Snorkelling-related deaths in Australia, 1994-2006

Effects of hyperventilation on oxygenation, apnea breaking points, diving response, and spleen contraction during serial static apneas

PURPOSE

Hyperventilation is considered a major risk factor for hypoxic blackout during breath-hold diving, as it delays the apnea breaking point. However, little is known about how it affects oxygenation, the diving response, and spleen contraction during serial breath-holding.

METHODS

18 volunteers with little or no experience in freediving performed two series of 5 apneas with cold facial immersion to maximal duration at 2-min intervals. In one series, apnea was preceded by normal breathing and in the other by 15 s of hyperventilation. End-tidal oxygen and end-tidal carbon dioxide were measured before and after every apnea, and peripheral oxygen saturation, heart rate, breathing movements, and skin blood flow were measured continuously. Spleen dimensions were measured every 15 s.

RESULTS

Apnea duration was longer after hyperventilation (133 vs 111 s). Hyperventilation reduced pre-apnea end-tidal CO2 (17.4 vs 29.0 mmHg) and post-apnea end-tidal CO2 (38.5 vs 40.3 mmHg), and delayed onset of involuntary breathing movements (112 vs 89 s). End-tidal O2 after apnea was lower in the hyperventilation trial (83.4 vs 89.4 mmHg) and so was the peripheral oxygen saturation nadir after apnea (90.6 vs 93.6%). During hyperventilation, the nadir peripheral oxygen saturation was lower in the last apnea than in the first (94.0% vs 86.7%). There were no differences in diving response or spleen volume reduction between conditions or across series.

CONCLUSIONS

Serial apneas  revealed a previously undescribed aspect of hyperventilation; a progressively increased desaturation across the series, not observed after normal breathing and could heighten the risk of a blackout.

Injuries and Fatalities Related to Freediving: A Case Report and Literature Review

This case report and literature review aim to explore the range of injuries sustained in the sport of freediving. The case report involves a 37-year-old patient who sustained a pneumothorax secondary to freediving. We conducted the literature review to analyse the injuries associated with freediving. We used the combination of search terms 'freediving", "injuries", and "breath-hold diving" on the database PubMed®. A total of 40 studies were eligible for inclusion in this review. The search revealed a wide range of ophthalmological, pulmonary, neurological, ear, nose, and throat injuries, along with several fatalities. Freediving is a sport performed in extreme environments and, if undertaken by inexperienced, untrained, or competition divers, can lead to severe injury or even death. However, the risk of damage can be reduced by performing it responsibly with the appropriate training and by using proper safety measures. Future research is warranted into the psychological, physiological, and economic benefits of freediving at both individual and community levels.

Snorkelling and breath-hold diving fatalities in New Zealand, 2007 to 2016

INTRODUCTION

New Zealand's (NZ) long coastline offers a diverse underwater environment with abundant opportunities for harvesting seafood and for recreation. Fatalities from snorkelling/breath-hold diving have been reported from the 1960s through to 2006. Those from 2007 to 2016 are reported here.

METHODS

The National Coronial Information System, the Australasian Diving Safety Foundation diving fatality database, and the Water Safety NZ "Drownbase" were searched and additional coronial data provided by the NZ Ministry of Justice. An anonymised database was created and analysed for multiple factors. A chain of events analysis was performed for each case.

RESULTS

There were 38 snorkelling or breath-hold-related deaths in NZ, 33 men and five women. Twenty-nine were breath-hold divers involved in gathering seafood, and six 'surface snorkellers', predominantly sightseeing. Two-thirds were diving alone and/or were not being observed by anyone out of the water. Twenty-eight victims were classified as overweight or obese and 19/38 were Maori. Pre-existing health factors that may have or definitely contributed to the fatality were present in 30 cases. The most common of these were cardiac (18/38). Two divers had insulin-dependent diabetes mellitus, one each epilepsy and asthma whilst cannabis and/or alcohol were possible factors in seven deaths. Five (possibly six) deaths resulted from apnoeic hypoxia.

CONCLUSIONS

Overall, death from snorkelling/breath-hold diving was an uncommon event (38 in 10 years). Poor judgement was a common feature. Middle-aged Maori men with pre-existing disease feature strongly. This suggests an on-going need for appropriate water safety education within and beyond the Maori community.

An underappreciated cause of ocean-related fatalities: A systematic review on the epidemiology, risk factors, and treatment of snorkelling-related drowning

Aim

Snorkelling is a popular aquatic activity which may result in fatal and non-fatal drowning. However, little is known about the scale of injury, factors impacting risk and strategies for prevention. This review assesses the current literature on snorkelling-related drowning with the aim of assessing available data, improving safety recommendations and reducing the global mortality burden.

