Search Results
Results 401 - 450 of 1875
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Sturini Evelina - - 2008
OBJECTIVE: To assess if the observed respiratory cycle-related variation in intra-abdominal pressure is reliably quantifiable and a possible indirect indicator of abdominal compliance. Secondary issues were to assess the roles played by respiratory parameters in determining this oscillation and by patients' position in increasing their intra-abdominal pressure. DESIGN AND SETTING: ...
Dong Fang - - 2008
Cheyne-Stokes respiration (CSR) is a periodic breathing pattern, characterized by short intervals of very little or no breathing (apnea), each followed by an interval of very heavy breathing (hyperpnea). This work presents a new compartmental model of the human cardio-respiratory system, simulating the factors that determine the concentrations of carbon ...
Brown R - - 2008
Measurement of haemodynamic responses and cutaneous blood flow during an inspiratory-capacity apnoea following spinal cord injury (SCI). To assess the capacity of the sympathetic nervous system to respond to a cardiovascular challenge following SCI. Prince of Wales Medical Research Institute, Australia. Thirteen spinal cord injured subjects with injuries ranging from ...
Volpato Gian Paolo - - 2008
Breathing hydrogen sulfide (H2S) has been reported to induce a suspended animation-like state with hypothermia and a concomitant metabolic reduction in rodents. However, the impact of H2S breathing on cardiovascular function remains incompletely understood. In this study, the authors investigated the cardiovascular and metabolic effects of inhaled H2S in a ...
Raghuraj P - - 2008
The effect of right, left, and alternate nostril yoga breathing (i.e., RNYB, LNYB, and ANYB, respectively) were compared with breath awareness (BAW) and normal breathing (CTL). Autonomic and respiratory variables were studied in 21 male volunteers with ages between 18 and 45 years and experience in the yoga breathing practices ...
Stafford R A - - 2008
BACKGROUND: A crossover study was performed in healthy volunteers to compare the efficacy of a self-inflating bag with the Mapleson C breathing system for pre-oxygenation. METHOD: 20 subjects breathed 100% oxygen for 3 min using each device, with a 30 min washout period. The end tidal oxygen concentration and subjective ...
Huang Y P - - 2008
This paper presents a simple alternative method and system for noninvasive respiratory airflow monitoring. The proposed system uses a piezoceramic transducer to measure respiratory airflow. When a piezoceramic transducer is impacted by respiratory airflow, there is a piezoelectric and a pyroelectric response to pressure and thermal airflow fluctuations. In this ...
Mangin Laurence - - 2008
Ventilatory flow measured at the airway opening in humans exhibits a complex dynamics that has the features of chaos. Currently available data point to a neural origin of this feature, but the role of respiratory mechanics has not been specifically assessed. In this aim, we studied 17 critically ill mechanically ...
Ryan Kathy L - - 2008
Inspiratory resistance induced by breathing through an impedance threshold device (ITD) reduces intrathoracic pressure and increases stroke volume (SV) in supine normovolemic humans. We hypothesized that breathing through an ITD would also be associated with a protection of SV and a subsequent increase in the tolerance to progressive central hypovolemia. ...
Andersson J P A - - 2009
Competitive breath-hold divers try to achieve maximum times, depths, or distances underwater, thereby risking hypoxic syncope. In the present study, the cardiorespiratory responses to dynamic apnea (simultaneously initiated apneas and dynamic leg exercise) were investigated in 10 breath-hold divers. The divers performed 60 s dynamic apneas with the face in ...
Keryvin Vincent - - 2008
The question of hydrostatic pressure or normal stress dependence of the flow and fracture behaviour of bulk metallic glasses is addressed. Data from several types of mechanical tests indicate that flow is hardly sensitive to pressures or normal stresses, while fracture is normal stress sensitive and not pressure dependent. Besides, ...
Shafford Heidi L - - 2008
OBJECTIVE: To quantify the respiratory and cardiovascular effects of intravenous or subcutaneous buprenorphine in conscious rabbits. STUDY DESIGN: Prospective experimental trial. ANIMALS: Eight healthy, young adult New Zealand white rabbits (four female). METHODS: Rabbits were instrumented with intraabdominal arterial and venous catheters and diaphragmatic electromyographic electrodes 2 weeks before experiments. ...
Dellweg Dominic - - 2008
The impact of the respiratory pattern on respiratory muscle workload represents an unresolved controversy and is important for the treatment of patients with respiratory disorders and respiratory muscle failure. We designed this study to investigate the relationship of respiratory pattern and inspiratory workload. We measured esophageal pressure and inspiratory flow ...
