NARD Diving MedicineDiving MD

Basics Of A Dive Accident

The two most serious dive related accidents are Air Embolism (arterial gas embolism), and Decompression Sickness (venous gas embolism). Heart attack, CVA, drowning, trauma, etc. are not diving accidents, though they may be aggravated by the act of diving. Consider all pressure related accidents as directly related to diving, and all other situations as whatever their root cause is. Treat medical emergencies as any other medical emergency. The fact that the victim was diving should not miss lead the rescuer from treating the victim appropriately. It is imperative that a rescuer be able to quickly and accurately distinguish the root cause of any victim. Several sign and symptoms for different maladies are the same or similar. Only by conducting a good patient evaluation and history can the rescuer be able to accurately treat the victim. Dive related injuries can occur to any person who has breathed air underwater, whatever the depth. Divers may encounter overexpansion injuries due to respiratory illness. If a diver has a history of any lung diseases from the flu, to tuberculosis, air trapping may result and injury can occur. Venous gas embolism occurs to individuals who violate or push the decompression tables. Even divers who use decompression computers fall victim to decompression sickness. When doing a patient history determine the victim's depth, and if a dive deeper than the previous one was made. Rescuers must be able to determine the problem and begin proper treatment. The biggest problem in managing a victim of diving related maladies is determining if the victim suffers from air embolism or decompression sickness. Take a good history of the dive, and if a repetitive dive, all dives going back to where the victim is a new diver.

Upon arriving at a scene, get the CHIEF COMPLAINT first. This is the reason you were called. It gives you the whole basis to work. Ask who ever called, why they called. At the same time you can be checking the victims AIRWAY, BREATHING, and CIRCULATION, and if trauma is involved protect the C-SPINE (ABC'S).

Establish the patients LEVEL OF CONSCIOUSNESS, if he can rationally communicate, have him express in his own words how he feels. DO NOT COACH THE PATIENT! Coaching is when the evaluator ask: ''Do you have ringing in your ears?'' ''Do you have a sharp pain in your chest''. The rescuer must be general and have the patient fill in the details. If the victim called because he felt fatigued and had pain in his chest one hour after making a dive, do not assume decompression sickness. The victim also could be having a heart attack. Ask him when the pain started and to describe it. Do not ask if the pain started an hour ago, and is the pain dull or sharp. By doing this you give the patient a choice. Patients a lot of times believe that a rescuer or other medical person knows what is wrong with him, and only ask questions to prove it. If your question are ''Is the pain sharp?'' The answer will almost always be ''yes''.

Get any past MEDICAL HISTORY and any MEDICATIONS used. Find out if the victim has any ALLERGIES and if he has been exposed to any of them directly or indirectly. Establish vital signs as soon as possible HEART RATE (pulse), RESPIRATIONS, and BLOOD PRESSURE (BP). This gives you a base line to work from if the patient starts to deteriorate. Try to take vital signs every ten to fifteen minutes. Write down all signs and symptoms presenting.

When a diving malady is believed to be the cause ask questions that will help establish if AGE or VGE. If the victim is unable to answer, ask his diving buddy, or whoever is with him or called. If no one is available, or the victim is to incoherent to answer assume air embolism and treat accordingly.

To determine a DIVING HISTORY ask:

Where you scuba diving within the last 24 hours?
  • An answer of yes to this question establishes that a directly related diving malady may exist.

How many dives have you made within the last 24 hours?
  • Make sure that the person you are asking understands this important question. Sometime the victim thinks 24 hours as only being that day. If the day is Sunday ask about Saturday, and if he dove on Saturday, ask about Friday until you get to a day without diving. The victim may have been repetitive diving for several days.

Where you within the no-decompression limits on all dives?
  • An answer of yes to this question does not rule out decompression sickness. Check the diver's log book (if he kept one) and determine if the dive profiles were worked properly, and determine if he pushed the tables in any way.

If not, did you make all required decompression stops?
  • Sometimes the answer will be yes but the diver did not stay at the stop for the required time. If he had to make a decompression stop it is clearly established that decompression sickness may exist. Any time a diver makes a REQUIRED stop a bell should ring.

What was the maximum depth obtained during the day's diving activity?
  • A lot of times the person may think you are only questioning the last dive made. If the first dive of the day was to 70 feet and the last dive was a beach dive to 25 feet a wide range is seen. By asking for the deepest dive of the day you avoid misunderstanding.

  • Just as important is what was the maximum depth every day going back to when the victim was a new diver. Again he may be on a continuous repetive dive profile. If this is the case then the diver may be making deeper dives than previous dives. Again the bell should ring. This is a strong history for decompression sickness.

Have you been flying and diving within the last two days?
  • Do not over look this important question. In today's world of fast air service the victim could have been diving in Mexico for the last four days, flew home yesterday, and is now making a recreational dive at home.

Was any sort of rapid ascent made during the dive?
  • This includes any training dives. Just because an Instructor was present, does not mean an accident will not occur. Ascent training can be dangerous and air embolism has occurred while doing it. Lift bag operations have turned into rapid ascents, though the diver does not think so.

