Search results for "Respiratory Mechanics"
showing 10 items of 43 documents
Determinants of physical activity in daily life in candidates for lung transplantation
2012
BACKGROUND: Participation in daily physical activity (PA) has never been objectively assessed in candidates for lung transplantation (LTx). The main research questions were: 1) How active are LTx-candidates in daily life? 2) What are determinants of activity behavior before LTX? METHODS: Ninety-six candidates for LTx (diagnosis of COPD or interstitial lung disease; mean age 55 ± 7 years) underwent measurements of PA, pulmonary function, 6-min walking distance (6MWD), muscle force and health-status (SF-36 scale). RESULTS: Patients were markedly inactive (5% of waking hours walking, 26% standing and 69% sedentary). Backward multiple regression identified 6MWD (expressed as % of predicted valu…
Chest wall mechanics during pressure support ventilation.
2005
Introduction During pressure support ventilation (PSV) a part of the breathing pattern is controlled by the patient, and synchronization of respiratory muscle action and the resulting chest wall kinematics is a valid indicator of the patient's adaptation to the ventilator. The aim of the present study was to analyze the effects of different PSV settings on ventilatory pattern, total and compartmental chest wall kinematics and dynamics, muscle pressures and work of breathing in patients with acute lung injury. Method In nine patients four different levels of PSV (5, 10, 15 and 25 cmH2O) were randomly applied with the same level of positive end-expiratory pressure (10 cmH2O). Flow, airway ope…
Cardiorespiratory and Neuromuscular Responses to Motocross Riding
2008
The aim of the present study was to examine physiological and neuromuscular responses during motocross riding at individual maximal speed together with the riding-induced changes in maximal isometric force production. Seven A-level (group A) and 5 hobby-class (group H) motocross-riders performed a 30-minute riding test on a motocross track and maximal muscle strength and oxygen uptake (VO2max) tests in a laboratory. During the riding the mean (+/-SD) VO2 reduced in group A from 86 +/- 10% to 69 +/- 6% of the maximum (P < 0.001), whereas in group H the corresponding reduction was from 94 +/- 25% to 82 +/- 20% (P < 0.05). This relative VO2 during the riding correlated with riding speed (r = 0…
The Effect of a Ketogenic Low-Carbohydrate, High-Fat Diet on Aerobic Capacity and Exercise Performance in Endurance Athletes: A Systematic Review and…
2021
A low-carbohydrate, high-fat (LCHF) diet has been proposed to enhance the fat utilization of muscle and the aerobic capacity of endurance athletes, thereby improving their exercise performance. However, it remains uncertain how the macronutrient intake shift from carbohydrate to fat affects endurance exercise training and performance. This study performed a systematic review and meta-analysis to explore the effects of a ketogenic low-carbohydrate, high-fat (K-LCHF) diet on aerobic capacity and exercise performance among endurance athletes. Searches were carried out in five electronic databases, and we followed the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) gu…
Mass Output and Particle Size Distribution of Glucocorticosteroids Emitted from Different Inhalation Devices Depending on Various Inspiratory Paramet…
2002
Efficient inhalation therapy depends on successful delivery of the drug to the lung. The efficacy of drug delivery is not only influenced by the characteristics of the inhalation device, but also by the patient's handling of the device and by the inspiratory maneuver achieved through the device. We analyzed the output characteristics of three different chlorofluorocarbon (CFC)-free breath-actuated inhalers for inhaled glucocorticosteroids (BUD Turbohaler, FP Diskus/Accuhaler and HFA-BDP Autohaler, respectively). Mass output and particle size distribution of drug aerosol delivered by the inhalers were determined depending on different inhalation parameters in vitro using an Andersen cascade …
Mixed predictability and cross-validation to assess non-linear Granger causality in short cardiovascular variability series
2006
A method to evaluate the direction and strength of causal interactions in bivariate cardiovascular and cardiorespiratory series is presented. The method is based on quantifying self and mixed predictability of the two series using nearest-neighbour local linear approximation. It returns two causal coupling indexes measuring the relative improvement in predictability along direct and reverse directions, and a directionality index indicating the preferential direction of interaction. The method was implemented through a cross-validation approach that allowed quantification of directionality without constraining the embedding of the series, and fully exploited the available data to maximise th…
Cardiopulmonary loading in motocross riding
2007
The present study was designed to examine physiological responses during motocross riding. Nine Finnish A-level motocross riders performed a 15-min ride at a motocross track and a test of maximal oxygen uptake (VO2max) in the laboratory. Cardiopulmonary strain was measured continuously during the ride as well as in the VO2max test. During the ride, mean VO2 was 32 ml x kg(-1) x min(-1) (s = 4), which was 71% (s = 12) of maximum, while ventilation (V(E)) was 73% (s = 15) of its maximum. The relative VO2 and V(E) values during the riding correlated with successful riding performance (r = 0.80, P < 0.01 and r = 0.79, P < 0.01, respectively). Mean heart rate was maintained at 95% (s = 7) of its…
The AVL-mode: a safe closed loop algorithm for ventilation during total intravenous anesthesia.
1994
The Adaptive Lung Ventilation Controller (ALV-Controller) represents a new approach to closed loop control of ventilation. It is based on a pressure controlled ventilation mode. Adaptive lung ventilation signifies automatic breath by breath adaptation of breathing patterns to the lung mechanics of an individual patient. The specific goals are to minimize work of breathing, to maintain a preset alveolar ventilation and to prevent the occurrence of intrinsic PEEP. We ventilated 5 patients undergoing major abdominal procedures using ALV. ALV was tolerated well in all patients. Alveolar ventilation was preset between 5500 and 6500 ml/min. Serial dead space (Vds) and respiratory time constant (r…
The Association of Intraoperative driving pressure with postoperative pulmonary complications in open versus closed abdominal surgery patients – a po…
2021
Abstract Background It is uncertain whether the association of the intraoperative driving pressure (ΔP) with postoperative pulmonary complications (PPCs) depends on the surgical approach during abdominal surgery. Our primary objective was to determine and compare the association of time–weighted average ΔP (ΔPTW) with PPCs. We also tested the association of ΔPTW with intraoperative adverse events. Methods Posthoc retrospective propensity score–weighted cohort analysis of patients undergoing open or closed abdominal surgery in the ‘Local ASsessment of Ventilatory management during General Anaesthesia for Surgery’ (LAS VEGAS) study, that included patients in 146 hospitals across 29 countries.…
Gastric insufflation pressure, air leakage and respiratory mechanics in the use of the laryngeal mask airway (LMA) in children.
2004
Summary Background : The objective of the present study was to evaluate the prelaryngeal position of the laryngeal mask airway (LMATM) in children, and to determine the influence of mask positioning on gastric insufflation and oropharyngeal air leakage. Methods : A total of 100 children, 3–11 years old, scheduled for surgical procedures in the supine position under general anaesthesia were studied. After clinically satisfactory LMA placement, tidal volumes were increased stepwise until air entered the stomach, airway pressure exceeded 30 cmH2O, or air leakage from the mask seal prevented further increases in tidal volume. LMA position in relation to the laryngeal entrance was verified using…