Hydration status during commercial saturation diving measured by bioimpedance and urine specific gravity (original) (raw)
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Prevalence of Inadequate Hydration Levels in Aquatic Safety Personnel: A Pilot Study
International Journal of Aquatic Research and Education, 2015
Lifeguards play an important role in the security and safety of those they are hired to protect. A performance issue may arise if they succumb to circumstances that cause them to become physically or psychologically compromised. Dehydration is one issue that can result in decreased levels of workplace performance and pose personal health risks. Certified lifeguards 15 years old and older were tested for urine specific gravity (USG) to determine their place within the dehydration spectrum. Participants (N = 55) were recruited from seven test sites offering a variety of designs (indoor/outdoor, traditional/waterpark) and classifications (private, semipublic, public). Testing involved the collection of a urine specimen from participants and immediate recording of specific gravity using a reagent test strip by researchers. A brief survey to collect demographic information from subjects was also administered. The majority of participants were found to reside along the dehydration spectrum (USG ≥ 1.015), several showing results toward the severe end of the scale. The sample provided adequate demographic variability among males and females and facility classification types. No statistically significant differences were found between the demographic variables and USG scores of subjects. Since the majority of lifeguards in the sample showed some level of dehydration, this indicated a need for more information concerning lifeguards and dehydration. Despite the lack of statistically significant differences among the demographic factors within this sample, future studies should incorporate other behavioral factors and dehydration testing methods to investigate the mechanisms for preventing dehydration as well as its impact on lifeguarding performance.
Thermal and metabolic responses of military divers during a 6-hour static dive in cold water
Aviation, space, and environmental medicine, 2014
Human thermal responses during prolonged whole-body immersion in cold water are of interest for the military, especially French SEALS. This study aims at describing the thermo-physiological responses. There were 10 male military divers who were randomly assigned to a full immersion in neutral (34 degrees C), moderately cold (18 degrees C), and cold (10 degrees C) water wearing their operational protective devices (5.5 mm wetsuit with 3.0 mm thick underwear) for 6 h in a static position. Rectal temperature (T(re)) and 14 skin temperatures (T(sk)), blood analysis (stress biomarkers, metabolic substrates), and oxygen consumption (Vo2) were collected. At 34 degrees C, there were no significant modifications of the thermo-physiological responses over time. The most interesting result was that rates of rectal temperature decrease (0.15 +/- 0.02 degrees C x min(-1)) were the same between the two cold stress experimental conditions (at 18 degrees C and 10 degrees C). At the final experiment...
Preventive effect of pre-dive hydration on bubble formation in divers
British Journal of Sports Medicine, 2009
Objective: To investigate whether prehydration 90 min before a dive could decrease bubble formation, and to evaluate the consequent adjustments in plasma volume (PV), water balance and plasma surface tension (ST). Methods: Eight military divers participated in a crossover trial of pre-dive hydration using saline-glucose beverage (protocol 1) and a control dive with no prehydration (protocol 2). Drink volume was 1300 ml (osmolality 324 mOsm/l) and drinking time was 50-60 min. The diving protocol consisted of an open sea field air dive at 30 msw depth for 30 min followed by a 9 min stop at 3 msw. Haemodynamic parameters, body weight measurements, urine volume and blood samples were taken before/after fluid intake and after the dive. Decompression bubbles were examined by a precordial pulsed Doppler. Results: Bubble activity was significantly lower for protocol 1 than for protocol 2. PV increased after fluid ingestion by 3.5% and returned toward baseline after diving for protocol 1, whereas it decreased by 2.2% after diving for protocol 2. Differences in post-dive PV between the two conditions were highly significant. Body weight loss before/after diving and post-dive urine volume after diving were significant in both protocols, but the relative decline in weight remained lower for protocol 1 than for protocol 2, with reduction of negative water balance due to higher fluid retention. There were no differences in ST after fluid intake and after diving for the two protocols. Conclusion: Pre-dive oral hydration decreases circulatory bubbles, thus offering a relatively easy means of reducing decompression sickness risk. The prehydration condition allowed attenuation of dehydration and prevention of hypovolaemia induced by the diving session. Hydration and diving did not change plasma surface tension in this study.
Hydration Status of Lifesaving Athletes During International Competition
This study investigated the hydration status of lifesaving athletes in situ during an international competition. Participants were 10 lifesaving athletes (6 male and 4 female) competing in pool-and ocean-based competition across three consecutive days. Assessment included upon-waking urine samples and body mass across 7 days including travel, training and competition days. Urine specific gravity was significantly lower while traveling compared with predeparture (p < .05). There were no gender differences for sweat rates, body mass changes, fluids consumed, or percentage dehydration during the training sessions (p > .05). Sweat rates were higher than previously reported and there were no significant differences identified for daily body mass changes (p > .05). The results of the current study found that lifesaving athletes were capable of maintaining favorable hydration status throughout the course of an international lifesaving event held in hot and humid conditions.
