Learning Objectives: After reading this article, the physician should be able to:
- Describe the epidemiology of hand burns and the proper way to apply a burn dressing to the hand.
- Recall the types of hand burns that require referral to a specialist.
- Identify the type of burns that result from automobile airbag inflation.
The majority of minor burns do quite well with a modicum of common-sense therapy that includes appropriate debridement, a proper burn dressing, and good follow-up in a compliant patient. Although no self-respecting emergency physician would discharge a burned patient from the ED without a smear of silvadene or some other topical concoction, this intervention is likely more placebo than true therapy. Fancy topicals do prompt the patient to look at his burn, and daily dressing changes promote debridement.
The clinical approach to burns has not significantly changed in the past 20 years. But old-time burn therapy still goes a long way in promoting an overall good feeling about the ED visit, even though there's not much science involved. Protecting the burn with a simple non-adherent dry dressing is very acceptable therapy, albeit less fancy. Bacitracin ointment without a covering is the best way to treat a face burn.
Most physicians are familiar with the treatment of minor outpatient thermal burns, but unusual burns may occasionally be encountered. This discussion will address issues involved with burns of the hands and burn injuries from airbags. These are specialized injuries, and there are a number of important issues involved in the emergency department approach to diagnosis and treatment.
Analysis of Reasons and Locations of Burns on the Hands, Magierski M, et al, Scand J Plast Reconstr Surg, 1979;13:141
This five-year retrospective analysis of 1,055 burns treated at a burn center in Scandinavia includes 461 patients with burns to the hand. About 44 percent of the total number of burn victims had burns to the hand. In most cases, both hands were included in the injury. The etiology of the thermal injury was from flame, explosions, hot liquids, a hot object, electrical currents, and chemical burns. The vast majority of burns occurred in the patient's home. Hand burns suffered in car accidents were usually caused by exposure to open flame. A large number of burns were circumferential (40%), indicating the severity of injury in this cohort of patients.
Interestingly, patients over age 65 or under age 14 had a preponderance of hand injuries. Another common cause was lighting a stove, often with highly inflammable agents such as chemical solvents. Children frequently burned their hands by spilling hot liquid or when their clothing caught fire. Those that were intoxicated received their burns by smoking in bed or by trying to light a kitchen gas stove.
A small number of patients suffered seizures or epilepsy, and burned their hands during a seizure. Other common scenarios were men who were burned at work. Of note, it was rare for a patient to burn just one hand; more often both were involved. The back of the hand, an area that could be protected by gloves, was often the site of the most severe injury.
Minor hand burns are within the province of EPs, but it is prudent to be liberal with referral
Comment: It is difficult to determine the epidemiology of hand burns in this country. I would suspect the hand burns seen in our EDs would be similar to those in this study. Hand burns present a very special type of burn assessment and management that requires aggressive and sophisticated care for all but the most minor injuries. Therefore, most emergency physicians will eventually refer patients who have significant hand burns to burn specialists.
Injuries in workers caused by chemicals or in children or the elderly also present unique rehabilitation issues. Other articles that address severe hand burns, particularly those that require skin grafting or injured joints, tendons, or bones, can be found primarily in the burn literature (Burns 1998;24:493 and J Trauma 1995;38:406).
Minor burns of the hand are well within the province of emergency physicians, but it is prudent to treat these injuries with respect and be liberal with appropriate referral. A few blisters from hot water or grease or minor burns from hot water or open flame can be handled similarly to other outpatient burns. Once the skin of the hand becomes blistered or significantly swollen or if the injuries involve children, the elderly, or workers, it's best to defer to the burn center. Despite the hand being only approximately two percent of body surface area, a hand burn is one of those injuries where a small body surface burn can be a devastating or disabling injury.
In the case of minor burns of the hand, the clinician should employ the principles discussed in previous columns. The initial first aid therapy is to immerse the hand in cool water, an easy way to control pain and perhaps limit injury. The hand certainly lends itself to this type of first aid. The principles are also the same for continuing burn care, topical treatment, and burn dressings.
