appendages involved + Decreased:
a. Moistness (Dry)
b. Color (Mottled red)
c. Blanching
d. Pain
>3 wks, usually requires surgical treatment
3rdFull thickness (epidermis + dermis + subcutaneous fat)Charred and Contractures (leathery dry, no blanching, painless)Rare, unless surgical treatment
4thEpidermis + dermis + subcutaneous fat + fascia/muscle/boneSurrounding area (second degree) pain increasedNever – requires surgical treatment

Burned Body Surface Area (BSA) for 2nd and 3rd degree burns

wallace rule of 9 burn
Jmarchn, CC BY-SA 3.0, via Wikimedia Commons

Wallace Rule of 9:

StructuresBSA (%) – AdultsBSA (%) – Infants
Head and neck918
Upper limbs (each)99
Trunk – anterior1818 (trunk and perineum)
Trunk – posterior1818 (including 2.5% for each buttock)
Lower limbs (each)1814
For each year after age >1 year: Decrease head by 1% and increase lower limb by 1% (0.5% in each).

Comparison with other methods

Lund & BrowderRule of 9sPalmar
TheoryAge-based assessmentBody divided in 9% areasPatient’s palm is 1%
Advantages“Gold-standard” accuracy EfficientMinor Burn Estimation 
DisadvantagesInefficientOver-estimation User variability

Mortality prediction:

3 factors: Mnemonic – BAI

  1. Burn BSA >40%
  2. Age >60 years
  3. Inhalational injury

Baux score (% mortality) = Age + BSA

  • BSA >70% in elderly or Baux score >130 = Near 100% mortality
  • Score <80 is considered good and >100 is considered bad

Revised Baux score = Baux score + 17 (for inhalational injury)

Urine output monitoring


  1. Adults: 0.5 ml/kg/hr
  2. Children <30 kg: 1 ml/kg/hr
  3. Electrical injury: 1-1.5 ml/kg/hr

Resuscitation and Referral

a. Early intubation: Indications –

  • Airway obstruction signs (hoarseness, stridor, retractions)
  • Burn surface area >40-50%
  • Circumferential neck burns
  • Deep facial burns
  • Edema (significant)
  • Fatigue of respiration
  • GCS <8
  • Hypoxemia despite 100% 0xygen, Hypoventilation (PCO2 >50 mmHg and pH <7.2)

b. Fluid resuscitation: For 2nd and 3rd degree burn >20% BSA

Initial resuscitation with warmed RL

FluidAdultPediatric (<14 year)Electrical burn
Rate2 ml X kg X BSA3 ml X kg X BSA4 ml X kg X BSA
Children <30 kg+ 3 ml X kg X BSA D5RL at maintenance rateRL
1/2 resuscitation fluid in 1st 8 hours (from time of injury) and remainder 1/2 in remaining 16 hours.
If the initial resuscitation rate fails to produce the target urine output, increase the fluid rate until the urine output goal is met.
Follow 4-2-1 rule for maintenance fluid rate.

c. Referral to burn center: Indications –

  1. Second degree (partial thickness) burn >10% BSA
  2. Third degree (full thickness) burn
  3. Burns to face, hand, feet, genitalia or major joints
  4. Electrical, chemical or inhalational burns
  5. Comorbidities
  6. Concomitant trauma
  7. Patients requiring special social, emotional or rehabilitative intervention
  8. Pediatric burns without qualified personnel or equipment

NG decompression


  1. Nausea/vomiting
  2. Abdominal distension
  3. Burns >20%


Conservative management is appropriate for superficial burns and mixed superficial burns that will heal in 2 weeks. More complex burns may require excision and skin grafting. Excision and primary closure is not generally practiced as there is a high risk of infection.


  • Indicated in circumferential full thickness burns to the torso or limbs.
  • Careful division of the encasing band of burn tissue will potentially improve ventilation (if the burn involves the torso), or relieve compartment syndrome and oedema (where a limb is involved)

Reference: ATLS 10th edition

Write your Viewpoint 💬

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.