UHM 2012, VOL. 39, NO. 6 – RESCUE OF AN UNRESPONSIVE DIVER Recommendations for rescue of a submerged unresponsive compressed-gas diver S.J. Mitchell 1,2, M.H. Bennett 1,3, N. Bird 1,4, D.J. Doolette 1,5, G.W. Hobbs 1,6,7, E. Kay 1,8, R.E. Moon 1,6, T.S. Neuman 1,9, R.D. Vann 1,4, R. Walker 1,6,7, H.A. Wyatt 1,10 1 The Undersea and Hyperbaric Medical Society Diving Committee 2 Department of Anesthesiology, University of Auckland, New Zealand 3 Department of Anesthesia, University of New South Wales, Sydney, Australia 4 Divers Alert Network, Durham, North Carolina, USA 5 Navy Experimental Diving Unit, Panama City, Florida, USA 6 Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina, USA 7 Rubicon Foundation Incorporated, Durham, North Carolina, USA 8 HealthForce Partners and University of Washington, Seattle Washington, USA 9 University of California San Diego, San Diego, USA 10 Department of Hyperbaric Medicine and Wound Care, West Jefferson Medical Center, Marrero, Louisiana, USA CORRESPONDING AUTHOR: Dr. Simon Mitchell – [email protected] _____________________________________________________________________________________________ ABSTRACT The Diving Committee of the Undersea and Hyperbaric has a decompression obligation, does this change the Medical Society has reviewed available evidence in ascent procedures? Is it necessary to hold the victim’s relation to the medical aspects of rescuing a submerged head in a particular position? Is it necessary to press unresponsive compressed-gas diver. The rescue process on the victim’s chest to ensure exhalation? Are there has been subdivided into three phases, and relevant any special considerations for rescuing rebreather questions have been addressed as follows. divers? Phase 1, preparation for ascent: If the regulator is out Phase 3, procedure at the surface: Is it possible to make of the mouth, should it be replaced? If the diver is in an assessment of breathing in the water? Can effective the tonic or clonic phase of a seizure, should the ascent rescue breaths be delivered in the water? What is the be delayed until the clonic phase has subsided? Are likelihood of persistent circulation after respiratory there any special considerations for rescuing rebreather arrest? Does the recent advocacy for “compression- divers? only resuscitation” suggest that rescue breaths should Phase 2, retrieval to the surface: What is a “safe” not be administered to a non-breathing diver? What ascent rate? If the rescuer has a decompression obliga- rules should guide the relative priority of in-water tion, should they take the victim to the surface? If the rescue breaths over accessing surface support where regulator is in the mouth and the victim is breathing, definitive CPR can be started? does this change the ascent procedures? If the regulator A “best practice” decision tree for submerged diver is in the mouth, the victim is breathing, and the victim rescue has been proposed. ____________________________________________________________________________________________ Copyright © 2012 Undersea & Hyperbaric Medical Society, Inc. 1099 UHM 2012, VOL. 39, NO. 6 – RESCUE OF AN UNRESPONSIVE DIVER INTRODUCTION Some of the controversies considered are also rel- The Diving Committee of the Undersea and Hyperbaric evant to recreational “technical diving,” in which gases Medical Society (UHMS) acts as a bridge between the other than air and equipment such as rebreathers are members of the Society and divers. The Committee customarily used, and in which decompression dives is occasionally asked to address a specific question are commonly performed. Advanced occupational sce- of practical significance to divers, but which requires narios such as diving with helmets and surface-supplied scientific or medical interpretation, and to make recom- gas, saturation diving, and bell diving are not discussed. mendations to the diving community. For the purpose of this review a “rescuer” is a diver This paper is a Diving Committee initiative to who has received specific training in diver rescue. This address the medical aspects of rescue and resuscitation is appropriate given that this review is largely a response of an unresponsive diver. This initiative was prompted to questions about the content of such training. There by requests from diver training agencies who wish to is no attempt to define appropriate practice for divers revise training material and by specific questions from who have not received training in rescue techniques. the scientific diving community. There is ongoing debate Finally, the purpose of this paper is to address certain over the optimal approach to rescue of an unresponsive medical aspects of diver rescue; and particularly those diver from