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.

Resuscitation and emergency care in drowning: A scoping review.

BACKGROUND: The ILCOR Basic Life Support Task Force and the international drowning research community considered it timely to undertake a scoping review of the literature to identify evidence relating to the initial resuscitation, hospital-based interventions and criteria for safe discharge related to drowning. METHODS: Medline, PreMedline, Embase, Cochrane Reviews and Cochrane CENTRAL were searched from 2000 to June 2020 to identify relevant literature. Titles and abstracts and if necessary full text were reviewed in duplicate. Studies were eligible for inclusion if they reported on the population (adults and children who are submerged in water), interventions (resuscitation in water/boats, airway management, oxygen administration, AED use, bystander CPR, ventilation strategies, ECMO, protocols for hospital discharge (I), comparator (standard care) and outcomes (O) survival, survival with a favourable neurological outcome, CPR quality, physiological end-points). RESULTS: The database search yielded 3242 references (Medline 1104, Pre-Medline 202, Embase 1722, Cochrane reviews 12, Cochrane CENTRAL 202). After removal of duplicates 2377 papers were left for screening titles and abstracts. In total 65 unique papers were included. The evidence identified was from predominantly high-income countries and lacked consistency in the populations, interventions and outcomes reported. Clinical studies were exclusively observational in nature. CONCLUSION: This scoping review found that there is very limited evidence from observational studies to inform evidence based clinical practice guidelines for drowning. The review highlights an urgent need for high quality research in drowning.

A systematic review on the effectiveness of anti-choking suction devices and identification of research gaps.

AIM: Despite an obstructed airway (choking) being a relatively preventable injury, it has a considerable mortality burden globally, with increasing incidence. Given new technologies in choking management, this systematic review aimed to assess current literature on the effectiveness of anti-choking suction devices at relieving obstructions. METHODS: Ovid MEDLINE, Embase, PubMed, The Cochrane Library, SCOPUS, Web of Science, CINAHL Plus and the English websites of the devices were searched on September 23, 2019. Studies were included if they reported the anti-choking devices' dislodgment success rate (primary outcome) or associated adverse events (secondary outcome). Articles, conference abstracts or technical reports were included if peer reviewed. Certainty of evidence was assessed in accordance with GRADE. RESULTS: Five studies satisfied the inclusion criteria for this review. Two studies (40%) reported findings of a single centre mannequin trial, one (20%) of a single centre cadaveric trial, and two (40%) were case series. Cohen's Kappa for the first and second round of screening was 0.904 and 0.674 respectively. Although several devices have been manufactured worldwide, the LifeVac© has been most extensively studied, with a combined dislodgement success rate of 94.3% on first attempt. However, certainty of evidence for the primary outcome was evaluated as very low. CONCLUSIONS: There are many weaknesses in the available data and few unbiased trials that test the effectiveness of anti-choking suction devices resulting in insufficient evidence to support or discourage their use. Practitioners should continue to adhere to guidelines authored by local resuscitation authorities which align with ILCOR recommendations.

Near-drowning and drowning classification: a proposal to stratify mortality based on the analysis of 1,831 cases.

STUDY OBJECTIVE: To establish an updated classification for near-drowning and drowning (ND/D) according to severity, based on mortality rate of the subgroups. MATERIALS AND METHODS: We reviewed 41,279 cases of predominantly sea water rescues from the coastal area of Rio de Janeiro City, Brazil, from 1972 to 1991. Of this total, 2,304 cases (5.5%) were referred to the Near-Drowning Recuperation Center, and this group was used as the study database. At the accident site, the following clinical parameters were recorded: presence of breathing, arterial pulse, pulmonary auscultation, and arterial BP. Cases lacking records of clinical parameters were not studied. The ND/D were classified in six subgroups: grade 1--normal pulmonary auscultation with coughing; grade 2--abnormal pulmonary auscultation with rales in some pulmonary fields; grade 3--pulmonary auscultation of acute pulmonary edema without arterial hypotension; grade 4--pulmonary auscultation of acute pulmonary edema with arterial hypotension; grade 5--isolated respiratory arrest; and grade 6--cardiopulmonary arrest. RESULTS: From 2,304 cases in the database, 1,831 cases presented all clinical parameters recorded and were selected for classification. From these 1,831 cases, 1,189 (65%) were classified as grade 1 (mortality=0%); 338 (18.4%) as grade 2 (mortality=0.6%); 58 (3.2%) as grade 3 (mortality=5.2%); 36 (2%) as grade 4 (mortality=19.4%); 25 (1.4%) as grade 5 (mortality=44%); and 185 (10%) as grade 6 (mortality=93%) (p<0.000001). CONCLUSION: The study revealed that it is possible to establish six subgroups based on mortality rate by applying clinical criteria obtained from first-aid observations. These subgroups constitute the basis of a new classification.

Drowning. Rescue, resuscitation, and reanimation.

Several myths about drowning have developed over the years. This article has attempted to dispel some of these myths, as follows: 1. Drowning victims are unable to call or wave for help. 2. "Dry drownings" probably do not exist; if there is no water in the lungs at autopsy, the victim probably was not alive when he or she entered the water. 3. Do not use furosemide to treat the pulmonary edema of drowning; victims may need volume. 4. Seawater drowning does not cause hypovolemia, and freshwater drowning does not cause hypervolemia, hemolysis, or hyperkalemia. 5. Drowning victims swallow much more water than they inhale, resulting in a high risk for vomiting spontaneously or on resuscitation. No discussion of drowning would be complete without mentioning the importance of prevention. Proper pool fencing and water safety training at a young age are instrumental in reducing the risk for drowning. Not leaving an infant or young child unattended in or near water can prevent many of these deaths, especially bathtub drownings. Also crucial is the use of personal flotation devices whenever boating. Proper training in water safety is crucial for participation in water recreation and sporting activities, including SCUBA diving. The incidence of pediatric drowning deaths in the United States has decreased steadily over the past decade, perhaps as a result of increased awareness and attention to drowning-prevention measures (Box 1).

A new definition of drowning: towards documentation and prevention of a global public health problem.

Drowning is a major global public health problem. Effective prevention of drowning requires programmes and policies that address known risk factors throughout the world. Surveillance, however, has been hampered by the lack of a uniform and internationally accepted definition that permits all relevant cases to be counted. To develop a new definition, an international consensus procedure was conducted. Experts in clinical medicine, injury epidemiology, prevention and rescue from all over the world participated in a series of "electronic" discussions and face-to-face workshops. The suitability of previous definitions and the major requirements of a new definition were intensely debated. The consensus was that the new definition should include both cases of fatal and nonfatal drowning. After considerable dialogue and debate, the following definition was adopted: "Drowning is the process of experiencing respiratory impairment from submersion/immersion in liquid." Drowning outcomes should be classified as: death, morbidity, and no morbidity. There was also consensus that the terms wet, dry, active, passive, silent, and secondary drowning should no longer be used. Thus a simple, comprehensive, and internationally accepted definition of drowning has been developed. Its use should support future activities in drowning surveillance worldwide, and lead to more reliable and comprehensive epidemiological information on this global, and frequently preventable, public health problem.