Fatal case of shallow water blackout (forensic medical analysis) = Утоплення у воді на фоні гіпервентиляції (судово - медичний анализ)

86 UDC 616.24-008.444-036.88:340.66 DOI http://dx.doi.org/10.5281/zenodo.17308063 Yevhenii Varfolomeiev, Alina Pletenetska FATAL CASE OF SHALLOW WATER BLACKOUT (FORENSIC MEDICAL ANALYSIS) O. O. Bogomolets Kyiv National Medical University Authors’ Information Варфоломеєв Є. А. ORCID ID: 0000 – 0003 -0539 -9682 Плетенецька А. О. ORCID ID: 0000 – 0002-7029-3377 Reseracher ID: AAZ – 9198 -2021 Summary. Varfolomeiev Yevhenii, Pletenetska Alina. FATAL CASE OF SHALLOW WATER BLACKOUT (FORENSIC MEDICAL ANALYSIS). - O. O. Bogomolets Kyiv National Medical University. - e-mail: [email protected]; Deaths from accidental drowning and immersion in water is a significant part in mortality, particularly in violent deaths. In the article, we have given the number of deaths due to drowning in Ukraine during 5 years, including deaths of athletes during swimming and other types of aquatic sports. We report as well a practical case - a forensic medical examination of the corpse of a free-diver. Besides the general signs of drowning, presence of deposits of lipofuscin granules in cardiomyocytes and brain cells were found. It can act as one of the markers that can indirectly confirm the athlete's practice of hyperventilation before diving while holding his breath, which in turn is a risk factor for the development of so-called hypoxic blackouts under freediving time. Key words: free-diving, shallow water blackout, forensic medical examination, hyperventilation, oxidative stress, lipofuscin. Реферат. Варфоломеєв Євгеній, Плетенецька Аліна. УТОПЛЕННЯ У ВОДІ НА ФОНІ ГІПЕРВЕНТИЛЯЦІЇ (СУДОВО - МЕДИЧНИЙ АНАЛИЗ). - Київський національний медичний університет імені О. О. Богомольця. - e-mail: [email protected]; Смерть від випадкового утоплення та занурення у воду становить значну частину фатальних випадків, особливо насильницьких. У статті наведено опис кільких смертей внаслідок утоплення, що малі місце в Україні протягом 5 років, включаючи смерть спортсменів під час плавання та заняття різними водними видами спорту. Також повідомлело про практичний випадок – судово - медичне дослідження трупа фрідайвера. Окрім загальних ознак утоплення, було виявлено наявність відкладень гранул ліпофусцину в кардіоміоцитах та клітинах мозку. Це може виступати одним із маркерів, що опосередковано підтверджують практику спортсменом гіпервентиляції перед зануренням із затримкою дихання, що, у свою чергу, є фактором ризику розвитку так званих гіпоксичних втрат свідомості під час фрідайвінгу. Ключові слова: фрідайвінг, занурення на мілководді, судово-медична експертиза, гіпервентиляція, оксидативний стрес, ліпофусцин. Introduction. According to statistical data, received from the official site of State Statistics Service of Ukraine, deaths from accidental drowning and immersion in water (W65-W74) in Ukraine only in January 2022 amounted to 46 (excluding the occupied territories (Crimea, Sevastopol, part of Donbas)) [1] the number of which increases significantly in the warm season and associated with the growth of active leisure and sports in open waters. The list of water activities includes such popular kind of sports as swimming, boating, scuba diving, surfing, sailing -------------------------------------------- © Varfolomeiev Yevhenii, Pletenetska Alina 87 and, among others, a variety of diving – free diving, which has been gaining popularity in recent decades. Free-diving, i.e., diving into water while holding your breath, without the use of breathing equipment, is a fairly common type of both active leisure time and a component of a significant number of competitive disciplines, such as diving without equipment indoors and in open water, underwater hunting while holding your breath, diving under the ice, scandalopetra diving and others [2]. It refers to a sea and ocean sport. While the practice of breath-holding diving, subject to compliance with safety rules, is a relatively safe sport and active recreation, with even the slightest violations of the safety rules of this sport, it can lead to accidents, and in a significant number of cases, with a fatal result for the athlete [3].One of the most common causes of accidents among free-divers is loss of consciousness at the height of breath holding while diving in water, the so-called hypoxic blackout or shallow water blackout [4]. The mechanism of development of blackout in athletes is the increase of hypoxemia against the background of the absence of hypercapnia, which under normal physiological conditions is the main factor in stimulating inhalation in humans [5].Pre-dive hyperventilation, which is a common practice among competitive athletes and is used to improve results in breath-hold duration, can develop such a condition [4] and can lead to fatal unconsciousness in the water. At the same time, the long-term consequences of the practice of active hyperventilation with