title: Mucosal fluid evaporation is not the method of heat dissipation from fourth-degree laryngopharyngeal burns.
abstract: This study was designed to explore whether mucosal fluid evaporation represents a method of heat dissipation from thermal air inhalation injury and to assess laryngopharyngeal tissue damage according to heat quantity changes of dry air and vapour. Fifteen adult male beagles were divided into five groups to inhale heated air or vapour for 10 min as follows: control group (ordinary air), group I (91-110 °C heated air), group II (148-175 °C heated air), group III (209-227 °C heated air), and group IV (96 °C saturated vapour). The heat quantity changes of the dry air and vapour were calculated via thermodynamic formulas. The macroscopic and histological features of the laryngopharynxes were examined and assessed by various tissue damage grading systems. Group IV exhibited the most serious laryngopharyngeal damage, including cilia exfoliation, submucosal thrombosis, glandular atrophy, and chondrocyte degeneration, which is indicative of fourth-degree injury. The quality, heat quantity, and proportional reduction of heat quantity of vapour in group IV were all higher than those in the other groups. Furthermore, we found that mucosal fluid evaporation is not the method of heat dissipation from thermal air inhalation injury used by the airways. Laryngopharyngeal tissue damage depends chiefly on the heat quantity of vapour in the air.
authors.affiliation: Department of Burns Surgery, Peking University Fourth School of Clinical Medicine, No. 31, Xinjiekou East Street, Xicheng District, Beijing 100035, PR China.
authors.forename: Jiang-Bo
authors.initials: JB
authors.lastname: Wan
authors.affiliation: Department of Burns Surgery, Peking University Fourth School of Clinical Medicine, No. 31, Xinjiekou East Street, Xicheng District, Beijing 100035, PR China.
authors.forename: Guo-An
authors.initials: GA
authors.lastname: Zhang
authors.affiliation: Department of Burns Surgery, Peking University Fourth School of Clinical Medicine, No. 31, Xinjiekou East Street, Xicheng District, Beijing 100035, PR China.
authors.forename: Yu-Xuan
authors.initials: YX
authors.lastname: Qiu
authors.affiliation: Department of Burns Surgery, Peking University Fourth School of Clinical Medicine, No. 31, Xinjiekou East Street, Xicheng District, Beijing 100035, PR China.
authors.forename: Chun-Quan
authors.initials: CQ
authors.lastname: Wen
authors.affiliation: Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, No. 1, Tsinghua Park, Haidian District, Beijing 100084, PR China.
authors.forename: Tai-Ran
authors.initials: TR
authors.lastname: Fu
mesh_terms: D000388:Air; D000465:Algorithms; D000818:Animals; D001826:Body Fluids / Q000378:metabolism*; D002059:Burns, Inhalation / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004285:Dogs; D006358:Hot Temperature; D007013:Hypopharynx / Q000293:injuries / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D009092:Mucous Membrane / Q000378:metabolism*; D012720:Severity of Illness Index; D013816:Thermodynamics; D000071436:Thermotolerance / Q000502:physiology*; D014835:Volatilization