Factors associated with residual symptoms after recompression in type I decompression sickness

The aim of this study is to investigate factors associated with residual symptoms after hyperbaric oxygen therapy (HBOT) in type I decompression sickness (DCS).

An HBOT registry, which includes patients with type I DCS, was analyzed retrospectively. We divided enrolled patients into two groups; complete resolution group and residual symptom (RS) group after a single HBOT session. We investigated factors associated with residual symptoms at discharge with univariable and multivariable analyses. Restrictive cubic spline curve and a test for trend analysis were used to show the trend of therapeutic response after HBOT based on time from symptom onset to HBOT.

In a total of 195 patients, 131 (67.2%) patients were included in the RS group after single HBOT. Prolonged time from symptom onset to recompression was independently associated with residual symptoms (P = .004). When patients who underwent recompression within 24 hours from symptom were included in the reference group, the adjusted odds ratios (AOR) (95% confidence interval) of residual symptoms after HBOT were the following: 24 to 96 hours, 2.24 (0.75-6.65); 96 to 240 hours, 3.31 (1.08-10.13); more than 240 hours, 22.83 (2.45-231.43). In terms of sort of diving, commercial and recreational divers had higher probability of residual symptoms than military divers (AOR, 4.78 and 33.36, respectively).

Early HBOT is associated with rapid symptom elimination after treatment in type I DCS. Military divers showed a more immediate response after recompression in comparison with commercial and recreational divers.