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Arterial Oxygen Pressure (arterial + oxygen_pressure)
Selected AbstractsAcute Hypervolaemia Improves Arterial Oxygen Pressure in Athletes with Exercise-Induced HypoxaemiaEXPERIMENTAL PHYSIOLOGY, Issue 4 2003Gerald S. Zavorsky The aim of this study was to determine the effect of acute plasma volume expansion on arterial blood-gas status during 6.5 min strenuous cycling exercise comparing six athletes with and six athletes without exercise-induced arterial hypoxaemia (EIAH). We hypothesized that plasma volume expansion could improve arterial oxygen pressure in a homogeneous sample of athletes - those with EIAH. In this paper we have extended the analysis and results of our recently published surprising findings that lengthening cardiopulmonary transit time did not improve arterial blood-gas status in a heterogeneous sample of endurance cyclists. One 500 ml bag of 10% Pentastarch (infusion condition) or 60 ml 0.9% saline (placebo) was infused prior to exercise in a randomized, double-blind fashion on two different days. Power output, cardiac output, oxygen consumption and arterial blood gases were measured during strenuous exercise. Cardiac output and oxygen consumption were not affected by acute hypervolaemia. There were group × condition interaction effects for arterial oxygen pressure and alveolar-arterial oxygen pressure difference, suggesting that those with hypoxaemia experienced improved arterial oxygen pressure (+4 mmHg) and lower alveolar-arterial oxygen pressure difference (-2 mmHg) with infusion. In conclusion, acute hypervolaemia improves blood-gas status in athletes with EIAH. The impairment of gas exchange occurs within the first minute of exercise, and is not impaired further throughout the remaining duration of exercise. This suggests that arterial oxygen pressure is only minimally mediated by cardiac output. [source] 3353: Response of the human eye against oxidative stress at high altitudesACTA OPHTHALMOLOGICA, Issue 2010S KARAKUCUK Purpose To evaluate the response of the anterior segment of the eye against oxidative stress during acute exposure to high altitudes. Methods Forty volunteers were examined and measurements performed at Erciyes University Medical Faculty,Ophthalmology Clinic, Kayseri,Turkey(1080m). On the following day, participants were transported to Mt. Erciyes Ski Center by bus(2200m); thereafter they climbed to an altitude of 2800m.with a moderate pace. Central corneal thickness, intraocular pressure,spheric equivalent of refraction, arterial oxygen pressure,blood pressure, pulse rate and body temperature were measured at both altitudes. Venous blood samples were taken from volunteers at both altitudes;total oxidant status (TOS),total antioxidant status(TAS),advanced oxidation protein products (AOPP), xanthine oxidase (XO), thiol, adenosine deaminase(ADA)levels were investigated at 1080m and 2800m. Results TOS(7.02µmol H2O2 equiv/L, range:0.49-22.07) and AOPP(220.74µmol/L,range:103.81-667.35)significantly increased at high altitude, compared to low altitude levels (3.32µmol H2O2 equiv/L range:0.92-18.41,and 195.58µmol/L,range:84.77-663.16, resp; p<0.05).IOP significantly elevated at high altitude (14.45±3.54mmHg vs 13.22±2.74mmHg; p<0.05). There was a significant positive correlation between IOP and TAS levels(p<0.05). No significant correlation was found between spherical equivalent or central corneal thickness with the investigated oxidation parameters at both altitudes Conclusion We conclude that oxidative stress markers, TOS and AOPP are increased along with IOP during acute exposure to hypoxic environment at high altitudes and that antioxidant system may have a limited capacity to counter balance this effect because of acute unacclimatized ascent. [source] Effects of sevoflurane on collagen production and growth factor expression in rats with an excision woundACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010H.-J. LEE Background: Sevoflurane is a widely used inhalation anesthetic, but there are no studies on its effect on the wound-healing process. This study was undertaken to evaluate the effect of exposure time to sevoflurane on wound healing. Method: Male Sprague,Dawley rats were used. Two circular full-thickness skin defects 8 mm in diameter were made on the dorsum of the rats. The animals were divided into six groups according to exposed gas type and time: S1 (sevoflurane, 1 h), S4 (sevoflurane, 4 h), S8 (sevoflurane, 8 h), O1 (oxygen, 1 h), O4 (oxygen, 4 h), and O8 (oxygen, 8 h). The surface area of the wounds was measured 0, 1, 3, and 7 days after surgery. Separately, the mean blood pressures (MBP) and arterial oxygen pressures (PaO2) were monitored during the sevoflurane exposure. Collagen type I production and transforming growth factor-,1 (TGF-,1) and basic fibroblast growth factor (bFGF) expression on the wound surface were analyzed. Routine histological analysis was also performed. Result: Exposure duration to sevoflurane had no influence on MBP and PaO2. The reduction in wound size and collagen type I production was delayed in S8. The expression of TGF-,1 and bFGF on the wound surface in S8 was significantly attenuated in S8. The histology of the S8 demonstrated a delayed healing status. Conclusions: Prolonged exposure to sevoflurane might alter the inflammatory phase of the wound-healing process by attenuation of growth factor expression such as TGF-,1 and bFGF and subsequently by reduced collagen production. [source] | ||||||||||