Drowning physiology relates to two different events: immersion (upper airway above water) and submersion (upper airway under water). Immersion involves integrated cardiorespiratory responses to skin and deep body temperature, including cold shock, physical incapacitation, and hypovolemia, as precursors of collapse and submersion. The physiology of submersion includes fear of drowning, diving response, autonomic conflict, upper airway reflexes, water aspiration and swallowing, emesis, and electrolyte disorders. Submersion outcome is determined by cardiac, pulmonary, and neurological injury. Knowledge of drowning physiology is scarce. Better understanding may identify methods to improve survival, particularly related to hot-water immersion, cold shock, cold-induced physical incapacitation, and fear of drowning.

Drowning is a leading cause of accidental death. Survivors may sustain severe neurologic morbidity. There is negligible research specific to brain injury in drowning making current clinical management non-specific to this disorder. This review represents an evidence-based consensus effort to provide recommendations for management and investigation of the drowning victim. Epidemiology, brain-oriented prehospital and intensive care, therapeutic hypothermia, neuroimaging/monitoring, biomarkers, and neuroresuscitative pharmacology are addressed. When cardiac arrest is present, chest compressions with rescue breathing are recommended due to the asphyxial insult. In the comatose patient with restoration of spontaneous circulation, hypoxemia and hyperoxemia should be avoided, hyperthermia treated, and induced hypothermia (32–34 °C) considered. Arterial hypotension/hypertension should be recognized and treated. Prevent hypoglycemia and treat hyperglycemia. Treat clinical seizures and consider treating non-convulsive status epilepticus. Serial neurologic examinations should be provided. Brain imaging and serial biomarker measurement may aid prognostication. Continuous electroencephalography and N20 somatosensory evoked potential monitoring may be considered. Serial biomarker measurement (e.g., neuron specific enolase) may aid prognostication. There is insufficient evidence to recommend use of any specific brain-oriented neuroresuscitative pharmacologic therapy other than that required to restore and maintain normal physiology. Following initial stabilization, victims should be transferred to centers with expertise in age-specific post-resuscitation neurocritical care. Care should be documented, reviewed, and quality improvement assessment performed. Preclinical research should focus on models of asphyxial cardiac arrest. Clinical research should focus on improved cardiopulmonary resuscitation, re-oxygenation/reperfusion strategies, therapeutic hypothermia, neuroprotection, neurorehabilitation, and consideration of drowning in advances made in treatment of other central nervous system disorders.

Objectives::: The aim of this qualitative, retrospective review is to identify and analyze the occurrence of recurrent problems in 20 processes that cover all relevant aspects of disaster health during the response phase. Consequently, an attempt is made to determine if there are generic themes of coherences in these problems.Methods::: Eight after-action reports of five consecutive disasters in the Netherlands, between 1996 and 2005, were integrally analyzed in a structured manner. The analysis was confined to processes from the start of the event up to and including the initial stages of hospital admission.Results::: Problems during all five disasters arose with eight processes: (1) submission of information to the ambulance dispatch center (ADC); (2) provision of information by the ADC to disaster response personnel; (3) scaling-up of prehospital response; (4) communication; (5) logistics; (6) registration; (7) multidisciplinary cooperation; and (8) preparation. Three generic themes of coherence were identified: (1) processes in which exchange of information among medical personal plays a major role are more likely to be affected by problems than processes in which this is less relevant; (2) processes in which disaster circumstances differ from day-to-day health care, or do not figure in day-to-day health care, are more likely to give rise to problems than processes that remain essentially similar; and (3) the existence of a protocol or disaster plan governing a process does not prevent problems.Conclusions::: The method used enables a systematic analysis of the problems in health-related processes following five consecutive disasters. The analysis confirms that the majority of problems are repeated. The identified themes of coherences are in agreement with case reports and expert opinions. They are now supported with a higher level of evidence.

Although drowning is a common phenomenon, the behaviour of drowning persons is poorly understood. The purpose of this study is to provide a quantitative and qualitative analysis of this behaviour. This was an observational study of drowning videos observed by 20 international experts in the field of water safety. For quantitative analysis, each video was analysed with Lince observation software by four participants. A Nominal Group Technique generated input for the qualitative analysis and the two principal investigators conducted a post-hoc analysis. A total of 87.5% of the 23 videos showed drowning in swimming pools, 50% of the drowned persons were male, and 58.3% were children or teenagers. Nineteen persons were rescued before unconsciousness and showed just the beginning of downing behaviour. Another five were rescued after unconsciousness, which allowed the observation of their drowning behaviour from the beginning to the end. Significant differences were found comparing both groups regarding the length of disappearances underwater, number, and length of resurfacing (resp. p = 0.003, 0.016, 0.005) and the interval from the beginning of the incident to the rescue (p = 0.004). All persons drowned within 2 min. The qualitative analysis showed previously suggested behaviour patterns (immediate disappearance n = 5, distress n = 6, instinctive drowning response n = 6, climbing ladder motion n = 3) but also a striking new pattern (backward water milling n = 19). This study confirms previous assumptions of drowning behaviour and provides novel evidence-based information about the large variety of visible behaviours of drowning persons. New behaviours, which mainly include high-frequency resurfacing during a struggle for less than 2 min and backward water milling, have been recognised in this study.

In many European countries prehospital care by emergency medical services (EMS) is supplemented by physician-staffed services. There is ongoing controversy on the benefits of a prehospital physician. Possible advantages are additional competencies of the physician. Similarities and differences in competencies of EMS providers and physicians have however never been studied. This study aims to compare competencies of ambulance nurses and helicopter EMS physicians in the Netherlands to gain better insight into the controversy of the prehospital physician. In this descriptive study, a quantitative inventory was made of the diagnostic, therapeutic, and clinical judgment competencies of the ambulance nurse and physician, based on analysis of protocols, registration, equipment, and personal interviews. We identified 438 mutual competencies of the ambulance nurse and physician and 62 physician-specific competencies. The ambulance nurse masters 278 diagnostic, 131 therapeutic, and 29 clinical judgment competencies. The physician masters 285 diagnostic, 175 therapeutic, and 40 clinical judgment competencies. Seventy-one percent of the physician-specific competencies are therapeutic and related to advanced life support. The ambulance nurse and physician have various mutual competencies. In addition, the physician can provide specific competencies on the scene. Knowing the exact overlap and differences in competencies is the first step to understand the prehospital physician controversy. Our results can be used as a tool for the next step in research on prehospital care by EMS providers and physicians and to improve prehospital care.