subsequent long-term breathlessness for the athlete's body remain poorly understood. Matherials and Methods. In the research, data from annual reports (years 2017-2021) of State Institution “Main bureau of forensic medicine of Ministry of Health of Ukraine”, concerning the causes of deaths established in forensic institutions in Ukraine, were analyzed. In the course of the study, the annual number of drownings (includingdeaths during swimming and other types of aquatic sports) and their percentage in the structure of violent death in Ukraine was established.The material of further study was a practical case - a forensic medical examination of the corpse of a free-diver, whose death occurred during free diving training in the pool. In the course of the research, an analysis of the medical documentation of the deceased was carried out with a reflection of the diseases transmitted from birth to the onset of death, the results of the sectional examination of the corpse, the pathohistological examination of pieces of internal organs using hematoxylin-eosin staining, the examination of the presence of diatom plankton in the tissues of the corpse, the toxicological examination of blood by chromatographic methods for the presence of alcohol, narcotic substances and some medications. Case report. Deaths from drowning and immersion in water constitutes a significant part in the structure of violent deaths. According the annual reports data of “Main bureau of forensic medicine of Ministry of Health of Ukraine” percentage of death caused by the drowning is relatively constant. Sо, during the 2017-2021 years percentage of deaths by drowning fluctuates within 6.28-6.6% in the structure of violent death and 19.2-20.62% in the structure of death from mechanical asphyxia with the total number – 9714 people in five years (Tab. 1). Table. 1 Deaths caused by drowning and mechanical asphyxia among violent causes of death Years 2017 2018 2019 2020 2021 Violent death 31219 31121 30121 28690 29219 Mechanical asphyxia N 10213 9904 9691 9381 9334 % 32,71 31,82 32,2 32,7 31,94 Drowning N 2033 1968 1987 1801 1925 % 6,5 6,32 6,6 6,28 6,59 An analysis of the age and gender of persons who died as a result of drowning showed that the highest percentage (76.44-78.76%) were adult men over 18 of age. In the vast majority of cases, the causes of drowning were accidents due to violation of safety rules in the water, including some cases of accidents among athletes during training or competitions in aquatic sports (swimming, diving, etc.). The case report concerns the death of free-diver athlete. The deceased, a 27-year-old man, was discovered by the coach and other athletes in the water of the pool after training. The body was located near the bottom of the pool, face up. From the circumstances of the case, it is known 88 that he remained after the training in the pool alone to continue the independent training in breathhold diving. According to the data received from other athletes and the coach, he actively practiced hyperventilation before diving into the water. The total experience of training in this sport is about 6-7 years. During the autopsy of the dead body, signs characteristic of drowning in water were found, including traces of whitish-colored foam in the lumen of the upper respiratory tract, indistinct hemorrhages on the surface of the lungs (Paltauf spots), imprints of ribs on the surface of the lungs, accumulation of free fluid in the pleural cavities, sinuses sphenoid bone, upper parts of the gastrointestinal tract. No injuries were found; changes on the part of internal organs that would indicate the presence of diseases were not detected. According to the results of the autopsy, the cause of death was established as a result of drowning in water. During toxicological research alcohol, narcotic substances, and medications were not detected during the toxicological examination of the blood. Pathohistological examination revealed changes in the form of presence of fluid mixed with erythrocytes in the lumens of small bronchi and alveoli, foci of emphysematous dilated alveoli, pleurisy of internal organs, cerebral edema. In addition, microscopic examination of heart and brain tissue revealed perinuclear accumulation of lipofuscin granules in cardiomyocytes and some neurons. Analysis of the deceased's medical records showed the presence of several episodes of allergic dermatitis in his childhood (up to 6 years old), as well as periodic requests for medical help for acute respiratory diseases. No injuries in the anamnesis, heredity is not burdened. After analyzing the medical documents, taking into account the known circumstances of the event, the results of the examination of the corpse and additional laboratory tests, the cause of the drowning was considered to be loss of consciousness during diving, which could have been influenced by hyperventilation previously performed by the athlete, against the background of violation of safety