Oxygen Intoxication Research Articles

Biochemical effects in deep-sea divers exposed to aquatic environmental factors

Relevance. Diving equipment and diving launch techniques witness continuous improvements, which allow individuals to more effectively perform various tasks underwater. A controlled electronic closed circuit rebreather has been used in amateur diving in our country for more than 20 years. It is therefore necessary to assess the biochemical effects in deep-sea divers wearing deep sea diving equipment to ensure its safety and functionality in professional diving and the activities of dedicated departmental structures.The objective is to assess the biochemical effects in deep-sea divers in controlled electronic closed circuit rebreather, with a similar level of intravascular decompression gas formation under the influence of aquatic environment factors.Methods. During the study, 9 blood biochemical parameters were evaluated using the Fujifilm DRI-CHEM NX500 apparatus in 6 divers before and after deep-sea descents. In total, 14 diving descents were performed in a controlled electronic closed circuit rebreather to depths from 60 to 100 m. Also, after each diving descent, the level of intravascular decompression gas formation was assessed using ultrasonic location with the constant-wave Doppler effect.Results and Discussion. As a result of these studies, a significant increase in the values of transaminases (ALT, AST) and urea was established, associated with increased partial pressure of oxygen in hyperbaric aquatic environment. The results of the analysis revealed that indicators of the CNS oxygen intoxication correlated with K+ ions concentration and glucose levels; a correlation between Na+ ions and Cl- ions concentration was established, as well as the inverse relationship between the concentration of urea and creatinine and the level of intravascular decompression gas formation. It is noteworthy that a correlation was found between the level of intravascular decompression gas formation and the CNS oxygen intoxication, whereby an increase in the CNS oxygen intoxication leads to increased levels of intravascular decompression gas formation.Conclusion. The studied blood biochemical parameters did not go beyond the reference values and had slight individual variations, which confirms the safety of the technology of descents in diving breathing apparatus with a controlled electronic closed circuit rebreather at depths of more than 60 m. The results of the correlation analysis revealed changes in carbohydrate and water-electrolyte metabolism in the body of divers after a deep-sea descent due to the action of an increased partial pressure of oxygen and intravascular decompression gas formation.

Kada kiseonik prestaje da bude lek?

Oxygen has been considered a potentially life-saving drug in life-threatening situations for decades. It is crucial in the perioperative period, where it is used daily by millions of surgical patients of all ages. Iatrogenic hyperoxia is as damaging as hypoxia, especially in young children and neonates. There is a growing awareness about this problem. Significant discoveries about the effect of oxygen on oxidative stress and cellular damage due to oxygen intoxication must contribute to developing hyperoxia monitoring, oxygen dosing guidelines, and revising the safe limits of hyperoxia. The consequences of hyperoxia can be irreversible damage to the vulnerable organs (lungs and brain), which mainly affects developing organisms.

Hyperbaric oxygenation for resuscitation and therapy of elderly patients with cerebral and cardio-respiratory dysfunction.

Hyperbaric oxygenation therapy (HBOT) has been gaining an increasing recognition as a versatile therapeutic approach. This article reviews the application of hyperbaric oxygenation as a method for resuscitation and therapy of elderly patients with cerebral and cardio-respiratory dysfunction, in acute as compared to chronic impairments. The vital role of proper dosage of HBO therapy to ensure both the efficacy and safety of the treatment is emphasized. We argue that in the acute stages of brain and cardiorespiratory impairment, the adequate hyperbaric oxygen dose is the most important condition for obtaining maximum therapeutic effect, due to the powerful anti-hypoxic capabilities of this method. In contrast, during the chronic course of such impairments, there is an increased importance of safe dosing for the prevention of oxygen intoxication. Further dosage adjustments need to be made for the elderly as compared to younger patients, while examining and taking into consideration long term therapy effects. Some potential geroprotective mechanisms of HBO therapy are considered, that may be analogous to other geroprotective medications.

