Citation

Motomura T, Matsumoto H, Yokota H, Suzuki M, Nishimoto T, Ujihashi S. J. Nippon Med. Sch. 2019; ePub(ePub): ePub.

Affiliation

Nippon Bunri University, Oita City.

Copyright

(Copyright © 2019, Medical Association of Nippon Medical School)

DOI

10.1272/jnms.JNMS.2019_86-607

PMID

31434839

Abstract

BACKGROUND: Traumatic asphyxia is a major cause of death in fatal crowd disasters, but the relationship between compression site, load magnitude, load time, and the medical event remains unclear. This study sought to estimate thoracoabdominal compression conditions (load magnitude, load time) resulting in respiratory failure in adults.

METHODS: A total of 8 load patterns-A (chest load: 0 kg, abdomen load: 10 kg), B (0, 20), C (10, 0), D (10, 10), E (10, 20), F (20, 0), G (20, 10), H (20, 20) -were applied in 14 healthy adult female subjects. Blood pressure, heart rate, respiratory rate, SpO₂, tidal volume, vital capacity, respiratory phase, and modified Borg dyspnea score were measured over time. The Breathing Intolerance Index (BITI) was also calculated.

RESULTS: Vital capacity decreased in patterns C, D, E, F, G, and H. BITI reached the critical range of ≥ 0.15, where respiratory failure occurs about 45 min later, after 14 min in pattern G and 2 min in pattern H. Vital capacity ≤ 1.85 L and modified Borg scale score  8.3 corresponded to BITI  0.15 and were regarded as equivalent to reaching the critical range. Furthermore, the change in chest load was positively correlated with BITI when abdominal load was kept constant.

CONCLUSIONS: In human women, respiratory failure could occur within 1 h due to respiratory muscle fatigue even when the total thoracoabdominal load is only about 60% of the body weight. Vital capacity ≤1.85 L and modified Borg scale score ≥8.3 can be considered as indices for predicting respiratory failure.

Language: en

Keywords

Breathing Intolerance Index (BITI); crowd accident; respiratory failure; stampede; traumatic asphyxia