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Arterial Oxygen (arterial + oxygen)

Distribution by Scientific Domains
Medical Sciences100%

Terms modified by Arterial Oxygen

  • arterial oxygen pressure
    		•
  • arterial oxygen saturation
    		•
  • arterial oxygen tension
    		•

    Selected Abstracts

    Gravity is an important determinant of oxygenation during one-lung ventilation

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010
    L. L. SZEGEDI
    Background: The role of gravity in the redistribution of pulmonary blood flow during one-lung ventilation (OLV) has been questioned recently. To address this controversial but clinically important issue, we used an experimental approach that allowed us to differentiate the effects of gravity from the effects of hypoxic pulmonary vasoconstriction (HPV) on arterial oxygenation during OLV in patients scheduled for thoracic surgery. Methods: Forty patients with chronic obstructive pulmonary disease scheduled for right lung tumour resection were randomized to undergo dependent (left) one-lung ventilation (D-OLV; n=20) or non-dependent (right) one-lung ventilation (ND-OLV; n=20) in the supine and left lateral positions. Partial pressure of arterial oxygen (PaO2) was measured as a surrogate for ventilation/perfusion matching. Patients were studied before surgery under closed chest conditions. Results: When compared with bilateral lung ventilation, both D-OLV and ND-OLV caused a significant and equal decrease in PaO2 in the supine position. However, D-OLV in the lateral position was associated with a higher PaO2 as compared with the supine position [274.2 (77.6) vs. 181.9 (68.3) mmHg, P<0.01, analysis of variance (ANOVA)]. In contrast, in patients undergoing ND-OLV, PaO2 was always lower in the lateral as compared with the supine position [105.3 (63.2) vs. 187 (63.1) mmHg, P<0.01, ANOVA]. Conclusion: The relative position of the ventilated vs. the non-ventilated lung markedly affects arterial oxygenation during OLV. These data suggest that gravity affects ventilation,perfusion matching independent of HPV. [source]

    Pilot study of pentoxifylline in hepatopulmonary syndrome,

    LIVER TRANSPLANTATION, Issue 8 2008
    Rajasekhar Tanikella
    Hepatopulmonary syndrome (HPS) results when chronic liver disease or portal hypertension causes intrapulmonary microvascular dilatation with hypoxemia. In experimental HPS, tumor necrosis factor alpha (TNF-,) overproduction contributes to vasodilatation, which is improved by pentoxifylline, a TNF-, inhibitor. The effectiveness of pentoxifylline in humans is unknown. The aim of this open-label, single-arm clinical trial was to assess the efficacy and tolerability of pentoxifylline in patients with cirrhosis and advanced HPS undergoing liver transplantation evaluation. Nine adults with cirrhosis and moderate to severe HPS were enrolled. All patients had an initial 2-week titration to a target dose of pentoxifylline of 400 mg by mouth every 8 hours, which was continued for 6 weeks. Baseline and follow-up arterial blood gases and TNF-, levels were evaluated. Adverse effects and tolerability were assessed. The 9 patients had a mean age of 55 ± 10 years, and 67% were female. The most common causes of cirrhosis were hepatitis C virus and alcohol (55%). The mean Model for End-Stage Liver Disease score was 11 (range, 6-19), and patients had advanced hypoxemia [mean partial pressure of arterial oxygen (PaO2) = 54 ± 12 mm Hg, mean alveolar-arterial oxygen gradient (A-a PaO2) = 57 ± 15 mm Hg]. Of the 9 patients enrolled, follow-up blood gases were done in 7. There was no significant change in PaO2 (P = 0.3) or A-a PaO2 (P = 0.3) with treatment. Pentoxifylline was poorly tolerated. Nausea (100%) and vomiting (56%) were the predominant side effects, and only a single patient was able to complete full-dose therapy. Treatment with pentoxifylline did not improve arterial oxygenation in advanced HPS, and tolerance was limited by gastrointestinal toxicity. Liver Transpl 14:1199,1203, 2008. © 2008 AASLD. [source]

