Tension Difference (tension + difference)

Distribution by Scientific Domains

Kinds of Tension Difference

  • alveolar-arterial oxygen tension difference
  • oxygen tension difference

  • Selected Abstracts

    Arterial oxygen tension increase 2,3 h after hyperbaric oxygen therapy: a prospective observational study

    B. Ratzenhofer-Komenda
    Background:, Inhalation of hyperbaric oxygen (HBO) has been reported to decrease arterial oxygen tension (PaO2) in the early period after exposure. The current investigation aimed at evaluating whether and to what extent arterial blood gases were affected in mechanically ventilated intensive care patients within 6 h after HBO treatment. Methods:, Arterial blood gases were measured in 11 ventilated subjects [nine males, two females, synchronized intermittent mandatory ventilation (SIMV) mode] undergoing HBO therapy for necrotizing soft tissue infection (seven patients), burn injury (two patients), crush injury (one patient) and major abdominal surgery (one patient). Blood gases were obtained with the patients in the supine position under continuous analgesia and sedation before the hyperbaric session (baseline), during isopression, after decompression, after each transport, and 1, 2, 3 and 6 h after exposure. Heart rates and blood pressures were recorded. Intensive care unit (ICU) ventilator settings remained unchanged. Transport and chamber ventilator settings were adjusted to baseline with maintenance of tidal volumes and positive end-expiratory pressure (PEEP) levels. The hyperbaric protocol consisted of 222.9 kPa (2.2 absolute atmospheres) and a 50-min isopression phase. The paired Wilcoxon's test was used. Results:, Major findings (median values, 25%/75% quantiles) as per cent change of baseline: PaO2 values decreased by 19.7% (7.0/31.7, P < 0.01) after 1 h and were elevated over baseline by 9.3% (1.5/13.7, P < 0.05) after 3 h. SaO2, alveolar-arterial oxygen tension difference and PaO2/FiO2 ratio behaved concomitantly. Acid-base status and carbon dioxide tension were unaffected. Conclusion:, Arterial oxygen tension declines transiently after HBO and subsequently improves over baseline in intensive care patients on volume-controlled mechanical ventilation. The effectiveness of other ventilation modes or a standardized recruitment manoeuvre has yet to be evaluated. [source]

    Pulmonary gas exchange abnormalities in liver transplant candidates

    Rosmawati Mohamed
    Abnormal diffusing capacity is the commonest pulmonary dysfunction in liver transplant candidates, but severe hypoxemia secondary to hepatopulmonary syndrome and significant pulmonary hypertension are pulmonary vascular manifestations of cirrhosis that may affect the perioperative course. We prospectively assessed the extent of pulmonary dysfunction in patients referred for liver transplantation. A total of 57 consecutive patients with chronic liver disease were evaluated. All patients had a chest radiograph, standing arterial blood gas on room air, pulmonary function testing, and Doppler echocardiogram. Those patients with arterial hypoxaemia (PaO2 < 10 kPa) also underwent 99mTc-macroaggregated albumin lung scan, and nine patients had agitated normal saline injection during echocardiography to define further the existence of pulmonary vascular dilatation. Reduced diffusing capacity for carbon monoxide less than 75% of the predicted value was found in 29 of 57 (51%) patients. Although elevated alveolar-arterial oxygen tension difference was detected in 35% (20/57) of the patients, only four (7%) patients had hypoxemia. We were unable to find evidence of intrapulmonary vascular dilatation either on the lung scan or saline-enhanced echocardiography in any of these patients. Reduction in diffusing capacity for carbon monoxide was noted in 75% (18/24) of patients who were transplanted for primary biliary cirrhosis and was accompanied by widened alveolar-arterial oxygen tension in 10 out of 18 (56%) of patients. This study shows that in liver transplant candidates, diffusion impairment and widened alveolar-arterial oxygen tension difference were frequently detected, especially in patients with primary biliary cirrhosis. [source]

    Childhood cirrhosis, hepatopulmonary syndrome and liver transplantation

    Gokhan Tumgor
    Abstract:, Objectives:, The hepatopulmonary syndrome (HPS) is characterized as a triad: liver disease, intrapulmonary vascular dilatatiton, and arterial hypoxemia. The aim of this study is to analyze outcome of children with HPS in liver transplant era. Methods:, Between September 1996 and November 2006, 172 cirrhotic patients (median age 5 years; range 0.2,22 years, M/F; 97/75) were followed at Ege University Pediatric Gastroenterology, Hepatology and Nutrition Unit. All patients were evaluated by chest radiography, arterial blood gas analysis, and alveolar-arterial oxygen tension difference, contrast echocardiography (CEE) after and before the liver transplantation. Results:, HPS was diagnosed in 33 patients (19%) by CEE. None of them had pulmonary hypertension. HPS was not found related to etiology of the liver disease. Portal hypertension was found related to the development of HPS (75.7% in patients with HPS and 54.6% in others, p = 0.02). 17 of 33 patients with HPS underwent liver transplantation. Preoperative and postoperative period of these patients was uneventful. Patients were extubated in the operating room except for two. Median follow up of transplanted children was 1.9 year (range; 0.75,10 years). Arterial blood gas analysis and CEE positivity regressed in all of them by postoperative 6th month. Conclusions:, HPS is a serious and important complication of cirrhotic children that leads to tissue hypoxia and central cyanosis. HPS seems reversible after liver transplantation in all patients. [source]

    Manual hyperinflation , Effects on respiratory parameters

    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]