technical The most important matters action will be to bring the victim to the sur- face safely and as quickly as reasonable.

Column by Cedric Verdier

Images courtesy of Jan Jørgensen jj-technique.com RescueHow to By Cedric Verdier Photos courtesy of Jan Jørgensen a diver

How to deal with The title of this article was originally: The purpose of this article is to In any rescue-scenario, not just div- the unconsciousness is not really more than a minute. an unconscious “What to do if a convulsion hap- provide some guidelines on how ing, it is paramount to first consider crucial, and the rescuer shouldn’t pens”. Based on a lot of discussion, to safely and efficiently deal the two following important factors waste precious time trying to deter- 2. The ‘Clonic’ phase during which rebreather diver? private or on various forums, the with an unconscious diver. These before taking any action: mine whether the root problem is the casualty undergoes true con- protocol being presented here guidelines are meant to be: , or . vulsions. This can last for widely can actually be used for any kind 1. The safety of the rescuer. Hyperoxia is a special case, varying periods of time. Based on of situation where an unconscious Simple and easy to remember. The victim is already in trouble. which requires observation as some studies and discussions with rebreather diver is found In a real life emergencies rescue Make sure that the rescuer doesn’t a convulsion could appear. medical experts (see reference), it underwater. techniques are always more get into trouble, too, and turn one Susceptibility to a high level of looks like the airway is not blocked complex to perform and more accident into two. varies both between indi- at this stage. difficult to remember, even if the viduals and within the same person rescuer practises it on a regular 2. What is the most life-threatening from day to day. A grand mal con- 3. The ‘Post-Ictal’ phase during basis. problem for the victim. In most of vulsion generally occurs in three which the victim rests and actually the cases regarding diving, drown- phases: resumes . Depending Flexible enough to be used in ing should be considered the major on the circumstances, the victim most of the circumstances: Dry threat. People can recover from 1. The ‘Tonic’ phase – a period can “wake-up” and be confused, suit or wet suit, overhead envi- DCS or even from AGE, but not characterised by body rigidity. disoriented or even combative for ronment or open water, deep from complete . Hypoxia In this phase, it is dangerous to quite a long time, or simply stay or shallow dive—and is also a very important issue. attempt to surface the casualty unconscious. Other convulsions with all the available because spasms of the glottis and may follow the first one, sooner or This diver (back-mounted/OTS CLs, SCR/ The most important action will be to respiratory muscles will cause inad- later. seems to be CCR, FFM, etc). bring the victim to the surface safe- equate exhalation that in turn may unconscious. ly and as quickly as reasonable. result in pulmonary . So, what to do? Now what? Establishing what initially caused Fortunately, this phase doesn’t last

74 X-RAY MAG : 20 : 2007 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED rebreather Is the mouthpiece still in the during the ascent. sion standpoint). Assessing the environment Rescue mouth? If not, do not attempt Is the loop content safe to In case of Mixed-gas diving, Is there any physical problem that to replace it but ensure that the breathe? This is only a concern if the Open Circuit mix has to be could delay the ascent? Step 1: Step 2: mouthpiece is switched to the breathes, and the air- breathable all the way up to the A strong could make the Stabilize the victim in the Assess the situation surface position. Try to seal the way is protected. The rescuer can surface, and the amount of gas in rescuer consider swimming to an water column. mouth and ascend immediately. check the pO2 readings to make the tank has to be sufficient (and ascent line rather than drifting far The rescuer has to assess the vic- sure that the the valve open). from the boat. An overhead envi- If the diver is found unconscious tim, the equipment and the envi- victim will be ronment (cave, ice, wreck pen- close to the bottom, find a stable ronment in order to determine the able to breathe Hypercapnia: Without a proper etration) could delay the ascent position on the bottom or a shot best course of action, and if the a safe mix dur- scrubber monitor, it will be dif- as the rescuer will have to swim to line. If the diver is found uncon- ascent has to be immediate or ing the ascent. ficult for the rescuer to assess the the exit point. scious in mid-water or during slightly delayed. In any case, this CO2 level in the loop, and it’s not deco, try to maintain the depth assessment should be quick and Hypoxia: It a major issue anyway. A diluent Is there any physiological concern by catching the ascent line. shouldn’t delay the rescue, but is crucial to flush will help in any case, as it that could delay the ascent? If the rescuer can attract atten- make it more efficient. The res- check the loop could also help in case of a par- If a breathing victim with a prop- tion and get some help, a second cuer has to deal with a high level content, as the tial loop flood. erly protected airway (Full face diver can be very handy to assist of stress as time is crucial. pO2 will drop mask, neck strap) has a significant the rescuer in doing the following: when ascend- Note: To efficiently flush the loop obligation, the Assessing the victim ing to the shal- on most of the units, the rescuer rescuer has to consider the pos- ● In open water, to send up an Is it an seizure? lows. has to open the over- sibility of performing the required emergency SMB to alert the In case of a convulsion underwa- valve first. stops to minimize the risks of DCS. surface support team ter, the dangerous part being the Hyperoxia: If the victim does not breathe ● In a cave, to aid going through Tonic phase that doesn’t last very Flushing the or does not have a properly pro- restrictions or simply to take long, the diver’s depth has only loop with dilu- If the victim doesn’t tected airway, the ascent to the care of the navigation to be kept constant at the very ent or switch- breathe or doesn’t surface should be immediate. ● At the surface, to help remov- beginning (a few seconds up to ing to an Nevertheless, the rescuer could ing the victim’s gear and to one minute). If drowning is the integrated OC have a properly pro- have a significant decompression provide major concern (as it should be second stage tected airway, the obligation as well. ● In general, to control if the rebreather diver does not (BOV) could In this case, three main options on the bottom and during the wear a FFM or a neckstrap that Is the mouthpiece still in the mouth? be an option ascent to the surface are available: ascent efficiently protects their airway), to consider. should be immediate. the main priority is to bring the Note: Opening the mouth to put (Remember that breathing a high 1. Ascending with the victim at victim as soon as safely possible. in a regulator might only achieve O2 content in the loop could also the surface, provide first aid or water introduction/drowning. be beneficial on a decompres- hand over the victim to the sur- Is the victim breathing? If there is Some rescuers feel con- face support, then eventually no obvious sign of breathing (no fident in attempting to follow a missed deco proce- bubble, no chest movement, no seal a second stage with dure movement of the counterlungs), a breathable mix against it is of the utmost importance the lips in the hope that 2. Handing the victim over to to bring the victim to surface to if breathing resumes air another diver with no/less administer artificial / will be inspired instead decompression obligation CPR. of water. None of these actions should delay the 3. Sending the victim to the sur- Assessing the equipment ascent or compromise the face on their own, hoping that Does the diver wear a full face efficiency of the rescue. the surface support will be effi- mask or a neckstrap that effi- cient and fast enough ciently protects the airway? If it Is there any water in the is not the case, even if the diver mask? Note: This is a personal decision, still has the mouthpiece in place, A partially or completely based on a lot of factors that drowning is a major concern and flooded mask could be have to be quickly considered by any delay in the ascent should be a major problem for the a highly stressed rescuer: avoided. victim’s airway. If it is the case, try to pinch the nose ● The apparent state of the vic- Is there any water in the mask?

