1 Burns.docx

PATHOPHYSIOLOGY OF BURNS Submitted by: Butao, Carla Antonette Calixtro, Cyril Hemedes, Ma. Isabel Montes, Sat Gian Carlos Manuel I. Introduction A Burn is a thermal injury caused by biological, chemical, electrical and physical agents with local and systemic repercussions, the most severe form of trauma that has afflicted humanity since ancient times and has improved the results in its treatment over the years and the scientific revolution. Burns are the most devastating form of trauma that has afflicted humanity, its short and long term effects leave severe squealing in the patients affected by them, the costs they generate for health systems are very high and are currently counted with few hospital centers specialized in the treatment of these diseases. Burns are classified as first, second, third, or fourth grade depending on how profoundly and severely they penetrate the surface of the skin. Burns in the first degree affect only the skin's outer layer, the epidermis. The site of burning is red, painful, dry and blister - free. For example, mild sunburn. Long - term tissue damage is rare and often involves increasing or decreasing the color of the skin. Second - degree burns involve the epidermis and the dermis, part of the skin's lower layer. The site of burning appears red, blistered, and can be swollen and painful. The epidermis and dermis are destroyed by third - degree burns. They may go into the subcutaneous tissue, the innermost layer of skin. The site of burning may look black or white and charred. Fourth - degree burns pass through both layers of the skin and underlying tissue as well as deeper tissue, which may involve muscle and bone. Since the nerve endings are destroyed, there is no feeling in the area. Different types of Burns can be classified as Thermal, Radiation, Chemical, Electrical and Cold burn injuries. Thermal burns are due to external heat sources that raise the skin and tissue temperature and cause death or charring of tissue cells. Hot metals, scalding liquids, steam, and flames may cause thermal burns when they come into contact with the skin. About 70% of children's burns are caused by scalds. Often they also occur in the elderly. Common mechanisms are the spilling or exposure of hot drinks or liquids to hot bathing water. Scalds tend to cause superficial dermal burning. Flame burns make up 50% of adult burns. Inhalational injury and other concomitant trauma are often associated with them. The flame burns tend to be thick or deep dermal. The object touched must either have been extremely hot or the contact was abnormally long in order to get a burn from direct contact. The latter is a more common reason, and it is common to see these types of burns in people with epilepsy or those who abuse alcohol or drugs. Radiation burns are due to prolonged exposure to ultraviolet sunlight or other radiation sources such as x – rays. Chemical burns are due to strong acids, alkali, detergents or solvents that come into contact with the skin and/or eyes. Electrical burns are from Electrical current burns, either alternating (AC) or direct (DC) current. Cold burn injuries is a medical condition in which skin and other

tissues are affected by localized damage due to freezing. Domestic Electricity: Low voltages tend to cause small, deep contact burns at the exit and entry sites. The alternating nature of domestic current can interfere with the cardiac cycle, giving rise to arrhythmias. Injuries of "true" high voltage occur when the voltage is 1000 V or higher. There is extensive damage to the tissue and frequently loss of limbs. Usually there is a large amount of necrosis of soft and bony tissue."Flash" injury may occur when an arc of current has arisen from a source of high voltage. Depending on the thickness of skin involved, burns can be classified as Partial thickness burns: it is red and painful, often with blisters, either first or second degree burning. A deep partial thickness burn involves most of the dermal layer being destroyed, with few remaining viable epidermal cells. Reepithelialization is slow, taking months at times given that the dead tissue layer is thick and adheres to the underlying viable dermis (eschar), blisters generally do not form. Full thickness burns: it is charred, insensitive, deep burns of the third degree that involve all layers of the skin. A subdermal burn involves complete epidermis and dermis destruction, with extension to underlying tissue such as connective tissue, muscle, and bone. The wound appears without sensation charred, dry, and brown or white ; typically, there is limited or no movement of the affected digit or extremity. The Wallace’s Rule of Nine is a method used by physicians and emergency physicians to easily calculate the treatment needs of a burned person. For adults, the rule of nines is: Body part

Percentage

Arm (including the hand)

9 percent each

Anterior trunk (front of the body)

18 percent

Genitalia

1 percent

Head and neck

9 percent

Legs (including the feet)

18 percent each

Posterior trunk (back of the body)

18 percent

For children, rules of nine is: Body part

Percent

Arm (including the hand)

9 percent each

Anterior trunk (front of the body)

18 percent

Head and neck

18 percent

Legs (including the feet)

14 percent each

Posterior trunk (back of the body)

18 percent

The Lund and Browder chart is a useful tool for burn management to estimate the total surface area of the body affected.