rules (diving alone, without the supervision of a trainer) and led to a fatal accident. Discussion. In this case, the diver's death was mostly marked by signs that are generally characteristic of drowning, and the cause of the athlete's death in general was beyond doubt. At the same time, among the findings during the examination of tissues of internal organs, it should be noted the presence of deposits of lipofuscin granules, the so-called "pigment of aging", in cardiomyocytes and brain cells, which is not usually characteristic of young age. The formation and accumulation of lipofuscin granules in tissues is explained by several theories, among which the theory of oxidative damage of molecules by free radicals, which are formed during oxidative reactions in cells intrinsically connected with vital processes, is the most popular and well-argued theory [6]. The natural imperfection of removal and processing of substances in cells leads to the accumulation of remnants of the natural functioning of the cell, such as old mitochondria, damaged proteins, including lipofuscin [7]. However, it should be noted that the accumulation of the specified biological "garbage" is usually observed with age, in the process of aging of the body and is not characteristic of young people, which was the case in this case. The formation of lipofuscin in the cells of the heart and central nervous system in this case can be explained by oxidative stress caused by hyperoxemia as a result of the athlete's constant practice of hyperventilation before a long breath hold. Thus, existing studies confirm the presence of markers of oxidative stress in divers practicing breath-hold diving, including changes in the concentration of NO, peroxynitrites, and thiols [8]. It is clear that a single observation can have an exclusively guiding value for the further study of morphological signs of oxidative stress in athletes practicing free-diving with breath holding after previously performed hyperventilation on a statistically significant number of observations. Conclusion. The practice of free-diving while holding the breath with prior hyperventilation can lead to oxidative stress with the accumulation of products of oxidative damage to macromolecules in the form of lipofuscin in body cells. The specified feature requires further study and verification on a statistically significant number of observations and, if confirmed, can act as one of the markers that can indirectly confirm the athlete's practice of hyperventilation before diving while holding his breath, which in turn is a risk factor for the development of so-called hypoxic blackouts under freediving time. 89 References: 1. State Statistics Service of Ukraine. Number of deaths by selected causes of death in January 2022 [Internet].http://db.ukrcensus.gov.ua/PXWEB2007/eng/news/op_died_e.asp 2. World Confederation of Underwater Activities: Documents of the Free Diving Comission [Internet]. https://www.cmas.org/apnoea/documents-of-the-apnoea-commission. 3. Dong G, Brenner R, Harris C, Helfrich E, and Tillmans F.Dan. Annual Diving Report 2020 Edition: A report on 2018 diving fatalities, injuries, and incidents. Durham (NC): Divers Alert Network; 2021.[Internet].https://www.ncbi.nlm.nih.gov/books/NBK582509/. 4. Bart RM.; Lau H. Shallow Water Blackout. Treasure Island (FL): Stat Pearls Publishing; 2022 Jan.[Internet]. https://www.ncbi.nlm.nih.gov/books/NBK554620/ 5. Albert B, and Craig JR. Causes of loss of consciousness during underwater swimming. Journal of Applied Physiology 1961 16:4, 583-586. https://doi.org/10.1152/jappl.1961.16.4.583 6. Craig JR. Summary of 58 cases of loss of consciousness during underwater swimming and diving. Med Sci Sports (1976). 8(3): 171-5. DOI: 10.1249/00005768-19760083000007. PMID: 979564 7. Terman A, Brunk UT. Lipofuscin: mechanisms of formation and increase with age. APMIS. 1998 Feb;106(2):265-76. doi: 10.1111/j.1699-0463.1998.tb01346.x. PMID: 9531959. 8. Terman A, Brunk UT. Oxidative stress, accumulation of biological 'garbage', and aging. Antioxid Redox Signal. 2006 Jan-Feb;8(1-2):197-204. doi: 10.1089/ars.2006.8.197. PMID: 16487053. 9. Theunissen S, Sponsiello N, Rozloznik M, Germonpré P, Guerrero F, Cialoni D, Balestra C. Oxidative stress in breath-hold divers after repetitive dives. Diving Hyperb Med. 2013 Jun;43(2):63-6. PMID: 23813458. Внесок авторів / authors’ contribution Автори внесли рівний вклад у написання роботию Автори прочитали й погодилися з опублікованою версією рукопису. Фінансування /Funding Це дослідження не отримало зовнішнього фінансування Висновок комісії по біоетиці/Institutional Review Board Statement Не потрібен Заява про поінформовану згоду /Informed Consent Statement Не потрібна Конфлікт інтересів /Conflicts of Interest Автори заявляють про відсутність конфлікту інтересів Використання ШІ/Use of AI Не використовували Робота надійшла в редакцію 11.09.2025 року. Рекомендована до друку на засіданні редакційної колегії після рецензування