Decompression Sickness
Decompression Sickness
Objectives
Diagnosis
Criteria for HBO therapy
Work-up Considerations
Treatment
Suggested Treatment Threshold
ICD 10 codes
Level of Evidence
Objectives
To reduce bubble size and eliminate gas nuclei. To maximise the diffusion gradient for elimination of inert gas and thereby accelerate gas ‘wash-out’. Hyper-oxygenation of hypoxic and/or ischemic tissue. Reduction of oedema. Attenuation of ischemia-reperfusion injury.
Diagnosis
Onset of musculoskeletal pain, cutaneous manifestations, central or peripheral neurological lesions or cardiopulmonary symptoms within 24 hours of completing a dive or series of dives to a depth that exceeds 9 metres sea water. Consider altitude provocation.
The ability to differentiate decompression sickness from cerebral arterial gas embolism in the acute treatment phase is no longer considered critical.
Diagnosis to be confirmed by a medical practitioner trained in diving medicine.
Criteria for HBO therapy
Symptom onset within 24 hours of completing a dive that involved moderate to high gas loading. Dives to the limit of or exceeding no decompression time frames. Obvious violation of decompression guidelines.
Treatment should not be commenced more than 14 days after exposure
Work-up Considerations
- Continue administration of 100% oxygen via non-rebreather mask, naso- or endo-tracheal tube for up to 16 hours.
- Complete dive history, including staged decompression and repetitive diving profiles.
- Past medical history.
- Physical examination including, but not limited to, a full neurological examination.
- Special examinations: Exclude pneumothorax before recompression; chest x-ray mandatory if lung over-expansion is suspected.Other special examinations as required.
- Signed informed consent for HBOT.
Treatment
- Fluid resuscitation (IV for severe cases. Avoid dextrose containing solutions.)
- Urine output monitoring. Exclude urinary retention; catheterise if necessary. Maintain at least 1-2 mL/kg/hr.
- Consider oral Tenoxicam or equal NSAID during recompression for musculo-skeletal DCS. DVT prophylaxis critical for paralysed divers. Sedation only if essential.
- Monitor vital signs.
- Prompt HBO with compression to 2.8 ATA:
- USNTT5 (or equivalent) only for asymptomatic, omitted decompression or pain-only DCS, with complete relief within 10 minutes at 2.8 ATA otherwise treat on USNTT 6.
- USNTT6 (or equivalent) for all other DCS including neurological or cardiopulmonary manifestations.
- Consider extensions at 2.8 ATA and/or 1.9 ATA where indicated.
- In case of CNS oxygen toxicity, interrupt oxygen breathing and allow 15 minutes of air breathing after reaction has entirely subsided. Resume treatment schedule at point of interruption.
- Retreat after 6 – 24 hours if residual symptoms remain:
- Major symptoms: Consider 1 – 2 further USNTT6.
- Minor symptoms: HBO at 2.0-2.4 ATA for 90 minutes daily.
- Refer patients with residual symptoms for rehabilitation.
- Risk assessment for return to diving, as indicated.
- Consider PFO screening where indicated.
Suggested Treatment Threshold
- Approximately 75% of cases have complete resolution following the 1st USN TT6.
- To be determined in consultation with DANSA
- Stop treatment if no functional improvement after 2 consecutive treatments
ICD 10 codes
| T70.3 | Caissons disease (decompression sickness) |
| T70.0 | Otitic barotrauma |
| T70.1 | Sinus barotrauma |
| T70.8 | Other effects of air pressure and water pressure. Blast injury syndrome |
| T70.9 | Effect of air pressure and water pressure, unspecified |
| T79.7 | Traumatic subcutaneous emphysema |
| S27.0 | Traumatic pneumothorax |
| J98.1 | Pulmonary collapse |
| J98.2 | Mediastinal emphysema |
| I26 | Pulmonary oedema |
| W94 | Exposure to high and low air pressure and changes in air pressure |
Level of Evidence
- Level C.
- All authorities consider it unethical to subject this indication to a randomised controlled trial with a non-treatment control group.