75 X-RAY MAG : 20 : 2007 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED rebreather ● Slowly inflate the victim’s BC to start Rescue ascending. ● Open the victim’s loop OPV (and the tim (not breathing for a very long time, purge if appropriate). etc.) ● Control the victim’s BCD purge. ● The amount of decompression obliga- tion and the perceived risk of DCS ● Control the rescuer’s own buoyancy. References:

● The accepted risk (that could depend Note: In case of a malfunctioning unit • The prevention and management of on the relationship with the victim) (leaking solenoid, ADV, manual injector, diving accidents (revised October 1997). BCD inflator, etc), it may be difficult for Royal Navy INM Report No. R97066 ● The efficiency and the availability of the rescuer to quickly find out if there is the surface support a leak, where it comes from and how to • U.S. Navy diving manual (Chapter 17 stop it. The rescuer has to be aware that and 17b), USN ● The surface condition (rough sea the rescue could end up in an uncon- where the victim will not be seen, etc) trolled ascent. • operations, OSHA Occupational Safety and Health Step 3: Establishing positive buoyancy Administration Ascending to the surface at the surface If the loop is not flooded, simply fully • Extreme survival: A deep technical div- Opening the airway inflate the victim’s BC should provide ing accident. Trytko B, Mitchell S. South Ensure that the victim’s airway is open by enough buoyancy to maintain the diver Pacific Underwater Medicine Society keeping the neck slightly extended. at the surface. Make sure that the DSV is Journal closed when removed from the mouth. Controlling the ascent Depending on the equipment or if the • Proceedings of rebreather forum 2.0, It is often very difficult to keep control of loop is flooded, it may be necessary to Michael Menduno. DSAT the buoyancy of two divers at the same release some or accessories (can- time, particularly in the shallows: ister light, sling tank, etc). • Oxygen toxicity protocol, Scott Hunsucker, WKPP

It is a challenge to control the ascent rate of two divers • Oxygen and the diver. Donald KM., England

Be prepared and stay safe. Enjoy your dive • A statistical analysis of recent NEDU single-depth human exposures to Step 4: 100-percent oxygen at pressure. Harabin Providing first aid support or swim to the nearest platform AL, Survanshi SS. Bethesda, M.D. Naval available (boat, shore, etc) in order to Medical Research Institute This means first care for the victim and provide better care (CPR/first aid/O2). the rescuer: • Glottal patency during experimental ● Arrange for evacuation (nearest cortical seizures in piglets. Leaming. ● Call for help. If no help is available, it chamber/ diving physician). Academic Emergency Medicine may be necessary for the rescuer to stop for a few seconds to keep the stress level ● The rescuer may perform missed deco • Current thoughts on mechanisms of reasonable and assess the victim and the procedures if appropriate (without delay- hyperoxic seizures. Johnny E. Brian Jr. resources available at the surface. ing evacuation). ■ University of Iowa Hospitals and Clinics

● Ensure the victim is breathing or initiate artificial ventilation (as taught in all the This document is only a guideline to help developing a widely accept- basic Rescue Diver courses). ed standard for rebreather rescue. Such a standard doesn’t exist in the ● Hand over the victim to the surface industry and may never exist.

76 X-RAY MAG : 20 : 2007 EDITORIAL FEATURES TRAVEL NEWS EQUIPMENT BOOKS SCIENCE & ECOLOGY EDUCATION PROFILES PORTFOLIO CLASSIFIED