Classifications and Assessments

OT Dude Academy’s Free NBCOT® Exam Prep Course Burns Classifications and Assessments

Mechanisms1 

Heat (Thermal)

Contact to an external heat source, e.g., flame, scalding water. Most thermal burns involve the epidermis because the thermal conductivity of skin is low.

Electrical

Electrical energy is transformed into heat as the current passes through body tissues. The magnitude of injury depends on the pathway of the current.

Friction

Caused by a combination of mechanical disruption of tissues and heat generated by friction.

Chemical

Caused by caustic reactions such as alteration of pH, disruption of cellular membranes, and direct toxic effects on metabolic processes. Acid and alkaline burns can cause necrosis of tissues. Systemic absorption of chemicals can be life-threatening, while local damage can include full-thickness burns of the skin and underlying tissues.

Radiation

Radiofrequency or ionizing radiation causes damage to the skin and tissues. Sunburn is the most common, but also from therapeutic radiation therapy. Radiation burns are often associated with cancer. The Severity depends on the dose, time of exposure, and type of particle and its energy.

Size and Severity

Determination of the total body surface area (TBSA) is important for fluid resuscitation, facility transfer decisions, management, prognosis, and research. Common methods used to estimate TBSA include the patient palm method, rule of nines, and the Lund and Browder chart. Computerized methods are also available as well as smartphone applications, but are not yet widely accepted in practice.2 

  • The patient palm “rule of palm” method uses the palmar surface of the adult hand to correspond to 1% of the body. This method may not be practical if the burn size is large.
  • Rule of Nines (Wallace Rule of Nines): assesses the TBSA in burn patients. Only used for 2nd and 3rd-degree burns. Alterations can be made based on BMI and age. Assigns a percentage to different body areas: head – 9% (4.5% anterior + 4.5% posterior), anterior chest – 9%, posterior chest – 9%, anterior abdomen – 9%, posterior abdomen – 9%, each upper extremity – 9% (4.5% anterior + 4.5% posterior), each lower extremity – 18% (9% anterior + 9% posterior), perineal – 1% = 100%
    • Infants (1-4): 20% head + 32% torso + 8% each upper extremity + 16% each lower extremity = 100%.
  • Examples of variations in the rule of 9’s
    • Pre-teenager/teenager (10-14): 13% head + 32% torso + 9.5% each upper extremity + 18% each lower extremity = 100%.
    • Children (5-9): 15% head + 32% torso + 9.5% each upper extremity + 17% each lower extremity = 100%.
  • Although the Lund and Browder (LB) chart is considered to be the most accurate of the three, it is still prone to errors. The LB chart is also more difficult to use as estimations have to be used with mental calculations being performed involving fractions making it prone to errors. Results may also vary significantly between observers. This makes the LB chart difficult to use during emergency situations compared to the other 2 methods. A modified LB chart that subdivides each chart region into quadrilaterals of 0.25% each, has been proposed by researchers with more consistency than the regular LB chart.2 
  • Mobile Apps: BurnMed

Accuracy

The rule of palm method can lead to an overestimation of 10% to 20%.3 

The Rule of 9’s may need to be adjusted for obese and pediatric populations. Obese patients have a closer approximation of 50% TBSA of the trunk, 15% for each leg, 7% for each arm, and 6% for the head. The rule of 8’s is a better approximation for infants weighing less than 10kg.4 

Studies have shown the rule of 9’s to overestimate TBSA by 20% compared to computer-based applications at 25%-35% TBSA. Overestimation of TBSA can lead to excessive IV fluid resuscitation and the potential for volume overload and pulmonary edema. Patients with preexisting comorbidities are at risk for acute cardiac and pulmonary decompensation.5 6 

Measurements made using BurnMed had lower variability than the Lund and Browder chart.7 

Depth1 8 

  • Superficial or epidermal burns (1st degree) involve only the epidermal layer of skin.
    • Skin redness
    • Blisters can be very painful
    • Heals within 7 days with minimal scarring.
  • Partial-thickness (2nd degree) burns involve the epidermis and portions of the dermis.
    • Superficial partial-thickness: involves the epidermis and upper dermis layers.
      • Red and weeping, blanches to pressure
      • Painful
      • Heals within 3 weeks.
    • Deep partial-thickness: involves the epidermis and deeper dermis layers.
      • Varies from white to red.
      • Painful to pressure only.
      • Often blister.
      • High risk for infection.
      • Heals within 9 weeks.
      • Hypertrophic scarring likely.
      • Differentiation from full-thickness burns is often difficult.
  • Full-thickness (3rd degree) burns extend through and destroy all layers of the dermis.
    • Leathery white to leathery gray to charred black appearance (eschar).
    • Skin is dry and does not blanch.
    • No pain.
    • Hairs can be easily pulled.
    • Skin grafts are needed.
    • Hypertrophic scarring is very high.
    • Eschar can compromise limb or torso if circumferential.
  • Deeper / subdermal (4th degree) burns extend through the skin into underlying soft tissues such as fascia, muscle, and/or bone.
    • Potentially life-threatening.
    • Charring with exposed underlying layers.
    • Significant nerve damage.
    • Surgery is often needed for wound healing.
    • Hypertrophic scarring risk is very high.

Sedation Scales

Occupational therapy practitioners working in the ICU should become familiar with the sedation scales that the facility uses for team communication, assessing the level of consciousness, and the patient’s appropriateness for therapy. Sedation should be evaluated regularly using appropriate scales by the team.9 

  • Glasgow Coma Scale (GCS) – Blog post & Quiz – commonly used, but not appropriate for this patient population as it is not a scale intended to be used for sedation.
  • Richmond Agitation Sedation Scale (RASS)
  • Ramsay Sedation Scale
  • Sedation-Agitation Scale
  1. Rice, P., & Orgill, D. (2019). Assessment and classification of burn injury. Uptodate [internet]. Waltham (MA): UpToDate Inc.[↩][↩]
  2. Murari, A., & Singh, K. N. (2019). Lund and Browder chart—modified versus original: a comparative study. Acute and critical care, 34(4), 276.[↩][↩]
  3. Kamolz LP, Lumenta DB, Parvizi D, Dirnberger J, Owen R, Höller J, et al. Smartphones and burn size estimation: “Rapid Burn Assessor” Ann Burns Fire Disasters. 2014;27:101–4.[↩]
  4. Moore, R. A., Waheed, A., & Burns, B. (2020). Rule of nines. StatPearls [Internet].[↩]
  5. Prieto MF, Acha B, Gómez-Cía T, Fondón I, Serrano C. A system for 3D representation of burns and calculation of burnt skin area. Burns. 2011 Nov;37(7):1233-40.[↩]
  6. Neaman KC, Andres LA, McClure AM, Burton ME, Kemmeter PR, Ford RD. A new method for estimation of involved BSAs for obese and normal-weight patients with burn injury. J Burn Care Res. 2011 May-Jun;32(3):421-8.[↩]
  7. Goldberg, H., Klaff, J., Spjut, A., & Milner, S. (2014). A mobile app for measuring the surface area of a burn in three dimensions: comparison to the Lund and Browder assessment. Journal of Burn Care & Research, 35(6), 480-483.[↩]
  8. Benson, A., Dickson, W. A., & Boyce, D. E. (2006). Burns. BMJ (Clinical research ed.), 332(7542), 649–652. https://doi.org/10.1136/bmj.332.7542.649[↩]
  9. Lavrentieva, A., Depetris, N., & Rodini, I. (2017). Analgesia, sedation and arousal status in burn patients: the gap between recommendations and current practices. Annals of burns and fire disasters, 30(2), 135–142.[↩]
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