Automatic Control of Fraction of Inspired Oxygen in Neonatal Oxygen Therapy using Fuzzy Logic Control

Premature babies of less than 37 weeks gestation might require oxygen therapy as an integral part of treatment and respiratory support. Because of their under-developed lungs, these socalled “preemies” might contract respiratory distress syndrome (RDS). To treat RDS, neonatal oxygen therapy is administered, where controlled oxygen gas is measured as a fraction of inspired oxygen (FiO₂). However, exposure to high oxygen content during long treatment could cause oxygen intoxication, which might cause permanent blindness due to retinopathy of prematurity (ROP), whereas insufficient oxygen exposure could cause severe hypoxia. A doctor would use oxygen saturation (SpO₂) data and prescribe a dose of FiO₂ to maintain SpO₂ within a suitable range. One objective is to maintain SpO₂ within the acceptable range using FiO₂that is as low as possible. Adjustment of FiO₂ would normally be done by nurses every 15 to 30 minutes, which might not be safe in many situations. An error in FiO2 adjustment during a manual procedure could be as large as +/- 2.5%. This paper presents a system that can determine an FiO2 value suitable to the current SpO₂ and that automatically adjusts FiO₂ with an error clearance of +/- 0.25%.

Hyperbaric Oxygen Therapy for Pancreatic and Gastrointestinal Disease

We report the results of hyperbaric oxygen therapy (HBO) for pancreatic and gastrointestinal disease. Thirty-nine patients received 100% oxygen at 2 atmospheres absolute pressure for 60 min. Results: In all four patients with liver abscess, feverishness subsided within 2.7 days after the start of HBO. All of three patients with infection after hepatic resection were relieved of systemic inflammatory response system (SIRS) and showed reduced CRP levels after HBO. In all of seven patients with acute appendicitis, pyrexia was relieved at 1.8 days after HBO introduction, and further surgery was not necessary. Among five patients with colorectal disease, HBO was effective in four, but ineffective in one. Five of six cases of infection after pancreatic resection were cured immediately after HBO. There were no complications such as middle ear inflammation, oxygen intoxication or pneumothorax. Conclusions: HBO is sometimes effective for treatment of refractory gastro enteric infections, especially those for which drainage is difficult. Pyrexia improved within 2.3 days after the start of HBO in most cases. If infection is refractory to standard antibiotics or drainage, HBO should be considered as an additional treatment. Since HBO is safe and generally cost-effective, it should be considered as an adjunct therapy for all gastro enteric infections.

COMPARING ANTIOXIDANT CAPACITY AND VITAMIN C VALUES BETWEEN UMBILICAL CORD AND MATERNAL BLOOD PLASMA AND THOSE IN NEWBORNS WITH HYPOXIA

Objective Oxygen intoxication plays an important role in the pathogenesis of some fetal diseases such as encephalopathy, ischemia& hypoxia. Antioxidants can reduce oxidative damage in newborns. The object of this research was measuring total value of antioxidant and vitamin C in blood sample of pregnant women before delivery, and also in umbilical cord blood of their newborn, and repeating these measurements 48 hours after birth in newborns with hypoxia and controlling group. Materials & Methods The sample included 32 healthy pregnant women presented for delivery & also their newborns. The total values of antioxidant & vitamin C in plasma were measured by staining methods. Results There was no statistical meaningful difference in total values of antioxidants & vitamin C in women's blood & their newborn's cord blood. Also total values of antioxidant & vitamin C meaningfully increased in newborns with hypoxia after 48 hours. Conclusion total values of antioxidant & vitamin C in blood plasma of newborn, increase in oxidative damage as a defense mechanism. Key words: Antioxidants , Ascorbic Acid , Hypoxia , Umbilical cord blood.

The role of band 3 protein in oxygen delivery by red blood cells

The synergistic effects of hemoglobin, carbonic anhydrase and the band 3 protein make red blood cells the ideal vehicle for oxygen delivering to the tissues. As long as oxygen is supplied by these ideal vehicles, oxygen intoxication of the tissues is precluded. Band 3 protein mediates the "Chloride-Shift", i.e., the anion exchange of Cl(-)/HCO(3) (-). Because of the Chloride-Shift, red blood cells are able to recognize metabolically active tissues and to supply the minimum amount of oxygen to the tissues. Investigation into the molecular mechanisms of the anion exchange mediated by the band 3 protein was introduced.

Respiratory failure and stimulation of glycolysis in Chinese hamster ovary cells exposed to normobaric hyperoxia.

