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Topic: Oxygen toxicity

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In the News (Wed 17 Jul 19)

  Oxygen - Wikipedia, the free encyclopedia
The atmospheric abundance of free oxygen in later geological epochs and up to the present has been largely driven by photosynthetic organisms, roughly three quarters by phytoplankton and algae in the oceans and one quarter from terrestrial plants.
Oxygen is a major component of air, produced by plants during photosynthesis, and is necessary for aerobic respiration in animals.
Oxygen is used in welding (such as the oxyacetylene torch), and in the making of steel and methanol.
en.wikipedia.org /wiki/Oxygen   (1211 words)

 Pulmonary and Critical Care Unit
Oxygen is a valuable therapeutic agent in treatment of respiratory and cardiovascular disorders.
The toxicity of oxygen is presumed to occur because of increased generation of reactive oxygen radicals which attack and modify cellular macromolecules including lipids, proteins, and nucleic acids.
Reactive oxygen species can attack both the phospho-diester backbone of DNA (leading to strand breaks) as well as the nitrogenous bases (leading to potentially mutagenic base alterations), but it is not clear which, if either, of these effects occurs in the native lung.
www.mgh.harvard.edu /pulmonarycare/research/dnadamage.html   (320 words)

 Oxygen toxicity
PO toxicity occurs when the diver is exposed to elevated levels oxygen for several hours.
PO toxicity manifests itself after the diver is exposed (12 hours or more) to relatively low levels of partial oxygen pressures (pO2), 0.6 ATA (atmospheres absolute) and up.
PO toxicity is not a serious problem since it is difficult to expose oneself to oxygen long enough for this to become a real problem.
members.tripod.com /tjaartdb0/html/oxygen_toxicity.html   (524 words)

 [No title]   (Site not responding. Last check: 2007-11-07)
Oxygen toxicity is precisely what it suggests; oxygen poisoning the human body.
Oxygen compatible refers to the materials comprising the equipment which is intended for use with pure oxygen.
Note that describing a material as oxygen compatible does not mean that the material is ready for use with pure oxygen, merely that the material itself is suitable, if properly prepared, for use with pure oxygen (see question [16]).
www.aquanaut.com /misc/nitrox.txt   (5488 words)

 Oxygen Bars: Is a Breath of Fresh Air Worth It?
Since oxygen bars were introduced in the United States in the late 1990s, the trend has caught on, and customers are bellying up to bars around the country to sniff oxygen through a plastic hose (cannula) inserted into their nostrils.
Although oxygen bars that dispense oxygen without a prescription violate FDA regulations, the agency applies regulatory discretion to permit the individual state boards of licensing to enforce the requirements pertaining to the dispensing of oxygen, says Szymanski.
Oxygen fans tout the benefits of oxygen as reducing stress, increasing energy and alertness, lessening the effects of hangovers, headaches, and sinus problems, and generally relaxing the body.
www.fda.gov /fdac/features/2002/602_air.html   (1275 words)

 Virtual Naval Hospital: United States Naval Flight Surgeon Manual: Third Edition 1991: Chapter 1: Oxygen Toxicity   (Site not responding. Last check: 2007-11-07)
The amounts of oxygen and oxygen partial pressures breathed by aviation personnel are usually not great enough to cause significant harm to the body.
Pulmonary oxygen toxicity can progress to a point where hypoxia can result in death unless the alveolar oxygen pressure is elevated to increase the oxygen diffusion gradient to elevate the arterial oxygen pressure.
The hypotension produced by the restoration of oxygen is probably due to vasodilation, which occurs by the direct action of oxygen on the pulmonary vascular bed.
www.vnh.org /FSManual/01/10OxygenToxic.html   (1321 words)

 Oxygen Therapy For Diving Accidents: At Atmospheric and Hyperbaric Pressure
Oxygen is also the most widely prescribed "drug" in hospitals; about a quarter of all patients entering an acute care hospital will receive inhaled oxygen at some point in their stay.
The actual percentage of oxygen delivered is determined by the type of appliance used to bring the pure oxygen from the wall source to the patient's face, e.g., nasal prongs or various types of face mask.
Oxygen pressure directly reflects the pressure of inhaled oxygen, and is due solely to the unbound (dissolved) fraction of oxygen in the blood; it is the same value regardless of the hemoglobin content.
www.lakesidepress.com /pulmonary/books/scuba/sectionh.htm   (6305 words)

 Humidity does not affect central nervous system oxygen toxicity -- Arieli and Moskovitz 91 (3): 1327 -- Journal of ...
Lin and Jamieson (10) suggested that humidity shortens the latency to CNS oxygen toxicity.
and latency to CNS oxygen toxicity at 507 or 608 kPa.
The presence of CO in the inspired oxygen reduces latency to CNS oxygen toxicity linearly with the increase in P
jap.physiology.org /cgi/content/full/91/3/1327   (3521 words)

