A5038350424- High Altitude and Hypoxia
- Neuroscience of respiration and sleep
- Traumatic Brain Injury and Neurovascular Disturbances
- Heart Rate Variability and Autonomic Control
- Obstructive Sleep Apnea Research
- Climate Change and Health Impacts
- Cardiac Arrest and Resuscitation
- Cardiovascular and Diving-Related Complications
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Respiratory Support and Mechanisms
- Hemodynamic Monitoring and Therapy
- Ultrasound in Clinical Applications
- Nasal Surgery and Airway Studies
- Blood Pressure and Hypertension Studies
- Mechanical Circulatory Support Devices
- Infection Control and Ventilation
- Head and Neck Surgical Oncology
- Blood disorders and treatments
- Cardiovascular Health and Disease Prevention
- Peripheral Artery Disease Management
- Traumatic Brain Injury Research
- Thermoregulation and physiological responses
- Congenital Diaphragmatic Hernia Studies
- Glaucoma and retinal disorders
- Thermal Regulation in Medicine
University of British Columbia
2023-2025
Vancouver General Hospital
2024-2025
Mount Royal University
2019-2024
Poole Hospital
2024
Okanagan University College
2023
What is the central question of this study? relative contribution a putative tonic splenic contraction to haematological acclimatization process during high altitude ascent in native lowlanders? main finding and its importance? Spleen volume decreased by -14.3% (-15.2 ml) per 1000 m ascent, with an attenuated apnoea-induced [Hb] increase, attesting ascent. The [Hb]-enhancing function may contribute restoring oxygen content early at altitude.Voluntary apnoea causes reductions heart rate (HR;...
Abstract High altitude (HA) ascent imposes systemic hypoxia and associated risk of acute mountain sickness. Acute elicits a hypoxic ventilatory response (HVR), which is augmented with chronic HA exposure (i.e., acclimatization; VA). However, laboratory‐based HVR tests lack portability feasibility in field studies. As an alternative, we aimed to characterize area under the curve (AUC) calculations on Fenn diagrams, modified by plotting portable measurements end‐tidal carbon dioxide () against...
Despite the known interplay between blood flow and function, to our knowledge, there is currently no minimally invasive method monitor diaphragm hemodynamics. We used contrast-enhanced ultrasound quantify relative (Q˙
Rapid ascent to high altitude imposes an acute hypoxic and acid-base challenge, with ventilatory renal acclimatization countering these perturbations. Specifically, improves oxygenation, but concomitant hypocapnia respiratory alkalosis. A compensatory, renally mediated relative metabolic acidosis follows via bicarbonate elimination, normalizing arterial pH(a). The time course magnitude of integrated processes are highly variable between individuals. Using a previously developed metric...
Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides surrogate for cerebral microvasculature, offering potential insight into in critical illness. In addition, although sex-specific differences cardiovascular diseases are strongly supported, few have focused on ocular blood flow. We evaluated males (n = 11) and females 7) using functional optical coherence tomography baseline (1,130 m) (day 0),...
Anecdotal reports suggest mild physiological effects of wearing surgical masks and/or N95 respirators, including heat trapping and rebreathing expired air. There are limited data directly comparing the medical barriers at rest. We found that time course magnitude changes to face microclimate temperature, end-tidal gases, venous blood gases acid-base variables were in magnitude, not physiologically relevant, equivalent between barrier types, immediately reversible on removal.
Oscillatory patterns in arterial pressure and blood flow (at ∼0.1 Hz) may protect tissue oxygenation during conditions of reduced cerebral perfusion and/or hypoxia. We hypothesized that inducing oscillations at 0.1 Hz would oxygen saturation exposure to a combination simulated hemorrhage sustained hypobaric
What is the central question of this study? We assessed utility a new metric for quantifying ventilatory acclimatization to high altitude, derived from differential ascent and descent steady-state cardiorespiratory variables (i.e. hysteresis). Furthermore, we aimed investigate whether magnitude hysteresis was associated with development acute mountain sickness. main finding its importance? Hysteresis in quantifies altitude. The during altitude significantly related symptoms chemoreflex drive...
Central sleep apnea (CSA) is universal during ascent to high altitude, with intermittent and transient fluctuations in oxygen saturation, but the consequences on mean sleeping blood oxygenation are unclear. We assessed indices of CSA peripheral saturation ([Formula: see text]) altitude using two profiles: rapid residence at 3,800 m incremental 5,160 m. The severity was not correlated [Formula: text] ascent.
Central sleep apnea (CSA) is pervasive during at high altitude, disproportionately impacting men and associated with increased peripheral chemosensitivity.
Lowlander, Andean, and Sherpa arterial blood data were combined across five independent high-altitude expeditions in the United States, Nepal, Peru to assess acid-base status at ∼3,800, ∼4,300, ∼5,000 m. The main finding was that Andean highlander populations have more acidic blood, due elevated carbon dioxide similar bicarbonate compared with acclimatizing lowlanders altitudes ≥4,300
Summary Use of high‐flow nasal oxygen to enable apnoeic oxygenation during tubeless airway surgery is well‐established. The use an ignition source in this oxygen‐rich environment increases the risk surgical fire. We present a case facial fire secondary carbon dioxide laser and procedure for subglottic stenosis. incident occurred when was being tested near patient, resulting superficial burns patient's face neck. unaffected were managed conservatively. This highlights important safety...
Background: High altitude sojourn challenges blood flow regulation in the brain, which may contribute to cognitive dysfunction. Neurovascular coupling (NVC) describes ability increase working regions of brain. Effects high on NVC frontal undergoing activation are unclear but be relevant executive function high-altitude hypoxia. This study sought examine effect incremental ascent very by measuring anterior cerebral artery (ACA) and middle (MCA) hemodynamic responses sustained activity....
Introduction: Inducing 0.1 Hz (10-s cycle) oscillations in cerebral blood flow attenuates the reduction tissue oxygenation during simulated hemorrhage humans. It is unknown, however, how stiffness of feed arteries influences magnitude oscillations, and/or protection oxygenation. When are induced hemorrhage, we hypothesize that: 1) arterial internal carotid artery (ICA) will increase from rest; 2) amplitude be higher individuals with stiffer arteries, and; 3) smaller oscillations. Methods: 8...
Obstructive sleep apnea (OSA) affects over a third of North Americans and is characterized by intermittent bouts hypoxia combined with hypercapnia during sleep. Intermittent hypercapnic can elicit long-lasting increases in ventilation, blood pressure, sympathetic nerve activity humans may underpin elevated daytime observed OSA patients (i.e., long-term facilitation; LTF). Although cardiorespiratory plasticity to are well studied, it unknown if (IHc) the absence leads humans. This study aimed...