Search Results
Results 401 - 450 of 1912
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Jerath Ravinder - - 2009
High blood pressure is an important component of pre-eclampsia. The underlying mechanism of development of hypertension in pre-eclampsia is complicated and still remains obscure. Several theories have been advanced including endothelial dysfunction, uteroplacental insufficiency leading to generalized vasoconstriction, increased cardiac output, and sympathetic hyperactivity. Increased blood flow and pressure are ...
Bhatt S P - - 2009
OBJECTIVE: To examine changes in respiratory dynamics in patients with chronic obstructive pulmonary disease (COPD) sitting leaning forward with hands supported on the knees (tripod position), a posture frequently assumed by patients in respiratory distress. METHODS: Spirometry, maximal inspiratory and expiratory pressures (MIP and MEP) generated at the mouth, and ...
Nemer Sérgio N - - 2009
PURPOSE: The objective of this study is to evaluate the predictive performance of maximal inspiratory pressure (Pimax), airway occlusion pressure (P 0.1), and its ratio (P 0.1/Pimax) in the weaning outcome. MATERIALS AND METHODS: Seventy patients on mechanical ventilation for more than 24 hours, who fulfilled weaning criteria, were prospectively ...
How Stephen C - - 2009
Large inspiratory pressures may impart stretch to airway smooth muscle and modify the response to deep inspiration (DI) in asthmatics. Respiratory system resistance (Rrs) was assessed in response to 5 inspiratory manoeuvres using the forced oscillation technique: (a) single unloaded DI; (b) single DI at 25 cmH(2)O; (c) single DI ...
Lecomte François - - 2009
This study evaluated the response to increasing levels of neurally adjusted ventilatory assist (NAVA), a mode converting electrical activity of the diaphragm (EAdi) into pressure, regulated by a proportionality constant called the NAVA level. Fourteen rabbits were studied during baseline, resistive loading and ramp increases of the NAVA level. EAdi, ...
Lumsden, Amanda Lloyd
Carp responded to changes in partial pressure of oxygen in the water, both increases and decreases, in a manner similar to other teleost fish. Hypoxia resulted in significant increases in ventilation (both frequency and amplitude). A reflex hypoxic bradycardia, however, was not observed in the present study and, in fact, ...
Patel Deena-Shefali - - 2009
OBJECTIVES: The objectives of this study were to determine the impact of different volume-targeted levels on the work of breathing and to investigate whether a level that reduced the work of breathing below that experienced during ventilatory support without volume targeting could be determined. METHODS: The transdiaphragmatic pressure-time product, as ...
Pramanik Tapas - - 2009
OBJECTIVES: The objective of this study was to evaluate the immediate effect of slow pace bhastrika pranayama (respiratory rate 6/min) for 5 minutes on heart rate and blood pressure and the effect of the same breathing exercise for the same duration of time (5 minutes) following oral intake of hyoscine-N-butylbromide ...
Garland, Rhonda J.
During hibernation the breathing pattern of the golden-mantled ground squirrel consists of short episodes of breathing separated by pauses ranging in length from less than a minute to greater than 30 minutes. A breathing pattern as such results in wide fluctuations in the partial pres sure of oxygen (PO₂ )and ...
Patel D-S - - 2009
OBJECTIVE: In a randomised trial, pressure support with synchronised intermittent mandatory ventilation (SIMV) compared to SIMV alone was associated with a significant reduction in supplementary oxygen duration. The hypothesis that the addition of pressure support to SIMV compared to SIMV alone would reduce the work of breathing was examined. DESIGN: ...
Padilha I T - - 2009
Multi-band systems such as inter-metallic and heavy fermion compounds have quasi-particles arising from different orbitals at their Fermi surface. Since these quasi-particles have different masses or densities, there is a natural mismatch of the Fermi wavevectors associated with different orbitals. This makes these materials potential candidates to observe exotic superconducting ...
Kirkpatrick Andrew W - - 2009
OBJECTIVE: Laparoscopic surgery (LS) is envisioned as an option for spaceflight, but requires intra-abdominal hypertension (IAH) to create the surgical domain. Prolonged weightlessness induces physiologic deconditioning that questions the ability of ill or injured astronauts to tolerate IAH. On earth, IAH results in marked ventilatory embarrassment. As there has been ...
Hongratanaworakit Tapanee - - 2009
One increasingly popular type of alternative therapy is aromatherapy, but scientific validation in this field is still rare. The aim of this study was to investigate the effect of rose oil (Rosa damascena Mill, Rosaceae) on human autonomic parameters and emotional responses in healthy subjects after transdermal absorption. In order ...
