Evidence Summary: Scuba-Diving Clodagh Toomey, PT, PhD Version 1 Month 2018 The British Columbia Injury Research and Prevention Unit (BCIRPU) was established by the Ministry of Health and the Minister’s Injury Prevention Advisory Committee in August 1997. BCIRPU is housed within the Evidence to Innovation research theme at BC Children’s Hospital (BCCH) and supported by the Provincial Health Services Authority (PHSA) and the University of British Columbia (UBC). BCIRPU’s vision is to be a leader in the production and transfer of injury prevention knowledge and the integration of evidence-based injury prevention practices into the daily lives of those at risk, those who care for them, and those with a mandate for public health and safety in British Columbia. Author: Clodagh Toomey Editors: Sarah A Richmond, Amanda Black Reproduction, in its original form, is permitted for background use for private study, education instruction and research, provided appropriate credit is given to the BC Injury Research and Prevention Unit. Citation in editorial copy, for newsprint, radio and television is permitted. The material may not be reproduced for commercial use or profit, promotion, resale, or publication in whole or in part without written permission from the BC Injury Research and Prevention Unit. For any questions regarding this report, contact: BC Injury Research and Prevention Unit F508 – 4480 Oak Street Vancouver, BC V6H 3V4 Email: [email protected] Phone: (604) 875-3776 Fax: (604) 875-3569 Website: www.injuryresearch.bc.ca Suggested Citation: Toomey C, Black A, Richmond SA, Babul S, Pike I. Evidence Summary: Scuba Diving. Active & Safe Central. BC Injury Research and Prevention Unit: Vancouver, BC; 2018. Available at http://activesafe.ca/. Evidence synthesis tool SPORT: Scuba-diving or snorkelling Target Group: Recreational divers (not occupational divers) Injury Mechanisms: All injury/diving-related incidents, fatalities, decompression sickness (DCS) and orofacial barotrauma Implementation/ Incidence/Prevalence Risk/Protective Factors Interventions Resources Evaluation All injury Risk Factors Clinical data to support No studies were found Divers Alert Network In a review of the epidemiology Age additional intervention that have evaluated (DAN) – the diving of injury in all recreational As divers age, there is an increased measures on DCS development implementation/ industry’s largest divers, the prevalence of risk for decompression illness and are lacking due in part to the evaluation strategies in association dedicated to incidents ranged from 7 to 35 diving fatality.11–14 Increased relative great inter/intra-variability this sport/activity. scuba diving safety. injuries per 10,000 divers and risks between older (>49 years) and between individuals regarding http://www.diversalertnet from 5 to 152 injuries per younger divers are found for arterial susceptibility to DCS. work.org/ 100,000 dives.1 gas embolism (RR=3.9), asphyxia (RR=2.5) and disabling cardiac injury Historically, preventing DCS has In a cross-sectional survey of (RR=12.9).13 Greater age (>42 years) been based upon the slow registered members of the is also a prognostic factor for ascent and increasing the Divers Alert Network in 2010- incomplete recovery from severe duration of decompression 2011, the overall rate of diving- decompression illness.11,14 stops, which dramatically related injury was 3.02 per 100 reduced the incidence and dives.2 Sex severity of DCS in developed The annual fatality rate for males is countries in the twentieth Diving Fatalities greater than for females by 10 per century.26 Recreational scuba diving 100,000 divers up to age 65 years, fatalities account for 0.013% of after which the rates are essentially Education all-cause mortality aged >15 the same for both sexes. Relative risk Although not tested in years.2 between males and females recreational divers, education Annual fatality rates in Australia decreased from 6 at age 25 years to or ascent training is an are 0.48 (0.37-0.59) deaths per 1 at age 65 years.13 important component of injury 100,000 dives, or 8.73 (6.85- prevention. Educating 10.96) deaths per 100,000 divers BMI fisherman divers in Vietnam on for Australian residents; 0.12 The odds of surviving arterial gas in-water recompression (0.05-0.25) deaths per 100,000 embolism are greater for divers with techniques, the incidence of dives, or 0.46 (0.20-0.91) deaths a normal BMI.13 severe DCS decreased by 75% in per 100,000 divers for 3 years; from 8±2 per 1000 international visitors to Asthma divers before 2009 to 2±1 per Queensland; and 1.64 (0.20-5.93) A systematic review in 2016 reported 1000 diver after the deaths per 100,000 dives for the that there are indications that intervention.27 dive operator in Victoria.3 recreational divers with asthma may be at increased risk for diving-related Pre-dive Checklist The mean