Search Results
Results 551 - 600 of 1429
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Kiefer P - - 2000
OBJECTIVE: To evaluate the acute effects of an increased positive end-expiratory pressure (PEEP) on splanchnic tissue perfusion. DESIGN: Clinical prospective study. SETTING: Intensive care unit in a university clinic. PATIENTS: Six patients with severe acute lung injury (ALI) requiring mechanical ventilation. All patients had bilateral infiltrates in chest X-ray, PaO2/FiO2 ...
Adams A B - - 2000
BACKGROUND: Noninvasive positive pressure ventilation (NPPV) has been studied in several settings and shown to reduce patient morbidity associated with endotracheal intubation. Intolerance to NPPV has been estimated at 25-33%, a substantial proportion of attempts to ventilate noninvasively. Bi-level pressure ventilators (BPVs) have been designed for NPPV, yet their response ...
Jellinek H - - 2000
OBJECTIVE: To evaluate if the preexistant filling state, assessed by right atrial pressure (RAP), pulmonary artery occlusion pressure (PAOP), and right ventricular end-diastolic volume index (EDVI), would define the subsequent hemodynamic effects of increases in airway pressure (Paw). DESIGN: Prospective open clinical study. SETTING: Postoperative intensive care unit, university hospital. ...
Sahebjami H - - 2000
A substantial number of patients with COPD are underweight (UW); they comprise the clinical subtype of "dyspneic" or emphysematous. To determine whether these patients are more dyspneic than normal weight (NW) patients with COPD, we quantitated the severity of dyspnea, using a modified Medical Research Council (MRC) dyspnea scale, in ...
Toung T J - - 2000
Mechanical ventilation with positive end-expiratory pressure (PEEP) may prevent venous air embolism in the sitting position because cerebral venous pressure (Pcev) could be increased by the PEEP-induced increase in right atrial pressure (Pra). Whereas it is clear that there is a linear transmission of the PEEP-induced increase in Pra to ...
Loeckinger A - - 2000
Laparoscopy is a surgical technique for a growing variety of abdominal operations. In patients undergoing this procedure, arterial blood oxygenation and hemodynamics are frequently depressed. This study evaluated the effect of different levels of positive end-expiratory pressure (PEEP) during intraperitoneal CO(2) insufflation on the lung's ventilation-perfusion distribution in a porcine ...
Smith R P - - 2000
We investigated the effects of positive end-expiratory pressure (PEEP) on carbon dioxide (CO2) elimination in a cross-over study of 14 patients whose lungs were ventilated after cardiac surgery. They initially received either 7.5 cm H2O PEEP or zero end-expiratory pressure and were then changed over to the other mode. We ...
Lu Q - - 2000
Physiological background concerning mechanics of the respiratory system, techniques of measurement and clinical implications of pressure-volume curve measurement in mechanically ventilated patients are discussed in the present review. The significance of lower and upper inflection points, the assessment of positive end-expiratory pressure (PEEP)-induced alveolar recruitment and overdistension and rationale for ...
JedliƄska B B Department of Anaesthesiology, Malmö University Hospital, Malmö, Sweden. - - 2000
Measurements of subcutaneous oxygen tension (PscO(2)), subcutaneous carbon dioxide tension (PscCO(2)) and subcutaneous pH (pHsc) were used for evaluation of peripheral oxygenation in pigs subjected to oleic acid-induced lung injury during ventilation with increasing levels of positive end-expiratory pressure (PEEP). Lung injury resulted in a decrease of arterial oxygen tension ...
Ferreyra G - - 2000
STUDY QUESTION: To determine whether a positive end-expiratory pressure (PEEP) level equivalent to the lower inflection point (LIP) could be identified by evaluation of the airway pressure, flow (f1. gif" BORDER="0">), and volume vs time waveforms during partial liquid ventilation (PLV). DESIGN: Prospective application of PEEP during PLV in a ...
Herrejón A - - 2000
To assess whether pleural pressure (PP) measurement is helpful in evaluating the evolution of spontaneous pneumothorax (SP). To measure the inspiratory and expiratory PP at tidal volume in the SP in 85 cases. Ninety-one percent were cured with medical treatment, whereas the remaining 9% required surgery. In the cases medically ...
Auler J O JO - - 2000
We prospectively evaluated the effects of positive end-expiratory pressure (PEEP) on the respiratory mechanical properties and hemodynamics of 10 postoperative adult cardiac patients undergoing mechanical ventilation while still anesthetized and paralyzed. The respiratory mechanics was evaluated by the inflation inspiratory occlusion method and hemodynamics by conventional methods. Each patient was ...
