RESUMO
Divers who wish to prolong their time underwater while carrying less equipment often use devices called rebreathers, which recycle the gas expired after each breath instead of discarding it as bubbles. However, rebreathers' need to replace oxygen used by breathing creates a failure mechanism that can and frequently does lead to hypoxia, loss of consciousness, and death. The purpose of this study was to determine whether a pulse oximeter could provide a useful amount of warning time to a diver with a rebreather after failure of the oxygen addition mechanism. Twenty-eight volunteer human subjects breathed on a mixed-gas rebreather in which the oxygen addition system had been disabled. The subjects were immersed in water in four separate environmental scenarios, including cold and warm water, and monitored using pulse oximeters placed at multiple locations. Pulse oximeters placed on the forehead and clipped on the nasal ala provided a mean of 32 s (±10 s SD) of warning time to divers with falling oxygen levels, prior to risk of loss of consciousness. These devices, if configured for underwater use, could provide a practical and inexpensive alarm system to warn of impending loss of consciousness in a manner that is redundant to the rebreather.
Assuntos
Mergulho/efeitos adversos , Oxigenoterapia Hiperbárica/efeitos adversos , Hipóxia/prevenção & controle , Monitorização Fisiológica/instrumentação , Oximetria/instrumentação , Adulto , Falha de Equipamento , Humanos , Hipóxia/etiologia , Masculino , RespiraçãoRESUMO
Immersion pulmonary edema, more commonly referred to as swimming-induced pulmonary edema (SIPE), is a well-documented condition believed to be a result of immersion physiologic condition that is characterized by a peripheral-to-central redistribution of blood volume. It disproportionally affects young, healthy athletes with no clinically overt cardiovascular or pulmonary conditions. We present four cases of healthy athletes with previously documented SIPE, who participated in Institutional Review Board-approved clinical studies that examined the pathophysiologic condition and prevention of SIPE. During standard recumbent echocardiography, trivial mitral regurgitation was observed in all four individuals. Acute exacerbation of their mitral regurgitation was observed during immersion with both immersed resting and immersed exercise echocardiography, contributing to the development of SIPE. These observations demonstrate that the occurrence of subclinical or trivial mitral valve regurgitation during dry rest is a novel risk factor for SIPE. We propose the use of immersion echocardiography as a useful investigative tool for otherwise healthy individuals with SIPE and no previously explainable cause.
Assuntos
Insuficiência da Valva Mitral , Edema Pulmonar , Humanos , Imersão/efeitos adversos , Insuficiência da Valva Mitral/diagnóstico , Insuficiência da Valva Mitral/etiologia , Edema Pulmonar/diagnóstico por imagem , Edema Pulmonar/etiologia , Fatores de Risco , Natação/fisiologiaRESUMO
Snakebite envenomings (SBEs) and other envenomings triggered by venomous animals (VAEs) represent a significant disease burden in Brazil, with 29,152 SBEs reported in 2021 alone with nearly half of those occurring in the remote Brazilian Amazon. In 2021, Brazil recorded 240,294 envenomings from snakes, scorpions, spiders, and caterpillars. Therefore, there is an unequal distribution of SBEs with high morbidity and mortality in the Brazilian Amazon. The severity of SBEs increases when patients require more than 6 h to access antivenom treatment, a common issue for the rural and indigenous populations. Understanding currently available resources and practices in Amazon remote areas of Brazil can serve to inform future interventions and guide health care policies. This study aims to develop a resource map of existing healthcare resources for the Brazilian Amazon's clinical management of VAEs with emphasis in SBEs, which will aid future strategic interventions. Data collection included a literature review, secondary data collected by government departments and organizational records, GIS mapping activities, and expert input. Our framework was guided by the three levels of healthcare service ecosystem analysis (macro, meso, and micro). Our resource map lays out a comprehensive overview of antivenom access, the distribution landscape, differences in patient transportation, and barriers to access healthcare that face populations in the Brazilian Amazon.