depth. There is a paucity of related research, that cause controversy. It does not address mechanical and this means that any recommendations on rescue details of practical rescue techniques (methods of technique will defer largely to “expert opinion.” buoyancy control during ascent, for example) unless Nevertheless, the UHMS Diving Committee is an there is particular relevance to a medical consideration. appropriate resource to consider relevant questions and The prescription of practical techniques is left to the promulgate recommendations. Indeed, with the exception respective diver training agencies. As a basis for discus- of the South Pacific Underwater Medicine Society Policy sion, this paper will refer to the methods recommended on Initial Management of Diving Injuries and Illnesses [1] in the Professional Association of Diving Instructors (which is now 14 years old and addressed in-water res- (PADI) Rescue Diver Manual [2]. cue only superficially) there is a conspicuous absence of recommendations from expert groups in relation to METHODS this matter. The key steps in the rescue of an unresponsive diver were defined, and a set of important questions in relation to SCOPE OF THE REVIEW those steps were generated. Two members of the diving This review addresses the course of action on find- committee (SJM, MHB) reviewed the relevant literature ing an unresponsive diver underwater in circumstances and drafted responses to these questions. These were either where the disabling event was witnessed or where distributed to participating committee members for the period of unresponsiveness is uncertain and resus- discussion. All participating members were invited to citation must therefore be considered possible. Thus, it submit comments, and where necessary, these were does not apply to “body recovery,” where resuscitation discussed prior to modification of the recommenda- will not be attempted. The focus is on diver rescue. tions. It can be assumed that recommendations made Methods of resuscitation per se are not discussed in this paper that are not referenced to external sources except where they have implications for the conduct of evidence represent the consensus opinion of the listed of the in-water phase of the rescue; neither is authors from the UHMS Diving Committee. The over- post-resuscitation care discussed. This review considers all content is endorsed by the committee. It should be only compressed-gas bounce dives (dives in which the noted that no participating members were employees duration from leaving to returning to surface is on the of a diving training organization, nor were there any order of minutes or hours) and dives conducted using a other potential conflicts of interest. The finalized half-face mask and separate mouthpiece. The principal recommendations were submitted for consideration by focus is on recreational diving using open circuit the UHMS Publications Committee, and for peer review “scuba” equipment supplying air, or occupational diving and publication in Undersea and Hyperbaric Medicine. using similar equipment configurations. 1100 S.J. Mitchell, M.H. Bennett, N. Bird et al. UHM 2012, VOL. 39, NO. 6 – RESCUE OF AN UNRESPONSIVE DIVER KEY STEPS IN DIVER RESCUE Procedure at the surface AND RELATED QUESTIONS Once at the surface the PADI Rescue Diver Manual [2] It is universally agreed that on finding an unresponsive instructs as follows: The diver be positioned face-up, diver underwater the overarching priority should be and positive buoyancy be established for both victim and to retrieve the diver to the surface and initiate resus- rescuer. A call for help should be made and the victim’s citative measures as quickly as practicable while avoiding airway opened followed by rescue breathing if there is harm to the rescuer. This process can be broken down no spontaneous respiration. into three phases: After two breaths with no victim response, the manual • preparation for ascent; prescribes evaluation of distance from surface support. • retrieval to the surface; and If surface support is less than five minutes away, inter- • procedures at the surface. mittent rescue breaths should be continued while towing the victim until surface support is reached and the diver Preparation for ascent is removed from the water (at which time a cardiopul- When an unresponsive diver is found at depth the rescuer monary resuscitation [CPR] protocol should be initiated). will take steps to position the victim appropriately If surface support is more than five minutes away the and initiate an ascent while controlling buoyancy and rescuer should remain where he/she is and provide rescue maintaining his/her own safety. The PADI Rescue breaths for one minute and check for response.