# Burns --- A **burn** is an [[injury]] that can come from heat, [[electromagnetic spectrum|UV radiation]], or chemical sources. Circumferential burns to the extremities can lead to vasoconstriction/[[compartment syndrome]]. ## Degrees Burns are classified into three degrees, *first*, *second* and *third* degree burns. **First degree burns** (or **superficial burns** only affect the [[epidermis]], such as what you might see after getting a sunburn. There is slight redness and pain, and this burn can be immersed in cool water to alleviate symptoms. **Second degree burns** (or **partial thickness**) involve the epidermis and the [[dermis]]. Skin is blistered and painful. **Third degree burns** (or **full thickness**) are the most serious, and they involve the epidermis, the dermis and the [[hypodermis|subcutaneous layer]]. There is an increased risk for infection and dehydration because the skin is gone. Healing from this type of injury is [[biological energy|Calorie]] intensive and patients need to take in a much higher calorie than average as they heal. High risk of contracture, lots of eshar. ## The Rule of Nines The **rule of nines** estimates the percentage of the **total body surface area** (TBSA) that a burn affects. The (adult) body is divided into regions that are either 9%, 4.5% (half of 9), or 18% (twice 9), and the genital region counts for the remaining 1%. Estimating the individual areas affected and thus can be used as a rule of thumb for calculating the total surface area. ![[rule of nines.png]] The ratios and percentages are calculated differently for children and infants. ## Types of Burns - heat - severity determined by temp and length of contact - chemical - acid or basic - acids cause "coagulation necrosis" - bases cause "liquefactive necrosis" - need to know what type to treat - rinse off immediately, or if it's a powder brush it off - electrical - follows path of least resistance, which for human bodies tends to be nerves and blood vessels - radiation - sun or other sources like xrya - skin and rapidly replicating cells like mucosa ## Inhalation Injuries Even from breathing in really hot air. If they have been trapped in a burning building, they might also have [[carbon monoxide|carbon monoxide poisoning]] or cyanide poisoning s/s - hoarseness or cough - labored breathing - difficulty swallowing - redness/blistering/burns around nose and mouth - singed facial hair - injury above glottis - edema peaks 24-48 hours post-injury - high risk of obstruction - treatment - 100% oxygen by a mask - injury below glottis - ronchi and wheezing - bronchial constriction & spasms - can lead to [[acute respiratory distress syndrome|ARDS]] - treatment - humidified ## Burn Healing Burn healing comes in three general phases, emergent, acute and then rehabilitation. During the whole process (except for the initial ebb phase, see below) the patient has high demand for [[biological energy|Calories]], [[protein]], [[vitamin C]] and fluids. Healing that much tissue is *expensive* and especially when there is a large surface area without skin the open wound can lose a lot of water. This is why we use skin grafts or allogenic grafts. - **Emergent phase** is the first part of the burn healing, where there is the highest risk of immediate, life-threatening problems. It ends with successful fluid resuscitation, which typically takes about 48-72 hours. - massive fluid loss - capillary walls are more permeable - water/sodium/albumin move into interstitial spaces - greatest threat is [[shock|hypovolemic shock]] - **consensus or parkland formula** - we want enough water in there to have 50 mL/hr of urine - 2-4 mL LR x TBSA% burned x pt wt (kg) - Infuse half of that amount over the first 8 hours - Infuse the second half over then following 16 hours - metabolic and GI effects - first 24 hours ebb phase (decreased metabolic need) - afterwards, flow phase (hypermetabolic) - we want to *be on top of this* - early and aggressive nutritional support. If the GI tract is working use it, but otherwise we can use TPN - decreased blood flow to the kidneys - myoglobinuria - damaged muscle cells break open and release myoglobin in the system, clog up the kidneys - **acute phase** takes weeks to months. From when the patient becomes hemodynamically stable, and ends when the wounds have healed or are covered by a permanent graft. - focus is on infection, sepsis, pain/itching, psychosocial - still need to work on cardiovascular/respiratory/msk (contractures)/GI - begin range of motion within 24 hours - **rehabilitation phase** begins after the wounds have healed, but these patients have a long way to go. Ends when they are able to resume the highest level of self-care activity possible - does overlap some with the acute phase - can wear something to put pressure on the wound to flatten it out - hot, itchy and annoying: compliance is an issue - in PT/OT a lot, every day like a part time job - Wound care - 1-2 times a day - sterile - very painful, be careful and premedicate - want to remove exudate - it might slough off - medical maggots - surgical sharps - some chemicals - start distally and work proximally - separate digits - skin grafts - temporary skin substitutes - other humans, pigs, tilapia - gold standard is to use one's own skin - **split thickness skin grafting** - permanent - can mesh the skin to spread it over a large area - might be hard to find a spot - cultured epithelial autograft ___