Jump to content

Burn

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Vrenator (talk | contribs) at 18:43, 15 December 2010 (Reverted edits by 66.236.0.12 (talk) to last revision by Minceymeatypie (HG)). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

This article is about the injury. For Burn (disambiguation), see Burn (disambiguation).
Burn
SpecialtyEmergency medicine Edit this on Wikidata

A burn is a type of injury to flesh caused by heat, electricity, chemicals, light, radiation or friction.[1][2][3] Most burns only affect the skin (epidermal tissue and dermis). Rarely deeper tissues, such as muscle, bone, and blood vessels can also be injured. Managing burns is important because they are common, painful and can result in disfiguring and disabling scarring. Burns can be complicated by shock, infection, multiple organ dysfunction syndrome, electrolyte imbalance and respiratory distress. Large burns can be fatal, but modern treatments, developed in the last 60 years, have significantly improved the prognosis of such burns, especially in children and young adults.[4][5]


Classification

Three degrees of burns

Burns can be classified by mechanism of injury, depth, extent and associated injuries and comorbidities. Currently, burns are described according to the depth of injury to the dermis and are loosely classified into first, second, third and fourth degrees. This system was devised by the French barber-surgeon Ambroise Pare and remains in use today. [6].

Note that an alternative form of reference to burns may describe burns according to the depth of injury to the dermis. [7]

It is often difficult to accurately determine the depth of a burn. This is especially so in the case of second degree burns, which can continue to evolve over time. As such, a second-degree partial-thickness burn can progress to a third-degree burn over time even after initial treatment. Distinguishing between the superficial-thickness burn and the partial-thickness burn is important, as the former may heal spontaneously whereas the latter often requires surgical excision.

The following tables describe degrees of burn injury under this system as well as provide pictorial examples.

Nomenclature Layer Involved Appearance Texture Sensation Time To Healing Complications Example
First degree Epidermis Redness (erythema) Dry Painful 1wk or less None A sunburn is a typical first degree burn.
Second degree (superficial thickness) Extends into superficial (papillary) dermis Red with clear blister. Blanches with pressure Moist Painful 2-3wks Local infection/cellulitis
Second degree (partial thickness) Extends into deep (reticular) dermis Red-and-white with bloody blisters. Less blanching. Moist Painful Weeks - may progress to third degree Scarring, contractures (may require excision and skin grafting) Second-degree burn caused by contact with boiling water
Third degree (full thickness) Extends through entire dermis Stiff and white/brown Dry Painless Requires excision Scarring, contractures, amputation Eight day old third-degree burn caused by motorcycle muffler.
Fourth degree Extends through skin, subcutaneous tissue and into underlying muscle and bone Charred with eschar Dry Painless Requires excision Amputation, significant functional impairment

Burn severity

With regards to classification, burns are also grouped into degrees of severity. This is assessed based on a number of factors, including total body surface area burnt, the involvement of specific anatomical zones, age of the burn victim and associated injuries.

Burn surface area

Main article: Total body surface area

Burns can also be assessed in terms of total body surface area (TBSA), which is the percentage affected by partial thickness or full thickness burns. First degree and second degree, superificial-thickness burns are not included in this estimation. The rule of nines is used as a quick and useful way to estimate the affected TBSA. More accurate estimation can be made using Lund & Browder charts which take into account the different proportions of body parts in adults and children.[8] The size of the patient's hand print (palm and fingers) is approximately 1% of their TBSA. The actual mean surface area is 0.8% so using 1% will slightly over estimate the size.[9] Burns of 10% in children or 15% in adults (or greater) are potentially life threatening injuries (because of the risk of hypovolaemic shock) and should have formal fluid resuscitation and monitoring in a burns unit.

Causes

Burns are caused by a wide variety of substances and external sources such as exposure to chemicals, friction, electricity, radiation, and heat.

Chemical

Main article: Chemical burn

Most chemicals that cause severe chemical burns are strong acids or bases.[10] Chemical burns can be caused by caustic chemical compounds such as sodium hydroxide or silver nitrate, and acids such as sulfuric acid.[11] Hydrofluoric acid can cause damage down to the bone and its burns are sometimes not immediately evident.[12]

Electrical

Electrical burns are caused by either an electric shock or an uncontrolled short circuit. (A burn from a hot, electrified heating element is not considered an electrical burn.) Common occurrences of electrical burns include workplace injuries, or being defibrillated or cardioverted without a conductive gel. Lightning is also a rare cause of electrical burns. Since normal physiology involves a vast number of applications of electrical forces, ranging from neuromuscular signaling to coordination of wound healing, biological systems are very vulnerable to application of supraphysiologic electric fields. Some electrocutions produce no external burns at all, as very little current is required to cause fibrillation of the heart muscle. Therefore, even when the injury does not involve any visible tissue damage, electrical shock survivors may experience significant internal injury.[13] The internal injuries sustained may be disproportionate to the size of the burns seen (if any), and the extent of the damage is not always obvious. Such injuries may lead to cardiac arrhythmias, cardiac arrest, and unexpected falls with resultant fractures.[14]