Weber-Carstens Steffen - - 2009
OBJECTIVE: The fibroproliferative phase of late ALI/ARDS as described by Hudson and Hough (Clin Chest Med 27:671-677, 2006) is associated with pronounced reductions in pulmonary compliance and an accompanying hypercapnia complicating low tidal volume mechanical ventilation. We report the effects of extracorporeal CO(2) removal by means of a novel pumpless ...
Murray Angus - - 2009
BACKGROUND AND OBJECTIVE: In patients after surgery, we observed large-amplitude low-frequency changes in digital plethysmograph measurements when DC coupling of the signal was used. We set out to assess factors that might contribute to these events and in particular to test the possibility that low-frequency signals could be used to ...
de Winter-de Groot K M - - 2009
BACKGROUND: Specific guidelines are developed for the measurement of bronchial FE(NO), however, nasal nitric oxide (nNO) measurement is not standardised yet, resulting in divergent nNO values. This study compares six different sampling methods for nNO as described in the literature, to analyse their outcome and short term and long term ...
Cavaliere Franco - - 2009
High levels of exhaled carbon monoxide (eCO) are a marker of airway or lung inflammation. We investigated whether hypo- or hyperventilation can affect measured values. Ten healthy volunteers were trained to achieve sustained end-tidal CO2 (etCO(2)) concentrations of 30 (hyperventilation), 40 (normoventilation), and 50 mmHg (hypoventilation). As soon as target ...
Krause K L - - 2009
Abrupt neurotoxic destruction of >70% of the pre-Bötzinger complex (preBötzC) in awake goats results in respiratory and cardiac failure (Wenninger JM, Pan LG, Klum L, Leekley T, Bastastic J, Hodges MR, Feroah TR, Davis S, Forster HV. J Appl Physiol 97: 1629-1636, 2004). However, in reduced preparations, rhythmic respiratory activity ...
Hansel Jochen - - 2009
The incidence and nature of cardiac arrhythmias during static apnea were studied by monitoring the electrocardiogram (ECG) and oxygen saturation (SaO(2)) of 16 recreational breath-hold divers. All subjects completed a maximal apnea with a mean (+/-SD) breath-hold duration of 281 (+/-73) s without clinical complications. Both heart rate (HR) and ...
Wojciechowski Piotr - - 2009
Biphalin (0.3 mg/kg) administered intravenously (i.v.) to urethane-chloralose anaesthetized rats consistently evoked apnoea, followed by breathing at subnormal respiratory rate with increased tidal volume. Mean arterial pressure and heart rate were lowered. Naloxone completely antagonized the respiratory and cardiovascular responses to biphalin. Midcervical vagotomy prevented all respiratory effects of biphalin, ...
Moon R E - - 2009
Diving-related pulmonary effects are due mostly to increased gas density, immersion-related increase in pulmonary blood volume, and (usually) a higher inspired Po(2). Higher gas density produces an increase in airways resistance and work of breathing, and a reduced maximum breathing capacity. An additional mechanical load is due to immersion, which ...
Grönkvist Mikael - - 2008
BACKGROUND: Positive pressure breathing (PPB) is commonly used in modern fighter aircraft as part of the anti-G ensemble. PPB is combined with a chest counterpressure bladder which is pressurized to the same magnitude as the breathing mask (balanced PPB). The chest counterpressure is expected to reduce the expiratory work of ...
Levin Daniel L - - 2008
OBJECTIVE: To study patients with respiratory syncytial virus bronchiolitis in respiratory failure to make specific measurements reflecting airway resistance before and after treatment with commonly used agents. We hypothesized that racemic epinephrine would decrease airways resistance more effectively than levalbuterol, and levalbuterol would decrease airways resistance more effectively than racemic ...
Weese-Mayer Debra E - - 2008
This study was designed to specifically characterize the autonomic phenotype of cardiorespiratory dysregulation during the nighttime in young girls with MECP2 mutation-confirmed Rett Syndrome (RS), studied in their home environment. Computerized breath-to-breath and beat-to-beat characterization of at-home continuously recorded respiratory inductance plethysmography of chest/abdomen and ECG (VivoMetrics, Inc.) was obtained ...
