The Cardiovascular
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Rule of Nines for Burn Surface Area

Estimates total body surface area burned in adults.

Rule of Nines for Burn Surface Area
Head and neck (9%)
Right arm - entire (9%)
Left arm - entire (9%)
Anterior trunk (18%)
Posterior trunk (18%)
Right leg - entire (18%)
Left leg - entire (18%)
Perineum / genitalia (1%)
Result0 % TBSA

Estimated total body surface area burned. Adults with >=15-20% TBSA usually need formal fluid resuscitation and burn-centre referral.

Total body surface area
0 %

When to use

  • Rapid bedside estimate of adult burn size to guide fluid resuscitation and transfer.
  • Count only partial- and full-thickness (second- and third-degree) burns.

Formula

Adult regional percentages: head/neck 9, each arm 9, anterior trunk 18, posterior trunk 18, each leg 18, perineum 1. Sum the involved regions (use partial fractions for incomplete regions).

Pearls and pitfalls

  • The adult scheme overestimates in young children, whose heads are relatively larger - use a paediatric (Lund-Browder) chart instead.
  • The patient's palm (including fingers) approximates 1% TBSA for scattered burns.

References

  1. Wallace AB. Lancet. 1951;1(6653):501-4.