 First Responder Concerns About Oxygen Toxicity
Oxygen is a primary component in the biochemical reactions that sustain life.
Problems, like CNS oxygen toxicity, occur when the amount of this “bad stuff” formed exceeds the body’s capacity to deactivate this "bad stuff." Le Chatelier’s principle (an increase in one of the components on the left side of a chemical reaction will force the reaction process to the right).
I believe the relative concerns are about oxygen toxicity can be best expressed by looking at some computer-generated numbers, with the understanding that different computer programs may give slightly different absolute values for the numbers quoted.
www.mindspring.com /~divegeek/oxyconcern.htm   (1844 words)

 Pulmonary Response to Hyperoxia: Effects of Magnesium   (Site not responding. Last check: 2007-11-07)
In a model of hyperoxic lung injury, rats were exposed to 100% oxygen for 48, 64, and 96 hr and several experiments were performed.
Oxygen concentrations in the chamber were monitored using an oxygen analyzer (Model 04066, Instrumentation Lab, Lexington, MA).
Pulmonary hyperoxic injury was induced in 26 rats by exposure to 100% oxygen for 48 hr.
ehp.niehs.nih.gov /members/1994/Suppl-10/dedhia-full.html   (3622 words)

 eMedicine - Hyperbaric Oxygen Therapy : Article by Michael Neumeister, MD, FRCSC, FACS   (Site not responding. Last check: 2007-11-07)
A distinct correlation between the number of treatments and oxygen toxicity is not apparent, but rather the duration of the treatments (ie, >2 h) and the patient's susceptibility appear to be related to toxicity.
Oxygen is required for angiogenesis (which is fostered by the increased oxygen gradient), collagen deposition, re-epithelialization, cellular respiration, and oxidative killing of bacteria.
Oxygen free radicals rise, thromboxane A2 and adhesion molecules are activated, platelet aggregation occurs, and vascular vasoconstriction activity is increased.
www.emedicine.com /plastic/topic526.htm   (5864 words)

 UpToDate Oxygen toxicity
— The potential toxicity of oxygen was appreciated soon after its discovery by Priestly in the late 18th century [1].
Oxygen free radicals may also promote a deleterious inflammatory response, leading to secondary tissue damage and/or apoptosis [9-11].
Lung tissue is exposed to the highest concentrations of oxygen in the body, placing cells that line the tracheobronchial tree and alveoli at the greatest risk for hyperoxic cytotoxicity [15].
patients.uptodate.com /topic.asp?file=cc_medi/20009   (491 words)

 Adverse Effects of Low-Flow Oxygen Therapy   (Site not responding. Last check: 2007-11-07)
Adaptive and Maladaptive Physiologic Responses to Low-Flow Oxygen
Almost from the time of its discovery excess oxygen was thought to be toxic to organisms, but the first documentation of oxygen toxicity was by Paul Bert, who described oxygen toxicity to the central nervous system.
Since the early descriptions of oxygen toxicity it has been learned that hyperoxia can have adverse effects on many types of tissues (Table 1- see RCJ) Inaddition to direct tissue toxicity, the major adverse effects of oxygen therapy are maladaptive physiologic responses (eg, hypercarbia) and nonmedical adverse effects (eg, oxygen therapy-related fires).
www.rcjournal.com /contents/01.00/01.00.0054.asp   (245 words)

 Oxygen Therapy   (Site not responding. Last check: 2007-11-07)
Oxygen therapy is the administration of oxygen at concentrations greater than that in ambient air with the intent of treating or preventing the symptoms, and manifestations of hypoxia.(1)
Oxygen therapy has only limited benefit for the treatment of hypoxia due to anemia, and benefit may be limited with circulatory disturbances.
Oxygen therapy should not be used in lieu of but in addition to mechanical ventilation when ventilatory support is indicated.
www.rcjournal.com /online_resources/cpgs/otachcpg.html   (1464 words)

 Oxygen Toxicity
Depending on the atmospheric pressure by which O2 is delivered, clinical signs of toxicity may be exhibited in the lungs or central nervous system.
Toxic metabolites have a high affinity for the electrons in nearby molecules; this can lead to oxidative damage to the molecules.
Pathologic CNS signs seen in study animals may include white matter necrosis with either pyknosis and hyperchromatosis of the neurons, vacuolization of the cytoplasm, and simultaneous swelling of the perineural glial processes or lysis within the nerve cell’s cytoplasm and karryorhexis.
www.vspn.org /vspnsearch/aow/oxygentoxicity.htm   (1715 words)

 Oxygen toxicity protocols   (Site not responding. Last check: 2007-11-07)
The purpose of this protocol will be to establish standard operational procedures for dealing with in water oxygen toxicity events by divers of the Woodville Karst Plain Project.
Notify a support diver that there has been an oxygen toxicity episode, give them the divers name, depth, and time of oxygen toxicity event; at this point the support diver should immediately inform the surface manager.
After the toxicity episode the diver should be attended by a safety diver for the remainder of his/her decompression.
www.the-scuba-shop.com /Oxtox.htm   (908 words)