The "palm rule" is another way of estimating a burn's size. The person's palm (not the finger or wrist area) is about 1% of the body. II. Statistics According to the World Health Organization (WHO): 

An estimated 180 000 deaths every year are caused by burns – the vast majority occur in low- and middle-income countries.

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Non-fatal burn injuries are a leading cause of morbidity Burns occur mainly in the home and workplace.

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Females have slightly higher rates of death from burns compared to males according to the most recent data. This is in contrast to the usual injury pattern, where rates of injury for the various injury mechanisms tend to be higher in males than females. The higher risk for females is associated with open fire cooking, or inherently unsafe cook stoves, which can ignite loose clothing. Open flames used for heating and lighting also pose risks, and self-directed or interpersonal violence are also factors (although understudied). Along with adult women, children are particularly vulnerable to burns. Burns are the fifth most common cause of non-fatal childhood injuries. While a major risk is improper adult supervision, a considerable number of burn injuries in children result from child maltreatment.

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People living in low- and middle-income countries are at higher risk for burns than people living in high-income countries. Within all countries however, burn risk correlates with socioeconomic status.

In the Philippines, according to an article published by PhilStar, the Bureau of Fire Protection (BFP) recorded:  from Jan. 1 to Dec. 27 showed that a total of 14,316 fires occurred, 3,943 of which were recorded in Metro Manila  injured persons at 671 is down by 12.17 percent  The top 3 causes of fire in the country are faulty electrical connections, lit cigarette butts, and open flames from unattended stoves. III. Pathophysiology The local pathophysiological changes were described by Jackson several years ago and consist in the formation of three zones (Garcia et al., 2017).  Zone of coagulation: o Center area of wound o Necrotic area with cellular disruption o Irreversible tissue damage with denaturation of proteins and Release of molecular patterns o Intimate contact with the aggressor agent  Zone of stasis o Surrounds coagulation area o Moderate insult with decreased tissue perfusion o Can survive or go on to coagulative necrosis depending on wound environment o Retains its blood flow which according to water resuscitation has a 50% chance of surviving  Zone of hyperemia o Unburned area surrounding zone of stasis that is red due to inflammation o Retains its blood flow and in most cases survives the injury (Garcia et al., 2017, Sharma, 2016, and Edison, 2015) Systemic Effects  Endolethial level "There is a severe dysfunction of the cells with severe capillary leakage which accentuates the shock state. Also, by the activation of the immune response, there is an increase in the production of nitric oxide synthase, which increases the vasodilatation and Capillary leakage. Systemic changes depend on the affected body surface, generally occurring on burned body surfaces greater than 10%. They severely alter homeostasis and are triggered by the release of insulin-regulating hormones and proinflammatory cytokines (associated with the severity of the lesions) that favor hyperglycemia and hyperinsulinemia and induce hypercatabolic states, humoral and cellular

immunodeficiency, water balance disorders, temperature, Hemodynamic and nutrient absorption" (Garcia et al., 2017).

Schematic diagram on systemic effect of burns in the endolethial level (Edison, 2015) 

Cardiovascular level o Reduced cardiac output

(Sharma, 2016)

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o Myocardial dysfunction: oxygen derived free radicals o Increased systemic vascular resistance Renal level o Diminished blood flow and cardiac output leads to decreased renal blood flow and GFR o Toxins released from the wound along with sepsis causes acute tubular necrosis o Myoglobin released from muscles (in case of electric injury or often from eschar) is most injurious to kidneys o Earlier resuscitation decreases renal failure and improves assosciated mortality (Edison, 2015)

Schematic diagram on systemic effect of burns in the renal system (Sharma, 2016) 

