MARSEILLE , May 8-10, 1996
RECOMMENDATIONS OF THE JURY*
|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 treatment of decompression accidents ?|
|QUESTION 6 :||Which treatment protocol for persistent symptoms after the initial recompression ?|
QUESTION 1 : Is there a difference between recreational and commercial 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 :
|QUESTION 2 : How to classify decompression accidents?|
Depending on the intended utilization objective, there are three possible ways to classify decompression accidents:
The recommendations of the Jury (Type 1 recommendation) are the following:
|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 that animal studies are still needed.
The recommendations of the jury (Type 1 recommendation) are the following:
Concerning methodology, the Jury recommends that studies:
|QUESTION 4 : Which initial recompression modality?|
Decompression accidents are true medical emergencies that must benefit from treatment in 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 and adequately trained medical and paramedical staff.
The victims of a decompression accident should be immediately directed from the site of the 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:
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):
Finally the jury recommends that :
|QUESTION 5 : Which fluid replacement protocol and which role for drugs 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 and disorder-related relative hypovolemia.
The degree of dehydration should be evaluated:
1. oral hydration is recommended only if the patient is conscious (Type 1 recommendation)
Contra-indications to oral re-hydration are stringent and include :
- any consciousness abnormality
- nausea and vomiting
- suspected lesions of the gastro-intestinal tract.
Oral re-hydration should be done with plain water, possibly with the addition of electrolytes but with no gas. The administered fluid should be cold if the patient is hyperthermic. Sugar is not recommended. The amount of fluids administered should be adapted to the patient's thirst and acceptance.
2. intravenous re-hydration should be preferred if a physician is present. Recommended procedures are as follows:
- use a peripheral venous catheter (18 gauge) and preferably Ringer Lactate as the infusion fluid. Glucose containing solutions are not recommended.
- the addition of colloids can be considered if large quantities of fluids are needed. Recommended colloids, in order of preference, are starch-containing solutions, gelatines, haptene added dextranes (Type 3 recommendation).
b) At the hospital:
3. intravenous re-hydration is recommended while controlling the routine physiological parameters: urinary output, hemodynamics, CVP, standard laboratory tests.
2 - Drug treatment
a) Strongly recommended (type 1 recommendation) :
The administration of normobaric oxygen allows for the treatment of hypoxemia and favours the elimination of inert gas bubbles. Oxygen should be administered with an oro-nasal mask with reservoir bag, at a minimal flow rate of 15 l/min, or with CPAP mask circuit, using either a free flow regulator or a demand valve, in such a way to obtain a FiO2 close to 1.
In case of respiratory distress, shock or coma, the patient should be intubated and ventilated with a FiO2 = 1 and setting the ventilator to avoid pressure and volume 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):
c) Optional (Type 3 recommendation):
|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 or recommended. 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 under pressure during the hyperbaric treatment sessions (Type 3 recommendation).