Burns: Clinical sciences

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Introduction0:00–0:42

Burns are injuries caused by heat, cold, friction, radiation, electricity, or chemical exposure. When significant heat is applied to the skin, either in the form of a hot liquid, solid object, or flame, this thermal energy can result in irreversible tissue destruction.
Extensive tissue destruction, especially in burns larger than 40% of the total body surface area, or TBSA; can cause fluid loss, and with it, hypovolemic shock!
Burns are classified based on the depth of injury into first-, second-, third-, and fourth-degree burns, as well as burns accompanied by smoke inhalation.
When evaluating a patient with burns, your first step should be an ABCDE assessment to see if the patient is unstable or stable.

Unstable patient0:42–1:05

If the patient is unstable, first stabilize their airway, breathing, and circulation. This means that you may need to intubate the patient, obtain IV access, and administer fluids before continuing with your assessment.

Stable patient1:05–1:28

Now let’s move on to the stable patients. If your patient is stable, start with a focused history and physical examination.
History reveals thermal injury and can identify the mechanism of injury, such as hot liquids, flames, or grease. The physical exam will vary depending on the depth of the burn.
Some burns might be accompanied by smoke inhalation, so let’s talk about that. History might reveal delayed extrication from a fire in an enclosed space.

Smoke inhalation1:28–3:33

On physical examination, your patient may have facial burns, singed facial hair, wheezing, or stridor. They may also cough up carbonaceous material, or soot.
Once you suspect inhalation injury, you should obtain labs, including an ABG and carboxyhemoglobin level. Findings may include decreased paO2 and oxygen saturation.
However, ABG might be completely normal initially. When it comes to carboxyhemoglobin, in non-smokers with inhalation injury it might increase over 3%; however, in smokers, those levels might be greater than 10%, since they are chronically exposed to carbon monoxide from tobacco smoke.
Next, order a chest x-ray. The initial chest x-ray can be normal; however, it is important to establish a baseline evaluation of the lungs.
If your patient is intubated, you should also perform a bronchoscopy, which may show carbonaceous deposits, edema, and erythema throughout the airway.
Other findings include bronchorrhea, or copious sputum, and bronchial obstruction. Mucosal sloughing typically appears later as bronchial inflammation worsens due to chemical byproducts in the inhaled smoke.
Based on all these findings, you can diagnose inhalation injury. The next step is to start inpatient management.
This includes administering high-flow oxygen to maintain oxygen saturations above 90%. If the patient develops drooling, wheezing, or stridor, or is unable to maintain oxygen saturations higher than 90%, they should be intubated if they aren’t already.
In an intubated patient, you can also perform serial bronchoscopies to monitor the progression of the injury and wash out any carbonaceous material within the lungs.
Burns are classified based on the depth of injury into first-, second-, third-, and fourth-degree burns. Let’s switch gears and talk about first-degree burns, also known as superficial because they involve only the epidermis.

First-degree burns3:33–4:22

To remember first-degree burns, just imagine a sunburn. So, on physical exam, the skin is soft; it blanches when pressure is applied; and is typically painful.
If you see this, then you are dealing with a first-degree burn. Once you diagnose a first-degree burn, you can treat them on an outpatient basis.
Management includes wound care, like cleaning the burn with cool tap water and mild soap and applying topical analgesia such as aloe vera if needed.
If they require additional pain management, acetaminophen is usually sufficient. Now, let’s move on to second-degree burns, also called partial thickness burns since they extend into the dermis.

Second-degree burns4:22–4:50

On a physical exam, the involved skin is usually warm, soft, and erythematous, and there might be pain to palpation. The skin may blanch when pressure is applied; however, blistering is often present.
Deep second-degree wounds are less painful since some nerve endings have been damaged. They also blanch less than superficial ones.
Alright, let’s switch gears and talk about third-degree burns. Third-degree burns, also called full-thickness burns, are deeper and extend to the subcutaneous fat.

Third- and fourth-degree burns4:50–5:31

Patients usually report little or no pain, due to significant nerve damage. On physical exam, the skin may appear white, brown, or charred, feel firm or leathery, and doesn’t blanch with pressure.
Lastly, let’s talk about the most severe burn category, fourth-degree burns. In fourth-degree burns, there is little or no pain due to extensive tissue necrosis.
On exam, the skin appears charred, and the burn extends down to the muscle, tendon, or bone. Once you diagnose the second-, third- and fourth-degree burn, calculate the TBSA to determine the treatment.
The first method to calculate TBSA is the Rule of Nines, which assigns specific percentages to different body surfaces. In adults, the head represents 9%, the anterior chest and abdomen are 18%, the back is 18%, and the perineum is 1%.

