Effects of High and Low Tidal Volumes on Arterial Oxygenation and Pulmonary Shunt During One-Lung...
Postoperative Lung InjuryThe ideal tidal volume (TV) during one-lung ventilation (OLV) remains controversial. High tidal volumes may increase the incidence of postoperative lung injury after thoracic surgery. The investigators thus evaluated the influence of low (5 ml/kg) and high (10 ml/kg) tidal volumes on arterial oxygenation and Intrapulmonary shunt during OLV. One hundred patients scheduled for thoracic surgery were enrolled. During OLV, patients were randomly assigned to 30 minutes of ventilation with high TV (10 ml/kg with zero end-expiratory pressure (ZEEP)) at a rate of 10 breaths/minute or low tidal volume (5 ml/kg with 5 cm H2O positive end-expiratory pressure (PEEP)) at a rate of 20 breaths/minute. During the subsequent 30 minutes, each patient received the alternative management. Minute volume was thus kept constant during each experimental condition. Arterial blood partial pressures, hemodynamic responses, and ventilatory parameters were recorded. Results are presented as means ± SDs; P < 0.05 was considered statistically significant.
Long-Term Results in Mechanically Ventilated Individuals With Acute Lung Injury/Acute Respiratory...
Respiratory Distress SyndromeAdultAcute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a severe lung condition that causes respiratory failure. Individuals with ALI/ARDS often require the use of a respirator or artificial breathing machine, known as a mechanical ventilator, while in an intensive care unit (ICU). Past research has shown that improved short-term clinical outcomes result from the use of a protective mechanical ventilation technique for the lungs. This study will evaluate the effects of lower tidal volume ventilation, and other aspects of critical illness and ICU care, on the long-term clinical outcomes of individuals with ALI/ARDS.
Radiation Induced Cardiopulmonary Injury in Humans
ThoracicPulmonary Injury1 moreThe purpose of the study is to assess the time, dose dependence, and fraction-size dependence of radiation (RT)-induced changes in regional lung and heart perfusion/function/structure following thoracic RT delivered using newer IMRT/conformal/radiosurgery techniques. The PI hopes to develop models to better relate and predict RT-induced changes in regional lung and heart perfusion/function/structure with changes in global cardiopulmonary function. Patients will undergo pre- and serial post-RT lung and heart assessments to better understand RT-induced regional heart/lung changes.
Predicting Lung Injury From Transfusion in Patients With Liver Disease
Transfusion-related Acute Lung InjuryChronic Liver Disease1 moreA certain molecule floating in the blood may represent a risk of lung injury after a transfusion. We are determining whether detection of this molecule on a simple blood clotting test will predict the development of lung injury due to transfusion in bleeding patients with chronic liver disease.
Effect of Mechanical Ventilation Strategy on Lung Injury in Patients With Less Severe Acute Respiratory...
Acute Respiratory Distress SyndromeDuring the past two decades, there current concept has evolved significantly that ventilator-induced lung injury (VILI) may not only impose a direct mechanical stress and subsequent injury to the lungs, but may also induce local as well as systemic inflammation responses, generally referred as biotrauma.1 Patients with ARDS often die of severe systemic inflammatory response syndrome (SIRS) and multiorgan dysfunction2 rather than refractory hypoxemia. Ranieri et al found that patients with less severe ARDS, i.e., a lung injury score of 2.5 or less, receiving ventilation with lung protective strategy involving low tidal volume (7.5 mL/kg PBW) and high PEEP could attenuate the pulmonary and systemic cytokine response compared with conventional ventilation with high tidal volume.3 Stuber et al found an increase in pro-inflammatory cytokines in the lung and plasma of patients with ARDS within 1 hour after switching the patients from a protective to non-protective ventilator strategy.4 The receptor for advanced glycation end-products (RAGE) was recently identified as a marker of injury to the alveolar type I epithelial cells5. Clinical studies showed that the plasma level of RAGE was associated with severity of lung injury and clinical outcome, and low tidal volume strategy ventilation accelerated the decline in plasma RAGE levels. These results suggest plasma RAGE level might be a reliable biomarker of alveolar epithelial injury in acute lung injury and may associated with ventilator induced lung injury6. Although, current approach to mechanical ventilation of a patient with ARDS emphasizes the use of lower tidal volumes with lower plateau pressures to avoid causing lung overdistension and ventilator associated lung injury (VILI)7; however, in the real world, some studies showed that strictly reduction of tidal volume to 6ml/kg PBW was modest in modern time, and was noticed only in patients with greater lung injury scores8. The benefit of VT strictly reduction to 6ml/kgPBW and its effect on VILI in patients with less severe ARDS whose Pplat are already below 30 cmH2O are controversy9. One of the possible solutions is to look at the biomarkers of injury to alveolar epithelial cells. Of these potentially promising markers, the receptor for advanced glycation end-product (RAGE) is of great interest. We hypothesize that a strategy with strict low tidal volume in less severe ARDS and ALI patients with good compliance may be beneficial to this patient population. Therefore, we wish to propose a prospective single-center study to investigate the effect of mechanical ventilation strategy on the plasma level of RAGE in patients with less severe ARDS and acute lung injury.
Evaluating a Web-Based Ventilator Management Educational Program for Clinicians (The Lung Injury...
