In-Service Exam
Burns - 2001





PHOTO

A 2-year-old boy is brought to the emergency department after sustaining a burn to the corner of the mouth when he bit on an electric cord. A photograph is shown above. The most appropriate management is splinting of the oral commissure for a minimum of what period of time?

(A) Six weeks
(B) Two to three months
(C) Six months
(D) One year

The correct response is Option C.

In this child who has sustained a burn to the oral commissure, the oral commissure should be splinted for a period of at least six months. Approximately 90% of all burns of the oral commissure occur in children younger than age 4 years, and boys are twice as likely to be injured; most of these injuries occur when a child places a live electric cord into the mouth. The flow of saliva produces an electrical short, resulting in thermal damage to the tissues.

Because long-term splinting has been shown to prevent microstomia and preserve function in patients who have injuries confined to the oral commissure, a custom-made device (either fixed or removable) should be applied to compress the commissure. It should be worn continuously for a minimum of six months and then at night only for several more months.

In these children, there is a 10% incidence of bleeding from the labial artery following injury. The child's parent should be instructed to place the thumb and finger on the artery to control the bleeding if this does occur.

In children who have more severe injuries or for whom splinting is not practical, early surgical intervention or delayed reconstruction following scar maturation is recommended. If the injury extends beyond the oral commissure, functional lip reconstruction should be performed.

References
1. Achauer BM. Reconstructing the burned face. Clin Plast Surg. 1992;19:623-636.
2. Gottlieb LJ, Beahm EK. Pediatric burn reconstruction. In: Bentz ML, ed. Pediatric Plastic Surgery. Stamford, Ct: Appleton & Lange; 1998:619-633.
3. Jordan RB, Daher J, Wasil K. Splints and scar management for acute and reconstructive burn care. Clin Plast Surg. 2000;27:71-85.

PHOTO

Eight months after sustaining a deep second-degree burn of the dorsal aspect of the right hand, a 45-year-old woman has hyperextension of the metacarpophalangeal joint of the little finger resulting from a progressively worsening scar contracture. A photograph is shown above. Intensive occupational therapy has not improved this patient's condition. Following release of the scar contracture, which of the following is the most appropriate operative management?

(A) Thin split-thickness skin grafting
(B) Full-thickness skin grafting
(C) Cultured epithelial autografting
(D) Coverage with a free lateral arm flap
(E) Coverage with a radial forearm flap

The correct response is Option B.

This patient has a significant scar contracture after sustaining a deep second-degree burn, which by nature is defined as a partial-thickness burn. This type of burn is often associated with hyperextension scarring and preservation of the underlying extensor tendon mechanism. Following release of the scar contracture, this patient should undergo full-thickness skin grafting of the hand. The paratenon of the extensor mechanism will readily accept a full-thickness skin graft, which will maximize long-term mobility of the metacarpophalangeal joint. In addition, full-thickness skin
Both thin and thick split-thickness skin grafts have higher secondary contraction rates than full-thickness skin grafts, with thin split-thickness skin grafts having the greatest rate of secondary contraction.

Because full-thickness skin grafting will provide the best thin coverage of the burn wound, more difficult and sophisticated procedures, such as autografting or coverage with free or pedicled flaps, are unnecessary.

References
1. Brown EZ. Skin grafts. In: Green DP, ed. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;3:1759-1780.
2. Cram AE. Split thickness skin grafts. In: Blair WF, ed. Techniques in Hand Surgery. Baltimore, Md: Williams & Wilkins; 1996:8-12.
3. Schenck RE. Full thickness skin grafts to the hand. In: Blair WF, ed. Techniques in Hand Surgery. Baltimore, Md: Williams & Wilkins; 1996:13-18.

Which of the following immunologic responses is most likely to be seen in a 50-year-old woman who has sustained a 50% total body surface area (TBSA) burn in a house fire?

(A) Augmented B lymphocyte function
(B) Decreased fibronectin levels
(C) Decreased quantity of suppressor T lymphocytes
(D) Increased complement activation
(E) Increased production of IgG and IgM antibodies

The correct response is Option B.
Immunologic responses anticipated in this 50-year-old woman who has sustained a 50% TBSA burn include decreased levels of fibronectin, diminished complement activation, and decreased production of immunoglobulin antibodies. Patients who sustain burn injuries enter into an immunocompromised state, in which the ability to perform the functions of phagocytosis and pathogen elimination are severely limited, resulting in an inability to produce fibronectin. In addition, there is a generalized depression of the cellular immune response, including a decrease in the quantity and function of both B and T lymphocytes; however, the number of suppressor T lymphocytes is actually increased following acute thermal injury.

