No Abstract available.
Diving

BACKGROUND: Recompression therapy is well established in the treatment of decompression sickness (DCS) including spinal type. However it was not confirm whether each United State Navy (USN) treatment tables had different therapeutic effect in spinal type of DCS. The purpose of this study is to find if the use of different tables results in a different outcome in spinal type of DCS. And we want to reconfirm an unsatisfactory cure rate of USN table 6. METHODS: We applied different USN treatment tables, 6, 6a and 6a1, to spinal type of DCS for 10 years. 68 patients with spinal type of DCS were treated with recompression therapy, 16 patients by table 6, 31 by 6a, and 21 by 6a1. We reviewed the outcome of motor power before and after each treatment. And we investigated age, diving experience, depth of dive, bottom time of dive, and onset of treatment before the treatment in each treatment group. RESULTS: There were no significant differences between each treatment group in age, diving experience, depth of dive, bottom time of dive, onset of treatment and the grade of motor power before the treatment. Marked motor power improvements were noticed in 59.6% (table 6; 18.7%, 6a; 74.2%, and 6a1; 81%). There were significant differences of motor power improvement between groups 6 and 6a (p=0.0057), 6 and 6a1 (p=0.0053) and 6a and 6a1 (p=0.0139). CONCLUSIONS: We think that table 6a1 should be used in spinal type of DCS. And table 6 is not useful in spinal type DCS.
Decompression Sickness* ; Decompression* ; Diving ; Humans ; Hyperbaric Oxygenation

SCUBA diving is becoming one of popular sport around the world even though it has serious accident potentials. The most common cause of death in underwater diving fatality is drowning, but in many cases it could be just a terminal event. The eventual target of forensic investigation in underwater diving accidents is to examine the underlying cause of death or accident, and therefore forensic pathologists should get an information about diving equipments which were used by the victim and about environmental factors. The author think a uniformed check list of underwater diving accidents should be available for postmortem investigation, and here propose it.
Cause of Death ; Checklist ; Diving ; Drowning ; Sports

Pulmonary barotrauma during ascent is a common complication in SCUBA diving. One of the most severe forms of pulmonary barotrauma is a cerebral arterial gas embolism(CAGE). It is reported to account for about 30% of diving related deaths. The early recognition of CAGE is very important for the emergency physician because prompt hyperbaric recompression therapy can improve the clinical course. Thus, the emergency physician should know the clinical manifestation of CAGE to apply several treatment modalities early. We report a case of cerebral arterial gas embolism presented with hemiparesis and blurred vision immediately after SCUBA diving at 13 meters.
Barotrauma ; Diving* ; Embolism, Air* ; Emergencies ; Paresis

Diving ; Humans ; Otitis Externa ; prevention & control

Scuba diving is a popular sports activity, even though it is associated with potential hazards. When a diver enters the water for an underwater expedition, he/she needs a series of diving gear, including a regulator, buoyancy compensator, diving suit, and weight belt, among others. Here, the author encountered a fatal diving accident wherein autopsy showed the evidence of death by drowning. The witness stated that the diver requested more weight to descend into the water, and the diver wore one more weight belt, totalling 26 kg. After a second trial of diving, he did not grab the regulator and disappeared into the water suddenly, and bubbles did not appear at the surface. Based on the witness statement and autopsy findings, the original cause of accident was concluded as an overweighted belt for descent into the water.
Autopsy ; Diving ; Drowning ; Expeditions ; Overweight ; Sports ; Water

Objective: To explore the characteristics and rules of blood pressure changes in oceanauts during simulated operation of manipulator and troubleshooting tasks with different difficulty. Methods: In July 2020, 8 deep-sea manned submersible oceanauts, 6 males and 2 females, were selected as objects. In the 1∶1 model of Jiaolong deep-sea manned submersible, the oceanauts performed manipulator operation tasks and troubleshooting tasks with different difficulties, measured the continuous blood pressure of the oceanauts, filled in the NASA Task Load Index (NASA-TLX scale) after the completion of a single mission, and the changes of systolic pressure (SBP), diastolic pressure (DBP), mean arterial pressure (MAP) and mental workload were analyzed. Results: In a single task, the SBP, DBP and MAP of the oceanauts increased first and then decreased. The blood pressure values at the third minute were significantly lower than those at the first minute (P<0.01), and those at the fifth minute were significantly higher than those at the third minute (P<0.01). When performing the same task, compared with the quiet state, SBP, DBP and MAP increased when the oceanauts performed low difficulty, high difficulty, high difficulty+2-back manipulator operation task and troubleshooting task (P<0.05). When the task difficulty was the same, the SBP and MAP of oceanauts performing manipulator operation tasks were higher than those of oceanauts performing troubleshooting tasks (P<0.05). Compared with low difficulty tasks, the scores of NASA-TLX scale for oceanauts performing high difficulty manipulator operationtasks were significantly higher (P<0.05). Compared with the low difficulty task and high difficulty task, the scale score of the high difficulty+2-back troubleshooting task was significantly higher (P<0.05). When the task difficulty was the same, the scale scores of low difficulty and high difficulty manipulator operation tasks were significantly higher than those of troubleshooting tasks (P<0.05). SBP, DBP, MAP of No. 1, No. 3, No. 4, No. 5, and No. 7 oceanauts (all of whom had 6 years of diving) were positively correlated with NASA-TLX scale scores (r>0.8, P<0.05) . Conclusion: In the process of manned deep-sea diving, when the oceanauts perform manipulator operation tasks and troubleshooting tasks, with the increase of task difficulty, the mental load of oceanauts increases, and the blood pressure index increases significantly in a short time. At the same time, improving the proficiency of operation can reduce the variation range of blood pressure indexes. Blood pressure can be used as an effective reference to evaluate the difficulty of operation and guide scientific training.
Female ; Male ; Humans ; Blood Pressure ; Diving ; Workload