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Respiratory level Toxic gas agents: o Carbon monoxide o Hydrogen cyanide o Hydrogen chloride o Nitrogen oxides o Kerosene (Sharma, 2016) Systemic effects: o Altered ventilation-perfusion ratio o Pulmonary oedema due to burn injury, fluid overload o Aspiration o Septicaemia (Edison, 2015) Gastrointestinal level o Mucosal atrophy o Decreased absorption & increased intestinal permeability o Increased bacterial translocation o Acute gastric dilatation which occurs in 2-4 days o Paralytic ileus o Curling’s ulcer o Abdominal Compartment syndrome (Edison, 2015) o Decreased absorption of glucose, amino acids & fatty acids (Sharma, 2016) Immune system level o Diminished production of macrophages o Increased neutrophil count (dysfunctional) followed by decrease after 48- 72 hrs o Impaired cytotoxic T cell activity o Increase risk of infections

o Depressed Th function (Sharma, 2016) Summary of Pathophysiology

Schematic diagram on the summary of systemic effects of burns (Edison, 2015) Causes of Death o Hypovolaemia (refractory and uncontrolled) and shock o Renal failure o Pulmonary oedema and ARDS o Septicaemia o Multiorgan failure o Acute airway block in head and neck burns (Edison, 2015) IV. Treatment The care of burns is divided in two types that could be treated as with pharmacological or non-pharmacological necessities. This could be helpful to direct the reassessment of the progression of the burns that would be given of the definitive treatment. There are also appropriate medicines and steps that should be followed to ensure that the patient would have recovery. Proper medication is important and should be given to the patients according to the severity of the burns. Non-Pharmacological Treatment tend to have first-hand medication that does not involve any medication and could be done at home due to having the minor type of burn. 

Bed rest. The use of prolonged bed rest in the treatment of patients with neck and low back pain and associated disorders is without any significant

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scientific merit. Bed rest supports immobilization with its deleterious effects on bone, connective tissue, muscle, and psychosocial well-being. Psychologic intervention. Psychology techniques such as relaxation, distraction, and cognitive-behavioral therapy, are beneficial for relieving anxiety and pain during rehabilitation. Hyponosis. It has been used in pain management in burn patients during procedures and to control anxiety. Neurophysiological studies support this therapy.

Pharmacological Treatment is based on intend medical care that is specialized to treat patients with appropriate first aid assessment connotes medications, wound dressing, therapy or even surgery. The main goal is to control pain, remove dead tissue, prevent infection, reduce scarring and regain function cells these medications or products are intended to encourage healing:       

Water-based treatments. Use techniques such as ultrasound mist therapy to clean and stimulate the wound tissue. Prevent dehydration. Intravenous (IV) fluids to prevent dehydration and organ failure. Pain and anxiety medications. You may need morphine and anti-anxiety especially for changing dressings. Burn creams and ointments. Select from a variety of topical products for wound healing, such as bacitracin and silver sulfadiazine (Silvadene). This help prevent infection and prepare the wound to close. Dressing. Wound dressings to prepare the wound to heal. Drugs that fight infections. Antibiotics is needs to prevent infections. Tetanus shot. Might be recommended after a burn injury.

There are different ways in diagnosing and treating burns depending on its level of severity. Thermal burnscan be treated by application of solid products such as Americaine Aerosol (benzocaine), Dermoplast (benzocaine) and Itch-X (hydrocortisone). Application of antibacterial to avoid infection. Due to possible allergy and contact to skin, use of Neomycin-free that includes Polysporin (bacitracin zinc, polymyxin B sulfate) and hydrogen peroxide.Minor thermal burns involve immediate place of flow of cool water not cold nor iced. The damaged area should be free of discomfort within the period of time. First aid consists of applying a topical nonprescription pain reliever. Burn self-Treatment is a treatment done that does not require physician care that can be done by oneself. Use of protectants or lubricants such as cocoa butter, glycerin and petroleum to help the burn feel less dry. Itching of burns can be soothe by products with the ingredients of benzocaine, dycloine, pramoxine and benzyl alcohol. Chemical burns caused exposure to dangerous acid or alkali. This may be removed by any clothing containing the chemical and flush the skin for at least 15 minutes with large amount of clean water before emergency care. Subdermal burnsdo not require amputation on the area as a treatment.