Radiation

Main article: radiation burn

Radiation burns are caused by protracted exposure to UV light (as from the sun), tanning booths, radiation therapy (as patients who are undergoing cancer therapy), sunlamps, radioactive fallout, and X-rays. By far the most common burn associated with radiation is sun exposure, specifically two wavelengths of light UVA, and UVB, the latter being more dangerous. Tanning booths also emit these wavelengths and may cause similar damage to the skin such as irritation, redness, swelling, and inflammation. More severe cases of sun burn result in what is known as sun poisoning. Microwave burns are caused by the thermal effects of microwave radiation.

Scalding

Two-day-old scald caused by boiling radiator fluid.

Scalding is caused by hot liquids (water or oil) or gases (steam), most commonly occurring from exposure to high temperature tap water in baths or showers or spilled hot drinks.[15] A so called immersion burn is created when an extremity is held under the surface of hot water, and is a common form of burn seen in child abuse.[16] A blister is a "bubble" in the skin filled with serous fluid as part of the body's reaction to the heat and nerve damage. The blister "roof" is dead. Steam is a common gas that causes scalds. The injury is usually regional and usually does not cause death. More damage can be caused if hot liquids enter an orifice. However, deaths have occurred in more unusual circumstances, such as when people have accidentally broken a steam pipe. The demographics that are of the highest risk to suffering from scalding are young children, with their delicate skin, and the elderly over 65 years of age.

Management

Burns over 10% in children and 15% in adults need hospital admission and fluid resuscitation due to the risk of hypovolaemic shock.[17]

First Aid

Regardless of the cause, the first step in managing a person with a burn is to stop the burning process at the source, and cool the burn wound (but not the patient. It is essential to avoid the "lethal triad" of hypothermia, acidosis and coagulopathy).[18] For instance, with dry powder burns, the powder should be brushed off first. With other burns, the affected area should be rinsed thoroughly with a large amount of clean water. However, cold water should not be applied to a person with extensive burns for a prolonged period (greater than 20 minutes), as it may result in hypothermia. Do not directly apply ice to a burn wound as it may compound the injury. Iced water, creams, or greasy substances such as butter, should not be applied either.[19]

To help ease pain people may be placed in a special burn recovery bed which evenly distributes body weight and helps to prevent painful pressure points and bed sores. Survival and outcome of severe burn injuries is remarkably improved if the patient is treated in a specialized burn center/unit rather than a hospital.

Intravenous fluids

Children with TBSA >10% and adults with TBSA > 15% need formal fluid resuscitation and monitoring (blood pressure, pulse rate, temperature and urine output).[20] Once the burning process has been stopped, the patient should be volume resuscitated according to the Parkland formula . This formula calculates the amount of Ringer's lactate required to be administered to the burn victim over the first 24hrs post-burn.

Parkland formula: 4mls x total body surface area sustaining 2nd/3rd/4th degree burns x patient's weight in kgs.

Half of this total volume should be administered over the first 8hrs, with the remainder given over the following 16hrs. It is important to note that this time frame is calculated from the time at which the burn is sustained, and not the time at which fluid resuscitation is begun. Children also require the addition of maintenance fluid volume. Such injuries can disturb a person's osmotic balance. [21] Inhalation injuries in conjunction with thermal burns initially require up to 40–50% more fluid.

The formula is a guide only and infusions must be tailored to the urine output and central venous pressure. Inadequate fluid resuscitation causes renal failure and death but over-resuscitation also causes morbidity and mortality. All resuscitation formulae should be delivered as a goal directed therapy to prevent the complications of hypovolaemic shock or over-hydration.

Wound management

Debridement cleaning and then dressings are important aspects of wound care. The wound should then be regularly re-evaluated until it is healed.[3] In the management of first and second degree burns little quality evidence exists to determine which type of dressing should be used.[22] Silver sulfadiazine (Flamazine) is not recommended as it potentially prolongs healing time[22] while biosynthetic dressings may speed healing.[23]

Antibiotics

Intravenous antibiotics may improve survival in those with large severe burns however due to the poor quality of the evidence routine use is not currently recommended.[24]

Analgesics

A number of different options are used for pain management. These include simple analgesics ( such as ibuprofen and acetaminophen ) and narcotics. A local anesthetic may help in managing pain of minor first-degree and second-degree burns.[25]

Surgery

Wounds requiring surgical closure with skin grafts or flaps should be dealt with as early as possible.[3] Circumferential burns of digits, limbs or the chest may need urgent surgical release of the burnt skin (escharotomy) to prevent problems with distal circulation or ventilation.[3]

