This Information sheet is designed for divers who are planning to return to diving after decompression illness (DCI).

You should usually have a gap of at least 3 months after the incident before diving again or the Hyperbaric Doctor in charge of your treatment may specify a time period. If in doubt then contact The Scottish Sub-Aqua Club at the head office for more details.

Will this happen again?
You have a higher risk of recurrence after one episode of DCI. In some cases this may because of hidden risk factors such as PFO (Patent Foramen Ovale) or hole in the heart. In others it may be because bubbles have damaged the circulation around the injured tissues and this may increase the risk of further bubble damage in the future.

Should I have a PFO test?
You should have completed an incident report form and this will be screened by the ScotSAC Medical Advisor. When you return to diving you should complete a new medical questionnaire and you will be advised if a PFO test should be performed. If in doubt contact the ScotSAC head office for more information. ScotSAC divers who have suffered from neurological or skin bends should have a PFO test. The chance of finding a PFO is highest in this group of divers (around 60%) especially if there is a history of migraine, or if there is a short gap after surfacing before symptoms develop (usually around 5 minutes). The PFO test involves a heart scan using ultrasound and the doctor performing the scan will inject a mixture of saline (salt) solution containing very small bubbles to see if they cross inside the heart through a small hole. The scan will usually involve doing the Valsalva movement to increase the pressure on the right inside of the heart. Around 20% of the population have PFO’s, but only 1% of the population have PFO’s big enough to cause problems when diving.

Can PFO’s be closed?
It is possible to close PFO’s under local anaesthetic. This may require one night in hospital. The procedure involves passing a wire from a vein in the top of the leg into the heart, then passing a device over the guide wire to close the hole. The wire is then removed, and the device remains in place inside the heart. It takes about 6 weeks after the procedure for the device to be fully effective and a scan is usually performed before returning to diving. Aspirin is required for 6 months but no other specific treatment is required. Like all procedures there are risks involved and these should be fully appreciated before undertaking this form of treatment. They will be explained in full by the cardiologist involved.

Can I dive without closing my PFO?
There is an increased risk of DCI which can be minimised by a maximum depth of 15 metres using NITROX on air tables. Using low bubble tables (such as DCIEM tables), slow controlled ascent rates, routine safety stops and avoiding decompression diving.

General advice
There are many conditions that increase the risk of DCI. While these should be picked up by the screening questionnaire and by medical examination where necessary, divers can do a lot to reduce the risks.

• Remember the tables include a finite rate of complications and so you should always include an extra safety margin, particularly when using dive computers.
• Have a break in the middle of a weeks diving.
• Avoid too much alcohol the night before diving, since this causes dehydration and low sugar levels.
• Build up your diving fitness rather than starting with deep dives at the beginning of the season or when on holiday.
• Watch your profiles to avoid bounce diving or rapid ascents.
• Finally, uncontrolled ascents remain the most common cause of DCI, particularly when surface marker buoys are involved, good planning and training should reduce these risks