Manaligod J M - - 2000
STUDY OBJECTIVES: To determine the effects of different levels of positive end-expiratory pressure (PEEP) during partial liquid ventilation (PLV) on gas exchange, lung compliance, and end-expiratory lung volume (EELV). DESIGN: Prospective animal study. SETTING: Animal physiology research laboratory. SUBJECTS: Nine piglets. INTERVENTIONS: Animals underwent saline solution lavage to produce lung ...
Kotzampassi K - - 2000
Experimental studies and clinical experience suggest that the combination of positive end-expiratory pressure (PEEP) ventilation and intra-abdominal hypertension might alter splanchnic hemodynamics to a significantly greater degree than the effect of either of them alone. Therefore, we assessed the intestinal and hepatic hemodynamics in two steps of PEEP ventilation, adding ...
MacIntyre N R - - 2000
A large body of animal literature has shown that lungs stretched beyond their normal maximum are likely to be injured and release inflammatory cytokines into the systemic circulation. Moreover, this injury seems to be compounded if alveolar collapse also occurs. This has give rise to the notion that adequate positive ...
Verbrugge S J - - 1999
BACKGROUND: Using an in vivo animal model of surfactant deficiency, the authors compared the effect of different ventilation strategies on oxygenation and inflammatory mediator release from the lung parenchyma. METHODS: In adult rats that were mechanically ventilated with 100% oxygen, acute lung injury was induced by repeated lung lavage to ...
Lichtwarck-Aschoff M - - 1999
Setting an appropriate positive end-expiratory pressure (PEEP) value is determined by respiratory mechanics, gas exchange and oxygen transport. As these variables may be optimal at different PEEP values, a unique PEEP value may not exist which satisfies both the demands of minimizing mechanical stress and optimizing oxygen transport. In 15 ...
Verbrugge S J - - 1999
OBJECTIVE: High-frequency oscillation studies have shown that ventilation at high end-expiratory lung volumes combined with small volume cycles at high rates best preserves exogenous surfactant and gas exchange in lavaged lungs. We investigated whether surfactant composition and gas exchange can also be preserved by conventional modes of mechanical ventilation, which ...
Pelosi P - - 1999
BACKGROUND: Morbidly obese patients, during anesthesia and paralysis, experience more severe impairment of respiratory mechanics and gas exchange than normal subjects. The authors hypothesized that positive end-expiratory pressure (PEEP) induces different responses in normal subjects (n = 9; body mass index < 25 kg/m2) versus obese patients (n = 9; ...
Kirmse M - - 1999
Although tracheal gas insufflation (TGI) has proved to be a useful adjunct to mechanical ventilation, end-inspiratory as well as end-expiratory pressures may increase. We investigated the ability of continuous-flow TGI to maintain eucapnia while reducing airway pressure (Paw) and tidal volume (VT). Seven sheep (36 +/- 2 kg) were ventilated ...
Dimitriou G - - 1999
Positive end expiratory pressure (PEEP) is routinely used when ventilating preterm infants, and high levels are recommended in those with severe respiratory distress syndrome (RDS). Elevation of PEEP increases lung volume, as does surfactant administration. We postulated that in surfactant-treated infants even modest PEEP levels could result in overdistension and ...
Guerin C - - 1999
OBJECTIVE: To investigate the effects of prone position (PP) on alveolar recruitment and oxygenation in acute respiratory failure. DESIGN: Prospective physiologic study. SETTING: Medical ICU two in a university hospital. PATIENTS: Twelve adult patients intubated and mechanically ventilated with medical primary acute lung injury/adult respiratory distress syndrome (ALI/ARDS) in whom ...
Papadopoulos G S - - 1999
We report the case of a patient, in whom a patent foramen ovale was detected. For the detection of a patent foramen ovale simulation of Valsalva's manoeuvre with a positive airway pressure of 20 cm H2O was applied. Change of ventilation manoeuvre by ventilation with positive airway pressure of 35/30/15 ...
Gookin J L - - 1999
This study was undertaken to determine if pleural effusion (PEF) increases central venous pressure (CVP) in cats, to define any relationship between volume of PEF and CVP and to ascertain the significance of CVP alterations in cats having PEF and suspected right heart failure (RHF). CVP was measured from a ...
Pinto A C - - 1999
Sleep disruption in ALS/MND is related to hypoventilation and nocturnal O(2) saturation. Maximal inspiratory pressure (PI(max)) proved sensitive in predicting nocturnal O(2) saturation. However, PI(max) is highly dependent on patient collaboration; on the other hand Mouth Occlusion Pressure (MOP) is a reliable, non-volitional parameter index of central respiratory drive. Since ...