References Bunman, S., Dumavibhat, N., Chatthanawaree, W., Ntalapaporn, S., Thuwachaosuan, T., &Thongchuan, C. (2017). Burn Wound Healing: Pathophysiology and Current Management of Burn Injury. The Bangkok Medical Journal, 13(02), 91-98. doi:10.31524/bkkmedj.2017.09.017 Burns. (2018, July 24). Retrieved from https://www.mayoclinic.org/diseasesconditions/burns/diagnosis-treatment/drc-20370545?fbclid=IwAR2cuAXhdhTJFZr-imCKtjO05Ku2OufCdBR06dESjPz6Zxuu_PaOh7esxY Burns. (n.d.). Retrieved from https://www.who.int/news-room/fact-sheets/detail/burns Castro, Alencar, R. J., Leal, Cunha, P., Sakata, & Kimiko, R. (n.d.). Pain management in burn patients. Retrieved from http://www.scielo.br/scielo.php?pid=S003470942013000100013&script=sci_arttext&tlng=en Classification of Burns. (n.d.). Retrieved from https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90& ContentID=P09575&fbclid=IwAR0yUdQx2rwjvgbWctqpN3aokMIx_gXxugGy4QF CzfGFItDuFi35DnssdN4 Demling, R. H. (2008, August). Burns: What are the pharmacological treatment options? Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/18627328/?fbclid=IwAR3eM_bx4Uo03Kmg uMJtN_mgaoFnJJTUMVgSpL9oMu06QOmhNSx5QOohNDo Different Types of Burns. (n.d.). Retrieved from https://stanfordhealthcare.org/medicalconditions/skin-hair-andnails/burns/types.html?fbclid=IwAR0sET7VQzokDQvd34GPHWumNZPikyvRoIda hoF2dQ5qnnMNzoF2ceK8Rr8 Edison, D. (2015, November 14). Pathophysiology of burns. Retrieved from https://www.slideshare.net/oswinissac1/pathophysiology-ofburns?fbclid=IwAR3RcRW20VW6vh8EtgJKnbtci2Pe0MLK33xGmC2kKJciQDeNTzA12Xx6L4 Estimating the Size of a Burn. (n.d.). Retrieved from https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=sig254759&fbclid =IwAR0sET7VQzokDQvd34GPHWumNZPikyvRoIdahoF2dQ5qnnMNzoF2ceK8 Rr8 Hettiaratchy, S., & Dziewulski, P. (2004, June 12). ABC of burns: Pathophysiology and types of burns. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC421790/?fbclid=IwAR3PfEdzeucJ X_9KkvRbpFYPjq7oG4ub6H5TaKK--JwSWuwTSoihJv0RXEM Jeffery, S. (2009). Current burn wound management. Trauma, 11(4), 241-248. doi:10.1177/1460408609350126 Murphy, K. D., Lee, J. O., & Herndon, D. N. (2003, March). Current pharmacotherapy for the treatment of severe burns. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12614189/?i=2&from=/18627328/related&f bclid=IwAR0HnoQH2BgRCpQyTb5VqdAQp1AfBE__ZOC70TVfRGi6q1MQGdP1XQxO-g

News, A. (2018, October 20). In the Know: The top 3 causes of fire in PH. Retrieved from https://news.abs-cbn.com/news/03/01/18/in-the-know-the-top-3-causes-offire-in-ph Rule of Nines: Burns, Children, Adults, Wallace, and More. (n.d.). Retrieved from https://www.healthline.com/health/rule-of-nines?fbclid=IwAR3vBUF8S4eZMFetv2ebB1asHNow98cBEPXLgfPFPs3M4BUZe9BoovX1j8#in-children The Royal Children's Hospital Melbourne. (n.d.). Retrieved from https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Nursing_manage ment_of_burn_injuries/?fbclid=IwAR19Wr8Lap5Ndb3VD_XgChZjAY3Fuh2wr2H0gr-0ExEIMGzRXLqF1rUanE Tupas, E. (2018, December 27). Fire incidents increased by .84 percent in 2018. Retrieved from https://www.philstar.com/nation/2018/12/28/1880369/fireincidents-increased-84-percent-2018