Search results for "respiration."
showing 10 items of 533 documents
Non-invasive ventilation in postoperative patients: A systematic review
2010
Background: Postoperative pulmonary complications, generally defined as any pulmonary abnormality occurring in the postoperative period, are still a significant issue in clinical practice increasing hospital length of stay, morbidity and mortality. Non-invasive ventilation (NIV), primarily applied in cardiogenic pulmonary edema, decompensated COPD and hypoxemic pulmonary failure, is nowadays also used in perioperative settings. Objective: Investigate the application and results of preventive and therapeutic NIV in postsurgical patients. Design: A systematic review. Data sources: Medical literature databases were searched for articles about "clinical trials," "randomized controlled trials" a…
Cell Line and Growth Site as Relevant Parameters Governing Tumor Tissue Oxygenation
1986
Experimental rodent tumors commonly used in radiobiology exhibit a large inter-individual variability in the oxygenation status [1,2] and in the hypoxic cell fraction [3,4]. Paramount factors contributing to this variability may be tumor growth stage or tumor size [5], the cell line used, the growth site, the use of anaesthesia and certain tumor-host interactions (e.g. tumor-induced anemia). Concerning the basic pathogenetic mechanisms through which the above mentioned parameters can modulate tumor tissue oxygenation, variations of nutritive blood flow, inherent characteristics of the cell line (e.g. respiration rate or tumor growth rate), and finally changes in the O2 transport capacity of…
Analysis of cardiac and pulmonary complication probabilities after radiation therapy for patients with early-stage breast cancer
2009
Objective. The purpose of this study was to evaluate the radiobiological implications of clinical use of respiratory-gated techniques for postoperative radiation therapy of early-stage left-sided breast cancer after breast-conserving surgery. Material and methods. Radiation therapy treatment plans of 80 patients with early-stage breast cancer (stage I–II), receiving whole breast irradiation after breast-conserving therapy, were analyzed. The control group consisting of 47 patients received standard radiation therapy, and the respiratory-gated group consisting of 33 patients received deep inspiration-gated radiation therapy. Normal tissue complication probabilities (NTCP) for cardiac mortali…
Oxygen consumption is a quality marker for human oocyte competence conditioned by ovarian stimulation regimens.
2011
Objective To evaluate the effect of different ovarian stimulation protocols on oocyte respiration and to investigate the relationship between oocyte oxygen consumption and reproductive outcome. Design Prospective observational cohort study. Setting Infertility clinic in a university hospital. Patient(s) A total of 349 oocytes from 56 IVF treatment cycles in our oocyte donation program. Intervention(s) None. Main Outcome Measure(s) Average oocyte oxygen consumption rate in fmol/s. We correlated oxygen consumption values with ovarian stimulation features, fertilization, embryo quality on days 2 and 3, and implantation. Result(s) Differences in the measured oxygen consumption rates were found …
Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling
2020
Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, α1RRI, α2RRI, α1Resp, α2Resp), Multiple Scaling Entropy (MSERRI1−4, MSERRI5−10, MSEResp1−4, MSEResp5−10), spectral coherence (CohRRI−Resp), cross DFA (ρ1 and ρ2) and cross MSE (XMSE1−4 and XMSE5−10) indices in four physiological conditions: supine with spontaneous breathing, stand…
Inspired supplemental oxygen reduces markers of oxidative stress during elective colon surgery.
2007
.Anaesthesia was induced with sodium thiopental andfentanyl, and maintained with sevoflurane. After inductionof anaesthesia, patients were randomly assigned 30 or80 per cent oxygen throughout surgery and for 6 hafterwards. During surgery, lungs were ventilated involume-controlled mode (10 ml/kg), whereas during the6 h afterwards respiration was spontaneous with an oxygenmask (16 l/min)
Transmission of arterial oxygen partial pressure oscillations to the cerebral microcirculation in a porcine model of acute lung injury caused by cycl…
2013
Cyclic recruitment and derecruitment (R/D) play a key role in the pathomechanism of acute lung injury (ALI) leading to respiration-dependent oscillations of arterial partial pressure of oxygen (Pa(O(2))). These Pa(O(2)) oscillations could also be forwarded to the cerebral microcirculation.In 12 pigs, partial pressure of oxygen was measured in the thoracic aorta (Pa(O(2))) and subcortical cerebral tissue (Pbr(O(2))). Cerebral cortical haemoglobin oxygen saturation (Sbr(O(2))), cerebral blood flow (CBF), and peripheral haemoglobin saturation (Sp(O(2))) were assessed by spectroscopy and laser Doppler flowmetry. Measurements at different fractions of inspired oxygen (F(I(O(2)))) were performed …
Multiscale Information Decomposition Dissects Control Mechanisms of Heart Rate Variability at Rest and During Physiological Stress.
2019
Heart rate variability (HRV