Tzeng Y C - - 2009
Respiratory sinus arrhythmia (RSA) may serve an inherent function in optimizing pulmonary gas exchange efficiency via clustering and scattering of heart beats during the inspiratory and expiratory phases of the respiratory cycle. This study sought to determine whether physiological levels of RSA, enhanced by slow paced breathing, caused more heart ...
Lindholm Peter - - 2009
This is a brief overview of physiological reactions, limitations, and pathophysiological mechanisms associated with human breath-hold diving. Breath-hold duration and ability to withstand compression at depth are the two main challenges that have been overcome to an amazing degree as evidenced by the current world records in breath-hold duration at ...
Van Diest Ilse - - 2009
This study aimed to investigate ventilatory correlates of conditioned fear responses. Respiratory, end-tidal carbon dioxide pressure (PetCO(2)) and heart rate changes were studied in a differential fear-conditioning paradigm. Forty-two participants viewed pictures of faces. One picture (CS+) was followed by a human scream (US) during the acquisition phase, but not ...
Chiti Linda - - 2008
We hypothesized that (1) in healthy humans subjected to intermittent positive pressure non-invasive ventilation, changes in the ventilator trigger sensitivity would be associated with increased scalene activity, (2) if properly processed - through inspiratory phase-locked averaging - surface electromyograms (EMG) of the scalenes would reliably detect and quantify this, (3) ...
Monge García Manuel Ignacio - - 2009
OBJECTIVE: To evaluate whether arterial pressure response during a Valsalva maneuver could predict fluid responsiveness in spontaneously breathing patients. DESIGN AND SETTING: Prospective clinical study in a 17-bed multidisciplinary intensive care unit. PATIENTS: Thirty patients without mechanical ventilation and equipped with a radial arterial catheter for whom the decision to ...
Anderson David E - - 2008
Previous research has reported that inhibition of breathing can be observed in hypertensive patients at rest during the daytime, as well as in sleep at night. The present study hypothesized that the variability of breathing and end-tidal CO(2) (PetCO(2)) in seated women at rest is positively associated with their 24-h ...
Van Diest Ilse - - 2009
The present study aimed to explore inspiratory motor drive as measured by inspiratory occlusion pressure (P100) during affective picture viewing. P100 is the decrease in mouth pressure that develops 100 ms after an inspiratory effort against a closed breathing circuit. The P100 is a measure of the "central respiratory drive." ...
Barbiero Eliane de Fáveri F Ede - - 2008
OBJECTIVES: Assess the effect of re-expansive respiratory patterns associated to respiratory biofeedback (RBF) on pulmonary function, respiratory muscle strength and habits in individuals with functional mouth breathing (FMB). METHODS: Sixty children with FMB were divided into experimental and control groups. The experimental group was submitted to 15 sessions of re-expansive ...
Geddes L A - - 2008
The objective of this 14-pig study was designed to determine the amount of lung ventilation obtainable by only rhythmic chest compression (100/min, 100 lbs). Tidal volume (TV), dead space (DS), and respiration rate (R) were measured with normal breathing and with rhythmic chest compression during ventricular fibrillation. The ratio of ...
Essouri Sandrine - - 2008
INTRODUCTION: A prospective physiological study was performed in 12 paediatric patients with acute moderate hypercapnic respiratory insufficiency to assess the ability of noninvasive positive pressure ventilation (NPPV) to unload the respiratory muscles and improve gas exchange. MATERIALS AND METHODS: Breathing pattern, gas exchange, and inspiratory muscle effort were measured during ...
Yang Chih-Wei - - 2008
OBJECTIVE: Both ventilations and compressions are important for victims of prolonged cardiopulmonary resuscitation (CPR) and asphyxial arrest. Dispatch assistance increases bystander CPR, but the quality of dispatcher-assisted CPR (DA-CPR), especially rescue breathing, remains unsatisfactory. This study was conducted to assess the impact of adding interactive video communication to dispatch instructions ...
Tanoubi Issam - - 2008
Introduction: Preoxygenation optimizes oxygen content in the functional residual capacity (FRC). Creating a better reservoir with the help of inspiratory support and PEEP could improve gas exchange and shorten the time needed for adequate preoxygenation, defined as expiratory oxygen fraction (FEO2) greater than 90%. The goal of this study was ...
Teboul Jean-Louis - - 2008
PURPOSE OF REVIEW: Predicting volume responsiveness in patients with spontaneous breathing activity is a difficult challenge in the emergency room as well as in the intensive care unit because heart-lung interactions indices cannot be reliably used as they can be in mechanically ventilated patients fully adapted to their ventilator. The ...
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 ...
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