Clinicians should not attempt to estimate the depth of a burn injury using only clinical judgment because that judgment may be incorrect, says the Medical Director of the Burn Program at the Hospital for Sick Children in Toronto, Canada, speaking at the annual meeting of the Canadian Association of Wound Care (CAWC) about burn injuries and burn scars.
"Keep in mind that emergency room clinical accuracy is only 30% among expert staff," says Joel Fish M.D., F.R.C.S.C., a plastic surgeon. "Burn depth is diagnosed incorrectly in emergency rooms because of a lack of understanding of the pathophysiology of burns. You cannot say a burn injury does not look too bad because you really don't know."
The pathophysiology of a burn involves hyperaemia, coagulation, and stasis, and the clinical appearance may be misleading in terms of representing the severity of the burn injury. Indeed, the appearance of a burn can change drastically in the first 48 to 72 hours after a burn is sustained.
"The ultimate depth of the wound can take more than two weeks until it is certain," Dr. Fish says.
The depth of the problem
Near-infrared spectroscopy (NIR) has been shown to be effective in classifying burn injuries. A study involving 16 patients with acute superficial and full-thickness burns showed that the use of NIR was able to differentiate between superficial and full-thickness burn injuries.1
NIR is available commercially in Canada through the Multispectral MOBile tiSsue Assessment device, referred to as MIMOSA. The device is a non-invasive technology that can photograph wounds using near-infrared light that, apart from classifying burn injuries, can also be used to predict when a diabetic foot ulcer will develop before it is apparent to the human eye.
For the time being, ERs will continue to rely on visual assessment in daily clinical practice to evaluate burn depth, and that assessment will not offer a high degree of accuracy.
"What is perceived as (a) minor (burn) is often not,” Dr. Fish says, “especially taking into consideration the point of view of parents (of a child). Even contact with a hot latte drink for two seconds can result in a full-thickness burn.