Oboli Victor N., Waseem Muhammad
New York City Health and Hospitals/Lincoln
Weill Cornell Medicine New York and New York Medical College, Valhalla NY
Burn injuries are commonly encountered in the emergency department (ED). While burn injuries may be induced by chemical or electrical sources, friction, cold, heat, or radiation, most burn injuries are secondary to exposure to heat from hot liquids, heated solids, or fire. Most burn injuries occur in children aged 1 to 16 and adults aged 20 to 59. Fire-related burn injuries account for 41% of burns, while scald injuries account for 31%. Emergency medical services (EMS) should assess the extent and severity of burns through visual inspection and calculation of the affected total body surface area (TBSA) before commencing fluid resuscitation in the field. In the United States, burns are the third most common cause of injury and mortality in children aged 5 to 9 years and the leading cause of death in children aged 1 to 14. The pediatric population is especially vulnerable to burn injuries; a severe burn in a pediatric patient is defined as greater than 10% TBSA affected. This sharply contrasts severe burns in adults, defined as 20% or more of TBSA affected.Burn injuries are especially dangerous due to distributive shock and the subsequent systemic inflammatory response. If inadequately treated, multiple organ failure may result. Severe burn injuries primarily affect the cardiovascular, gastrointestinal, renal, respiratory, and integumentary systems. EMS traditionally employs the "Rule of Nines" tool to assess the TBSA affected by burns in patients with second- and third-degree burns. The Rule of Nines assigns each body part a percentage, usually 9%, or a multiple thereof 9 (see Diagram of the Rule of 9s for Adults). These percentages can be used to quickly calculate the affected TBSA in pediatric and adult populations (see Diagram of Rule of 9s Modifications for Pediatric Patients). The Parkland formula uses this estimated TBSA percentage to determine the appropriate total fluid resuscitation for patients with severe burns. The Parkland formula multiplies the patient's total body weight by 4 and multiplies that value by the affected TBSA to calculate the total required resuscitative fluid volume. The Parkland formula recommends administering half of the required fluid volume over the first 8 hours of resuscitation and the remaining half over the subsequent 16 hours. The Parkland formula is favored because it relies on visual estimates but is limited by approximating total patient body weight if that value is immediately unavailable. The "Rule of Tens" improves upon The Rule of Nines by simplifying the initial fluid resuscitation calculation. The only variable required is the affected TBSA rounded up to the nearest 10 (% TBSA x 10 = initial fluid rate in mL/h). The Rule of Tens was developed for combat prehospital providers needing a quick way to estimate resuscitation volumes for multiple burn victims in the field. The Rule of Tens aims to streamline the initial TBSA calculation and gradually reperfuse the patient, preventing any potential complications from volume overload. The Rule of Tens eliminates the need for an exact patient weight if the patient falls within the 40 to 80 kg range. By removing the need for an exact weight calculation, EMS can use the Rule of Tens to initiate initial fluid resuscitation quickly. The Rule of Tens also permits adjustments to the rate of fluid resuscitation as the patient is stabilized; this is in contrast to the Parkland formula, which requires the administration of a total volume over 24 hours.
烧伤在急诊科很常见。虽然烧伤可能由化学或电、摩擦、寒冷、热或辐射引起,但大多数烧伤是由于接触热液体、热固体或火产生的热所致。大多数烧伤发生在1至16岁的儿童和20至59岁的成年人中。与火灾相关的烧伤占烧伤总数的41%,而烫伤占31%。紧急医疗服务(EMS)应在现场开始液体复苏前,通过目视检查和计算受影响的全身表面积(TBSA)来评估烧伤的范围和严重程度。在美国,烧伤是5至9岁儿童受伤和死亡的第三大常见原因,也是1至14岁儿童死亡的主要原因。儿科人群尤其容易受到烧伤;儿科患者的严重烧伤定义为受影响的TBSA大于10%。这与成人严重烧伤形成鲜明对比,成人严重烧伤定义为受影响的TBSA为20%或更多。由于分布性休克和随后的全身炎症反应,烧伤尤其危险。如果治疗不当,可能会导致多器官功能衰竭。严重烧伤主要影响心血管、胃肠道、肾脏、呼吸和皮肤系统。传统上,EMS使用“九分法”工具来评估二度和三度烧伤患者受烧伤影响的TBSA。九分法为身体的每个部位分配一个百分比,通常为9%,或其倍数9(见成人九分法示意图)。这些百分比可用于快速计算儿科和成人人群中受影响的TBSA(见儿科患者九分法修改示意图)。帕克兰公式使用这个估计的TBSA百分比来确定严重烧伤患者适当总的液体复苏量。帕克兰公式将患者的总体重乘以4,再将该值乘以受影响的TBSA,以计算所需复苏液体的总量。帕克兰公式建议在复苏的前8小时内输注所需液体量的一半,其余一半在随后的16小时内输注。帕克兰公式受到青睐,因为它依赖于目视估计,但如果无法立即获得患者总体重的值,则会因近似估计而受到限制。“十分法”通过简化初始液体复苏计算对九分法进行了改进。唯一需要的变量是向上取整到最接近10的受影响TBSA(%TBSA×10 = 初始液体输注速率,单位为mL/h)。十分法是为战斗中的院前急救人员开发的,他们需要一种快速方法来估计现场多名烧伤受害者的复苏量。十分法旨在简化初始TBSA计算,并逐步使患者再灌注,防止因容量过载引起的任何潜在并发症。如果患者体重在40至80千克范围内,十分法无需精确的患者体重。通过无需精确计算体重,EMS可以使用十分法快速开始初始液体复苏。十分法还允许在患者病情稳定时调整液体复苏速率;这与帕克兰公式不同,帕克兰公式要求在24小时内输注总量。