HBOT in Decompression Illness
Shi Lu1, Li Zhuo2, Li Yangyang3, Long Ying4, Gao Chunjin2
1Institute of Underwater Technology, Shanghai Jiao Tong University, Shanghai 200231;; Shanghai Jiao Tong University-Chiba University International Cooperative Research Center, Shanghai 200240, TBD, China
2Department of Hyperbaric Oxygen, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, TBD, China
3Institute of Underwater Technology, Shanghai Jiao Tong University, Shanghai 200231;;, TBD, China
4Shenzhen People’s Hospital, Shenzhen 518020, TBD, China
Background: Decompression illness (DCI) includes decompression sickness (DCS) related to gas freed from solution in tissues during decompression and arterial gas embolism (AGE) usually caused by penetration of alveolar gas into the circulation, one of the critical complications of pulmonary barotrauma (PBT). The dysbaric osteonecrosis (DON) is one of the main sequelae of DCI. Hyperbaric oxygen therapy (HBOT) is breathing oxygen while under increased atmospheric pressure. During the past decades, tens of thousands of divers engaged in seafood harvesting and thousands suffered from DCI among fishery areas in China. Currently there are about 5,400 HBO chambers in China. HBOT and recompression emergency treatment is widely used in the treatment of majority of the cases.
Methods: We summarized the general situation such as the influencing factors, geographical distribution, gender, age, main symptoms, therapeutic schedule and HBOT intervention of DCI among Chinese divers.
Results: The factors leading to DCI mainly include working conditions (diving depth, diving time, violation of diving rules) and protective measures (diving knowledge, technical training, decompression mode).The population of DCI is mainly concentrated in Circum-Bohai Sea Region and Coastal Areas of Fujian Province. The cases are almost exclusively male, ages range from 18~58 y, diving depth range from 8 m~70 m. A survey in 2010 reported that in Dalian region, 545 DCI cases were identified in 416,069 dives, with an incidence rate of 0.13%. All DCI cases were treated with the recompression schedules first. For all schedules, pure oxygen breathing begins on arrival at 18 m (Equivalent to HBOT). Adjuvant HBOT (2.0~2.5ATA, one time per day, 5~30 sessions generally) was recommended for all severe patients and mild to moderate patients who recovered incompletely after the first recompression. The pressure and duration of oxygen breathing depends on the severity of manifestation, the response to recompression, delay to treatment, the depth-time of the incident dive(s). Adjuvant therapy including liquids and drugs is indispensable and critical for better outcomes, especially for severe cases. Li et al reported 1236 DCI cases from 1995~2000 in Dalian, 8.90% cases received recompression emergency treatment (or HBOT) in 2 hrs, 38.83% in 8 hrs, 33.98% in 24 hrs, 18.28% beyond 24 hrs respectively. According to a 5278 cases study, the latent time from surfacing to the onset of DCI symptoms were all within 48 h, with a median latency of 62 min; from the onset of symptoms to the treatment, with a median delay of 9 h ; 98% patients receiving additional HBOT recovered completely or improved significantly in this study. Unfortunately, most of the patients chose to abort continuing treatment after the first recompression.
Conclusions: DCI presents specific occurrence rules. Initial recompression and adjuvant HBOT should be administered as soon as possible and should never be abandoned irrespective of the delay. Emphasizing the seriousness and harmfulness of DCI, eliminating violations of the diving rules as far as possible should have positive effect on reducing the occurrence of DCI.
[Key words] Decompression illness, Hyperbaric oxygen therapy, Emergency treatment