Extent of a Burn

The extent of a burn is expressed as the total percentage of body surface area (TBSA) affected by the injury. Accurate estimation of the TBSA of a burn is essential to guide management.

Multiple methods have been developed to estimate the TBSA of burns. These methods are not used for superficial burns. The best known method, the "rule of nines," is appropriate for use in all adults and when

a quick assessment is needed for a child.
More accurate methods are required for definitive estimation of the extent of burns in children. The Lund and Browder method covers all age groups and is considered the most accurate method to use in pediatric patients. Chart for Estimating Area of Burns
The surface area of a patient’s palm can also be used to estimate the extent of small or patchy burns. Classically, the palm has been considered to represent 1 percent of the TBSA. However, a recent study demonstrated that the palm more accurately represents 0.4 percent of the TBSA, and the entire hand represents 0.8 percent of the TBSA.

Inpatient Treatment and Burn Unit Referral Patients considered to have moderate burns based on the grading system developed by the American Burn Association (ABA) should be admitted for intravenous hydration and surgical care of their wounds (Table 2). Because of the initial difficulties in differentiating deep partial-thickness burns from full-thickness burns, family physicians should strongly consider obtaining a surgical consultation for what appears to be a deep partial-thickness burn affecting more than 3 percent TBSA.

Pulmonary insufficiency is responsible for more than 75 percent of fire-related deaths.
Because of the possibility of progressive edema, patients with suspected inhalation injury should be observed for at least 12 to 24 hours. Historical or physical findings that raise concern about inhalation injury include coughing, wheezing, dyspnea, facial burns, sooty mucus and laryngeal edema. Fiberoptic bronchoscopy results in more frequent and earlier diagnosis of inhalation injury. One of these examinations should be performed if the diagnosis of inhalation injury is in doubt. Patients at risk for inhalation injury should also be checked for carbon monoxide poisoning. An arterial carboxyhemoglobin level of greater than 10 percent tends to indicate carbon monoxide exposure. Hyperbaric oxygen is the treatment.

Hospital admission is necessary for patients who have circumferential partial-thickness or full-thickness burns, patients who have burn injury and are considered to be predisposed to infection (e.g., those with diabetes), and patients who have sustained a high-voltage electrical injury. Cardiac arrhythmias can occur up to 72 hours after high-voltage electrical injury. Nonspecific changes in ST-T waves are the most common abnormalities noted on electrocardiograms (ECGs) obtained subsequent to electrical injuries. Observation is warranted until the ECG becomes normal.

Children with burns should be admitted to a hospital whenever child abuse is suspected. From 9 to 11 percent of burns in children are nonaccidental injuries, with a peak incidence at 13 to 24 months of age. Immersion scalds are classic burn injuries in child abuse, but abuse should be suspected with any scald injury, especially if there is sharp demarcation between burned and normal skin or splash marks are absent. Child abuse should also be strongly suspected in children with burns suggestive of cigarette or hot-iron injuries. Similarly all burns in women must be considered to have element of abuse until proven otherwise.