Editing In-water recompression (section)

== Protocol ==
Recompression with hyperbaric oxygen administered in a recompression chamber is recognised as the standard of care for decompression sickness, but the infrastructure is expensive and may not be used very often, so many locations do not have convenient access to a suitable facility. If symptoms are significant or deteriorating, in-water recompression using oxygen is an option where groups of divers, including the symptomatic diver, have relevant prior training that allows an understanding of the associated risks and a collective informed acceptance of responsibility for the decision to proceed with treatment. Observational evidence has shown that very early recompression on oxygen usually results in good outcomes, or at least better outcomes than treatment after longer delays.<ref name="Doolette and Mitchell 2018" />

Recompression on air will initially produce a compression of existing bubbles, and may produce associated clinical improvement, but bubbles will dissolve more slowly due to the lower concentration gradient, and some tissues will absorb more nitrogen. Bubbles nor completely resolved will re-expand during decompression, and may take up more gas, which may cause symptoms to recur or get worse. There is also observational evidence that IWR on air is less effective, so only oxygen is recommended as a treatment gas.<ref name="Doolette and Mitchell 2018" />

The minimum team would comprise the symptomatic diver, a dive buddy to accompany the diver during the recompression, and a surface supervisor, who must all be competent at decompression procedures using 100% oxygen as the breathing gas.<ref name="Doolette and Mitchell 2018" />

The team should be suitably equipped with adequate thermal protection, an adequate oxygen supply, a means of delivering oxygen at or near 100% for the duration of both underwater and surface phases of the treatment, a means of voice or written communication, and a method of keeping the diver at the appropriate depth and maintaining position. A full-face mask or mouthpiece retaining strap is strongly recommended as there is observational evidence of these devices preventing drowning of an unconscious diver underwater.<ref name="Doolette and Mitchell 2018" /> [[surface supplied diving|Surface supplied]] oxygen delivered to the casualty by umbilical or airline, and voice communication are desirable options as they allow the surface team members to keep control of the breathing gas supply and allow better monitoring of the diver's condition. Positive pressure masks have been recommended for use with open circuit oxygen, as giving more secure protection of the airway, after their successful use in rescuing the trapped [[Tham Luang cave rescue|Tham Luang cave group]] while anaesthetised.<ref name="Mitchell 2022" />

Although the IWR tables are shorter and shallower than most hyperbaric treatment tables, a substantial supply of oxygen is required. The US Navy Type 1 IWR table requires about {{convert|160|cuft|litres}} of oxygen for a diver with a surface consumption rate of {{convert|0.5|cuft|litres}} per minute, and the Type 2 table would use about {{convert|180|cuft|litres}}. The rate of {{convert|0.5|cuft|liters}} per minute may be optimistic if the diver is stressed due to injury, discomfort, or cold, or if some models of full-face mask are used.<ref name="Walker and Murphy-Lavoie" />

Recognised IWR protocols include the "Clipperton protocol", "Australian method", and the US Navy method for in-water recompression on oxygen.<ref name="Doolette and Mitchell 2018" />

In-water recompression may not produce complete resolution of DCI, and signs or symptoms may recur. Any diver completing an in-water recompression should consult a [[diving medical practitioner]] as soon as reasonably practicable.<ref name="Doolette and Mitchell 2018" />