Burns can be extremely painful for the patient and difficult to manage for the clinician. Over the years I treated many burns including babies, children and older adults. Understanding burns is the basic requirement that is absolutely necessary in the healing process. During the initial assessment staging the wound is vital and is done by sensation tests throughout the involved tissue because the entire burn will vary in depth causing sensation changes over the peri wound and wound itself.
First degree wounds are the most painful because nerve endings are inflamed and fully exposed encompassing the epidermis layer causing redness and swelling (MedlinePlus, 2014). First degree burns usually heal in 7 to 10 days with topical medication and light debridement. Second degree burns involve the epidermis and dermal layers and remain painful because the nerves are exposed causing redness, swelling and blisters (MedlinePlus, 2014).
Second degree burns heal in 10 to 21 days requiring topical medication and moderate firm debridement timely to avoid scaring. Third degree burns involve the epidermis, dermis and hypodermis layers with much less pain because the nerves are fully damaged causing numbness, redness, swelling, blisters and thick eschar (MedlinePlus, 2014). Third degree burns heal in 21 days to months and usually require surgical debridement, skin grafting resulting in severe scaring and soft tissue restrictions.
Burns are devided into 4 categories of depth: epidermial, superficial partial thickness, deep partial thickness and full-thickess (Devgan et al. 2006). Epidermal and superficial partial thickness are considered 1st and 2nd degree requiring non-operative wound treatment, but deep partial thickness and full-thickness are considered 3rd degree burns and often require operative more invasive care (Devgan et al. 2006).
Clinical understanding of these categories is vital in the wound healing process because burn wounds undergo a conversion process that imped healing (Devgan et al. 2006). The conversion process is described as 3 complicated zones: viable zone of coagulation, continued viable stasis zone and edematous zone of hyperemia (obstruction of blood flow) (Devgan et al. 2006). Wound healing is interrupted in these 3 zones requiring timely assessment and intervention, which is why this research article looked at various modalities to improve depth assessment (Devgan et al. 2006). The most used and cost effective method is bedside clinical exam with an accuracy of two thirds of burns assessing appearance, staging of capillary refill, capillary staining and sensation testing with light touch and pin prick (Devgan et al. 2006).
However, bedside assessment limitations are consistent clinical knowledge of burns leading to error of overestimation of burn depth and validity of diagnosis (Devgan et al. 2006). The available modalities that are listed in this article are: biopsy and histology, thermography, vial dyes, indocyanine green video angiography and laser doppler flowmetry (Devgan et al. 2006).
Biopsy and histology is 100% accurate but has drawbacks of invasiveness and added tissue damage and scarring, increased cost of experienced pathologist and subjective interpretation (Devgan et al. 2006). Thermography is a modality that measures tissue temperature to diagnose burn depth with an accuracy of 90%, but has disadvantages of false positive depth secondary to loss of heat within the tissue after 3 days of the burn (Devgan et al. 2006).
Vital dyes is a modality rarely used that employs intravenous injection of fluorescein dye surveyed by illumination of 360 to 400 ultraviolet light over damaged tissue looking for depth but cannot differentiate between superficial and deep partial-thickness wounds or recognize healthy tissue covered with eschar (Devgan et al. 2006).
Indocyanine green video angiography (ICG) is a modality that uses videography that pictures changes in tissue perfusion with intravenous injection of IGC looking for dye uptake within the damaged tissue (Devgan et al. 2006). This modality has the potential to gain popularity but has disadvantages of cost and large infrastructure requirements as well as interference with topical medication used for burn intervention (Devgan et al. 2006).
Laser doppler flowmetry monitors perfusion using mono frequency light waves with an accuracy of 90 to 97% (Devgan et al. 2006).
However, this modality has limitations as well because it involves using a probe and pressure directly on the burned tissue subjecting the tissue to infection and additional wound trauma (Devgan et al. 2006). In addition to the above modalities there is considerable research that is underway using advance modalities of: Optic measurements, nuclear imaging, and non-contact high frequency US to improve burn depth assessment (Devgan et al. 2006).
All of the mentioned modalities sound very promising in assessing burn depth to aide in diagnosing and timely intervention in burn victims. However, in my opinion improvement in consistent clinician assessment is necessary followed by a referral as soon as possible to the next level of care for the best outcome.
Sherri Boos, PT, DPT
Figure 1 (MedlinePlus Medical Encyclopedia Image, 2014).
Burns: MedlinePlus Medical Encyclopedia Image. (n.d.). Retrieved August 3, 2014, from
Devgan, L., Bhat, S., Aylward, S., & Spence, R. J. (2006). Modalities for the assessment of burn
wound depth. Journal of Burns and Wounds, 5, 7-15. Retrieved from Utica College.