Treatment5:31–10:38

Each arm is 9%, while each leg is 18%. Another method is the palmar method, which involves estimating the affected area based on the size of the patient’s palm, which represents 0.5% of their BSA; or their hand, which represents 1% of their BSA.
The last method, called the Lund and Browder chart, is the most accurate but lengthy method. Here you mark an outline of the burn on printed body diagrams, calculate the affected area in each region, and add all the areas to obtain the TBSA.
Once you determine the TBSA for your patient, you should decide whether they meet the criteria for inpatient management and even transfer to a dedicated burn center.
Comorbidities or immunocompromised state, multiple trauma, any partial thickness burn greater than 10% TBSA, any full thickness burn, any burns to the face, hands, perineum, feet, or over joints, and any circumferential burns are criteria for inpatient burn treatment.
If the patient doesn’t meet these criteria, you can start outpatient management. This is the case with partial-thickness burns that are less than 10% TBSA.
Outpatient management includes daily dressing changes and the application of topical antimicrobial agents such as bacitracin or silver sulfadiazine to deep partial-thickness burns.
Alright, if the patient meets the criteria, admit them to the hospital and order labs, including CBC and CMP. You may identify electrolyte abnormalities, especially in larger burns with TBSA > 20%.
When it comes to management, the main goal is fluid resuscitation. If your patient’s TBSA is 10-20%, start maintenance lactated Ringer’s solution to maintain urine output at 0.5 ml/kg/hour.
If the TBSA is >20%, use the Parkland formula to determine your patient’s fluid deficit. The Parkland formula is as follows: 4 ml multiplied by %TBSA multiplied by the patient’s weight in kilograms.
This will give you the total amount of crystalloid fluid needed in the first 24 hours, with half of the volume administered in the first 8 hours and the remaining amount given over the next 16 hours.
Then administer lactated Ringer’s to replace losses and maintain urine output at 0.5 ml/kg/hour. Remember that in patients with severe burns, exclusive use of crystalloid fluid may result in over-resuscitation, which can lead to complications like bowel and pulmonary edema.
Next, you should initiate pain management, with medications like acetaminophen, gabapentin, or narcotics. In intubated patients, you should also administer sedation.
Now, always remember that burn patients are in a hypermetabolic state, meaning their bodies break down more protein. In terms of nutrition, burn patients have higher caloric and protein needs.
If they can tolerate oral intake, start them on a high-protein diet. If they are intubated, initiate enteral nutrition, and start prophylaxis to prevent stress ulcers.
Here’s a clinical pearl. Since burns are open wounds, be sure to monitor closely for signs of infection.
For non-surgical management, topical antimicrobials like bacitracin, mupirocin, silver sulfadiazine, or mafenide can be applied prophylactically over the damaged skin; while the use of oral or IV antibiotics hasn’t shown any proven benefit or improved outcomes.
Additionally, if they are not up to date on their immunization, make sure to give them a vaccine or prophylaxis for tetanus.
Alright, when it comes to surgical management, patients with partial thickness burns usually need wound debridement, and sometimes skin grafting.
Grafts for partial thickness burns include xenografts and synthetic dermal substitutes. Patients with full-thickness burns will often require a different type of graft called an autograft, which uses the patient’s own skin.
Allografts, or skin from cadavers, may be used temporarily for deeper burns that can’t be immediately staged. Now, if your patient has a circumferential burn, you might need to perform an emergency escharotomy.
This involves making an incision through the burnt skin to release the eschar and restore circulation to the area, or in the case of a circumferential chest burn, to allow for adequate ventilation.
Finally, fourth-degree burns that extend down to the bone might require amputation of the involved limb. Alright, as a quick recap… Burns are classified depending on depth into first-, second-, third-, and fourth-degree, and some burns might be accompanied by smoke inhalation causing inhalation injury to the airways.
Treatment is based on the type of burn and the TBSA involvement. First- and superficial second-degree burns are treated non-surgically with dressing changes and topical agents.

Review10:38–11:33

Deep second-degree burns involving over 10% TBSA, third-degree and fourth-degree burns should be managed as inpatients. Administer fluid resuscitation with crystalloid, pain management, and nutritional support.
Surgical treatment involves xenografting, allografting, or autografting. In the case of fourth-degree burns, amputation may be necessary if the burn extends to the bone.
third degree and fourth degree burns should be managed as inpatient administer fluid resuscitation with crystalloid pain management and nutritional support Surgical treatment involves xenograft allograft or or autografting In the case of fourth degree burns amputation may be
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