Woda R P - - 1999
OBJECTIVE: Auto-positive end-expiratory pressure (auto-PEEP) is a physiologic phenomenon defined as the positive alveolar pressure that exists at the end of expiration. Normally, the alveolar pressure is near zero at the end of expiration. However, certain ventilatory and/or physiologic paradigms can cause the development of auto-PEEP during cardiopulmonary resuscitation (CPR). ...
Liu J M - - 1999
OBJECTIVE: To study pressure-volume (P/V) curves over a wide pressure and volume range in pigs. DESIGN: Dynamic and static P/V curves (P(dyn)/V and P(st)/V) and compliance of the respiratory system were studied. The effects of recruitment, positive end-expiratory pressure (PEEP) and body position were analysed. SETTING: Research animal laboratory. MATERIALS: ...
Jardin F F Medical Intensive Care Unit, University Hospital Ambroise Paré, Assistance Publique-Hôpitaux de Paris, 9 avenue Charles de Gaulle, F-92 104 Boulogne Cedex, - - 1999
Evaluation of the impact of low-volume, pressure-limited ventilation on the recovery rate of acute respiratory distress syndrome (ARDS). Prospective observational clinical study with historical control. University hospital intensive care unit (ICU). We studied two groups of, respectively, 33 and 37 ARDS patients separated by 15 years ("historical", June 1978-April 1981, ...
Frerichs I - - 1999
The aim of the study was to analyze thoracic electrical impedance tomographic (EIT) measurements accomplished under conditions comparable with clinical situations during artificial ventilation. Multiple EIT measurements were performed in pigs in three transverse thoracic planes during the volume controlled mode of mechanical ventilation at various tidal volumes (V(T)) and ...
Rimensberger P C - - 1999
OBJECTIVES: Ventilation with positive end-expiratory pressure (PEEP) above the inflection point (P(inf)) has been shown to reduce lung injury by recruiting previously closed alveolar regions; however, it carries the risk of hyperinflating the lungs. The present study examined the hypothesis that a new strategy of recruiting the lung with a ...
Zobel G - - 1999
OBJECTIVES: To investigate the effects of positive end-expiratory pressure (PEEP) application during partial liquid ventilation (PLV) on gas exchange, lung mechanics, and hemodynamics in acute lung injury. DESIGN: Prospective, randomized, experimental study. SETTING: University research laboratory. SUBJECTS: Six piglets weighing 7 to 12 kg. INTERVENTIONS: After induction of anesthesia, tracheostomy, ...
Ben-Abraham R - - 1999
PURPOSE: The clinical literature on the incidence and subsequent mortality of adult respiratory distress syndrome (ARDS) has come primarily from the experiences of large tertiary referral centers, particularly in Western Europe and North America. Consequently, very little has been published on the incidence, management, and outcome of ARDS in smaller ...
Villar J - - 1999
BACKGROUND: Despite intensive research, there are no universally accepted clinical definitions for acute lung injury (ALI) or the acute respiratory distress syndrome (ARDS). A recent joint American-European Consensus Conference on ARDS formally defined the difference between ALI and ARDS based on the degree of oxygenation impairment. However, this definition may ...
Yu J - - 1999
In open-chest artificially ventilated rabbits, removal followed by replacement of positive end-expiratory pressure (PEEP maneuver) favors stimulation of airway rapidly adapting receptors (RARs). The purpose of the present study was to determine whether activation of RARs can cause bronchoconstriction. We measured airway pressure, airflow, and tidal volume, and calculated dynamic ...
Connery L E - - 1999
Chronic obstructive pulmonary disease (COPD) is commonly associated with positive alveolar pressure at end-expiration (intrinsic PEEP or PEEPi) caused by a prolonged expiratory time constant. Positive pressure ventilation (PPV) with large tidal volumes and high ventilatory frequencies may cause pulmonary hyperinflation, with increases in intrathoracic pressure and cardiopulmonary effects. We ...
Hughes P D - - 1999
Reduced respiratory muscle strength has been reported in chronic heart failure (CHF) in several studies. The data supporting this conclusion come almost exclusively from static inspiratory and expiratory mouth pressure maneuvers (MIP, MEP), which many subjects find difficult to perform. We therefore performed a study using measurements that are less ...
Yamada T - - 1999
The effect of positive end-expiratory pressure (PEEP) on left and right ventricular diastolic filling dynamics was assessed by transmitral and transtricuspid flow patterns. Using transoesophageal Doppler echocardiography in fourteen ASA physical status 1 female patients, the following measurements were performed at baseline (0 cm H2O PEEP) and at 5, 10, ...
Heard S O SO Department of Anesthesiology, UMass Memorial Medical Center, Worcester 01655, USA. - - 1999
Hydrogen peroxide (H2O2) levels are increased in the exhaled breath of patients with the acute respiratory distress syndrome (ARDS). Because liposome-encapsulated prostaglandin E1 (PGE1) downregulates the CD11/CD18 receptor of the neutrophil, thereby limiting endothelial adhesion, the use of this drug should decrease the excretion of H2O2 in the expiratory condensate ...