Which of the following physiologic mechanisms is increased during the first 24 hours following thermal burn injury?

(A) Cardiac output
(B) Central venous pressure
(C) Circulating erythrocyte volume
(D) Circulating glucose concentration
(E) Plasma volume

The correct response is Option D.

The circulating glucose concentration is increased during the first 24 hours following thermal burn injury. The affected patient develops glucose intolerance due to the release of catecholamines from the burn site. Because of this, glucose should not added to the fluids given intravenously for acute resuscitation.

Following burn injury, the release of myocardial depressants diminishes cardiac output. Cardiac output is decreased to 40% to 60% of normal as a result of decreased plasma volume and increased systemic vascular resistance. Cardiac output then returns to normal but is not increased. The aforementioned decrease in plasma volume, which occurs in part from a capillary leak, subsequently leads to a decrease in central venous pressure. In addition, there is a decrease in circulating erythrocyte volume, due in part to a direct destruction of erythrocytes by the injured tissue.

References
1. Press B. Thermal, electrical, and chemical injuries. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:161-189.
2. Yamaguchi Y, Yu YM, Zupke C, et al. Effect of burn injury on glucose and nitrogen metabolism in the liver: preliminary studies in a perfused liver system. Surgery. 1997;121:295.

In a patient who has an acute deep partial-thickness burn of the ear, which of the following is the most appropriate immediate management?

(A) Application of silver nitrate soaks
(B) Application of mafenide acetate dressings
(C) Application of silver sulfadiazine dressings
(D) Debridement of the wound and splinting
(E) Excision of the burn eschar and grafting

The correct response is Option B.

In a patient who has an acute deep partial-thickness burn of the ear, the most appropriate management is application of mafenide acetate dressings every 12 hours. This topical antimicrobial therapy will prevent the development of suppurative chondritis, a painful condition that develops within the auricular cartilage in patients with this type of burn. It is first seen three to five weeks after initial injury and is extremely difficult to treat once it is acquired. Because mafenide acetate has a broad antibacterial spectrum and will easily penetrate ear cartilage, it is advocated as initial treatment.

Silver nitrate has a broad antimicrobial spectrum but penetrates the burn wound only minimally. Although silver sulfadiazine is most commonly used for topical therapy in patients with burn wounds, it contains lower antibacterial levels than mafenide acetate and will not penetrate burn eschar. Avoiding aggressive debridement and extreme pressure on the affected ear (ie, the use of excessive dressings or a pillow) has been shown to markedly decrease the incidence of chondritis. Early excision and grafting are not recommended.

References
1. Bernard SL. Reconstruction of the burned nose and ear. Clin Plast Surg. 2000;27:97-112.
2. Press D. Thermal, electrical, and chemical injuries. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:161-191.
3. Rosenthal JS. The thermally injured ear: a systematic approach to reconstruction. Clin Plast Surg. 1992;19:645-661.

A 25-year-old man has burn alopecia after sustaining a burn wound involving 35% of the hair-bearing scalp. Which of the following is the most appropriate method of reconstruction in this patient?

(A) Free flap reconstruction
(B) Micrografting
(C) Minigrafting
(D) Strip grafting
(E) Tissue expansion

The correct response is Option E.

In patients with burn alopecia, the hair-bearing area of the scalp is amenable to tissue expansion; therefore, it is most appropriate for reconstruction in this patient. With this technique, large areas of the scalp can be resurfaced with similar tissue, resulting in reliable, consistent hair growth.

Grafting techniques, such as the use of micrografts, minigrafts, or strip grafts, are appropriate for management of male pattern alopecia but are unreliable in a patient with a compromised recipient site, such as a burn wound. Free flap reconstruction will allow rapid wound healing in a patient who has acute extensive and/or deep injuries involving exposed, devitalized skull.

Although hair transplantation is an option in patients with burn-related alopecia, it would not be the treatment of choice in this patient because of the diminished vascularity and severe scarring seen in the recipient bed.

References
1. Achauer BM. Reconstruction of the burned face. Clin Plast Surg. 1992;19:623-636.
2. Barrera A. The use of micrografts and minigrafts for the treatment of burn alopecia. Plast Reconstr Surg. 1999;103:581-584.
3. Press B. Thermal, electrical, and chemical injuries. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:161-190.