Respiratory Distress SyndromeAdultAcute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a severe lung condition that causes respiratory failure. Individuals with ALI/ARDS often require the use of a respirator or artificial breathing machine, known as a mechanical ventilator, while in an intensive care unit (ICU). Research has shown that lung protective ventilation (LPV), a type of mechanical ventilation technique, is an effective way to reduce the number of deaths due to ALI/ARDS. This study will evaluate the effectiveness of a Web-based educational program that aims to educate ICU clinicians about the use of LPV in patients with ALI/ARDS.
Driving Pressure Variation: NAVA vs PSV
Mechanical Ventilation ComplicationVentilator-Induced Lung InjuryAssisted ventilation represents, nowadays, the preferred ventilation mode in clinical practice.It has been shown that assisted ventilation modes improve ventilation/perfusion matching, descrease risk of Ventilator induced lung injury and muscle atrophy and have less influence on haemodynamic function. However, PSV (Pressure Support Ventilation) is not free from complications: it may worsen or cause lung injuries by increasing alveolar and intrathoracic negative pressure and by loosing control on Tidal Volume (Vt). Indeed, it has been demonstrated that Vt is the main factor related to VILI. It has been shown that lower Vt and higher PEEP can improve clinical outcome only if associated with a simultaneous reduction in Driving Pressure. Increase in Driving Pressure resulted strongly associated with negative outcomes, especially if higher than 15 cm H2O. PSV is currently the most used assisted ventilation mode. NAVA (Neurally Adjusted Ventilatory Assist) is a ventilation mode in which the diaphragmatic electrical activity (EAdi) is used as a trigger to start a mechanical breath, applying positive pressure during patient's inspiration. Diaphragmatic electrical activity (EAdi) can be detected by a particular nasogastric tube (EAdi catheter). EAdi is the currently available signal closest to the neural breathing centers, which can estimate the patient's respiratory drive, if phrenic nerves are not damaged. It has been demonstrated that NAVA ventilation can reduce the incidence of patient-ventilator asynchronies, because the delivery of the support and the cycling between inspiration and expiration are completely controlled by the patient. However, although PSV and NAVA have been widely compared in many investigations, up to now there are no studies about driving pressure variation during these two modalities of mechanical assisted ventilation. The aim of this study is to measure changes in driving pressure at different levels of ventilatory assistance in PSV and NAVA ventilation modes. Secondary end points are respiratory mechanics indices and patient/ventilator related asynchrony evaluation and comparison.
Positioning During SBT in NICU Infants
Respiratory Distress SyndromeNewborn1 moreMechanical ventilation is a life-sustaining intervention in premature infants with respiratory difficulties. There is relative consensus when to intubate and provide positive pressure mechanical ventilation in the presence of respiratory failure. In contrast, discontinuation of mechanical ventilation during recovery remains largely subjective. A potential predictive tool for neonatal extubation is the Spontaneous Breathing Trial (SBT). The efficacy of SBT or other tests used in older patient populations in improving clinical judgment is questionable in the neonatal population with its unique physiology, respiratory mechanics and drive factors. Christiana Care Health System NICU currently uses the SBT as a standard part of neonatal assessment for extubation from mechanical ventilation. Infants in the CCHS NICU are routinely cared for in multiple positions (prone, supine, lateral) throughout the day. What is unknown is the impact of infant positioning on the SBT. An SBT performed in one position may not predict infant respiratory status after extubation in another position. Understanding the impact of infant positioning and work of breathing indices independently or in combination with an SBT will aid clinicians in decision-making and potentially decrease neonatal morbidity (inaccuracy with timing and safety of extubation). This pilot study will begin to explore these clinically relevant factors. Objectives: This pilot study will investigate the (1) role of infant position on SBT score and (2) the relationship of work of breathing indices in reference to the SBT score and infant position.
Effect of PEEP on Lung Recruitment and Homogeneity Over Time in Moderate to Severe ARDS
ARDSCritical Illness1 moreThis study evaluates the effect of airway pressure release ventilation (APRV) on lung homogeneity and recruitment in patients with moderate to severe acute respiratory distress syndrome (ARDS). It will do this by comparing the homogeneity of ventilation and recruitment prior to a patient being ventilated on APRV, and at 30, 60 and 120 minutes after starting APRV.
Assessing Respiratory Variability During Mechanical Ventilation in Acute Lung Injury (ALI)
Acute Lung InjuryAdult Respiratory Distress SyndromeHealthy biological systems are characterized by a normal range of "variability" in organ function. For example, many studies of heart rate clearly document that loss of the normal level of intrinsic, beat-to-beat variability in heart rate is associated with poor prognosis and early death. Unlike the heart, little is known about patterns of respiratory variability in illness. What is known is that, like the heart, healthy subjects have a specific range of variability in breath- to-breath depth and timing. Additionally, in animal models, ventilator strategies that re-introduce normal variability to the breathing pattern significantly reduce ventilator-associated lung injury. Critically ill patients requiring mechanical ventilation offer an opportunity to observe and analyze respiratory patterns in a completely non-invasive manner. Current mechanical ventilators produce real-time output of respiratory tracings that can analyzed for variability. The investigators propose to non-invasively record these tracings from patients ventilated in the intensive care units for mathematical variability analysis. The purpose of these pilot analyses are to: (1) demonstrate the range of respiratory variability present in the mechanically ve ventilated critically ill and (2) demonstrate the ventilator modality that delivers or permits the closest approximation to previously described beneficial or normal levels of variability. Future studies will use this pilot data in order to determine if the observed patterns of respiratory variability in mechanically ventilated critically ill subjects have prognostic or therapeutic implications.