Christopher Edge
Chair, UK Sports Diving Medical Committee
Introduction.
The ban on diving diabetics started in the mid-1970s, after an accident
involving a diving diabetic. This diver had suffered from sudden onset
decompression illness, but there was no evidence that his diabetic condition
had contributed to this. Despite this, a complete ban was imposed on diving
diabetics with the exception of those diabetics controlled by diet alone.
In the early 1990s, a further examination of the case and a review of
the post-mortem results showed the presence of a patent foramen ovale
(PFO, a hole-in-the-heart between the right and left atria) in the diabetic
diver, which may or may not have contributed to this particular incident.
Further, a survey was carried out on those diabetic divers who were still
diving (despite the ban) and this showed that none of these diabetics
had suffered from an increased incidence of decompression illness or,
more importantly, suffered from hypoglycaemic attacks whilst diving. Therefore,
in 1992, the British Sub-Aqua Club decided to readmit diabetics into the
Club, provided that certain strict medical criteria were met.
To be allowed to dive, the diabetic must not only satisfy
medical criteria, but he or she must take additional precautions when
diving, both to ensure the well-being of him/herself and also the well-
being of the diving buddy and the rest of the party of divers. These conditions
are set out below.
Medical conditions.
The diver should not have any of the long-term complications of diabetes.
The medical conditions apply equally to insulin-dependent and non-insulin-dependent
diabetics. Although hypoglycaemia is a relatively uncommon complication
in non-insulin-dependent diabetics the risks are not negligible and any
potential diver should be using a short-acting anti-diabetic drug, if
such medication is necessary. However, it does appear that non-insulin-dependent
diabetics can generally exercise without fear of a deleterious metabolic
response. The diving clubs in the U.K. (BSAC, SAA and SSAC) issue a common
set of forms for the diabetic and his/her diabetologist to complete which
ask if any of the following statements are true:
- Has the diabetic's medication regime altered within the last year?
- Have any episodes of hypoglycaemia occurred within the last year
and if so, under what circumstances did these occur?
- Has the diabetic been hospitalised within the last year for any
condition related to diabetes?
- Has the diabetic's level of control been in any way unsatisfactory
throughout the last year?
- Is microalbuminuria present?
- Is there any degree of retinopathy present?
- Is there any degree of neuropathy (sensory, motor or autonomic)
present?
- Is there any evidence of vascular or micro-vascular disease present
and, if so, where?
The diabetologist is also asked to comment whether in
his/her opinion, the diabetic is in any way mentally or physically unfit
to undertake the degree of strenuous exercise that scuba-diving demands.
If the answer to any of these questions is "yes" then the diabetic
would not normally be allowed to dive. An exception is normally made if
the diabetic has only mild background retinopathy. The diabetic must undergo
a complete physical examination on an annual basis and be passed as fit
to dive by a physician with a special interest in scuba diving after reviewing
the answers to the questions posed above. In addition, for diabetic divers
over the age of 50, an exercise ECG is mandatory. Finally, a copy of the
forms is sent to Dr. Chris. Edge in order that a database can be built
up on the diabetic divers for future reference.
Diabetic diving standards.
The diabetic should be prepared to give an annual lecture to his/her club
on the problems associated with diabetes and diving. Practical illustrations
of the administration of glucose and the measurement of blood glucose
are also helpful. This allows the club members to gain experience, not
only with the problems specific to diabetes, but also in the handling
of emergencies in general.
It is advisable that diabetics dive only a maximum of twice per day, and
not on more than three consecutive days. This helps to avoid the build-up
of an excessive tissue nitrogen load.
The dive itself can be divided into three parts: pre-dive,
dive and post-dive. There are guidelines to follow for each of these three
stages which are aimed to allow the diabetic diver, his/her buddy and
the club to dive safely and enjoyably.
Pre-dive.
The diving diabetic should be as fit and mentally prepared to dive as
his or her non-diabetic buddy. They should preferably be wearing at all
times an SOS (Medic Alert) bracelet stating that the bearer is a diabetic
and also a diver and that therefore the possibility of decompression illness
must be considered should the diver be taken ill. The diabetic diver should
be especially careful with regard to being adequately hydrated as there
is some evidence that the level of hydration affects the chances of experiencing
decompression sickness. The dive marshal should be aware that the subject
is a diabetic and should also be informed of the profile of the dive (plan
the dive and dive the plan). The diabetic diver's buddy should be a person
who is either i) a regular diving partner and who is familiar with the
diabetic and the problems he or she is likely to experience or ii) a trained
medic or paramedic who is familiar with the problems of diabetics. Clearly,
the buddy should not also be diabetic. The diabetic should carry with
them on a dive a kit consisting of:
- Two separate packs of oral glucose paste or tablets in waterproof
containers.
