Decompression sickness syndrome (DCS) is caused by microbubbles forming in blood vessels or tissues during a reduction in environmental pressure (decompression). Bubbles have mechanical, embolic and biochemical effects with manifestations ranging from none to fatal. By reducing bubble volume and hastening inert gas elimination, recompression therapy with hyperbaric treatment remains the main therapy for DCS. The most common hyperbaric protocol used, is based on US Navy Treatment table 6, started as early as possible after surfacing. The outcome of hyperbaric therapy varies with reported complete resolution in 13%-63% of the patients suffering from severe DCS, and in 73%-100% of the patients with mild-moderate DCS.

The significance of time to recompression is controversial. It has been suggested that early hyperbaric treatment improves the outcome by decreasing bubble size and avoiding further tissue injury. However, in recent studies time to recompression had very little effect on clinical recovery. Moreover, the time beyond which hyperbaric treatment isn't effective has not been determined yet.

The aim of this study was to evaluate the clinical outcome of delayed hyperbaric treatment to divers who referred to tertiary care hospital hyperbaric unit, more than 48 hours after surfacing. The clinical outcome of the delayed hyperbaric treatments was compared to early treatments given at the same hyperbaric unit.

From January 2000 to February 2014, 204 divers were treated for DCS in the institute of Hyperbaric Medicine, Assaf Harofeh Medical Center, Israel.

The data will be collected retrospectively from medical records and include age, sex, diving experience, maximal depth, DCS possible cause, DCS type, symptoms, time from surfacing to symptoms onset, time from surfacing to recompression, recompression table, additional treatment after the first recompression and treatment outcome.

Statistical analysis will be done using univariant analysis was performed using Spearman's correlation and Chi-Square in categoric variabales, independent t-test in numeric variables. This will be performed in SPSS v.21 software.

Inclusion Criteria:

• Decompression sickness after diving
• Recompression Treatment between 2000-2014 in Assaf HaRofe medical center hyperbaric institute

Exclusion Criteria:

• Decompression sickness excluded

Decompression sickness patients treated with hyperbaric recompression