The Underestimated Compression Effect of Neoprene Wetsuit on Divers Hydromineral Homeostasis
International Journal of Sports Medicine
This study aimed at demonstrating that the neoprene wetsuit provides not only thermal protection. Compression it exerts on the diver's shell significantly impacts hydromineral homeostasis by restraining the systemic vascular capacity and secondarily increasing urine output on dry land and during scuba diving. 8 healthy divers underwent five 2-h sessions: sitting out of water in trunks (control situation), sitting out of water wearing a wetsuit, and 3 wetsuit scuba-immersed sessions at 1, 6 and 12 msw depth, respectively. Urine volumes and blood samples were collected. Hemoglobin (Hb), hematocrit (Ht) and plasma sodium concentration were measured. Interface pressure between the garment and the skin was measured at 17 sites of the body shell, with a pressure transducer. Mean interface pressures between wetsuit and skin amounted to: 25.8±2.8 mm Hg. Whatever the depth, elastic recoil tension of wetsuit material was unchanged by immersion. Weight loss was respectively 2 and 3 times g...
Comparative data from 2250 male and female sports divers: diving patterns and decompression sickness
Aviation, space, and environmental medicine, 2002
The aim of the study was to compare the diving habits and histories of men and women in recreational scuba diving. More than 10,000 questionnaires were circulated to recreational divers in the United Kingdom. Retrospective, broad-based information was requested concerning general health, smoking, alcohol, recreational drug use, diving habits and histories, and physician-confirmed and self-diagnosed episodes of decompression sickness (DCS). Data relating only to women were also gathered. Questionnaires were anonymous. Over four years, 2250 divers responded, 47% of whom were women. Of the 458,827 dives reported, 310% were by women. Differences in diving habits were observed between men and women, which included number of dives per annum, maximum depths dived, and dives with extra stops. When the level of experience was taken into account in this study group, the estimated rate of DCS in men was 2.60 times greater than for women. In this study, comparison between men and women in recre...
Frontiers in Physiology, 2019
Introduction: When divers are compressed to water depths deeper than 150 meter sea water (msw), symptoms of high-pressure neurological syndrome (HPNS) might appear due to rapid increase in pressure on the central nervous system during compression. The aim of this study was to first operate a new computerized tool, designed to monitor divers' wellbeing and cognitive function, and to record the results. The second aim was to evaluate the feasibility and validity of the Physiopad software and HPNS questionnaires as a new tool for monitoring divers wellbeing in an operational setting, including sensible visualization and presentation of results. Methods: The Physiopad was operated onboard Deep Arctic (TechnipFMC Diving Support Vessel). The diving work was performed between 180 and 207 msw. The data from 46 divers were collected from the HPNS questionnaires, Hand dynamometry test, Critical Flicker Fusion Frequency test (CFFF), Adaptive Visual Analog Scale (AVAS), Simple Math Process (MathProc test), Perceptual Vigilance Task (PVT), and Time Estimation Task (time-wall). Result: Diver's subjective evaluation revealed different symptoms, possibly also HPNS related, which lasted from 1 to 5 days in storage, with the common duration being 1 day. The results from Physiopad battery testing showed no signs of significant neurological alteration. Conclusion: The present study showed that there was no association between subjective measurements of HPNS and neuropsychometric test results. We also confirmed the feasibility of using the computerized test battery to monitor saturation divers at work. The HPNS battery and Physiopad software could be an important tool for monitoring diver's health in the future. This tool was not used during the Bahr Essalam project to operationally evaluate any HPNS effect on divers as data analysis was performed post-project.
Malaysian Journal of Nursing
Background: Diving activities have a risk of disease called decompression sickness. One of the risks for the incidence of decompression sickness is the number of hours of diving and diving experience. This study aims to analyze the number of dives in a week and the experience of diving on the occurrence of decompression sickness. Methods: The study used an observational analytic design with a cross-sectional approach, involving 66 divers as research samples taken by simple random sampling. Data were collected using questionnaires and observations of divers' health status to see the incidence of decompression in divers. Data were analyzed using logistic regression with a significance value of P<0.05. Results: The results showed that the number of hours of diving in one week, and diving experience influenced the incidence of decompression sickness experienced by divers (p<0.05). The results of the regression test showed an Exp (B) value of 10,540 for the number of dives in a...
Frontiers in Physiology, 2021
Deep freediving exposes humans to hypoxia and dramatic changes in pressure. The effect of depth on gas exchange may enhance risk of hypoxic blackout (BO) during the last part of the ascent. Our aim was to investigate arterial oxygen saturation (SpO2) and heart rate (HR) in shallow and deep freedives, central variables, which have rarely been studied underwater in deep freediving. Four male elite competitive freedivers volunteered to wear a newly developed underwater pulse oximeter for continuous monitoring of SpO2 and HR during self-initiated training in the sea. Two probes were placed on the temples, connected to a recording unit on the back of the freediver. Divers performed one “shallow” and one “deep” constant weight dive with fins. Plethysmograms were recorded at 30 Hz, and SpO2 and HR were extracted. Mean ± SD depth of shallow dives was 19 ± 3 m, and 73 ± 12 m for deep dives. Duration was 82 ± 36 s in shallow and 150 ± 27 s in deep dives. All divers desaturated more during dee...