Decompression illness (DCI) incident during routine decompression of divers from saturation

  • Safety Flash
  • Published on 10 April 2014
  • Generated on 26 December 2024
  • IMCA SF 05/14
  • 3 minute read

A member has reported a decompression illness incident during a ‘routine’ and planned decompression of divers in saturation chambers from a storage depth of -160 metres sea water (msw).

What happened?

During the course of the decompression one of the divers complained of pain in his pelvis and knees. The pressure in the saturation chamber at the time of the incident was -93 msw.

Following this report a Diver Medical Technician (DMT) inside the chamber carried out a physical and neurological examination of the affected diver. This found that, aside from the presence of pain in both knees and hips, the condition of the diver appeared essentially normal. On a scale of one to ten the pain experienced by the diver was described as a two. An initial diagnosis of Type 1 (mild) decompression illness was made.

In accordance with standard diving procedures the diver was recompressed to a depth where the pain disappeared (-128 msw). He was then provided with a suitable therapeutic gas treatment mixture through the chamber built-in breathing system (BIBS). On advice from the contracted diving specialist medical adviser the diver (and his two colleagues) were then stabilised and observed at -128 metres for a period of twelve hours. Thereafter normal decompression was recommenced. No re-occurrence of symptoms was experienced by the diver and the team reached surface without further mishap. Following a standard bend watch period all the divers were released to return to their homes.

An investigation team considered if any of the following physiological and environmental factors known to influence DCI had caused or contributed to the incident:

  • dehydration
  • age
  • physical fitness/obesity
  • meals
  • exertion
  • temperature
  • previous history of DCI
  • multiple dives
  • nature of dive profiles, including upwards and downwards excursions
  • omitted decompression
  • drugs and alcohol
  • sleep pattern and conditions
  • emotional state/stress.

In addition the investigation team examined the competence and compliance to process of key personnel.

Our member’s investigation concluded the following:

The investigators concluded that the incident could only be attributed to the individual diver’s physiology. However, the following findings were identified:

  • the diver’s level of hydration at the time of the incident could not be categorically confirmed.
  • Non-approved personal vitamin/protein supplements were taken into saturation.
  • No deviations from approved procedure were observed;
  • Competence levels were high.
  • The diving contractor maintained a very good diving safety culture.

The following recommendations were made:

  • Health check, water/fluid intake and urine colour questions should be asked on a daily basis, and the results should be recorded.
  • Bag searches should be conducted prior to entering saturation to ensure only controlled items can be taken into saturation.
  • Personal vitamin/protein supplements need to be declared prior to entering saturation.

Latest Safety Flashes:

Structural failure of rescue boat

A rescue boat suffered a catastrophic structural failure whilst unattended on the davit.

Read more
High potential: spontaneous opening of hydraulic release shackle (HRS) pin

During lifting operations on a vessel, a hydraulic release shackle pin opened on its own.

Read more
NTSB: diesel generator engine failure

The National Transportation Safety Board of the United States (NTSB) published "Safer Seas Digest 2023".

Read more
LTI: fall from height during anchor chain handling operation

A worker fell through an opening from one deck to another, and was injured as a result.

Read more
Sudden disconnection of pressurised hose

A contractor was performing maintenance on the bulk cargo methanol system on deck of a vessel.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.