Methods

A systematic review of peer-reviewed literature in English, Spanish and Portuguese language published between 1 January 1980 and 31 October 2020 was conducted using the PRISMA guidelines. CINAHL Complete, Embase, Medline (Ovid), PubMed, SafetyLit, SportDiscus and grey literature were searched to identify studies reporting the incidence of fatal and non-fatal snorkelling-related drowning, or associated risk factors, prevention strategies, treatments or casualty characteristics. Quality was assessed using the NIH Quality Assessment Tool.

Results

Forty-three studies were included (26 reporting population data, 17 case series), of which 27 (62.8%) studies reported data from Australia. Incidence was reported as about 8% of total ocean-related drownings. Case series documented 144 fatalities over 17 years. Frequent casualty characteristics include male (82.6%), pre-existing heart disease (59.4%), tourists (73%) who were inexperienced (71.0%), and lack of a buddy system (89.6%). Two at-risk profiles identified were older adult tourists with pre-existing medical conditions and local, experienced spearfishers. Twenty-two expert recommendations were developed to improve the safety of snorkellers related to individuals, tourism companies, government agencies and diving organisations.

Conclusion

Snorkelling-related drownings are not infrequent, and there are many opportunities to improve the safety of this activity based on available data.

Snorkelling and breath-hold diving fatalities in Australia, 2001 to 2013. Demographics, characteristics and chain of events

INTRODUCTION

The aim of this study was to identify characteristics of victims of fatal snorkelling and breath-hold diving accidents in Australia from 2001-2013, inclusive, to determine underlying factors and risks associated with such activities and inform appropriate countermeasures.

METHODS

The National Coronial Information System (NCIS) was searched to identify snorkelling and breath-hold diving-related cases reported to Australian coroners for the years 2001-2013, inclusive. Coronial data in the form of findings, witness and police reports, medical histories and autopsies were collected and collated, and descriptive statistics were used to analyse these data. A chain of events analysis was used to determine the likely sequence of events.

RESULTS

There were 175 identified snorkelling-related fatalities during the study period. Most victims were middle-aged males (mean age 49 years). Pre-existing health conditions were possible contributors to 41% of the deaths, the main being ischaemic heart disease. The majority of deaths occurred in Queensland in inexperienced snorkellers, often in commercial settings. The victim's plight often went unnoticed as they were alone, or poorly supervised, when the incident occurred. Apnoeic hypoxia appeared to have been associated with at least 12.5% of the deaths. The main disabling injuries were asphyxia (40%) and cardiac incidents (35%).

CONCLUSION

Human factors, such as chronic health conditions, poor skills and inexperience and poor planning can play a substantial role throughout the chain of events leading to a snorkelling fatality. It is important to educate the community, doctors and dive industry professionals about potential problems associated with the interaction between certain health-related conditions, especially cardiovascular conditions, and snorkelling. Close supervision is strongly recommended for inexperienced snorkellers due to their likely poor skills, as well as for experienced breath-hold divers due to the potential for apnoeic hypoxia.

Efficacy of Early Noninvasive Ventilation in Three Cases of Nonfatal Drowning with Pulmonary Oedema in the Paediatric Emergency Department

Drowning is still one of the most important causes of the preventable mortality worldwide. Some patients should be treated with noninvasive ventilation immediately in the emergency department (ED). The practice of noninvasive ventilation has been increased recently in the paediatric ED. We present here three nonfatal drowning patients with pulmonary oedema and hypoxia who were successfully treated with noninvasive ventilation in the paediatric emergency department. All of the patients had aspirated sea water during swimming. In addition, two of the patients had aspirated water during snorkeling. Noninvasive ventilation was applied to the patients immediately in paediatric emergency service. All of the patient's clinical and radiological findings recovered rapidly. There are limited reports about use of noninvasive ventilation in nonfatal drowning cases in the paediatric emergency department. We emphasize that the early application of noninvasive ventilation should be a preventive method for reducing the morbidity of nonfatal drowning cases. (Hong Kong j.emerg.med. 2016;23:42-46)

Drowning fatalities in childhood: the role of pre-existing medical conditions

OBJECTIVES

This study is an analysis of the contribution of pre-existing medical conditions to unintentional fatal child (0-14 years) drowning and a of critique prevention stratagems, with an exploration of issues of equity in recreation.

DESIGN

This study is a total population, cross-sectional audit of all demographic, forensic and on-site situational details surrounding unintentional fatal drowning of children 0-14 years in Australia for the period of 1 July 2002 to 30 June 2012. Data were sourced from the National (Australia) Coronial Information System. Age-specific disease patterns in the general population were obtained from the Australian Institute of Health and Welfare.

RESULTS

Four hundred and sixty-eight children drowned during the study period. Fifty-three (11.3%) had a pre-existing medical condition, of whom 19 suffered from epilepsy, 13 from autism and 5 with non-specific intellectual disabilities. Epilepsy is a risk factor in childhood drowning deaths, with a prevalence of 4.1% of drowning fatalities, compared with 0.7%-1.7% among the general 0-14 years population (relative risk: 2.4-5.8). Epilepsy was deemed to be contributory in 16 of 19 cases (84.2% of epilepsy cases) with a median age of 8 years. Asthma and intellectual disabilities were under-represented in the drowning cohort.