BACKGROUND: Scuba diving has become increasingly popular in Korea. Medical problems are common with dives, especially decompression sickness(DCS). This study was performed to obtain an useful information of hyperbaric oxygen therapy in DCS in Korea. METHOD: We reviewed the 62 cases of Korean divers, who were diagnosed as DCS and received recompression therapy according to U.S. Navy Standard Recompression Treatment Table at Ocean and Underwater Medical Research and Training Center of ROK Navy, for 6 years from Jan. 1993 to Nov. 1998. RESULT: 1) the mean no-decompression limit excess time between type I DCS group(72.7 min.) and type II DCS group(92.8min.) showed significant difference. 2) The rate of symptoms appeared on surfacing and within 10min. after surfacing of type I and type II DCS were 41.4%and 72.7% respectively. 3) The cure late of type I and type II were 75.9%and 42.4% respectively. In type II DCS group, the cure rate of the group within 12 hour-delayed recompression treatment and the group above 12 hour-delayed treatment were 64.3%and time 26.3% respectively, and in type I DCS group, 100% and 66.7% respectively. CONCLUSION: These findings suggest that the education of safety, the strict observance of the standard decompression table, and the avoidance of excessive repeated diving are important for reducing the risk of diving related disease. And to offer proper management of DCS, there should be more multiplace hyperbaric oxygen chambers, the suitable transport system, and the specialist of diving medicine or hyperbaric medicine in Korea.
Decompression Sickness* ; Decompression* ; Diving ; Education ; Hyperbaric Oxygenation* ; Korea ; Oxygen ; Specialization

Spinal trauma produced from motor vehicle accidents, diving accidents, or falls occur at high rates of loading. This study was undertaken to reproduce clinically relevant cervical spine injuries under controlled conditions. Six isolated head-T2 human cadaveric preparations were tested using an electrohydraulic piston actuator at loading rates from 295 to 813 cm/sec. The Hybrid III head-neck was tested similarly at rates from 401 to 683 cm/sec. The input forces for specimen tests were of higher magnitude and shorter duration than the distally measured forces. In contrast, the Hybrid III head-neck revealed similar magnitude and duration force traces from input to output. The specimen preparations were analyzed kinematically at 1200 frame/sec with 20 to 30 retroreflective targets fixed to each level of the cervical spine. With this technique it is possible to temporally follow cervical damage as a function of applied forces. Wedge, burst, and anterior compression fractures were documented using CT and cryosectioning techniques. This pathology can be evaluated quantitatively using the target analysis. For example, a burst fracture occurred suddenly and 2.5 msec, whereas wedge fractures were progressive and took 4 to 5 msec to occur.
Cadaver* ; Cryoultramicrotomy ; Diving ; Fractures, Compression ; Humans* ; Motor Vehicles ; Pathology ; Spine

OBJECTIVETo explore the underwater decompression schedule for 100 m Trimix conventional diving operations and evaluate its safety through a simulated rabbits Trimix conventional diving.

METHODSAccording to the Haldane theory, the assumed time units, the classification of tissue compartments, the nitrogen super-saturation safety coefficient and the selection of methods used for the calculation of the simulated 100 m Trimix conventional diving schedule were properly selected, and the calculating method for the dive decompression schedule was thus firmly established. In our experiments, five tissue compartments were selected during the calculation of decompression schedule: 5 min, 10 min, 20 min, 40 min and 75 min, and the nitrogen super-saturation safety coefficient was calculated by 1.6. Eight New Zealand rabbits were performed a simulated 100 m Trimix dive program which was established according to the Haldane theory, and eight rabbits for intact group. The tissues wet/dry ratio and ethology were detected and observed before and after the simulated diving to evaluate the safety of decompression schedule.

RESULTSBy using the developed underwater decompression schedule, abnormal ethology changes in rabbits could not be observed after compression and decompression to the surface; and the tissues wet/dry ratio of simulated diving rabbits had no significant changes compared with the intact group (P > 0.05).

CONCLUSIONThe decompression schedule calculated by Haldane theory seemed to be safe and reliable, the diving breathing gas concentration did not cause oxygen toxicity and nitrogen narcosis among the dive rabbits, and dive efficiency was greatly improved by using enriched oxygen gas in UPTD safety range during decompression.