Davis Bayli P, Pang Alan, Tapp Robyn, Anding Catherine, Griswold John
Pulmonary and Critical Care Medicine, Texas Tech University Health Sciences Center, Lubbock, USA.
Surgery, Texas Tech University Health Sciences Center, Lubbock, USA.
Cureus. 2023 Sep 1;15(9):e44524. doi: 10.7759/cureus.44524. eCollection 2023 Sep.
In patients with inhalation injury associated with major burns, the primary mechanism of tissue harm depends on the location within the respiratory tract. Proximal to the trachea, the upper respiratory tract epithelium is classically injured via direct thermal injury. Such injury occurs due to the inhalation of high-temperature air. These upper airway structures and the tracheobronchial tree's dense vasculature protect the lower airways and lung parenchyma from direct thermal damage. The lower respiratory tract epithelium and lung parenchyma typically become injured secondary to the cytotoxic effects of chemical irritants inhaled in smoke as well as delayed inflammatory host responses. This paper documents a rare case in which a patient demonstrated evidence of direct thermal injury to the lower respiratory tract epithelium. A 26-year-old Caucasian male presented to the emergency room with 66% total body surface area thermal burns and grade 4 inhalation injury after a kitchen fire. Instead of visualizing carbonaceous deposits in the bronchi, a finding common in inhalation injury, initial bronchoscopy revealed bronchial mucosa carpeted with hundreds of bullae. Despite the maximum grade of inhalation injury per the abbreviated injury score and a 100% chance of mortality predicted with the revised Baux score, as well as a clinical course complicated by pneumonia development, bacteremia, and polymicrobial external wound infection, this patient survived. This dissonance between his expected and observed clinical outcome suggests that the applicability of current inhalation injury classification systems depends on the precise mechanism of injury to the respiratory tract. The flaws of these grading scales and prognostic indicators may be rooted in their failure to account for other pathophysiologic processes involved in inhalation injury. It may be necessary to develop new grading and prognostic systems for inhalation injury that acknowledge and better account for unusual pathophysiologic mechanisms of tissue damage.
在伴有大面积烧伤的吸入性损伤患者中，组织损伤的主要机制取决于呼吸道内的位置。在气管近端，上呼吸道上皮通常因直接热损伤而受损。这种损伤是由于吸入高温空气所致。这些上气道结构以及气管支气管树丰富的血管系统可保护下气道和肺实质免受直接热损伤。下呼吸道上皮和肺实质通常因吸入烟雾中的化学刺激物的细胞毒性作用以及延迟的炎症宿主反应而继发损伤。本文记录了一例罕见病例，该患者显示出下呼吸道上皮直接热损伤的证据。一名26岁的白种男性在厨房火灾后因全身66%体表面积的热烧伤和4级吸入性损伤被送往急诊室。最初的支气管镜检查未发现吸入性损伤中常见的支气管内碳质沉着，而是发现支气管黏膜布满了数百个大疱。尽管根据简略损伤评分该患者的吸入性损伤程度最高，且根据修订的博克斯评分预测死亡率为100%，以及临床过程因肺炎、菌血症和多微生物伤口感染而复杂化，但该患者存活了下来。他预期和观察到的临床结果之间的这种不一致表明，当前吸入性损伤分类系统的适用性取决于呼吸道损伤的确切机制。这些分级量表和预后指标的缺陷可能源于它们未能考虑到吸入性损伤中涉及的其他病理生理过程。可能有必要开发新的吸入性损伤分级和预后系统，以认识并更好地考虑组织损伤的异常病理生理机制。
