浅深度空气预饱和对150m快速上浮脱险安全性的动物实验研究

Experimental research on the effects of air pre-saturation at shallow depths on safety of 150 m fast buoyancy ascent in submarine escape

目的 探索不同深度空气预饱和后150 m快速上浮脱险的安全性.方法 山羊8只,体质量18 ～ 20 kg,逐次进行深度相对压力（后同）为60、70、80、120 kPa的预暴露后脱险实验.先加压到预饱和深度,然后采用类似150 m快速上浮脱险的快速加压、短暂停留和快速减压方式进行高气压暴露,比较暴露前后血管内气泡分级和临床表现.结果 60、70 kPa预饱和脱险后动物未见明显异常表现;80 kPa预饱和脱险后1只动物出现轻型减压病症状,未予治疗后自愈;120 kPa预饱和脱险后3只动物均检测到3级（Spenser分级）气泡音,其中1只4d后死亡,解剖见肺组织明显充血肿胀,大脑未见明显出血点及梗死病灶.结论 70 kPa空气预饱和后150 m快速上浮脱险是相对安全的;更大深度空气预饱和暴露后,虽然减压病发病概率较高,但致死原因可能主要为肺损伤.

Objective To explore the safety of 150 m fast buoyancy ascent in submarine escape following air saturation at various depths.Methods Eight adult goats with average body mass of 18-20 kg were used in our experiment.Followingpre-air-saturation at simulated depths of 60,70,80 and 120 kPa,the animals underwent a series of escape experiments.First,the experimental animals were pressurized to pre-airsaturation depths,then,received rapid pressurization in accordance with the 150 m fast buoyancy ascent profile,had a brief stop and were fast decompressed to the surface.After exposure,Doppler ultrasonic grading of vascular air bubbles and clinical manifestations were compared both before and after exposure.Results Following pre-air-saturation and escape at simulated depths of 60 and 70 kPa,no obvious abnormal manifestations could be seen in all the animals.However,following pre-air-saturation and escape at a simulated depth of 80 kPa,one animal displayed some light DCS symptoms,but was recovered without any treatment.Following pre-air-saturation and escape at a simulated depth of 120 kPa,grade 3 air bubbles （Spenser classification） were detected in all the 3 animals,one of which died 4 days later.Anatomy revealed that congestion of the lung tissue was quite apparent,but without obvious cerebral hemorrhage and infarct foci.Conclusions Following pre-air-saturation at a simulated depth of 70 kPa,fast buoyancy ascent escape at a depth of 150 m was relatively safe.Nevertheless,greater pre-air-saturation exposure could induce relatively high incidence of DCS,with the prevalent lethal factor being serious damage to the lung tissue.