González Cruz - - 2008
AIM: To evaluate the influence of respiratory muscle overload and right cardiac overload among the possible risk factors of hospital readmission in a 1-year follow-up of a cohort of patients with moderate-to-severe COPD. METHODS: A total of 112 COPD patients who were admitted consecutively to the hospital for acute exacerbation. ...
Banner Michael J - - 2008
BACKGROUND: Loads on the respiratory muscles, reflected by noninvasive measurement of the real-time power of breathing (POBn), and tolerance of these loads, reflected by spontaneous breathing frequency (f) and tidal volume (Vt), should be considered when evaluating patients with respiratory failure. Pressure support ventilation (PSV) should be applied so that ...
Kabitz Hans-Joachim - - 2008
It has been suggested that impaired respiratory muscle function occurs in patients with PH (pulmonary hypertension); however, comprehensive investigations of respiratory muscle function, including the application of non-volitional tests, needed to verify impairment of respiratory muscle strength in patients with PH have not yet been performed. In the present study, ...
Fang Yong - - 2008
We studied the effects of different respiratory patterns, namely, spontaneous breathing, paced breathing (at a rate of 10 breaths/min and at their mean spontaneous breathing frequency) and breath holding, on the nonlinear characteristics of heart rate variability (HRV). The results showed that paced breathing at both rates significantly diminished the ...
Morgenstern C - - 2008
Detection of inspiratory flow limitation (IFL) is being recognized of increasing importance in order to diagnose pathologies related to sleep disordered breathing. Currently, IFL is usually identified with the help of invasive esophageal pressure measurement, still considered the gold-standard reference to assess respiratory effort. But the invasiveness of esophageal pressure ...
Koumoundouros E - - 2008
An airway monitoring system was developed to record the lung dynamics of sheep using oesophageal pressure techniques. These techniques are minimally invasive and do not impede the animal from breathing spontaneously. This study investigates three methods for deriving lung resistance (R) and compliance (C) by evaluating their ability to select ...
Fauroux Brigitte - - 2008
STUDY OBJECTIVES: To analyze the physiologic effects and tolerance of mechanical insufflation-exsufflation (MI-E) by means of mechanical cough assistance (Cough Assist; JH Emerson Company; Cambridge, MA) for children with neuromuscular disease. DESIGN: Prospective clinical trial. SETTING: Physiology laboratory of a pediatric pulmonary department of a university hospital. PATIENTS: Seventeen children ...
Dellweg Dominic - - 2007
BACKGROUND: Tracheostomy decreases airway resistance and work of breathing. No comprehensive data are available on respiratory mechanics after tracheostomy decannulation. We evaluated respiratory mechanics after decannulation. METHODS: Twenty-five patients with tracheostomy were included. Measurement of arterial blood gases, air-flow, and esophageal pressure during spontaneous breathing were evaluated. RESULTS: Overall arterial ...
Lin Hua - - 2007
The effects of inspiratory muscle (IM) warm-up on IM function and on the maximum distance covered in a subsequent incremental badminton-footwork test (FWmax) were examined. Ten male badminton players were recruited to perform identical tests in three different trials in a random order. The control trial did not involve an ...
Dellweg Dominic - - 2007
BACKGROUND: Noninvasive positive-pressure ventilation (NPPV) unloads respiratory muscles. Spontaneous-breathing ventilation modes require patient effort to trigger the ventilator, whereas controlled modes potentially economize on patient triggering effort and thus achieve more complete respiratory muscle rest. Data on controlled NPPV have not been published to date. We hypothesize that controlled ventilation ...
McKenzie D J - - 2007
The jeju is a teleost fish with bimodal respiration that utilizes a modified swim bladder as an air-breathing organ (ABO). Like all air-breathing fish studied to date, jeju exhibit pronounced changes in heart rate (fH) during air-breathing events, and it is believed that these may facilitate oxygen uptake (MO2) from ...
Luo Y M - - 2008
For a given neural drive, oesophageal pressure during apnoeic episodes may differ from that during airflow, since inspiratory airflow and increased lung volume both reduce pressure generation. It was, therefore, hypothesised that diaphragm electromyography (EMG) may provide additional data to oesophageal pressure when used for the assessment of neural drive ...
