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Respiratory Care Oct 2014Oxygen is essential for normal aerobic metabolism in mammals. Hypoxia is the presence of lower than normal oxygen content and pressure in the cell. Causes of hypoxia... (Review)
Review
Oxygen is essential for normal aerobic metabolism in mammals. Hypoxia is the presence of lower than normal oxygen content and pressure in the cell. Causes of hypoxia include hypoxemia (low blood oxygen content and pressure), impaired oxygen delivery, and impaired cellular oxygen uptake/utilization. Many compensatory mechanisms exist at the global, regional, and cellular levels to allow cells to function in a hypoxic environment. Clinical management of tissue hypoxia usually focuses on global hypoxemia and oxygen delivery. As we move into the future, the clinical focus needs to change to assessing and managing mission-critical regional hypoxia to avoid unnecessary and potential toxic global strategies. We also need to focus on understanding and better harnessing the body's own adaptive mechanisms to hypoxia.
Topics: Adaptation, Physiological; Humans; Hypoxia; Oxygen; Oxygen Inhalation Therapy
PubMed: 25161296
DOI: 10.4187/respcare.03357 -
Respiratory Care Jul 2021Hypoxemia is common in postoperative patients and is associated with prolonged hospital stays, high costs, and increased mortality. This review discusses the... (Review)
Review
Hypoxemia is common in postoperative patients and is associated with prolonged hospital stays, high costs, and increased mortality. This review discusses the postoperative management of hypoxemia in regard to the use of conventional oxygen therapy, high-flow nasal cannula oxygen therapy, CPAP, and noninvasive ventilation. The recommendations made are based on the currently available evidence.
Topics: Cannula; Continuous Positive Airway Pressure; Humans; Hypoxia; Noninvasive Ventilation; Oxygen; Oxygen Inhalation Therapy
PubMed: 34006596
DOI: 10.4187/respcare.08929 -
Nature Reviews. Drug Discovery Mar 2024Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that are crucial for adaptation of metazoans to limited oxygen availability. Recently, HIF... (Review)
Review
Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that are crucial for adaptation of metazoans to limited oxygen availability. Recently, HIF activation and inhibition have emerged as therapeutic targets in various human diseases. Pharmacologically desirable effects of HIF activation include erythropoiesis stimulation, cellular metabolism optimization during hypoxia and adaptive responses during ischaemia and inflammation. By contrast, HIF inhibition has been explored as a therapy for various cancers, retinal neovascularization and pulmonary hypertension. This Review discusses the biochemical mechanisms that control HIF stabilization and the molecular strategies that can be exploited pharmacologically to activate or inhibit HIFs. In addition, we examine medical conditions that benefit from targeting HIFs, the potential side effects of HIF activation or inhibition and future challenges in this field.
Topics: Humans; Basic Helix-Loop-Helix Transcription Factors; Hypoxia; Transcription Factors; Neoplasms; Oxygen
PubMed: 38123660
DOI: 10.1038/s41573-023-00848-6 -
American Journal of Physiology.... Nov 2014Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in... (Review)
Review
Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in multiple physiological systems. Here, we review the extensive literature concerning IH and its impact on the respiratory, cardiovascular, immune, metabolic, bone, and nervous systems. One major goal is to define relevant IH characteristics leading to safe, protective, and/or therapeutic effects vs. pathogenesis. To understand the impact of IH, it is essential to define critical characteristics of the IH protocol under investigation, including potentially the severity of hypoxia within episodes, the duration of hypoxic episodes, the number of hypoxic episodes per day, the pattern of presentation across time (e.g., within vs. consecutive vs. alternating days), and the cumulative time of exposure. Not surprisingly, severe/chronic IH protocols tend to be pathogenic, whereas any beneficial effects are more likely to arise from modest/acute IH exposures. Features of the IH protocol most highly associated with beneficial vs. pathogenic outcomes include the level of hypoxemia within episodes and the number of episodes per day. Modest hypoxia (9-16% inspired O2) and low cycle numbers (3-15 episodes per day) most often lead to beneficial effects without pathology, whereas severe hypoxia (2-8% inspired O2) and more episodes per day (48-2,400 episodes/day) elicit progressively greater pathology. Accumulating evidence suggests that "low dose" IH (modest hypoxia, few episodes) may be a simple, safe, and effective treatment with considerable therapeutic potential for multiple clinical disorders.
