Gestión de Accidentes de Buceo
A Power Point Presentation in Spanish
by Ernest S Campbell, MD, FACS
scubadoc@scuba-doc.com
| Introduction | Rescue | Resuscitation | Position | Oxygen |
| IV fluids | Medications | InWaterTreatment | Transportation | Summary |
It is desirable to have a standard approach to the initial management (i.e. first-aid) of an injured diver.
Coincidentally, a diver may have a non-diving related illness or injury, but in general, symptoms and signs following a dive are likely to be due to that dive.
An injured diver must be removed from the water as quickly as possible. If the diver is unconscious and beneath the surface of the water, then they should be surfaced and decompressed in the head upright, normal anatomic position with special attention being paid by the rescuer to the maintenance of a patent airway. Surfacing feet first would delay the initiation of mouth to mouth for a short period. Air would continue to be forced from the lungs by ascent either way you raise the diver. PADI states that head up is the appropriate method. On the surface, the 'do-ci-do' left sided position is what is being taught for mouth to mouth initiation of breathing.
Getting the unconscious diver to the surface as fast as reasonably possible, head up and with the regulator in place would be my recommendation. NOAA does not address this in their new manual and I cannot find any reference to position of retrieval
in the Navy manual.
For other articles about diving safety see http://www.scuba-doc.com/dvsaf.html
A SCUBA diver in this context should have their regulator placed in their mouth, but no attempt at "purging" gas into the injured diver should be made. Divers using rebreathing systems, full-face masks, band masks or helmets should be "flushed-through' with fresh gas, preferably from an alternative emergency gas supply, before swimming them to the surface or recovering them to a platform or bell. Specific techniques for recovery of a diver into and resuscitation of a diver in a bell or hyperbaric rescue vessel are needed and must be practiced.
In the absence of such a platform, the injured diver should be made positively buoyant by removing their weight-belt and perhaps by inflating their buoyancy-compensator (providing it neither limits access for the rescuer nor causes the injured diver to float "face-down'). The injured diver's air tank should be left in-situ as it acts as a keel. The rescuer should adjust their own buoyancy by buoyancy-compensator inflation and not by dropping their weight-belt in case they lose hold of the injured diver and have to recover them again from underwater.
The utility of expired-air-resuscitation (EAR) in the water, either directly or via a snorkel, is debatable. Certainly there is a significant difference between conducting EAR in a swimming pool and in the ocean in this context, effective in-water EAR is only possible with continual practice in the ocean and, in general, an injured diver's best interests are usually served by protecting their airway and getting them out of the water as quickly as possible.
Effective EAR and chest compression ( which obviously should not be attempted in the water ) are life-saving if cardiorespiratory arrest occurs, regardless of the cause of the injury.
Techniques should not vary between the diver who has drowned and the diver who has been envenomated, nor should it be altered for a hypothermic diver (in whom it must never be abandoned until after re-warming has been completed).
If any form of decompression illness (DCI) is suspected, then the diver must be laid flat and not allowed to sit-up or stand as this may cause bubbles to distribute from the left ventricle and aorta to the brain. Although such posture-induced phenomena are unusual (rare), they have a very poor outcome. This posture must be maintained until the injured diver with DCI is inside a recompression chamber (RCC). A headdown posture is no longer advocated as it may increase the return of and subsequent "arterialization" of venous bubbles, it causes cephalic-venous engorgement such that subsequent middle-ear inflation (e.g. in a RCC during treatment) is very difficult, it limits access for resuscitation and assessment, and, in animal-model studies it actually retards the recovery of brain function in comparison to the horizontal posture.
With the exception of oxygen toxicity, administration of 100% oxygen is useful in all diving accidents. Although divers who have pulmonary oxygen toxicity need to breathe a PiO2 of less than 0.6 Bars, many of those who have had an oxygen-induced convulsion will subsequently become hypoxic and need oxygen administration.
To administer 100% oxygen, a sealing anesthetic-type mask is needed (unless a mouthpiece and nose-clip in a conscious diver or an endotracheal tube is used) and a circuit with high gas flow-rates and a gas reservoir must be used. Air breaks, to retard pulmonary damage, may be needed, but should be minimized as must all other interruptions. This is one of the reasons why oral rehydration is not particularly useful.
It is noteworthy that administration of 100% oxygen is the definitive treatment of the salt-water aspiration syndrome and most pulmonary barotrauma, including the majority of pneumothoraces. Indeed, chest cannulation is rarely needed.