Argent Andrew C - - 2008
RATIONALE: The assessment of the severity of croup and response to therapy has remained a clinical one. Despite recognition of the importance of a reproducible and easily applicable method for objectively measuring severity, currently, no such technique exists. OBJECTIVES: We postulated that measurements of air flow and intrathoracic pressure changes ...
Novalija J - - 2007
Breath-hold divers use glossopharyngeal breathing to inhale above total lung capacity (glossopharyngeal insufflation, GI) or exhale below residual volume (glossopharyngeal exsufflation, GE). In these maneuvers, air is moved using glossopharyngeal rather than respiratory muscle activity. Four competitive divers performed several GI and GE maneuvers in sitting or standing position, while ...
Tafil-Klawe M - - 2007
We evaluated daily variability in the cardiovascular response to arterial chemoreceptors activation during breath holding in shift workers who were obstructive sleep apnea patients. Ten patients and 10 weight and age-matched control subjects were enrolled in the study. The experimental sessions consisted of 10 episodes of breath holding on inspiration ...
Yang Pearl - - 2007
INTRODUCTION: Prolonged +G,-exposure eventually decreases a pilot's ability to maintain an effective anti-G straining maneuver (AGSM). Previous studies have implicated the respiratory muscles (RMs) as main contributors to this AGSM-induced fatigue. Thus, this study aimed to investigate if respiratory muscle training (RMT) may be of benefit to improve RM strength, ...
Sumners David Paul - - 2008
OBJECTIVE: To investigate whether 10 breaths against a vibration stimulus elicits increments of spontaneous and maximal inspiratory mouth pressure (maxMP) and tidal mean inspiratory flow (iV(T)/T(I)) upon stimulus removal. METHODS: Twelve healthy subjects (8 female, 4 male; 22-50 years old), recruited from the University student body, completed 3 maximal inspirations ...
Clemens Katri Elina - - 2008
GOALS: This study assessed the effect of hydromorphone treatment on ventilation and the intensity of dyspnea in palliative care patients. The assessments measured changes in peripheral oxygen saturation (SaO(2)), transcutaneous arterial pressure of carbon dioxide (tcpaCO(2)), respiratory rate (f), and pulse frequency (PF) during the titration phase with hydromorphone for ...
Someya Nami - - 2007
Breathing including abdominal movement could affect the blood velocity (BV) measurement in the visceral arteries. The present study investigated the effect of breathing frequency on the renal artery (RA) and superior mesenteric artery (SMA) BV measurements. We measured mean arterial pressure (MAP), heart rate (HR) and BV in the RA ...
Foschino Barbaro M P - - 2007
Chronic obstructive pulmonary diseases (COPD) is a pulmonary disease characterized by systemic abnormalities. The aim of this study is to investigate inflammation and systemic effects in mild COPD. Twenty-seven mild stable smoking related COPD patients and 15 age-matched healthy subjects were enrolled in the study. IL-6, TNF-alpha and IL-4 in ...
Terzi N - - 2008
Inspiratory muscle strength monitoring is crucial in patients with neuromuscular disorders. The sniff nasal inspiratory pressure (SNIP) and maximal inspiratory pressure (P(I,max)) are usually measured. The present study investigated whether the test yielding the best value at baseline continued to yield the best value during follow-up. The present study included ...
Qureshi Ahmad S - - 2007
OBJECTIVE: To assess whether subtracting the expiratory change in intra-abdominal (bladder) pressure (Delta IAP) from central venous pressure (CVP) provides a reliable estimate of transmural CVP in spontaneously breathing patients with expiratory muscle activity. DESIGN AND SETTING: Prospective observational study in a medical ICU. PATIENTS: Twenty-four spontaneously breathing patients with ...
Bellemare Patrick - - 2007
A readily available assessment of changes in pleural pressure would be useful for ventilator and fluid management in critically ill patients. We examined whether changes in pulmonary artery occlusion pressure (Ppao) adequately reflect respiratory changes in pleural pressure as assessed by changes in intraesophageal balloon pressure (Peso). We studied patients ...
Nilsson L - - 2007
BACKGROUND: The non-invasive photoplethysmographic (PPG) signal reflects blood flow and volume in a tissue. The PPG signal shows variation synchronous with heartbeat (PPGc), as used in pulse oximetry, and variations synchronous with breathing (PPGr). PPGr has been used for non-invasive monitoring of respiration with promising results. Our aim was to ...
Thijs Roland D - - 2007
BACKGROUND: Selective increase of inspiratory impedance augments blood pressure in healthy subjects through activation of the respiratory pump. We studied the efficacy of respiratory maneuvers to reduce orthostatic hypotension in autonomic failure. METHODS: Mean arterial pressure (MAP) after standing up was recorded in 10 patients in five conditions: normal standing, ...
