Summary of study session VIII
In study session VIII you have learnt
- Burn is an injury to the skin or tissue results from excessive exposure to thermal, electrical, chemical and radioactive agents. Determination of the size and depth of a burn sets the guidelines for resuscitation.
- Burn depth is classified as first, second, or third degree. First degree burns result from damage to the superficial layers of the epidermis. They are characterized by erythema and pain. Extension of thermal damage to the dermis results in second degree burns. Coagulation of the entire dermis results in third degree burns. These wounds may be charred (blacken) or white to deep red. They are insensate to pain, although pressure may be noted with palpation.
- The size of the burned area as a fraction of the total body surface area is estimated by the rule of nines. In an adult, the head contributes to 9%; the upper extremities, 18%; the trunk, 36%; and the lower extremities, 36% of the TBSA. These proportions are somewhat different in children, depending on the age and size.
- Pathophysiology of burn may be local accompanied by capillary injury which become leaky and produce edema, and systemic which release inflammatory substance and produce hypovolemia
- Upper airway inhalation injury is usually due to a heat injury that leads to swelling and upper airway obstruction secondary to edema of the posterior pharynx and supraglottic regions. 100% oxygen is the initial treatment and may necessitate intubation and ventilation.
- After the evaluation and treatment of disorders of the airway and breathing, the circulation must be assessed. All of the various formulas used to estimate the amounts of fluid to be given to a burn patient are based on the total body surface area burned.
- The most widely used formula to estimate the initial fluid requirements for a burned patient is the. The 24-hour fluid requirement is estimated based on the Parkland Formula: 4 mL/kg per percent TBSA burned. Half of this amount of fluid is given in the first 8 hours following the burn with the remainder given over the next 16 hours. Urinary output is the most reliable guide to the adequacy of resuscitation.
- Deep second degree and third degree wounds require excision and grafting for sizable burns, and the initial dressing should be aimed at holding bacterial proliferation in check until the initial operation is performed for which anesthesia is required.
- Before anesthesia we have to assess the patient and consider the pathophysiologic changes such as reduced circulating blood volume, anemia, renal failure, etc on you anesthetic management.
- Vital signs (blood pressure, pulse rate, temperature and respiratory rate) and urine output measurement are considered the standard of care in the resuscitation assessment of the burn patient.
- Ketamine 0.5- 1.0 mg/kg IV can be given for dressing, debridement and grafting of facial burns, where the use of a mask is impossible.
- Endotracheal anesthesia is useful for surgery in the area of the head and neck. It is also useful for prolonged surgery and surgery performed in abnormal positions.
- Inhalational anesthesia is useful for short procedures performed in the supine position, in a patient with a secured airway but may be difficult in patients with facial burns.
- Suxamethonium is contraindicated after 48 hours of burn up to two years.
- Excisional treatment of burn wounds is usually associated with a large operative blood loss. Appropriate fluid resuscitation is imperative to improving mortality, especially in the initial phase of treatment and during operative excision and grafting.
- Burn patients often receive large volumes of fluid during their resuscitation and therefore develop significant soft-tissue edema. Tracheal extubation should always be delayed until the tissue edema resolves. When planning to extubate the patient's trachea, it is important to wait until an air leak occurs around the endotracheal tube when the cuff is deflated before extubation.
Last modified: Sunday, 20 November 2016, 12:06 PM