One exception is the special requirement of a burn dressing of a hand. It is paramount that each digit of the hand (and also the toes) be individually wrapped or separated underneath a fluffy absorbent dressing. Failure to separate the digits is an invitation to maceration and increased tissue loss. Hand dressings are difficult, if not impossible, for a person to change himself, and the home environment and social situations are particularly important. When both hands are burned, one readily sees the issues with outpatient care. If a patient with a burned hand is admitted, elevation of the injured part should begin in the emergency department, along with appropriate pain control and attention to other injuries.
Gatoff et al (Chest 2002;121;289) present an interesting observation on a patient with minor bilateral thumb burns. They report a case of a 29-year-old woman who came to the ED with respiratory distress from pneumonia. They noticed burn lesions on the inner aspect of both thumbs, consistent with thermal burns.
Although pneumonia was easily detected, the authors report that the thumb burns were caused by lighting a crack pipe with a butane lighter that, although directed downward into the pipe, flamed up onto her thumbs. The patient finally admitted to repeatedly burning her thumbs with a lighter while smoking crack cocaine. The authors conclude that finding thermal injuries to the fingertips should suggest crack cocaine use, a possible confounding factor in the treatment of other diseases.
Burn Injuries Caused by Airbag Deployment, Ulrich D, et al, Burns 2001;26(2):196
Although automobile airbags are considered an effective measure to reduce morbidity and mortality in motor vehicle accidents, a variety of medical problems have been attributed to their deployment. A plethora of traumatic injuries to the face, head, and neck have been noted, including thermal burns. These authors present a case history of two automobile drivers who had front-end collisions causing the airbags to inflate. Both drivers sustained superficial partial thickness burns that were directly related to the deployment of the airbag.
For an airbag to be deployed, an aerosol must be created by a minor explosion. The current airbags contain sodium azide and sodium hydroxide, creating high temperature thermal gases to inflate an airbag. When the airbags deflate, these substances can cause a thermal or alkali burn, complicating the friction burns directly related to contact with the rapidly expanding airbag.
Other authors have noted that airbag deployment can cause burns, usually of second degree and located in the upper extremities, trunk, and face. Thermal, chemical, and friction components are all culpable. The alkali involved in the airbag inflation probably will not cause a major caustic burn, but can cause chemical injuries to the eye. Fortunately, most burns from airbags are minor, and they are considered a reasonable trade-off for the protection they provide. Facial and upper extremity burns secondary to airbag deployment are treated in the usual manner.
Comment: Almost 20 million cars in the United States have driver and passenger side airbags, and these cars will be involved in more than 650,000 crashes. All new cars in this country must have them. All studies agree that airbags have decreased morbidity and mortality from otherwise fatal crashes, and lives absolutely have been saved by them. If patients do not wear their seatbelts or if they lie against the mechanism that inflates the airbag at high speeds, serious and fatal injuries from the airbag deployment itself may be seen.
Airbag ventilation holes are often right where most drivers grasp the steering wheel, creating the potential for burns
The general public is well aware of injuries to children when placed in car seats in front of an airbag. New developments, such as smart airbags that inflate at various speeds based on the severity of the crash and the position and the weight of the occupant, will likely reduce airbag injuries.
The mechanics of airbag inflation are somewhat difficult to unravel (Ann Plast Surg 1997;39:111). All airbags require a chemical reaction that produce hot nitrogen gas within the bag. An airbag will inflate within 10 milliseconds of a crash, and deflation occurs within two seconds as the hot gases are vented through exhaust ports on the back of the airbag. If a part of the body, such as hands on the steering wheel, comes in contact with the escaping hot air, thermal injuries may occur. It is estimated that about eight percent of injuries from airbags are due to thermal burns.
Hendrick et al (J Am Acad Dermatol 2002;46:S25) reported a case where a patient suffered second-degree burns of the wrist and hand when the hot air from a deflating airbag actually melted the driver's clothing. They noted that the ventilation holes on airbags are often at 9 and 3 o'clock, positions where most drivers grasp the steering wheel.
Airbags also contain starch or talc to lubricate the airbag, and that gives the appearance of smoke following inflation. The difference in speed and force of deployment, size, and shape of the airbag and the manner in which they unfold or inflate can cause a variety of traumatic injuries. There is, however, no explosion in the strict sense of the word that would put a patient at risk for significant direct thermal injury. Fortunately, the majority of burn injuries from airbags are superficial, and require only minimal therapy (J Am Acad Dermatol 2002;46:S25; Ann Plast Surg 1997;39:111).