Topics: Animals; Bone and Bones; Cardiovascular System; Humans; Hypoxia; Inflammation; Nervous System; Oxygen; Respiratory System; Time Factors
PubMed: 25231353
DOI: 10.1152/ajpregu.00208.2014 -
Journal of Cardiothoracic and Vascular... Oct 2018
Review
Topics: Global Health; Humans; Hypoxia; Incidence; Intraoperative Complications; Lung Diseases; One-Lung Ventilation; Thoracic Surgical Procedures
PubMed: 29361458
DOI: 10.1053/j.jvca.2017.12.026 -
Kardiologia Polska Jun 2019High altitude is a fascinating model of hypoxia effects on the human body but is also an extreme environment which directly influences millions of people who either... (Review)
Review
High altitude is a fascinating model of hypoxia effects on the human body but is also an extreme environment which directly influences millions of people who either travel to high altitude locations or live there permanently. A significant progress was made over the past decades in the understanding of physiological background of responses to altitude, and recently a number of studies regarding clinical aspects of high altitude exposure were published. In particular, more is known about the changes occurring in systemic blood pressure in individuals exposed to high altitude as well as on the effects of antihypertensive drugs in this setting. The present article provides an overview of principal physiological and clinical aspects related to systemic blood pressure control and its changes at high altitude, mainly during the acute exposure. The evidence on blood pressure changes at rest and during exercise is discussed, as well as the underlying mechanisms and possible clinical implications.
Topics: Altitude; Altitude Sickness; Antihypertensive Agents; Atmospheric Pressure; Blood Pressure; Humans; Hypertension; Hypoxia
PubMed: 31099758
DOI: 10.33963/KP.14832 -
Experimental Neurology Feb 2022
Topics: Animals; Humans; Hypoxia; Neuronal Plasticity; Reactive Oxygen Species; Time Factors
PubMed: 34955452
DOI: 10.1016/j.expneurol.2021.113951 -
Anesthesia and Analgesia May 2023Critically injured patients who are agitated and delirious on arrival do not allow optimal preoxygenation in the emergency area. We investigated whether the... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Critically injured patients who are agitated and delirious on arrival do not allow optimal preoxygenation in the emergency area. We investigated whether the administration of intravenous (IV) ketamine 3 minutes before administration of a muscle relaxant is associated with better oxygen saturation levels while intubating these patients.
METHODS
Two hundred critically injured patients who required definitive airway management on arrival were recruited. The subjects were randomized as delayed sequence intubation (group DSI) or rapid sequence intubation (group RSI). In group DSI, patients received a dissociative dose of ketamine followed by 3 minutes of preoxygenation and paralysis using IV succinylcholine for intubation. In group RSI, a 3-minute preoxygenation was performed before induction and paralysis using the same drugs, as described conventionally. The primary outcome was incidence of peri-intubation hypoxia. Secondary outcomes were first-attempt success rate, use of adjuncts, airway injuries, and hemodynamic parameters.
RESULTS
Peri-intubation hypoxia was significantly lower in group DSI (8 [8%]) compared to group RSI (35 [35%]; P = .001). First-attempt success rate was higher in group DSI (83% vs 69%; P = .02). A significant improvement in mean oxygen saturation levels from baseline values was seen in group DSI only. There was no incidence of hemodynamic instability. There was no statistically significant difference in airway-related adverse events.
CONCLUSIONS
DSI appears promising in critically injured trauma patients who do not allow adequate preoxygenation due to agitation and delirium and require definitive airway on arrival.
Topics: Humans; Ketamine; Rapid Sequence Induction and Intubation; Intubation, Intratracheal; Triage; Hypoxia; Paralysis
PubMed: 37058727
DOI: 10.1213/ANE.0000000000006171 -
Ugeskrift For Laeger Dec 2023Home oxygen therapy is an acknowledged treatment for patients suffering from chronic hypoxaemia, due to pulmonary or cardiac disease, and may have positive effects on... (Review)
Review
Home oxygen therapy is an acknowledged treatment for patients suffering from chronic hypoxaemia, due to pulmonary or cardiac disease, and may have positive effects on survival and quality of life. The risks and side effects of the treatment are usually mild, and the equipment has developed to become relatively affordable, accessible and easy to transport. Adjustments in the oxygen settings can be necessary when travelling by airplane or during physical effort or sleep. Prescription and follow-ups are usually best maintained by hospital departments with expertise in pulmonary medicine, as argued in this review.
Topics: Humans; Quality of Life; Oxygen Inhalation Therapy; Lung; Oxygen; Denmark; Hypoxia
PubMed: 38078470
DOI: No ID Found -
Ugeskrift For Laeger Nov 2022Oxygen is a standard treatment for patients with chronic lung diseases and hypoxemia. The two main groups of lung diseases leading to oxygen treatment is chronic... (Review)
Review
Oxygen is a standard treatment for patients with chronic lung diseases and hypoxemia. The two main groups of lung diseases leading to oxygen treatment is chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Several guidelines for home oxygen therapy for patients with ILD is, however, based on older observation and extrapolations from studies on COPD. This review focuses on the different oxygen treatment modalities for patients with ILD focusing on present evidence and upcoming trials that might change the oxygen therapy approach for patients with ILD.
Topics: Humans; Oxygen Inhalation Therapy; Lung Diseases, Interstitial; Pulmonary Disease, Chronic Obstructive; Oxygen; Hypoxia
PubMed: 36426814
DOI: No ID Found