Decompression sickness and recreational scuba divers

Decompression illness in Finnish technical divers: a follow-up study on incidence and self-treatment

INTRODUCTION

Technical diving is increasing in popularity in Finland, and therefore the number of decompression illness (DCI) cases is also increasing among technical divers. Although hyperbaric oxygen treatment (HBOT) remains the standard of care, there are anecdotal reports of technical divers treating mild DCI symptoms themselves and not seeking a medical evaluation and possible recompression therapy. This study aimed to make an epidemiologic inventory of technical diving-related DCI symptoms, to establish the incidence of self-treatment and to determine the apparent effectiveness of different treatment methods.

METHODS

A one-year prospective survey with online questionnaires was conducted. Fifty-five experienced and highly trained Finnish technical divers answered the survey and reported their diving activity, DCI symptoms, symptom treatment, and treatment outcome.

RESULTS

Of the reported 2,983 dives, 27 resulted in symptoms of DCI, which yielded an incidence of 91 per 10,000 dives in this study. All of the reported DCI symptoms were mild, and only one diver received HBOT. The most common self-treatments were oral hydration and rest. First aid oxygen (FAO₂) was used in 21% of cases. Eventually, none of the divers had residual symptoms.

CONCLUSIONS

The incidence of self-treated DCI cases was 27 times higher than that of HBO-treated DCI cases. There is a need to improve divers' awareness of the importance of FAO₂ and other recommended first aid procedures and to encourage divers to seek medical attention in case of suspected DCI.

Effects of Hyperbaric Nitrogen Narcosis on Cognitive Performance in Recreational air SCUBA Divers: An Auditory Event-related Brain Potentials Study

BACKGROUND

The narcotic effect of hyperbaric nitrogen is most pronounced in air-breathing divers because it impairs diver's cognitive and behavioral performance, and limits the depth of dive profiles. We aimed to investigate the cognitive effects of simulated (500 kPa) air environments in recreational SCUBA divers, revealed by auditory event-related potentials (AERPs).

METHODS

A total of 18 healthy volunteer recreational air SCUBA divers participated in the study. AERPs were recorded in pre-dive, deep-dive, and post-dive sessions.

RESULTS

False-positive score variables were found with significantly higher differences and longer reaction times of hits during deep-dive and post-dive than pre-dive sessions. Also, P3 amplitudes were significantly reduced and peak latencies were prolonged during both deep-dive and post-dive compared with pre-dive sessions.

CONCLUSION

We observed that nitrogen narcosis at 500 kPa pressure in the dry hyperbaric chamber has a mild-to-moderate negative effect on the cognitive performance of recreational air SCUBA divers, which threatened the safety of diving. Although relatively decreased, this effect also continued in the post-dive sessions. These negative effects are especially important for divers engaged in open-sea diving. Our results show crucial implications for the kinds of control measures that can help to prevent nitrogen narcosis and diving accidents at depths up to 40 msw.

Recreational diving-related injury insurance claims among Divers Alert Network Japan members: Retrospective analysis of 321 cases from 2010 to 2014

INTRODUCTION

Monitoring trends in diving-related injuries enables implementation of effective safety measures. Divers Alert Network Japan (DAN Japan) membership includes insurance covering recreational diving-related injuries and fatalities. Use of claim data provides both a known denominator and demographic data about injured members.

METHODS

The study analysed 325 insurance claims reported to DAN Japan from 2010 to 2014. Four fatalities were excluded, leaving 321 claims for analysis. Claimants were divided into three age groups: young adults (< 40 years); middle-aged (40-59 years) and older adults (≥ 60 years). The total injury claims rate (ICR), decompression illness (DCI) rate (DCR) and trauma rate (TCR) were calculated. Differences between the sexes within each age group were analysed.

RESULTS

The total number of DAN Japan member-years in the period was 80,617, with a mean age of 45 years. Claims were made by 153 males and 168 females with a mean and median age of 46 years. Trauma was the most frequent reason for a claim (113 cases, 35%), followed by DCI (109 cases, 34%). The ICR (per 104 member-years) was 39.8 (95% confidence interval 35.5 to 44.2) and the TCR was 14.0 (11.4 to 16.6). For every age group, the ICR and TCR were significantly higher for females than males. The DCR was 13.5 (11.0 to 16.1) and did not significantly differ between the sexes.

CONCLUSIONS

The incidence of trauma-related diving injuries exceeds that of claims related to DCI. Females appear to have a higher risk of injury than the general diving population.

