Motomura Tomokazu, Matsumoto Hisashi, Yokota Hiroyuki, Suzuki Mototsugu, Nishimoto Tetsuya, Ujihashi Sadayuki
Department of Emergency and Critical Care Medicine, Shock and Trauma Center, Nippon Medical School Chiba Hokusoh Hospital.
Department of Emergency and Critical Care Medicine, Nippon Medical School.
J Nippon Med Sch. 2020 Jan 10;86(6):310-321. doi: 10.1272/jnms.JNMS.2019_86-607. Epub 2019 Aug 20.
Traumatic asphyxia is a major cause of death in fatal crowd disasters, but the relationships between compression site, load magnitude, load time, and medical outcomes are unclear. This study estimated thoracoabdominal compression conditions (load magnitude, load time) that could result in respiratory failure in adults.
Eight load patterns-A (chest load: 0 kg, abdominal load: 10 kg), B (0, 20), C (10, 0), D (10, 10), E (10, 20), F (20, 0), G (20, 10), and H (20, 20)-were applied to 14 healthy women. Blood pressure, heart rate, respiratory rate, SpO, tidal volume, vital capacity, respiratory phase, and modified Borg dyspnea score were measured over time. Breathing Intolerance Index (BITI) was also calculated.
Vital capacity decreased in patterns C, D, E, F, G, and H. BITI reached the critical range of ≥0.15 (at which respiratory failure occurs after about 45 min) after 14 min in pattern G and 2 min in pattern H. A vital capacity ≤1.85 L and a modified Borg scale score ≥8.3 corresponded to a BITI of ≥0.15 and were regarded as equivalent to reaching the critical range. Furthermore, change in chest load was positively correlated with BITI when abdominal load remained constant.
In women, respiratory failure can occur within 1 h from respiratory muscle fatigue, even when total thoracoabdominal load is only about 60% of body weight. A vital capacity ≤1.85 L and modified Borg scale score ≥8.3 can be regarded as indices for predicting respiratory failure.
创伤性窒息是致命人群灾难中的主要死亡原因，但压迫部位、负荷大小、负荷时间与医学结果之间的关系尚不清楚。本研究估计了可能导致成人呼吸衰竭的胸腹压迫条件（负荷大小、负荷时间）。
对14名健康女性施加8种负荷模式——A（胸部负荷：0千克，腹部负荷：10千克）、B（0，20）、C（10，0）、D（10，10）、E（10，20）、F（20，0）、G（20，10）和H（20，20）。随时间测量血压、心率、呼吸频率、血氧饱和度、潮气量、肺活量、呼吸阶段和改良Borg呼吸困难评分。还计算了呼吸不耐受指数（BITI）。
模式C、D、E、F、G和H中肺活量下降。模式G在14分钟后、模式H在2分钟后，BITI达到≥0.15的临界范围（约45分钟后会发生呼吸衰竭）。肺活量≤1.85升和改良Borg量表评分≥8.3对应于BITI≥0.15，被视为等同于达到临界范围。此外，当腹部负荷保持恒定时，胸部负荷的变化与BITI呈正相关。
在女性中，即使胸腹总负荷仅约为体重的60%，呼吸肌疲劳后1小时内也可能发生呼吸衰竭。肺活量≤1.85升和改良Borg量表评分≥8.3可被视为预测呼吸衰竭的指标。