    Manual hyperinflation , Effects on respiratory parameters

    PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 3 2000
    Shane Patman
    Abstract Background and Purpose Manual hyperinflation (MH) of the lungs is commonly used by physiotherapists in the treatment of intubated mechanically ventilated patients with the aim of increasing alveolar oxygenation, reversing atelectasis or mobilizing pulmonary secretions. However, the efficacy of MH, used in isolation, has not been clearly established. Method This randomized, controlled trial investigated the effects of MH on lung compliance (CL), the arterial oxygen to fraction of inspired oxygen ratio (PaO2:FIO2) and the alveolar,arterial oxygen tension difference (A,a)PO2 in 100 medically stable, mechanically ventilated subjects who had undergone coronary artery surgery (CAS). Post-CAS subjects were used for this study as they constitute a large, homogeneous and accessible group. Subjects were randomized to either a control group (non-MH group) or to a treatment group (MH group) which received MH within four hours of surgery. Results After four minutes of MH there were significant improvements in CL, PaO2:FIO2 and (A,a)PO2 with values remaining above baseline measures at 60 min post-intervention. The mean improvement in CL was 6 ml/cmH2O (approximately 15%), 56 mmHg for PaO2:FIO2 (approximately 17%) and 29 mmHg for (A,a)PO2 (approximately 17%) immediately post-intervention. No significant changes in mean CL, PaO2:FIO2 or (A,a)PO2 were seen in the non-MH group. Conclusions MH performed in the stable ventilated patient significantly increased CL and PaO2:FIO2 and decreased (A,a)PO2, but the clinical significance of this improvement is unclear. Further investigations are required to validate the findings of this study as well as to determine the therapeutic value of MH on patient outcome. Copyright © 2000 Whurr Publishers Ltd. [source]

    Improved Survival After Liver Transplantation in Patients with Hepatopulmonary Syndrome

    AMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010
    S. Gupta
    Hepatopulmonary syndrome (HPS) is present in 10,32% of chronic liver disease patients, carries a poor prognosis and is treatable by liver transplantation (LT). Previous reports have shown high LT mortality in HPS and severe HPS (arterial oxygen (PaO2) ,50 mmHg). We reviewed outcomes in HPS patients who received LT between 2002 and 2008 at two transplant centers supported by a dedicated HPS clinic. We assessed mortality, complications and gas exchange in 21 HPS patients (mean age 51 years, MELD score 14), including 11/21 (52%) with severe HPS and 5/21 (24%) with living donor LT (median follow-up 20.2 months after LT). Overall mortality was 1/21 (5%); mortality in severe HPS was 1/11 (9%). Peritransplant hypoxemic respiratory failure occurred in 5/21 (24%), biliary complications in 8/21 (38%) and bleeding or vascular complications in 6/21 (29%). Oxygenation improved in all 19 patients in whom PaO2 or SaO2 were recorded. PaO2 increased from 52.2 ± 13.2 to 90.3 ± 11.5 mmHg (room air) (p < 0.0001) (12 patients); a higher baseline macroaggregated albumin shunt fraction predicted a lower rate of postoperative improvement (p = 0.045) (7 patients). Liver transplant survival in HPS and severe HPS was higher than previously demonstrated. Severity of HPS should not be the basis for transplant refusal. [source]

    Protective role of Coenzyme Q10 in two models of rat lung injury

    ANZ JOURNAL OF SURGERY, Issue 4 2010
    Hou-Kiat Lim
    Abstract Background:, Ischaemia-reperfusion injury is a life-threatening complication of lung transplantation. Attempts to ameliorate this injury have included optimization of donor management and improving techniques of lung preservation. However, few investigators have sought to pretreat potential recipients. Coenzyme Q10 (CoQ10) is a potent antioxidant and cellular energizer that has been shown to protect the heart against injury. However, its protective effect in the lung is unknown. We therefore set out to study the impact of Coenzyme Q10 pretreatment in a model of mild and severe lung injury. Methods:, We evaluated the impact of CoQ10 in a two-stage laboratory study. In the first stage, in order to measure the magnitude of increase in tissue and plasma CoQ10 following oral therapy we administered high-dose oral CoQ10 to rats (n = 6). In the second stage we evaluated the impact of CoQ10 in the rat lung (n = 10) that was subjected to 230 min of normoxic lung injury or 90 min of warm ischaemia and 120 min of reperfusion in a model of lung transplantation. Results:, High-dose oral CoQ10 for 7 days produced a 15-fold increase in plasma and a 3-fold increase in lung CoQ10. In the normoxic lung, the injury-induced rise in peak airway pressure was reduced by CoQ10 treatment at 90 min (P = 0.037) and at 120 min (P = 0.005) without any change in arterial oxygen. In the lung subjected to severe ischaemia-reperfusion injury, CoQ10 did not reduce the injury-induced increase in peak airway pressure (P = 0.599) nor the decrease in arterial oxygen (P = 0.844). However, CoQ10 markedly reduced the increase in tumour necrosis factor-alpha in ischaemic compared with normoxic lung (P = 0.027). Conclusions:, The effect of CoQ10 pretreatment is insufficient to protect the lung against severe ischaemia-reperfusion as may occur in lung transplantation. However, in the setting of less severe pulmonary injury as in anaesthesia and non-transplant surgery, CoQ10 may have a protective role. [source]