Did you or your buddy run out of air and make an emergency ascent or buddy breathing ascent?
  • An emergency ascent to some people means a ''blow and go'' ascent, however any time a dive is aborted for any reason it must be considered an emergency ascent. Blow and go ascents lend themselves to possible AGE while aborted dives lend themselves to omitted decompression. Assisted or buoyant ascents are also emergency ascents. Buoyant ascents can lead to AGE and VGE due to the rapid rate of ascent. A buddy breathing ascent is one in which the divers share the same second stage. Using a safe second or alternate air source is not buddy breathing. The passing of the regulator back and forth can lead to breath holding and AGE. Also omitted decompression could be involved due to an out of air situation. If the ascent was made with an alternate air source and both divers did not panic or race to the surface than omitted decompression also could be there.

Did you drop your weights at any time?
  • This indicates that a situation arose to which the diver thought he was too heavy and had to ditch his weight belt. This indicates a problem dive and further investigation is indicated. If he was on the surface, it may not be dive related, but underwater it could lead to buoyant ascents.

Next do a NEUROLOGICAL EVALUATION with a DIVING ACCIDENT VICTIM EXAM. This is done with the history and patient evaluation. The sooner it is done the better base line as to progression or regression can be determined. First determine if the patient is orientated to TIME, PLACE, and PERSON. The victim should be completely orientated to all three. When doing the exam start at the head and work to the toes or start at the toes and work towards the head. No matter where you start do not skip around.

Not all victims demand immediate recompression. Sometimes the delay may be permissible as during transportation. As soon as it has been determined that the victim is suffering from a diving malady, place him on 100% oxygen by demand valve. Have the victim lay down, and elevate his feet, as in the shock position. If the victim is unconscious he should be put on his left side, to prevent aspiration should vomiting arise. Keep the victim warm and watch for formation of life threatening symptoms. Remember the victim may have internal trauma, and investigate for it. An isotonic IV should be started TKO in case acute symptoms develop. When transporting to the chamber keep him lying down. Do not put the patient head down. This lends itself cerebral edema and the patient aspirating his stomach contents. If this happens the victim may develop aspiration pneumonia or Adult Respiratory Distress Syndrome (ARDS), and he already has enough problems without you adding these to his situation. Watch for signs of deterioration. Always keep in mind there may be more than air embolism or the bends, but also severe internal injuries, such as pneumothorax. Always have the victim breathing 100% oxygen during transport. If symptoms are relieved or improve during transportation, chamber treatment should be conducted as if they were still present.

It is best to take the victim to a nearby Emergency Room for evaluation. The attending physician can consult with a DAN physician or the chamber. If you are in an area where initial routing to the chamber is accepted, establish radio communications with them. This will enable you to consult with them while in transit. If that is not feasible, call ahead before transporting, to insure that they are expecting the victim.

Positioning a dive accident patient for transport, has always been a point of controversy. According to the U.S. Navy Diving Manual, dive accident victims should be transported lying flat. Although most of the diving community teaches that victims should be transported with the victim on his left side, head lower than the rest of the body. To do this, the victim is placed on a backboard, or other rigid device, and the board is tilted 30 head down. The term Modified Trendelenburg Position has been used to depict this position. Trendelenburg was a surgeon who formulated the position for abdominal surgery. The actual position places the patient inclined head down, on an operating table, with legs bent. The function of the position is to allow gravity to move the small intestine (viscera) away from the lower abdominal region, so a surgeon can operate there, as in pelvic operations.

We will discus here the head down position for those dive teams who wish to employ it. It is preferable to call the position the Dive Accident Management Position. The supposition behind the head down position is to vasodilate the cerebral circulation, thereby forcing the bubbles deeper into smaller vessels, or passing some into venous return, but this position has draw backs. It is presumably, only good during the first hour after surfacing. It encourages cerebral edema, aspiration of stomach contents, and breathing discomfort. If the victim is conscious he will probably not allow much elevation, and then only for about 20 minutes. If the patient is unconscious, only leave him in this position for 15 to 30 minutes, to reduce the chance of cerebral edema. Be sure to always monitor the patient's breathing patterns when positioned this way. If the victim is in, or develops cardiac arrest lay him flat, CPR cannot be effectively done in any other position than supine.

When placing a victim in the Dive Accident Management Position lay him flat on a backboard. The only time a victim should be placed on his side is if a pneumothorax exist, or there is a possibility of regurgitation. If the patient has a pneumothorax, place him on the affected side.

To calculate the height of the backboard to get the recommended 30 simple geometry is used. The height (H), equals the length of the backboard (x), divided by 2, or H = x/2. If the backboard is 6 ft. or 72 inches in length then H = 72/2 which equals 36 inches. Most backboards are 7 feet or 84 inches in length, then the elevation would be 42 inches. Obtaining 30 is almost an impossibility in reality. When situating a patient in this position, elevate him based on how the victim feels, when discomfort is felt stop elevating. After the first half hour following surfacing, move the victim into the shock position. When moving a patient out of the head down position, do it slowly. A sudden shift of blood can occur if the victim is just lied flat, which can cause nausea and dizziness. A compromise position is can used to aid in cerebral circulation, and prevent breathing discomfort or aspiration. This is the shock position, which is having the victim resting supine with the legs elevated.

We recommend the use of the shock position with the victim laying flat as indicated in the U.S. Navy Dive Manual. However, we know there are those out there who will say that the head down position has been taught for years, and will pull out many sport diving manuals to prove. So to go with understanding what the Dive Accident Management Position does to a patient we propose the following experiment. Put each member of the Dive Team in the position. This means strapped to the back board, and elevated 42 inches, head down for at least 10 minutes. After this test, decide for yourselves, which is in the patients best interest. Remember you are to provide patient care and insure that no other harm befalls any patient under your care.

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