A5048355723- Cardiovascular and Diving-Related Complications
- High Altitude and Hypoxia
- Neuroscience of respiration and sleep
- Obstructive Sleep Apnea Research
- Cardiovascular and exercise physiology
- Spaceflight effects on biology
- Respiratory Support and Mechanisms
- Cardiac Arrest and Resuscitation
- Non-Invasive Vital Sign Monitoring
- Heart Rate Variability and Autonomic Control
- Nitric Oxide and Endothelin Effects
- Traumatic Brain Injury and Neurovascular Disturbances
- Sports Performance and Training
- Congenital Heart Disease Studies
- Cardiovascular Effects of Exercise
- Marine animal studies overview
- Climate Change and Health Impacts
- Exercise and Physiological Responses
- Muscle metabolism and nutrition
- Thermoregulation and physiological responses
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Hemodynamic Monitoring and Therapy
- Airway Management and Intubation Techniques
- Muscle and Compartmental Disorders
- Restraint-Related Deaths
Mid Sweden University
2016-2025
Östersunds Hospital
2014
Lund University
1995-2002
This study addressed the interaction between short-term adaptation to apneas with face immersion and erythrocyte release from spleen. Twenty healthy volunteers, including ten splenectomized subjects, participated. After prone rest, they performed five maximal-duration in 10°C water, 2-min intervals. Cardiorespiratory parameters venous blood samples were collected. In subjects spleens, hematocrit hemoglobin concentration increased by 6.4% 3.3%, respectively, over serial returned baseline 10...
This study addressed the effects of apnea in air and with face immersion cold water (10°C) on diving response arterial oxygen saturation during dynamic exercise. Eight trained breath-hold divers performed steady-state exercise a cycle ergometer at 100 W. During exercise, each subject 30-s apneas immersion. The heart rate decreased blood pressure increased apneas. Compared air, augmented reduction from 21 to 33% ( P < 0.001) increase 34 42% 0.05). eupneic control was 6.8% 5.2% results...
The effect of the diving response on alveolar gas exchange was investigated in 15 subjects. During steady-state exercise (80 W) a cycle ergometer, subjects performed 40-s apneas air and with face immersion cold (10 degrees C) water. Heart rate decreased blood pressure increased during apneas, responses were augmented by immersion. Oxygen uptake from lungs apnea (-22% compared eupneic control) further reduced (-25% control). plasma lactate concentration control (11%) after even more (20%),...
Humans share with e.g. seals the ability to contract spleen and increase circulating hematocrit, which may improve apneic performance by enhancing gas storage. Seals have large spleens while human size is small in comparison, it shows great individual variation. Unlike many marine mammals, divers rely a extent on lung oxygen stores, but impact of volume competitive apnea has never been determined. We studied if spleen- correlated elite divers. Volunteers were 14 male world championship...
Breath-hold diving performances are typically better in men than women. However, it is still being determined if there differences the physiological responses to breath-holding between sexes. We conducted a study comparing maximum breath-hold duration, heart rate (HR) reduction, peripheral oxygen saturation (SpO 2 ), and spleen volume contraction 37 44 women, all of whom had no prior experience. They performed two dry apneas separated by min; first was limited 60 s, followed maximal effort...
Three potentially protective responses to hypoxia have been reported be enhanced in divers: (1) the diving response, (2) blood‐boosting spleen contraction, and (3) a long‐term enhancement of hemoglobin concentration ( Hb ). Longitudinal studies, however, lacking except concerning response. Ten untrained subjects followed 2‐week training program with 10 maximal effort apneas per day, pre‐ posttraining measurements during three duration apneas, an additional post‐training series when apneic...
Abstract Purpose Hypoxia and exercise are known to separately trigger spleen contraction, leading release of stored erythrocytes. We studied volume hemoglobin concentration (Hb) during rest at three altitudes. Methods Eleven healthy lowlanders did a 5-min modified Harvard step test 1370, 3700 4200 m altitude. Spleen was measured via ultrasonic imaging capillary Hb with Hemocue after the test, arterial oxygen saturation (SaO 2 ), heart rate (HR), expiratory CO (ETCO ) respiratory (RR) across...
Hyperventilation before breath-hold diving (freediving) is widely accepted as a risk factor for hypoxic syncope or blackout (BO), but there no practical way to address it dives. This study explores the feasibility of using force sensor predict end-tidal carbon dioxide (P ETCO2) assess hyperventilation in freedivers. Twenty-one freedivers volunteered participate during two national competitions. The divers were instructed breathe normally and perform three dry apneas 1, 2, 3-min duration at...
Continuous measurements of haemodynamic and oxygenation changes in free living animals remain elusive. However, developments biomedical technologies may help to fill this knowledge gap. One such technology is continuous-wave near-infrared spectroscopy (CW-NIRS)—a wearable non-invasive optical technology. Here, we develop a marinized CW-NIRS system deploy it on elite competition freedivers test its capacity function during deep freediving 107 m depth. We use the oxyhaemoglobin...
The human spleen contracts in response to stress-induced catecholamine secretion, resulting a temporary rise haemoglobin concentration ([Hb]). Recent findings highlighted enhanced splenic exercise at high altitude Sherpa, possibly due blunted hypoxia. To explore the potential contraction Sherpas altitude, we examined changes volume during hyperoxic breathing, comparing acclimatized Sherpa with individuals of lowland ancestry. Our study included 14 non-Sherpa (7 female) residing for mean...
Abstract The human spleen acts as a reservoir for red blood cells, which is mobilized into the systemic circulation during various conditions such hypoxia and physical exertion. Cross-country (XC) skiers, renowned their exceptional aerobic capacity, are regularly exposed to high-intensity exercise local oxygen deficits. We investigated putative dose-dependent relationship between splenic contraction concomitant hemoglobin concentration ([Hb]) elevation across four intensities in well-trained...
Human splenic contraction occurs both during apnea and maximal exercise, increasing the circulating erythrocyte volume. We investigated hematological responses to 3 apneas performed by elite apneic divers, cross-country skiers, untrained subjects. Post-apnea hemoglobin concentration had increased in all groups, but especially divers. The increases disappeared within 10 min of recovery. Apneic duration across also most Responses divers could be more pronounced as a result training. Key words:...
Spleen contraction occurs in humans during exercise, apnea, and simulated altitude, resulting ejection of stored red blood cells into circulation. The mechanisms responsible for initiating the are not fully known: hypoxia is likely involved, but other, unknown factors may also contribute. To reveal factors, we studied its occurrence two different situations involving similar reductions arterial oxygen saturation (SaO2). We hypothesized that spleen responses would result if level main factor...