Sharma R R - - 1999
BACKGROUND: Laparoscopic cholecystectomy is presumed to induce a reduction in diaphragmatic activity. Indirect indices of diaphragmatic function based on tidal changes in pressures and cross-section area measurements can be unreliable in the postoperative phase. The present study evaluates diaphragmatic activity by directly recording diaphragmatic EMG (EMGdia) data, along with indirect ...
Ranieri V M VM Istituto di Anestesiologia e Rianimazione, Università di Bari, Ospedale Policlinico, Italy. - - 1999
Studies have shown that an inflammatory response may be elicited by mechanical ventilation used for recruitment or derecruitment of collapsed lung units or to overdistend alveolar regions, and that a lung-protective strategy may reduce this response. To test the hypothesis that mechanical ventilation induces a pulmonary and systemic cytokine response ...
Seeman-Lodding H - - 1999
BACKGROUND: Endothelium-derived tissue-type plasminogen activator, t-PA, is the key enzyme in the initiation of endogenous thrombolysis. Plasma levels of t-PA increase in response to sympatho-adrenergic activation. In the mesenteric vascular bed an increased norepinephrine spillover has been observed during positive end-expiratory pressure ventilation, PEEP. This experimental study examines the effects ...
Venkataraman S T - - 1999
We analyzed the effect of two levels of positive end-expiratory pressure (PEEP: 10 and 15 cm H2O) on pulmonary hemodynamics in neonatal piglet lungs isolated in situ and perfused extracorporeally using pulmonary artery pressure-flow (Pa/Q) relationships. Pulmonary artery pressure (Pa) was measured at flow rates of 50, 75, 100, 125, ...
Richecoeur J - - 1999
The aim of this study was to compare three ventilatory techniques for reducing PaCO2 in patients with severe acute respiratory distress syndrome treated with permissive hypercapnia: (1) expiratory washout alone at a flow of 15 L/min, (2) optimized mechanical ventilation defined as an increase in the respiratory frequency to the ...
Panczel G - - 1999
BACKGROUND AND PURPOSE: Diminished vasoreactivity (VR) has been evidenced in patients with hemispheric small vessel disease, however, there is no data regarding vertebrobasilar (VB) territory VR changes in patients with subcortical vascular encephalopathy located in the brainstem. Therefore, we compared the cerebral blood flow velocity (CBFV) responses of the VB ...
Weytjens K - - 1999
BACKGROUND: FEV1 is more sensitive than PEF in assessing late asthmatic responses (LAR) after specific inhalation challenges (SIC) with occupational agents. As immediate asthmatic reactions (IAR) mainly involve proximal airways, PEF may, however, be as valid as FEV1. METHODS: Thirty-seven subjects who experienced an immediate fall in FEV1 of > ...
Blanch L - - 1999
The aim of the study was to analyse the effects of positive end-expiratory pressure (PEEP) on volumetric capnography and respiratory system mechanics in mechanically ventilated patients. Eight normal subjects (control group), nine patients with moderate acute lung injury (ALI group) and eight patients with acute respiratory distress syndrome (ARDS group) ...
Theres H - - 1999
OBJECTIVE: To examine determinants of right ventricular function throughout the ventilatory cycle under volume-controlled mechanical ventilation with various positive end-expiratory pressure (PEEP) stages. DESIGN: Prospective observational animal pilot study. SETTING: Animal research laboratory at a university hospital. SUBJECTS: Eight healthy swine under volume- controlled mechanical ventilation. INTERVENTIONS: Flow probes were ...
Jonson B - - 1999
Measuring elastic pressure-volume (Pel-V) curves of the respiratory system and the volume recruited by a positive end-expiratory pressure (PEEP) allows one to study the pressure range over which recruitment occurs in acute lung injury (ALI), and to explain how recruitment affects the compliance. Pel-V curves were measured with the low ...
Fujino Y - - 1999
Partial liquid ventilation (PLV) has been shown to be an effective means of improving oxygenation in the injured lung. However, little is known about how approach to ventilation during PLV affects gas exchange and pulmonary mechanics. We hypothesized that gas exchange and pulmonary mechanics would be best with positive end-expiratory ...
Fujino Y - - 1999
OBJECTIVE: Dynamic intrinsic PEEP (PEEPi-dyn) is the airway pressure required to overcome expiratory flow and is considered to represent the lowest regional PEEPi. However, there are few data to validate this assumption. We investigated if PEEPi-dyn represents the lowest PEEPi. SETTING: The animal laboratory at the Osaka University Medical School. ...
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