GB/T 17870-2026Technical requirements for recompression therapy of decompression sickness (English PDF)

Foreword

This document was issued on 30 July 2026 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 November 2026.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies.

It is classified under ICS 13.100 and Chinese classification C 65.

The document runs to 19 pages. The identification, the dates, the classification and the table of contents on this page are taken from the cover and the printed contents of the standard itself.

This document was drafted in accordance with GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

This document replaces GB/T 17870-1999 "Technical requirements for recompression therapy of decompression sickness". Compared with the 1999 edition, apart from structural adjustments and editorial changes, the main technical changes are as follows:

a) the field of application has been changed (see Clause 1; Clause 1 of the 1999 edition);

b) the definitions of "decompression sickness" and "recompression therapy" have been changed (see 3.1 and 3.2; 3.1 and 3.3 of the 1999 edition);

c) the terms "acute decompression sickness", "pulmonary barotrauma" and "oxygen toxicity" have been deleted (see 3.2, 3.4 and 3.5 of the 1999 edition);

d) the grading criteria for acute decompression sickness have been changed (see 4.1; A.1 of the 1999 edition);

e) a classification of chronic decompression sickness has been added (see 4.2);

f) the explanation of the treatment schedules and of the treatment pressure bands has been deleted (see 4.1 of the 1999 edition);

g) the classification of treatment schedules and the oxygen breathing conditions have been changed (see 5.1.1; 4.2 of the 1999 edition);

h) flow charts for the recompression therapy of mild decompression sickness and for the recompression therapy of severe decompression sickness or of arterial gas embolism caused by pulmonary barotrauma have been added (see 5.1.2, Figure 1 and Figure 2);

i) the recompression therapy schedules for acute decompression sickness at treatment gauge pressures below 0.50 MPa have been changed (see Table 1; Table 1 and A.2 and A.3 of the 1999 edition);

j) the requirement for recompression therapy of those who could not obtain timely treatment has been deleted (see 4.4 of the 1999 edition);

k) the choice of recompression therapy schedule for pulmonary barotrauma and for severe decompression sickness has been changed (see 5.2.1 and 5.2.2).

1 Scope

GB/T 17870 sets the technical requirements for recompression therapy of decompression sickness: the treatment a diver receives in a chamber when nitrogen has come out of solution in their tissues. It specifies the classification of decompression sickness, the recompression therapy of acute decompression sickness at treatment gauge pressures below and above 0.50 MPa, and the recompression therapy of chronic decompression sickness. It applies to the treatment of decompression sickness arising from air diving and to arterial gas embolism caused by pulmonary barotrauma, and it may be used as a reference for decompression sickness arising from mixed gas diving, saturation diving and hyperbaric work. An informative annex gives further schedules for chronic cases. The 2026 edition replaces GB/T 17870-1999, adding a classification of chronic decompression sickness, flow charts for mild and for severe cases, and revised treatment schedules. For a commercial diving contractor, a hyperbaric medical facility or an offshore operator working in China, this is the text a treatment protocol is written against.

2 Normative references

The contents of the following documents constitute indispensable provisions of this document through normative reference in the text. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition, including all amendments, applies.

JT/T 1452 Terminology of diving and salvage.

3 Terms and definitions

The terms and definitions given in JT/T 1452, together with the following, apply to this document.

3.1 decompression sickness (DCS): the disease caused when, after a body has been exposed to a given pressure environment for a certain time, the pressure of that environment falls too quickly or by too much, so that the inert gas dissolved in the body tissues comes out of solution and forms bubbles. [SOURCE: JT/T 1452-2022, 3.3.52, modified]

3.2 recompression therapy: the intervention by which a person suffering from decompression sickness, or from arterial gas embolism caused by pulmonary barotrauma, is exposed to raised pressure in order to eliminate the bubbles in the body tissues and the sequence of pathological changes the bubbles cause. [SOURCE: JT/T 1452-2022, 3.3.72, modified]

4 Classification of decompression sickness

4.1 Acute decompression sickness. Signs and symptoms of decompression sickness appearing during decompression or within 36 h after it. According to severity it is divided into mild and severe: mild decompression sickness presents only skin symptoms, swollen lymph nodes, and joint and muscle pain; severe decompression sickness is accompanied by signs and symptoms of the nervous, respiratory or circulatory system.

4.2 Chronic decompression sickness. Decompression sickness in which the signs and symptoms appearing after exposure to a hyperbaric environment were not treated in time, or were treated but not completely, so that the symptoms persist and can still be improved by recompression alone; and the sequelae of decompression sickness accompanied by long-standing residual symptoms, including dysbaric osteonecrosis.