Decompression illness and other injuries in a recreational dive charter operation

INTRODUCTION

Health and safety within the recreational diving industry are poorly described. We aimed to obtain the true prevalence of decompression illness (DCI) and other diving and non-diving injuries, including occupational injuries, in a large recreational diving charter operation.

METHODS

A New Zealand recreational diving operator keeps detailed records of diving activity and event/incident reports. We extracted passenger and crew numbers, dive numbers and incident statistics from all boat trips and associated work-related injuries between 01 January 2008 and 31 December 2014. The records of divers referred to the regional hyperbaric unit for suspected DCI were reviewed retrospectively. Using these data the prevalence of DCI and non-diving injuries were calculated.

RESULTS

There were 65,536 person-trips to sea and 57,072 divers undertook 97,144 dives. Fifty-five injury events were documented over seven years, 31 in customers and 24 in staff. Four divers (including one staff member) diagnosed with DCI underwent recompression therapy, giving a prevalence of 0.41 cases requiring recompression per 10,000 dives, or one case per 24,386 dives, whilst five other divers were assessed as not having DCI. There was one cardiac-related fatality. Thirty-five non-diving injuries (mainly lacerations and minor musculoskeletal injuries) were documented in 30 people resulting in 10 consulting a general practitioner and seven presenting to the local regional hospital emergency department.

CONCLUSIONS

DCI requiring recompression was relatively rare in this supervised recreational diving operation. Minor non-diving injuries were the most common adverse event. Compared to other adventure sports, the prevalence of injury in recreational scuba diving is low.

Epidemiology of morbidity and mortality in US and Canadian recreational scuba diving

OBJECTIVES

This study investigates morbidity and mortality suffered by divers in the USA and Canada.

STUDY DESIGN

Prospectively recruited probability-weighted sample for estimating the national burden of injury and a weighted retrospective survey for estimating exposure.

METHODS

The National Electronic Surveillance System and Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were searched for scuba diving injuries. The Divers Alert Network diving fatality database was searched for deaths, and Sports and Fitness Industry Association estimates for diving were obtained from annual surveys.

RESULTS

In the USA, there were an estimated 1394 emergency department (ED) presentations annually for scuba-related injuries. The majority (80%) were treated and/or released. There were an estimated 306 million dives made by the US residents 2006-2015 and concurrently 563 recreational diving deaths, a fatality rate of 0.18 per 10⁵ dives and 1.8 per 10⁵ diver-years. There were 658 diving deaths in the US 2006-2015 and 13,943 ED presentations for scuba injuries, giving a ratio of 47 diving deaths in the USA for every 1000 ED presentations. There were 98 cases of scuba-related injuries identified in the CHIRPP data. The prevalence of scuba-related injuries for patients aged 3-17 years was 1.5 per 10⁵ cases, and the prevalence of scuba-related injuries to patients 18-62 years was 16.5 per 10⁵ cases.

DISCUSSION

In Canada and the USA, only one out of every 10,000 ED presentations is due to a scuba-related injury. That there are 47 deaths for every 1000 ED presentations for scuba injuries speaks to the relatively unforgiving environment in which scuba diving takes place. For 1.8 deaths per million recreational dives, mortality in scuba diving is nonetheless relatively low.

[Diving Accidents in Lakes - a Retrospective Study of a Level-1 Emergency Centre in Switzerland]

Diving Accidents in Lakes - a Retrospective Study of a Level-1 Emergency Centre in Switzerland Abstract. Switzerland is a country in the middle of Europe without access to an open sea. Here one does not assume a noteworthy number of diving accidents. However, this study shows a large number and attempts to explore the main risks of diving accidents. The data from 2001 to 2016 of patients had been collected und retrospectively evaluated using the electronic database of the emergency center of the university hospital in Bern, Switzerland. Barotrauma of the ear (69.0 %), decompression accidents (20.7 %) as well as cardiovascular complications (13.8 %) appeared quite frequently during scuba diving in Switzerland. In contrast, otitis occurred only at a very low percentage (3.5 %). The risk of diving accidents is clearly underestimated. Preventative measures should include more emphasis on the vertical diving profile with increasing diving depths and on the hazards of cardiovascular diseases with increasing age.

A technical diving-related burns case: treatment in a remote location

Injuries suffered as a result of a rebreather oxygen explosion and fire occurred to a diver on vacation in the island state of Chuuk, Micronesia. The medical and logistical management of the diver in a remote location are described. The mechanism of both the fire and the subsequent blast and burn injuries are discussed. Prevention of and preparation for such incidents are discussed in the context of the increasing frequency of dive and adventure travel to remote areas.