CONCLUSION

Except for epilepsy, this research has indicated that the risks of drowning while undertaking aquatic activities are not increased in children with pre-existing medical conditions. Children with pre-existing medical conditions can enjoy aquatic activities when appropriately supervised.

The Hidden Tragedy of Rivers: A Decade of Unintentional Fatal Drowning in Australia

OBJECTIVE(S)

Describe unintentional drowning deaths in rivers, creeks and streams (rivers) in Australia and identify risk factors to inform prevention.

DESIGN & SETTING

This study is a cross-sectional, total population audit of all unintentional fatal drownings in Australian rivers between 1-July-2002 and 30-June-2012 using Australian coronial data. A modified Bonferroni test has been applied, deeming statistical significance p<0.03 and p<0.04 respectively.

RESULTS

Rivers (n = 770; 26.6%) were the leading location among the 2,892 people who died from unintentional fatal drowning. This is a rate of 0.37/100,000 people / annum. Within river drowning deaths common groups include; males (80.4%), adults (85.3%), adults who have consumed alcohol (25.5%), people who fell in (21.3%), people involved in non-aquatic transport incidents (18.2%) and locals (74.0%). Children were 1.75 times more likely than adults (p<0.04) to drown in rivers as a result of a fall and adults 1.50 times more likely to drown in rivers as a result of watercraft incidents when compared to children. When compared to males, females were 2.27 and 4.45 times respectively more likely to drown in rivers as a result of incidents involving non-aquatic transport (p<0.04) and being swept away by floodwaters (p<0.04). Males were 2.66 and 4.27 times respectively more likely to drown in rivers as a result of watercraft incidents (p<0.04) and as a result of jumping in (p<0.04) when compared to females.

CONCLUSION(S)

While rivers are the leading location for drowning in Australia, little is understood about the risks. This study has identified key groups (males, adults, locals) and activities. While males were more likely to drown, the risk profile for females differed.

The utility of medico-legal databases for public health research: a systematic review of peer-reviewed publications using the National Coronial Information System

BACKGROUND

Medico-legal death investigations are a recognised data source for public health endeavours and its accessibility has increased following the development of electronic data systems. Despite time and cost savings, the strengths and limitations of this method and impact on research findings remain untested. This study examines this issue using the National Coronial Information System (NCIS).

METHODS

PubMed, ProQuest and Informit were searched to identify publications where the NCIS was used as a data source for research published during the period 2000-2014. A descriptive analysis was performed to describe the frequency and characteristics of the publications identified. A content analysis was performed to identify the nature and impact of strengths and limitations of the NCIS as reported by researchers.

RESULTS

Of the 106 publications included, 30 reported strengths and limitations, 37 reported limitations only, seven reported strengths only and 32 reported neither. The impact of the reported strengths of the NCIS was described in 14 publications, whilst 46 publications discussed the impacts of limitations. The NCIS was reported to be a reliable source of quality, detailed information with comprehensive coverage of deaths of interest, making it a powerful injury surveillance tool. Despite these strengths, researchers reported that open cases and missing information created the potential for selection and reporting biases and may preclude the identification and control of confounders.

CONCLUSIONS

To ensure research results are valid and inform health policy, it is essential to consider and seek to overcome the limitations of data sources that may have an impact on results.

Dive-related fatalities among tourist and local divers in the northern Croatian littoral (1980-2010)

BACKGROUND

The aim of the study was to retrospectively analyze diving fatalities occurring in Primorje-Gorski Kotar County (northern Croatian littoral), Croatia between 1980 and 2010 in order to identify differences between fatally injured tourist and resident divers, as well as temporal changes in the frequency of diver deaths.

METHODS

Medico-legal and police reports of 47 consecutive fatal diving cases were reviewed to determine the frequency of death among divers in relation to year and month of death, age, sex, nationality, organization of diving, diving type, and health condition.

RESULTS

The majority of victims were foreign citizens (59.6%) most of whom fell victim to scuba diving (70.4%). It was found that 79% of resident divers succumbed during free-diving. The number of diving fatalities increased significantly in the last three decades, especially among free-divers. Of the victims, 93% were males, usually belonging to younger age groups with tourist divers being significantly older than local divers. And 31.9% of divers, mostly tourists, showed signs of acute, chronic, or congenital pathological conditions.

CONCLUSION

Fatally injured foreign divers differ from resident diver fatalities in diving method and age. Tourists are the group most at risk while scuba diving according to the Croatian sample. Occupational scuba divers and free-divers are the group most at risk among resident divers. This study is an important tool in uncovering the most common victims of diving and the related risk factors. It also highlights the problems present in the legal and medical monitoring of recreational divers and discusses possible pre-event, event, and post-event preventive actions that could lead to reduced mortality rates in divers.