Evaluation of diving operations for fish cage farming in the Aegean Sea

Mariculture represents approximate 50 percent of global aquaculture production by weight. Fish cages, which consist simply HDPE frame, netting, and mooring system, in fish farming are key elements of sea cage aquaculture. Aquaculture divers are responsible for inspection and maintenance of the underwater structures such as nets, mooring line and anchor, removing dead fish, monitoring the abnormal behavior of fish, assistance harvesting of fish and other periodic underwater works in fish cage farms. In recent years, the demand for aquaculture divers has increased in fish cage farms in both northern and southern Aegean Sea with enhancement of fish production in mariculture. On the other hand, various problems (diving accidents, faulty diving operations, lack of training etc.) related to work conditions and legal regulations of aquaculture divers have emerged. In the study, with the questionnaire consisting of 49 questions, face to face surveys were performed with 162 aquaculture divers in fish farms around Muğla and İzmir provinces between February and May 2019. Results showed the presence that there are three main problems consisting of diving regulations for professional divers, the candidate diving system and diving education which may cause fatal accidents should be improved and revised urgently.

Teaching Self-Assessment of Doppler Ultrasound for Bubble Grading in Divers: Learning Curve, Reliability, and Surveying Precision.

BackgroundObserving modern decompression protocols alone cannot fully prevent Diving Accidents especially in repetitive diving. Audio Doppler bubble measurements to estimate supersaturation are done in special professional settings only, being not available for the broad community of sports SCUBA divers. In case SCUBA divers without medical and ultrasound training could learn audio Doppler self-assessment for reliable bubble grading on a stable skill level and with an efficient single teaching intervention, this skill could add significantly to diving safety. MethodsWe taught audio Doppler self-assessment of the subclavian vein and cardiac precordial probe position to 41 divers in a 45-minute standardized training session. Assessment was made of 684 audio Doppler measurements by both the trained divers and a medical professional plus additional 2D-echocardiography as reference. ResultsAll air dives were within normal sports diving limits and decompression bubbles were observable via echocardiography in 32.3% of all measurements. The specificity of audio bubble detection was 96.1% but the sensitivity was low for lower bubble grades, increasing to 25%, 35% and 67% for higher echo-detected bubble grades 3, 4 and 5. The number of attempts to achieve a reliable venous signal within 30 seconds was 13 at the subclavian position and 18 at the precordial position. More bubble positive measurements could be detected at the precordial position for both self and medical professional assessment. The performance level of the taught skill remained stable over six months without further practice.ConclusionAudio Doppler self-assessment can be learned by people without medical and ultrasound training and a reliable venous signal can be achieved after a comparably steep learning curve. However, accurate bubble grading is not possible using audio Doppler as only higher bubble grades can be detected. Nevertheless, this qualitative finding can be important in self-evaluating decompression stress and potentially help the diver to judge on measures for avoiding decompression accidents.

Diving Accident Evacuations by Helicopter and Immersion Pulmonary Edema

BACKGROUND: Scuba diving activities expose divers to serious accidents, which can require early hospitalization. Helicopters are used for early evacuation. On the French Mediterranean coast, rescue is made offshore mainly by a French Navy Dauphin or at a landing zone by an emergency unit EC 135 helicopter.METHODS: We retrospectively analyzed diving accidents evacuated by helicopter on the French Mediterranean coast from 1 September 2014 to 31 August 2016. We gathered data at the Center for Hyperbaric Medicine and Diving Expertise (SMHEP) of the Sainte-Anne Military Hospital (Toulon, France), the 35 F squadron at Hyres (France) Naval Air Station, and the SAMU 83 emergency unit (Toulon, France).RESULTS: A total of 23 diving accidents were evacuated offshore by Dauphin helicopter and 23 at a landing zone on the coast by EC 135 helicopter without hoist. Immersion pulmonary edema (IPE) accounted for one-third of the total diving accidents evacuated by helicopter with identified causes. It was responsible for at least half of the deaths at the dive place. A quarter of the rescued IPE victims died because of early cardiac arrest.DISCUSSION: Helicopter evacuation is indicated when vital prognosis (IPE and pulmonary overpressure in particular) or neurological functional prognosis (decompression sickness) is of concern. IPE is the primary etiology in patients with serious dive injuries that are life-threatening and who will benefit from helicopter evacuation. A non-invasive ventilation device with inspiratory support and positive expiratory pressure must be used, in particular for IPE.Corgie L, Huiban N, Pontier J-M, Brocq F-X, Boulard J-F, Monteil M. Diving accident evacuations by helicopter and immersion pulmonary edema. Aerosp Med Hum Perform. 2020; 91(10):806811.

Immersion pulmonary edema: case reports from Oceania

Introduction: We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive. Method: Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded. Results: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. Conclusions: Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.

Immersion pulmonary edema: an analysis of 31 cases from Oceania

Aim: To review incidents of immersion pulmonary edema (IPE) from Oceania, to determine the demographics, diving parameters, and comorbidities that may be related to this disorder. Method: Incidents of IPE, most of which were documented by Divers Alert Network Asia-Pacific (DAN AP) or reported in our medical literature, were analyzed. They included interviews with the survivors and a review of available medical records. Only incidents diagnosed as IPE by specialist diving physicians or pathologists with experience in the investigation of diving accidents were included. Results: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers, which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 msw for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities in this cohort. Medical comorbidities were recorded in 68%, with 42% being cardiac. The latter included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. Conclusion: IPE was more likely in middle-aged females, in experienced divers, and during ascent or after surfacing. Commonly reported associations such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, tight wetsuit, aspiration and certain medications were identified. This series supports the hypothesis that the elderly IPE subjects are likely to have comorbidities and be susceptible to IPE recurrences and fatalities unless the contributing factors can be identified and addressed.

The problem of experiencing anxiety among divers. Experiment in hyperbaric exposure conditions

The aim of the article is a review of psychological literature relating to the problem of anxiety in divers, where an emphasis is placed on the degree of mental adaptation of the individual to the underwater environment, primarily highlighting the trait of anxiety and the neuroticism of a person involved in a specific type of diving. The article presents selected reports from all over the world regarding research on anxiety in divers. Treating a high level of the indicator of anxiety as a predictor of panic anxiety reveals the importance of this trait in predicting the risk of an occurrence of diving accidents during the operation under water. In the own research presented in the article, the results on the levels of anxiety as a trait and a state in divers taking part in hyperbaric exposures indicate the fact that the majority of the examined divers have low levels of anxiety both as a trait and a state, which most probably indicates the good psychological condition of the examined divers.

Utilising a Skin Prick Test for the determination of the presence of allergic rhinitis in divers

Allergic rhinitis occurs in various regions of the world and affects from 10 to 40% of the population. The skin prick test is the “gold standard” for the detection of type I allergic diseases according to the Gella and Coombs classification, which is mediated by IgE. For our experiment, skin prick tests were performed on 60 divers aged between 30 and 40 years of age. The following tests for airborne allergens were used: tests for pollen from trees, grasses, cereals, weeds, proteins from house dust mites, animal hair and epidermis, and moulds. On the basis of an interview and a positive skin prick test allergic rhinitis was diagnosed in 17 divers. Conclusions: Allergic rhinitis can cause health problems in divers and be the cause of diving accidents. The application of the skin prick test during the health qualification in the Military Maritime Health Commission, would allow the exclusion of diver candidates suffering from allergies.