Alternative treatments

Hyperbaric oxygenation has not been shown to be a useful adjunct to traditional treatments.[26] Honey has been used since ancient times to aid wound healing and may be beneficial in first and second degree burns, but may cause infection.[27]

Prognosis

The outcome of any injury or disease depends on three things: the nature of the injury, the nature of the patient and the treatment available. In terms of injury factors in burns the prognosis depends primarily on the burn surface area (% TBSA) and the age of the patient. The presence of smoke inhalation injury, other significant injuries such as long bone fractures and serious co-morbidities (heart disease, diabetes, psychiatric illness, suicidal intent etc.) will also adversely influence prognosis. Advances in resuscitation, surgical management, control of infection, control of the hyper-metabolic response and rehabilitation have resulted in dramatic improvements in burn mortality and morbidity in the last 60 years. Following a major burn injury, heart rate and peripheral vascular resistance increase. This is due to the release of catecholamines from injured tissues, and the relative hypovolemia that occurs from fluid volume shifts. Initially cardiac output decreases. At approximately 24 hours after burn injuries (for patients receiving fluid resuscitation) cardiac output returns to normal, then increases to meet the hypermetabolic needs of the body.

Infection is a major complication of burns. Infection is linked to impaired resistance from disruption of the skin's mechanical integrity and generalized immune suppression. The skin barrier is replaced by eschar. This moist, protein rich avascular environment encourages microbial growth. Migration of immune cells is hampered, and there is a release of intermediaries that impede the immune response. Eschar also restricts distribution of systemically administered antibiotics because of its avascularity.

Risk factors of burn wound infection include:

  • Burn > 30% TBS
  • Full-thickness burn
  • Extremes in age (very young, very old)
  • Preexisting disease e.g. diabetes
  • Virulence and antibiotic resistance of colonizing organism
  • Failed skin graft
  • Improper initial burn wound care
  • Prolonged open burn wound

Burn wounds are prone to tetanus. A tetanus booster shot is required if individual has not been immunized within the last 5 years.

Circumferential burns of extremities may compromise circulation. Elevation of limb may help to prevent dependent edema. An Escharotomy may be required.

Acute Tubular Necrosis of the kidneys can be caused by myoglobin and hemoglobin released from damaged muscles and red blood cells. This is common in electrical burns or crush injuries where adequate fluid resuscitation has not been achieved.

Epidemiology

Disability-adjusted life years for fires per 100,000 inhabitants in 2004.[28]
  no data
  < 50
  50-100
  100-150
  150-200
  200-250
  250-300
  300-350
  350-400
  400-450
  450-500
  500-600
  > 600

According to the American Burn Association[29], an estimated 500,000 burn injuries receive medical treatment yearly in the United States. The 2009 National Burn Repository reports the most common cause of burns as direct fire/flame (43%) followed by scalds (30%). Scald injuries were the predominant cause in children under the age of 5. Burns sustained at home accounted for 65.5% of all burn injuries in the United States that year, and had a mortality rate of 4% overall. This mortality rate was directly associated with advancing age, burn size and the presence of inhalational injury. [30] It is estimated that approximately 75% of deaths from burns and fires in the United States occur either at the scene of the incident or enroute to medical facilities. Demographically, burn victims in the United States tended to be male (70%) and to have suffered their injuries in a residential setting (43%).[29]

In India about 700,000 patients a year are admitted to hospital, though very few are looked after in specialist burn units.[31] About 90% of burns occur in the developing world and 70% of these are in children. Survival of injuries greater than 40% TBSA is rare in the developing world.[32]