Continuous exposure of Chinese hamster ovary (CHO) cells to an atmosphere of 98% O2, 2% CO2 (normobaric hyperoxia) leads within a period of several days to cytostasis and clonogenic cell death. Here we report respiratory failure as an important early symptom of oxygen intoxication in CHO cells, resulting in a more than 80% inhibition of oxygen consumption within 3 days of hyperoxic exposure. This inhibition appeared to be correlated with selective inactivation of three mitochondrial key enzymes, NADH dehydrogenase, succinate dehydrogenase, and alpha-ketoglutarate dehydrogenase. The latter enzyme controls the influx of glutamate into the Krebs cycle and is particularly critical for oxidative ATP generation in most cultured cells, which depends on exogenous glutamine rather than glucose as a carbon source. As expected, the inactivation of alpha-ketoglutarate dehydrogenase was correlated with a fall in cellular glutamine utilization, which became apparent from the first day of hyperoxic exposure. Thereafter, glucose utilization and lactate excretion started to increase, up to 3-fold, indicating a cellular response to respiratory failure aimed at increased ATP generation from glycolysis. However, in spite of this response, the cellular ATP level progressively decreased, up to 2.5-fold. Thus, killing of CHO cells by normobaric hyperoxia seems to be due to a severe disturbance of mitochondrial metabolism eventually leading to a depletion of cellular ATP pools.

Acute respiratory failure induced by mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH20

The effects of high pressure mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH(2)O were studied on the lungs of healthy newborn pigs (14-21 days after birth). Forty percent oxygen in nitrogen was used for ventilation to prevent oxygen intoxication. The control group (6 pigs) was ventilated for 48 hours at a peak inspiratory pressure less than 18 cmH(2)O and a PEEP of 3-5 cmH(2)O with a normal tidal volume, and a respiratory rate of 20 times/min. The control group showed few deleterious changes in the lungs for 48 hours. Eleven newborn pigs were ventilated at a peak inspiratory pressure of 40 cmH(2)O with a PEEP of 3-5 cmH(2)O and a respiratory rate of 20 times/min. To avoid respiratory alkalosis, a dead space was placed in the respiratory circuit, and normocarbia was maintained by adjusting dead space volume. In all cases in the latter group, severe pulmonary impairments, such as abnormal chest roentgenograms, hypoxemia, decreased total static lung compliance, high incidence of pneumothorax, congestive atelectasis, and increased lung weight were found within 48 hours of ventilation. When the pulmonary impairments became manifest, 6 of the 11 newborn pigs were switched to the conventional medical and ventilatory therapies for 3-6 days. However, all of them became ventilator dependent, and severe lung pathology was found at autopsy. These pulmonary insults by high pressure mechanical pulmonary ventilation could be occurring not infrequently in the respiratory management of patients with respiratory failure.

Role of Free Radical Reactions in Myelodysplastic Syndrome

Activities of glutathione linked enzymes in red blood cells and concentrations of other free radical scavengers in red blood cells and in plasma were assayed in patients with myelodysplastic syndromes (MDS). Glutathione peroxidase (GSH-Px) activity, concentrations of both reduced glutathione and oxidized glutathione in red blood cells, and lipid peroxide levels in plasma were all significantly increased in MDS patients. Levels of other free radical scavengers in plasma (total vitamin B2, FAD, and coenzyme Q10), however, were decreased. The data suggest that MDS patients may have been exposed to free radicals, and may be hypersensitive to the oxygen intoxication.

Bronchiolitis induced by experimental acute and chronic oxygen intoxication in young adult rats

Bronchiolitis induced by experimental acute and chronic oxygen intoxication in young adult rats

Effects of high oxygen pressures on the eye.

WITH the increasing use of oxygen at greater than atmospheric partial pressure for treatment of patients and for clinical research, it is inevitable that oxygen intoxication is also being induced. ...

Blood gas and neurological responses to inhalation of oxygen at 3 atmospheres.

SummaryArterial blood gas tensions, pulse and blood pressure were monitored repeatedly in 7 normal young men while they breathed 99% oxygen at 3 atmospheres in a hyperbaric chamber for periods of up to 3 hours. There was evidence that 6 of these subjects hyperventilated during the exposure. Arterial Pco2 began to fall during the first 5 minutes of exposure and continued to decline to 35 mm Hg during the first 90 minutes. It tended to remain constant during the rest of the exposure. Arterial Po2 rose to 2000 mm Hg during the first 5 minutes of exposure and remained at this level. The pulse rate fell by 25% and remained at this level for at least 2 hours when it began to increase. Blood pressure was constant for the first 2 hours of exposure and began to rise at the same time as the pulse. Loss of peripheral vision as well as subjective signs of oxygen intoxication (dizziness, nausea, etc.) began to appear during the third hour of exposure but no convulsions were produced.