Reitz Christiane - - 2007
Over the past decade several studies have assessed the relation of blood pressure with cognitive function and dementia. While some cross-sectional studies have shown an inverse association between blood pressure levels and cognitive performance or dementia, longitudinal studies yielded controversial results. Most studies relating blood pressure levels in mid-life with ...
Kallet Richard H - - 2007
BACKGROUND: The spontaneous breathing pattern and its relationship to compliance, resistance, and work of breathing (WOB) has not been examined in patients with acute respiratory distress syndrome (ARDS) or acute lung injury (ALI). Clinically, the ratio of respiratory frequency to tidal volume (f/VT) during spontaneous breathing may reflect adaptation to ...
Haouzi Philippe - - 2007
This study addresses the following question: does the ventilatory control system adjust total ventilation in accord with the regulatory demands of the physiological dead space ventilation (VD) when the breathing frequency changes, and if so, how? A simple proportionality between the amplitude of the respiratory motor output (VT) and the ...
Alton Lesley A - - 2007
The effects of experimental alterations of aerial O2 partial pressure (PO2,air) on bimodal gas exchange and air-breathing behaviour were investigated in the aquatic air-breathing fish Trichogaster leeri in normoxic water. Fish responded to increasing PO2,air by decreasing air-breathing frequency, increasing aerial O2 consumption rate (VO2), increasing mean O2 uptake per ...
Mirkovic Tomislav - - 2007
PURPOSE: Proportional assist ventilation (PAV) uses volume assist (VAV) and flow assist ventilation (FAV) to reduce elastic and resistive effort, respectively. Proportional assist ventilation may be difficult to apply clinically, particularly due to FAV related considerations. It was hypothesized that regulating tracheal (Ptr) rather than airway opening pressure (Pao), to ...
Caldiroli D - - 2007
BACKGROUND AND OBJECTIVE: The importance of monitoring the breathing pattern during sedation of children undergoing magnetic resonance scans is indicated in guidelines, but no appropriate magnetic resonance-compatible devices are available. We report preliminary findings from a technique referred to as remote pressure sensor respiratory plethysmography. METHODS: A data acquisition system ...
Soubrier Stéphane - - 2007
OBJECTIVE: To investigate whether the respiratory changes in arterial pulse (DeltaPP) and in systolic pressure (DeltaSP) could predict fluid responsiveness in spontaneously breathing (SB) patients. Because changes in intrathoracic pressure during spontaneous breathing (SB) might be insufficient to modify loading conditions of the ventricles, performances of indicators were also assessed ...
Kolodziej M A - - 2007
The present systematic review examined the effectiveness of bilevel noninvasive positive pressure ventilation (NIPPV) in the management of chronic respiratory failure (CRF) due to severe stable chronic obstructive pulmonary disease (COPD). Randomised controlled trials (RCTs) and non-RCTs (crossover design) of adults with severe stable COPD and CRF receiving bilevel NIPPV ...
Slessarev Marat - - 2007
Current methods of forcing end-tidal PCO2 (PETCO2) and PO2 (PETO2) rely on breath-by-breath adjustment of inspired gas concentrations using feedback loop algorithms. Such servo-control mechanisms are complex because they have to anticipate and compensate for the respiratory response to a given inspiratory gas concentration on a breath-by-breath basis. In this ...
Longhurst M J - - 2007
The pressure dependence of shifts in the vibrational modes of individual carbon nanotubes is strongly affected by the nature of the pressure transmitting medium as a result of adsorption at the nanotube surface. The adsorbate is treated as an elastic shell which couples with the radial breathing mode (RBM) of ...
Ivancev Vladimir - - 2007
Hypercapnic cerebrovascular reactivity is decreased in obstructive sleep apnoea and congestive heart disease perhaps as a result of repeated apnoeas. To test the hypothesis that repeated apnoeas blunt cerebrovascular reactivity to hypercapnia, we studied breath hold divers and determined cerebrovascular reactivity by measuring changes in middle cerebral artery velocity (MCAV, ...
Yates Adam Michael - - 2007
OBJECTIVE: We were aware of a small number of cases in our EMS system where patients in respiratory distress had a worsening of their condition after being removed from the home on a Reeves stretcher (RS). We sought to determine if this prehospital lifting device causes additional respiratory effort used ...
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