Neurological complications of underwater diving

The diver's nervous system is extremely sensitive to high ambient pressure, which is the sum of atmospheric and hydrostatic pressure. Neurological complications associated with diving are a difficult diagnostic and therapeutic challenge. They occur in both commercial and recreational diving and are connected with increasing interest in the sport of diving. Hence it is very important to know the possible complications associated with this kind of sport. Complications of the nervous system may result from decompression sickness, pulmonary barotrauma associated with cerebral arterial air embolism (AGE), otic and sinus barotrauma, high pressure neurological syndrome (HPNS) and undesirable effect of gases used for breathing. The purpose of this review is to discuss the range of neurological symptoms that can occur during diving accidents and also the role of patent foramen ovale (PFO) and internal carotid artery (ICA) dissection in pathogenesis of stroke in divers.

Health-related adverse events and associated factors in recreational divers with different certification levels

BACKGROUND

There is a paucity of research on diving-related health issues and associated factors. This study aimed to examine the health problems encountered during diving and to ascertain the factors associated with adverse events.

METHODS

The sample of this descriptive study consisted of 132 recreational divers from diving schools in Ankara. The researchers collected the data using a questionnaire developed according to the relevant literature.

RESULTS

Diving-related health issues including barotraumas, nitrogen narcosis, and decompression sickness were mostly dependent on depth. The divers with higher certification levels witnessed diving-related adverse events more frequently and a significant increase in health problems with greater depth attained (p < 0.05). More experienced divers with longer duration of diving (p < 0.05) and greater number of dives reported more health problems associated with diving between 41 and 65 m. Adverse events did not differ according to diving-related educational features (p > 0.05).

CONCLUSIONS

The finding implies the importance of adherence to the depth limit of 40 m for recreational divers, being a slow ascend diver, and utilization of a buddy system in order to prevent diving-related adverse events. A data recording system related to diving and regulations particularly for tourist divers in the countries attracting tourists is required.

Risk factors for dive injury: a survey study

Scuba diving is a world sport, but it is not medically regulated. Study objectives sought to identify risk behaviors, preexisting medical conditions, compliance to dive guidelines, and injury patterns of recreational scuba divers. An Internet-based survey examined risk behaviors and diver safety practices. Responses from 682 of 770 (88.6%) divers revealed that 80.6% were certified; 51.7% of certified divers reported diving injuries versus 75.0% for noncertified divers (RR = 1.31; 95% CI: 1.16-1.48; P < 0.001); suspected decompression symptoms were witnessed by 52.6% of divers; 32.7% of certified divers reported medical problems including hypertension, asthma, diabetes, and epilepsy. No significant differences were observed in injuries among the certified divers based on dive frequency (P = 1.000), medical conditions (P = 0.750), smoking (P = 0.545), alcohol (P = 0.649), or illicit substances use (P = 0.230). Among certified divers, there was a positive association with fewer diving injuries but not with diving frequency, preexisting medical condition(s), smoking, alcohol, or illicit substance use.

Recompression treatment of Red Sea diving accidents: a 23-year summary

OBJECTIVE

The growing popularity of diving sport has resulted in more diving accidents. Our objective was to characterize Red Sea divers requiring recompression treatment in Eilat, to recognize 23-year trends of diving accidents, and to facilitate appropriate administrative and treatment tools for diving accident in this area.

DESIGN

Retrospective, uncontrolled study.

SETTING

Recompression unit at a Red Sea medical center.

PATIENTS

Charts of all divers treated at Eilat's recompression chamber from October 1976 to December 1999 were reviewed.

INTERVENTIONS

Recompression treatment.

RESULTS

During this period, annual crude numbers increased 5-fold, and a total of 453 patients were treated. Of them, 68% were Israelis and 32% tourists; 76% were males and 23% females; and 21.6% were diving buddies of injured divers (omitted decompression). The mean diving depth causing the accident was 30.2 +/- 13.1 m, and >50% of accidents occurred between 11 and 30 m. Over 42% suffered from decompression sickness (DCS) type 2, 26% from DCS type 1, and 7% from barotraumas. Women, unlike men, presented predominantly DCS type 2 (54% vs. 39%; P = 0.01) and sustained DCS at shallower waters (25.2 +/- 9.1 m) than men (31.8 +/- 13.8 m; P < 0.0001). Primarily, treatment followed recompression in alternating cycles of oxygen and air as stipulated in US Navy Tables 5 (18.1%) and 6 (37.5%). The 48-hour case fatality rate was 0.09%.

CONCLUSIONS

This large survey of open sea diving accidents accentuated the need for a national registry of diving accidents and a national database of diving activities.