annual fatality rate for injuries compared to non-asthmatic Compared with a control group, insured members of the Divers divers. However, limited high quality use of a pre-dive checklist Alert Network was 16.7 deaths evidence was available.15 decreased the incidence of per 100,000 divers with 95% CI major mishaps in the 14.2-19.0 over the period 2000- Diabetes intervention group by 36%, 2006 (1 death in 6,000 per Divers with diabetes mellitus may be minor mishaps by 26% and all annum).4 at greater risk of (a) death due to mishaps by 32%. On average, chronic cardiac disease and (b) there was one fewer mishap in Decompression Sickness (DCS) unexplained loss of consciousness.13 every 25 intervention dives Incidence of self-reported DCS amongst 1,043 experienced symptoms was 1.55 per 1,000 Right-to-left shunt divers during 2,041 dives.28 dives and treated DCS was 5.72 In a 2009 meta-analysis, the per 100,000 dives amongst combined odds ratio of neurological Pre-conditioning methods Divers Alert Network members. decompression sickness in divers Experimental evidence suggests 4 with right-to-left shunt (RLS) was that, for a population of trained Rate of occurrence (per dive) for 4.23 (3.05-5.87). The systematic and military divers, endurance recreational divers in the USA is screening of RLS in recreational exercise (even in a warm estimated as 0.017 to 0.2%.5 divers seems unnecessary. In environment) associated with professional divers, because of a oral hydration prior to the dive Following DCS, the prevalence of chronic exposition and unknown is beneficial in vascular bubble dysbaric osteonecrosis in consequences of cerebral reduction. These methods have hyperbaric centres in Southern asymptomatic lesions, screening is not been tested in the form of a France was 19%, suggesting MRI appropriate.16 randomized controlled trial.29 for routine screening is justified in recreational divers treated for Spinal Stenosis musculoskeletal DCS before they Divers with cervical and thoracic return to diving.6 spinal canal stenosis, mainly due to disk degeneration, are at increased In a meta-analysis of MRI studies, risk for the occurrence of spinal cord results suggest that repeated decompression sickness.17 hyperbaric exposure increases the prevalence of white matter Training/Experience factors injury in experienced healthy Fatal arterial gas embolism was divers without neurological associated with divers in their first decompression illness (OR 2.654, year of certification.13 The relative 95% CI 1.718 to 4.102).7 risk for non-certified divers reporting diving injury vs. certified divers is Orofacial Injury 1.31 (95% CI 1.16-1.48).18 However, An investigation of orofacial risk of lower pack pain in divers is barotrauma symptoms in 163 associated with a higher dive Saudi divers reported a certificate (p=0.007).10 prevalence 51.9% for dry mouth, Greatest risk of fatal arterial gas 32.5% for clenching and 19.5% embolism occurred on the first dive for temperomandibular pain of the day. A study in Belgium found during a dive. The most frequent 100–400 times increased risk of symptoms after a dive were dry pulmonary barotrauma during mouth (22.7%) followed by training dives. Emergency free- clenching and facial pain ascent training is associated with (16.9%).8 500-1,500 times greater risk of pulmonary barotrauma.13 In a survey of 100 certified recreational divers, 41% percent Exercise after diving of the respondents experienced Exertive exercise following a dive dental symptoms during a dive. increases the risk of arterialization Barodontalgia was the most from 13% at rest to 52%.19 Evidence frequently experienced dental suggests arterialization likely symptom during a dive.9 increases relative risk of neurological DCS.20 Lower back pain Lifetime and 1-year prevalence Flying after diving of LBP among 181 recreational For a single no-decompression dive, Flemish scuba divers were 55.8% one should wait at least 12 hours and 50.3%, respectively.10 before flying; for multiple dives per day or multiple days of diving, 18 hours is suggested, and for any decompression dives, substantially longer than 18 hours appears prudent to reduce risk of DCS.21 Equipment factors Arterial gas embolism and asphyxia are associated with buoyancy trouble, equipment trouble, gas supply trouble and ascent time/trouble.12 Biting on the mouthpiece (OR=1.598), clenching (OR=2.466) and the quality rating of the mouthpiece (OR=0.887) are risk factors for presence of temperomandibular pain in divers.22 Scuba divers with lower back pain use significantly more weights on their weight belts during indoor training (p=0.003) and during outdoor dives with a dry suit (p=0.044) as compared to asymptomatic scuba.10 Protective Factors Repetitive diving Completion of identical daily dives resulted in progressively decreasing odds of having relatively higher grade bubbles on consecutive days.