SECOND EUROPEAN CONSENSUS CONFERENCE
ON HYPERBARIC MEDICINETHE TREATMENT OF DECOMPRESSION ACCIDENTS IN
RECREATIONAL DIVINGMARSEILLE , May 8-10, 1996

RECOMMENDATIONS OF THEJURY*QUESTION 1 : Is there a difference between recreational and commercial diving
decompression accidents?
QUESTION 2 : How to classify decompression accidents?
QUESTION 3 : Which experimental model for decompression studies?
QUESTION 4 : Which initial recompression modality?
QUESTION 5 : Which fluid replacement protocol and which role for drugs in the treatmentof decompression accidents ?
QUESTION 6 : Which treatment protocol for persistent symptoms after the initialrecompression ?

QUESTION 1 : Is there a difference between recreational andcommercial diving decompression accidents?
Whatever the reasons and the methods for diving, they all share similar risk (the same
decompression profile after the same dive will bring about the same decompression risk),similar physiopathology (a decompression accident will generate similar disorders in both
circumstances) and similar results (if the delay to treatment is similar).
The observed differences between decompression accidents in the two types of diving
essentially regard the degree of risk (fitness to dive, training, work load, depth,environment, safety standards) and the delay before treatment (symptom recognition,hyperbaric chamber availability).
The recommendations of the jury (Type 1 recommendation) are the following :•••••implementing fitness to dive standards, both for recreational and commercialdiving.
implementing an adequate classification of Decompression Accidents
implementing a coordinated network for the collection and the retrospective
analysis of data concerning decompression accidents
improving the recreational diving safety standards to approach the current
standards applied in commercial diving, with special regard to :o availability of oxygen on every dive siteo availability of a recompression chamber within a delay of 4 hours
o preparation of an emergency plan before any diverecreational divers should be trained, like commercial divers are, to recognize
signs and symptoms of decompression accidents.

QUESTION 2 : How to classify decompression accidents?
Depending on the intended utilization objective, there are three possible ways to classifydecompression accidents:•••

immediate clinical use, need for rapid and efficient communication between
divers and Emergency Services, on site first aid and medical evacuation of injured
divers, data selection and availability for clinical studies.
epidemiological use for the retrospective analysis of data and of treatment results.
description of lesions based on anatomical-pathological observations.

The recommendations of the Jury (Type 1 recommendation) are the following:••

immediate use classification should be simple and objective. The jury
recommends that it is based on that adopted by the UHMS (Smith and Francis).
epidemiological use classification for retrospective analysis should allow for theinstitution of a data bank collecting the observations from a great numbers ofcountries. To this purpose, harmonization between national classifications shouldbe established in order to allow transcodification. This classification should:
o be multithematic in its conceptiono include the type of diving, chronological data, clinical manifestations and a
two-year follow-up.

QUESTION 3 : Which experimental model for decompression
studies?
Considering the complexity of the question and the difficulty in conducting rigorous
clinical studies with sufficient numbers of experimental subjects, the Jury agreed thatanimal studies are still needed.
The recommendations of the jury (Type 1 recommendation) are the following:••••

experimental studies are necessary for more information on decompression
accidents
the variables to study are many and include:o the bubble phenomenono central neurological manifestationso bone and skin manifestations
o pulmonary disorders
o cardio-vascular disorders.
as a general principle in vitro studies should precede in vivo studies, and in vitro
studies should be done before in vivo ones.
among the animal models so far used, small animals (rodents) do not seem toadequately reproduce the human observations. Among the larger animals, the dog
is less and less used, sheep and ewes are mainly used for pulmonary studies,while the pig seems to be the animal that better reflects human reactions todecompression.

Concerning methodology, the Jury recommends that studies:•••consider clinically significant parameters,
consider experimental conditions, particularly when anesthesia modalities may
interfere with the observations,include a detailed description of the animal model in each published paper.

QUESTION 4 : Which initial recompression modality?
Decompression accidents are true medical emergencies that must benefit from treatmentin specialized centers as soon as possible. A specialized center is considered as a hospital
based facility, having not only a hyperbaric chamber but also a permanent andadequately trained medical and paramedical staff.
The victims of a decompression accident should be immediately directed from the site ofthe diving accident to the closest specialized center (Type 1 recommendation).
Minor decompression accidents (pain only) should be treated with oxygen recompression
tables at 18 meters depth maximum (Type 1 recommendation).
Regarding more serious decompression accidents (neurological and vestibular accidents),
the jury observed that there are presently two acceptable protocols, as neither one has
been proved better by any scientifically valid study to date:••oxygen recompression tables at 2.8 ATA (with possible extensions)
hyperoxygenated breathing mixtures at 4.0 ATA.

