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Decompression Sickness S006

Last amended 
28 April 2020
Current RMA Instruments
Reasonable Hypothesis SOP
13 of 2015
Balance of Probabilities SOP
14 of 2015
Changes from previous Instruments

SOP Bulletin 179

 ICD Coding
  • ICD-9-CM Codes: 993.30
  • ICD-10-AM Codes: T70.30
Brief description

Also known as 'the bends', this is a condition that can occur in scuba divers on returning to the surface after an underwater dive, or in others exposed to a decrease in atmospheric pressure (typically after being in an environment of increased pressure).  It is caused by the formation of gas (nitrogen and oxygen) bubbles in the tissues/blood as the gases expand with lower pressure.  It occurs generally if the change in atmospheric pressure is to rapid for the body to cope with.  These gas bubbles can cause a range of problems throughout the body.

Confirming the diagnosis

The diagnosis is made clinically, based on the history and physical findings.

The relevant medical specialist is a physician.

Additional diagnoses covered by SOP
  • The bends
  • Caisson disease
Conditions excluded from SOP
  • Pulmonary barotrauma*
  • Osteonecrosis (dysbaric)*
  • Fat embolism#

* another SOP applies

# Non-SOP condition

Clinical onset

The clinical onset will be acute, with the development of symptoms in most cases within one hour after an episode of decompression.  90% of cases will have symptoms within 12 hours.  A small number may develop symptoms more than 24 hours after decompression.  

Clinical worsening

This is an acute injury event.  The only SOP worsening factor is for inability to obtain appropriate clinical management.  Appropriate treatment in other than mild cases is recompression in a hyperbaric chamber, initiated as quickly as possible.