- Emergency intramuscular injection of glucagon.
- Glucose oxidase sticks together with the necessary glucose-measuring
instrument and instructions for the use of such kit.
- Normal diver safety equipment with one or more of the following
items: surface marker buoy; flag; personal flares; emergency beacon.
Diabetics should plan to carry glucose tablets or paste
with them in a small waterproof casing or bag during the dive. The diving
buddy must know the whereabouts of these tablets or paste and be able
to gain access to it quickly in the event of an emergency. It is essential
that there is at least one person in the dive party of the diabetic who
is able to use and administer the glucose tablets and intramuscular injection
of glucagon. Just prior to diving, it is sensible for the diabetic diver
to ensure that he or she has a slightly higher than normal blood sugar
level by consuming glucose in whatever form takes their preference (glucose
tablets, barley sugar sweets etc.). Blood glucose should be measured at
this time.
Dive.
A diabetic diver should not dive deeper than 30 metres until a considerable
experience of diving and its associated problems has been gathered by
the Medical Committee. He or she should remain well within the tables
or have more than 2 minutes no-stop time left on a dive computer.
Post-dive.
On arrival back at the boat (or on shore if a shore-dive) the diabetic
must check his/her glucose level and, if necessary, correct it in the
appropriate manner. Any adverse symptoms or signs should be reported immediately
either to the diving buddy or to the dive marshal and should not be passed
off as merely "part of diving". The instructions to the diabetic
diver and the diving officer are at pains to emphasise that the symptoms
of low blood sugar may mimic those of neurological decompression illness
or a gas embolism and vice-versa, e.g. confusion, unconsciousness, fits.
In this situation, first aid therapy must be given to the diabetic casualty
as though both conditions were present i.e. 100% oxygen and treatment
for low blood sugar. In the event of there being an incident in the water
or on the boat, the diabetic diver should be brought to the boat or shore
as soon as possible. The blood glucose should be measured using the equipment
in the diabetic emergency kit if this can be swiftly performed. Oral glucose
should be administered to the subject with low blood sugar if conscious;
otherwise, an intramuscular injection of glucagon (1 mg) should be given.
Medical attention and recompression facilities should be sought as soon
as possible.
Experience to date.
Since November 1991, the Medical Committee has allowed more than eighty
diabetic divers to dive. The age range is approximately 17-50. Both insulin-dependent
and non-insulin-dependent diabetics are registered. Currently, there are
three National Instructors (the highest teaching grade within the BSAC)
who are registered. So far (February 1995) there have been no diving deaths
attributable to diabetes and only two reported incidents of mild hypoglycaemia
in the water (both incidents were on the surface and the divers reported
feeling slightly light-headed; both were able to correct this using the
glucose paste that they carried). As of March 1994, 702 person dives had
been logged with 220 in the depth range 0-10 metres, 252 in the range
11-20 metres, 165 at 21-30 metres and 65 over 30 metres. 31 of these dives
involved decompression stops.
The Medical Committee hopes that the standards set out above are such
that adherence to them will allow certain diabetics to dive safely and
enjoyably. The situation is kept under constant review, but so far appears
to work reasonably well. The Committee has had enquiries about the standards
from the U.S., Egypt, Denmark, Holland, Saudi Arabia, Australia and Cuba
and it appears that several diving organisations may adopt them in the
future.
Enquiries to:
Dr. C.J. Edge, The Stone Barn, Gravel Lane, Drayton, Abingdon, Oxon. OX14
4HY
Tel. +44-1235-529-888
e-mail: cjedge@vax.ox.ac.uk
or edge_c@snd02.pcr.co.uk
or 100117.3646@compuserve.com
The set of three forms are available as a 58Kbyte PDF File
You can preview them as GIFs:
Form A (to be completed by the diabetic diver on an annual basis) page
1 and page 2
Form B (to be completed by the physician-in-charge) page
1 and page 2
Form C (to be given by the diabetic individual to the
Branch Diving Officer on successful completion of the medical examination)
page 1 and page
2
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