Effect of oxygen breathing at atmospheric pressure on pulmonary surfactant

To evaluate the effects of oxygen breathing at atmospheric pressure on pulmonary surfactant, cats, rabbits, and rats were continuously kept in 98% oxygen until death occurred. Pulmonary surfactant was extracted by mincing of the lung and by foam fractionation of the lung. Surface tension of the extracts was measured on a Wilhelmy balance. Lung extracts prepared by both methods from the cats and rabbits kept in oxygen had greater surface tension than lung extracts from control animals. Surface tension of extracts prepared by foam fractionation of lungs of rats kept in oxygen did not differ from that of extracts of lungs of control rats, whereas surface tension of extracts prepared by mincing lungs of rats kept in oxygen had minimum surface tension greater than that of lung extracts of control rats. This species difference in the effects of oxygen breathing on pulmonary surfactant may reflect a difference in the pathogenesis of oxygen intoxication. oxygen intoxication; surface tension Submitted on October 19, 1964

Cardiovascular and blood gas responses to hyperbaric oxygenation

Ten normal subjects were studied while they breathed air and 100% oxygen at 1 and 3.04 atmospheres. Oxygen inhalation at 3.04 atmospheres was associated with a significant increase in arterial and venous pO 2 and O 2 content. Hemoglobin in the venous circulation was completely saturated in 8 of 10 subjects. Oxygen inhalation at 3.04 atmospheres produced a small but significant increase in venous pCO 2, presumably due to the loss of the buffering effect of reduced hemoglobin. Heart rate and cardiac output fell significantly with little change in stroke volume during oxygen inhalation at 3.04 atmospheres, indicating that the decrease in cardiac output was rate-dependent. There was little change in mean arterial pressure but an increase in calculated peripheral resistance during oxygen inhalation at 3.04 atmospheres. Two subjects who demonstrated signs of acute oxygen intoxication did not differ significantly from the group as a whole either in terms of blood gas values or patterns of hemodynamic response.

Effect of oxygen intoxication on pulmonary surfactant in dogs, rabbits and rats

Effect of oxygen intoxication on pulmonary surfactant in dogs, rabbits and rats

The effect of pure oxygen inhalation on the lungs and heart of white rats

The state of the heart and lungs was studied in albino rats subjected to oxygen intoxication. Roentgeno- and electrocardiographic methods were used for that purpose. A number of animals were also autopsied. As established, albino rats kept in a 90–100% oxygen atmosphere begin to develop severe effects on the lungs usually by the end of the first 48 hours. If the animal is removed from the oxygen atmosphere after having been kept in it for a period of 48–52 hours these changes disappear without leaving any trace. Inhalation of a gas mixture containing 60–80% of oxygen for a period of up to 30 days provoked but insignificant changes in the roentgenological picture of the lungs and heart.

Respiratory physiology and skin diving.

Skin diving with self-contained underwater breathing apparatus (scuba) has hazards that distinguish it both from free diving during short periods of voluntary apnea and from traditional diving with helmet, pump, and connecting tubes. It is also necessary to distinguish between the type of scuba in which the expired carbon dioxide is absorbed chemically, the needed oxygen is added, and the nitrogen is rebreathed from the type in which the expired air is simply discharged into the water as bubbles. Although the latter form is less dangerous, it has its hazards, including air embolism, decompression illness, nitrogen narcosis, oxygen intoxication, rupture of eardrums, and squeeze. Squeeze, the pressing of body tissues into air-filled spaces in the diving costume, is particularly damaging to the eyes. The bulging of the eyes into goggles is hard to avoid, but if a mask is worn instead of goggles the danger can be decreased by discharging air from the nose into the mask whenever pressures increase.

Ether Day at the Massachusetts General Hospital — Report of the Massachusetts State Board of Insanity — Oxygen Intoxication — Medical Notes

Ether Day at the Massachusetts General Hospital — Report of the Massachusetts State Board of Insanity — Oxygen Intoxication — Medical Notes