See also

References

  1. ^ MedlinePlus. "Burns". Retrieved 2010-09-22.
  2. ^ WebMD (January 7, 2009). "Burns-Topic Overview". firstaid&emergencies. Retrieved 2010-09-22.
  3. ^ a b c d Total Burn Care, 3rd Edition, Edited by David Herndon, Saunders, 2007.
  4. ^ Total Burn Care 3rd Edition. Editied David Herndon. Chapter 1 [1] Accessed January 8, 2010
  5. ^ Sevitt S (1979). "A review of the complications of burns, their origin and importance for illness and death". J Trauma. 19 (5): 358–69. doi:10.1097/00005373-197905000-00010. PMID 448773. {{cite journal}}: Unknown parameter |month= ignored (help)
  6. ^ Ron Walls MD; John J. Ratey MD; Robert I. Simon MD (2009). Rosen's Emergency Medicine: Expert Consult Premium Edition - Enhanced Online Features and Print (Rosen's Emergency Medicine: Concepts & Clinical Practice (2v.)). St. Louis: Mosby. ISBN 0-323-05472-2.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. ^ {Tintinalli, Judith E. (2010). Emergency Medicine: A Comprehensive Study Guide (Emergency Medicine (Tintinalli)). New York: McGraw-Hill Companies. ISBN 0-07-148480-9.
  8. ^ Ames WA (1999). "Management of the Major Burn". Update in Anaesthesia (10). Nuffield Department of Anaesthesia, Oxford, UK. Retrieved 2010-01-22.
  9. ^ Perry RJ, Moore CA, Morgan BD, Plummer DL (1996). "Determining the approximate area of a burn: an inconsistency investigated and re-evaluated". BMJ. 312 (7042): 1338. PMC 2350999. PMID 8646048. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  10. ^ Chemical Burn Causes emedicine Health Accessed February 24, 2008
  11. ^ Chemical Burn Causes eMedicine Accessed February 24, 2008
  12. ^ Hydrofluoric Acid Burns emedicine Accessed February 24, 2008
  13. ^ Mechanism of Electrical Injury Chicago Electrical Trauma Research Institute Accessed April 27, 2010
  14. ^ Electrical Burns: First Aid Mayo Clinic Accessed February 24, 2008
  15. ^ Scald and Burn Care, Public Education City of Rochester Hills Accessed February 24, 2008
  16. ^ Allasio D, Fischer H (2005). "Immersion scald burns and the ability of young children to climb into a bathtub". Pediatrics. 115 (5): 1419–21. doi:10.1542/peds.2004-1550. PMID 15867058. {{cite journal}}: Unknown parameter |month= ignored (help)
  17. ^ Hettiaratchy S, Papini R (2004). "Initial management of a major burn: II--assessment and resuscitation". BMJ. 329 (7457): 101–3. doi:10.1136/bmj.329.7457.101. PMC 449823. PMID 15242917. {{cite journal}}: Unknown parameter |month= ignored (help)
  18. ^ Jansen JO, Thomas R, Loudon MA, Brooks A (2009). "Damage control resuscitation for patients with major trauma". BMJ. 338: b1778. doi:10.1136/bmj.b1778. PMID 19502278.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  19. ^ NHS Choices (3 July 2008). "How do I deal with minor burns?". Retrieved 2010-09-22.
  20. ^ Herndon, David N. (2007). "Chapter 9 Total Burn Care". Total Burn Care. Philadelphia: Saunders. p. 880. ISBN 1-4160-3274-6.
  21. ^ Lee JA (1981). "Sydney Ringer (1834-1910) and Alexis Hartmann (1898-1964)" (PDF). Anaesthesia. 36 (12): 1115–21. doi:10.1111/j.1365-2044.1981.tb08698.x. PMID 7034584. {{cite journal}}: Unknown parameter |month= ignored (help)
  22. ^ a b Wasiak J, Cleland H, Campbell F (2008). "Dressings for superficial and partial thickness burns". Cochrane Database Syst Rev (4): CD002106. doi:10.1002/14651858.CD002106.pub3. PMID 18843629.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  23. ^ Hubley P (2009). "Review: evidence on dressings for superficial burns is of poor quality". Evid Based Nurs. 12 (3): 78. doi:10.1136/ebn.12.3.78. PMID 19553415. {{cite journal}}: Unknown parameter |month= ignored (help)
  24. ^ Avni T, Levcovich A, Ad-El DD, Leibovici L, Paul M (2010). "Prophylactic antibiotics for burns patients: systematic review and meta-analysis". BMJ. 340: c241. doi:10.1136/bmj.c241. PMC 2822136. PMID 20156911.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  25. ^ Minor Burns quickcare.org Accessed February 25, 2008
  26. ^ Villanueva E, Bennett MH, Wasiak J, Lehm JP (2004). "Hyperbaric oxygen therapy for thermal burns". Cochrane Database Syst Rev (3): CD004727. doi:10.1002/14651858.CD004727.pub2. PMID 15266540.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  27. ^ Jull AB, Rodgers A, Walker N (2008). "Honey as a topical treatment for wounds". Cochrane Database Syst Rev (4): CD005083. doi:10.1002/14651858.CD005083.pub2. PMID 18843679.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  28. ^ "WHO Disease and injury country estimates". World Health Organization. 2009. Retrieved Nov. 11, 2009. {{cite web}}: Check date values in: |accessdate= (help)
  29. ^ a b "American Burn Association".
  30. ^ "American Burn Association".
  31. ^ Bhattacharya S. Principles and Practice of Burn Care. Indian J Plast Surg 2009;42:282-3
  32. ^ Potokar T, Chamania S, Ali S. International network for training, education and research in burns. Indian J Plast Surg 2007;40:107

Further reading

Herndon, David (2007). Total Burn Care. Saunders. ISBN 978-1-4160-3274-8.

Wikimedia Commons has media related to burns.

Template:Link FA

Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Burn&oldid=402554904"