As with oxygen, aggressive intravenous rehydration is probably of benefit to all injured divers, even those who have drowned. Certainly, such therapy is of considerable benefit in DCI. Isotonic solutions should be used. Glucose solutions should be avoided as they have been shown to increase damage in neurological trauma.
An indwelling catheter should be inserted (filled with water, not air) and an accurate fluid balance is essential. A persistent poor urinary output despite adequate fluid replacement may indicate either persistent hemoconcentration or bladder dysfunction. Either indicates severe DCI and warrants both bladder catheterization and further fluid replacement.
There are no drugs of proven benefit in the treatment of DCI. Corticosteroids, anti-platelet drugs, aspirin have been tried without success. Lignocaine has been shown to improve neurological outcome of DCS, particularly when added to oxygen. Diazepam is used to prevent and treat oxygen convulsions and to control vestibular symptoms. It makes titration of treatment almost impossible because it masks the symptoms. Indomethacin is useful only when used in combination with prostaglandin and heparin.
Nasal decongestants and analgesics are useful in many divers with aural barotrauma, and, rarely, antibiotics may be indicated.
Some chemotherapy is useful for marine animal injuries. Many coelenterate (jelly-fish) tentacle nematocysts are inactivated by being doused with vinegar. Fish-sting pain is markedly reduced by immersion of the sting-site in hot water.
Box jelly fish injury
Box jelly fish
Compression-immobilization bandages should be used where possible. Analgesia often requires regional or local anesthetic-blockade and there are specific anti-venoms available for the box jelly fish (Sea wasp), the stone fish and for sea snakes
In-water treatment of DCI is practiced and advocated by some, but is logistically difficult, requires dedicated and effective equipment (e.g. full-face mask; umbilical and breathing system cleaned for oxygen; cradle, chair or platform that can be lowered to the desired depth; warm, calm water without current and dangerous marine animals; and, adequate supplies of oxygen), and clearly should not be used for unconscious, confused or nauseated divers. In general, the diver should be retrieved as quickly as possible to a definitive treatment facility.
As for any retrieval of an injured person, stabilization of the diver must precede transportation. This will include resuscitation, delivery of oxygen, insertion of an intravenous line, correction of hypothermia (in divers in the field this should be based on passive re-warming using dry clothes and blankets) or hyperthermia (most likely in closed-diving systems and again the response will need to be specifically developed and practiced), control of hemorrhage and splinting of fractures. A record of oxygen administration and fluid balance is essential.
If DCI is suspected, then the retrieval must not exceed 1000 ft above sea level. A transportable recompression chamber is ideal, but hyperbaric transportations are logistically difficult and considerable time-savings are needed to justify this activity. Many aircraft can be pressurized to "sea-level' during flight, although this usually limits the altitude at which they can fly (and hence makes the retrieval slower and more fuel-expensive). Unpressurized aircraft are intrinsically unsuitable and must fly at less than 1000 feet, which is often not possible. Road transport may also be inappropriate depending upon the road's altitude, contour and surface.
Summary
It is desirable to have a standard approach to the initial management (i.e. first-aid) of an injured diver. An injured diver must be removed from the water as quickly as possible. An injured diver usually requires oxygenation and rehydration. Attention to these, and early adequate retrieval can significantly improve outcome.
Management where no chamber is available
a. 100% O2 by tight-fitting mask in all cases. Continue to treat and transport even if becomes asymptomatic!
b. Oral fluids - 1 liter (non-alcoholic)per hour.
c. IV fluids as soon as possible. Avoid over-loading. One to 2 liters in first hour, then 100 cc per hour. Glucose containing fluids should not be given in the event of neurological DCS. Hyperglycemia increases the chance of neurological damage.
-Ringer's solution without dextrose. Hartmann's, Lactated Ringer's or Normal saline preferred.
-Normal saline
-LMW Dextran (Dextran 40, Rheomacrodex) in saline (alters the charge of the RBC, preventing Rouleaux formation). 500 cc twice daily. Beware of adverse effects of anaphylaxis and pulmonary edema.
d. Medications
1. Glucocorticoids in neurological DCS.
2. Diazepam (Valium) 10-15 mg IV or per rectum to control seizures and severe vertigo.
3. Aspirin is given by some.
4. Lidocaine is being used by some but is still not yet proven.
e. Catheterization for the paraplegic. Use water in the balloon rather than air. Protect pressure points.
f. Pleurocentesis, if indicated.
Transport, transport, transport! Fly in aircraft pressurized at sea level or as low as possible. Beware driving through mountain passes. Have diver accompanied by a person familiar with the facts.
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