The choice between the two may depend on personal experience and on local logistics.
However, under no circumstance the un-availability of one of the two accepted modalities
should delay the treatment (type 1 recommendation).
The jury also considered the following optional treatment modalities (type 3
recommendation):••compression to 6 ATA in case of cerebral arterial gas embolism, with the condition
that this compression is performed using hyperoxygenated mixtures and notcompressed air and that the delay to treatment is not more than a few hours.
saturation treatment tables in case of persistent symptoms.

Finally the jury recommends that :••in water recompression should never be undertaken as the initial recompression
modality for a decompression accident (Type 1 recommendation).
all decompression accidents should be the object of a standardized recording
method aimed at the creation of database for epidemiological studies (type 1recommendation).

QUESTION 5 : Which fluid replacement protocol and which role fordrugs in the treatment of decompression accidents ?
1 - Fluid treatment
Victims of decompression accidents generally suffer from a certain degree of dehydration,
depending on decreased fluid input, increased urinary output, capillary fluid leakage anddisorder-related relative hypovolemia.
The degree of dehydration should be evaluated:

1. on site: history, dive conditions, thirst, clinical evaluation of neurologicalconditions, hemodynamics, temperature, vasoconstriction, dryness of mucosae,urinary output.
2. at hospital: urinary output, hemodynamics to include CVP, hematocrit, plasma
proteins and electrolytes.
3. Recommended hydration protocols:a) Pre-hospital:
1. oral hydration is recommended only if thepatient is conscious (Type 1 recommendation)
Contra-indications to oral re-hydration
are stringent and include :o any consciousness abnormality
o nausea and vomitingo suspected lesions of the gastrointestinal tract.
Oral re-hydration should be done withplain water, possibly with the additionof electrolytes but with no gas. The
administered fluid should be cold if thepatient is hyperthermic. Sugar is notrecommended. The amount of fluids
administered should be adapted to thepatient's thirst and acceptance.
2. intravenous re-hydration should be preferred
if a physician is present. Recommended procedures
are as follows:o use a peripheral venous catheter (18gauge) and preferably Ringer Lactate
as the infusion fluid. Glucose containing
solutions are not recommended.
o the addition of colloids can beconsidered if large quantities of fluids
are needed. Recommended colloids, inorder of preference, are starchcontaining solutions, gelatines, haptene

added dextranes (Type 3recommendation).
b) At the hospital:
3. intravenous re-hydration is recommended
while controlling the routine physiologicalparameters: urinary output, hemodynamics, CVP,
standard laboratory tests.
2 - Drug treatmenta) Strongly recommended (type 1 recommendation) :•normobaric oxygen
The administration of normobaric oxygen allows for the treatment of hypoxemia
and favours the elimination of inert gas bubbles. Oxygen should be administeredwith an oro-nasal mask with reservoir bag, at a minimal flow rate of 15 l/min, orwith CPAP mask circuit, using either a free flow regulator or a demand valve, insuch a way to obtain a FiO2 close to 1.
In case of respiratory distress, shock or coma, the patient should be intubatedand ventilated with a FiO2 = 1 and setting the ventilator to avoid pressure andvolume trauma. Normobaric oxygen should be continued until hyperbaric
recompression is started (with a maximum of 6 hours when the FiO2 is 1).

b) Recommended (Type 2 recommendation):•

any necessary drug for the support treatment of an intensive care patient(adequate first aid kit)c) Optional (Type 3 recommendation):••on siteo any way to prevent hyperthermia
o aspirin: 500 mg orally in the adult patient (contra-indications similar tooral re-hydration)at the hospital : use drugs having no significant collateral effects, such as:o aspirin : 500 mg if not already administered or contraindicatedo lignocaine
o low dose heparin (avoid complete decoagulation)o steroids, calcium channel blockers, antioxydants

QUESTION 6: Which treatment protocol for persistent symptoms
after the initial recompression ?
The Jury concluded that there are no scientifically valid data to allow for a recommended
approach to this issue.
More studies are necessary as well as the adoption of standardized evaluation methods.
Concerning spinal cord injuries, a specific scoring system (such as the ASIA scale) is
recommended for pre and post treatment evaluation and during the two-year follow up.
Randomized prospective studies are needed to better evaluate the efficacy of hyperbaric
oxygen therapy and of rehabilitation before any protocol can be proposed orrecommended. However, in analogy with any other neurological injury, rehabilitation
should be started as soon as possible (Type 1 recommendation).
Hyperbaric oxygen treatment is recommended to a maximum of 10 treatment sessions
after the initial recompression, in combination and during rehabilitation therapy. The
continuation of HBO therapy can be accepted if objective improvement is observed underpressure during the hyperbaric treatment sessions (Type 3 recommendation).