 Session Abstract #20   (Site not responding. Last check: 2007-11-07)
We made a quantitative study of the effect of inspired CO on sensitivity to oxygen toxicity in the rat.
The slopes (absolute value) and intercepts of latency to the FED as a function of CO decreased with the increase in oxygen pressure.
It is suggested that in closed circuit oxygen diving, any accumulation of CO should be avoided in order to minimize the risk of CNS oxygen toxicity.
medic.bgu.ac.il /ispp/session_abstract_20.htm   (321 words)

 PCO2 threshold for CNS oxygen toxicity in rats in the low range of hyperbaric PO2 -- Arieli et al. 91 (4): 1582 -- ...
We have recently shown (2) that the latency to CNS oxygen toxicity decreased linearly as a function of the inspired P
Because the physiology causing CNS oxygen toxicity is similar in humans and rats, with the appropriate parameters (as yet
of oxygen toxicity (17) as, for example, in nitrox diving (14).
jap.physiology.org /cgi/content/full/91/4/1582   (3881 words)

 Bibliography: Oxygen   (Site not responding. Last check: 2007-11-07)
Oxygen: Is It A Miracle Drug For Divers, Ocean Realm, Fall, 1986, 13-16.
Oxygen Toxicity And Its Prevention In The Saturation Diving Associated With Project Flare, in J. Banbury (Ed.) PROCEEDINGS OF THE FIFTH ANNUAL SEMINAR ON CAVE DIVING, NACD, Miami FL.
The Use of Oxygen In Decompression, in I. Nashimoto and E. Lanphier (Eds.) DECOMPRESSION IN SURFACE-BASED DIVING, UHMS, Bethesda, MD. 1987, 13-19.
home.earthlink.net /~divegeeked/biblios/oxygen.htm   (2247 words)

 Oxygen Toxicity at Birth: The Pieces Are Put Together -- SAUGSTAD 54 (6): 789 -- Pediatric Research   (Site not responding. Last check: 2007-11-07)
Oxygen Toxicity at Birth: The Pieces Are Put Together -- SAUGSTAD 54 (6): 789 -- Pediatric Research
Oxygen Toxicity at Birth: The Pieces Are Put Together
might be more toxic than believed up to now (8).
www.pedresearch.org /cgi/content/full/54/6/789   (765 words)

 Oxygen Therapy, Oxygen Toxicity, and the STOP-ROP Trial -- Hay et al. 105 (2): 424 -- Pediatrics
Oxygen Therapy, Oxygen Toxicity, and the STOP-ROP Trial -- Hay et al.
Oxygen Therapy, Oxygen Toxicity, and the STOP-ROP Trial
The assertion that liberal oxygen supplementation increases pulmonary risk is a conservative one.
pediatrics.aappublications.org /cgi/content/full/105/2/424   (1215 words)

 eMedicine - Toxicity, Carbon Monoxide : Article by Guy Shochat, MD   (Site not responding. Last check: 2007-11-07)
Commonly overlooked or misdiagnosed, CO intoxication often presents a significant challenge, as treatment protocols, especially for hyperbaric oxygen therapy, remain controversial because of a paucity of definitive clinical studies.
Binding of CO to hemoglobin causes an increased binding of oxygen molecules at the 3 other oxygen binding sites, resulting in a leftward shift in the oxyhemoglobin dissociation curve and decreasing the availability of oxygen to the already hypoxic tissues.
Seizures are most often secondary to oxygen toxicity and do not mandate anticonvulsant therapy or discontinuation of HBO therapy.
www.emedicine.com /emerg/topic817.htm   (4699 words)

 Barotrauma, Oxygen Toxicity, and Chronic Lung Disease -- Mammel et al. 108 (2): 525 -- Pediatrics
Barotrauma, Oxygen Toxicity, and Chronic Lung Disease -- Mammel et al.
A major problem with this study is the use of the "oxygen at 36 weeks" surrogate for chronic lung disease (CLD).
Van Marter et al have demonstrated a differing incidence of the use of oxygen at 36 weeks' postconceptional age between centers.
pediatrics.aappublications.org /cgi/content/full/108/2/525   (1207 words)

 Nitrox & Rebreather Diving with Bali Hai Divers Tioman, Tioman Island, Malaysia (Tech)   (Site not responding. Last check: 2007-11-07)
Critical oxygen limits vary drastically with partial pressure.
As the oxygen percentage in Nitrox increases, the depth at which the
The reason the tank must be oxygen compatible is that a common
www.balihaidivers.net /tech   (1385 words)

 Comments: PEDS - Potential for oxygen toxicity (A)
Comments: PEDS - Potential for oxygen toxicity (A) Comments: PEDS - Potential for oxygen toxicity (A)
While the implication that ventilation with room air may be more "neuro-safe" than with 100% O2 for primary cardiac arrest in peds and adults with good lung and heart function prior to the cardiac arrest, could you comment on the situation of respiratory arrest only, cardiac arrest yet to occur.
I have previously been Director of Emergency Services at the USAF Hospital, Andrews and Medical Director of the American Safety & Health Institute.
www.americanheart.org /presenter.jhtml?identifier=3027933   (123 words)

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