BACKGROUND: Mechanical ventilation is delivered to sedated patients during anesthesia, but also to nonsedated patients (ventilator weaning, noninvasive ventilation). In these circumstances, patient-ventilator asynchrony may occur, provoking discomfort and unduly increasing work of breathing. In certain cases, it is associated with an increased inspiratory load. Inspiratory loading in awake humans ...

Continuous positive airway pressure ventilation (CPAP) and non-invasive positive pressure ventilation (NPPV) are accepted treatments in acute cardiogenic pulmonary edema (ACPE) and acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The aim of the study was a comparison of effectiveness, safety, and management of NPPV in ACPE and AECOPD trying ...

OBJECTIVE: During pressure support ventilation, ventilator inspiration ends when inspiratory flow drops to a given percentage of the peak inspiratory flow cycling-off criteria. This study evaluated the effect of two different cycling-off criteria on breathing pattern, respiratory effort, and gas exchange in patients with chronic obstructive pulmonary disease. DESIGN: Clinical ...

BACKGROUND: Aerosolized iloprost, an inhaled synthetic analogue of prostacyclin, is an approved therapy for stage III and IV pulmonary hypertension. However, currently iloprost is delivered via a device that requires a clinically stable patient who can use a hand-held nebulizer. We designed separate aerosol delivery systems to nebulize iloprost to ...

BACKGROUND: Acute respiratory failure (ARF) is a relatively common complication after abdominal surgery. METHODS: We compared the efficacy of noninvasive positive-pressure ventilation (NPPV) delivered via helmet versus via face mask in patients with ARF after abdominal surgery in 2 intensive care units (31 beds) in the hospital affiliated with the ...

OBJECTIVE: During pressure support ventilation (PS), an abrupt increase in ventilator pressure above the pre-set level is considered to signify expiratory muscle activity. However, relaxation of inspiratory muscles may also cause the same phenomenon, and this hypothesis has not been explored. The aim of this study is to examine the ...

OBJECTIVE: To compare in intubated patients manually ventilated in order to mirror the ventilator, the respiratory and hemodynamic effects induced by a bag device equipped with an inspiratory gas flow-limiting valve (Smart Bag, 0-Two Medical Technologies Inc., Mississauga, ON, Canada) and a Standard bag. DESIGN: Non-randomized crossover study comparing 13 ...

BACKGROUND: Special equipment for emergency percutaneous transtracheal ventilation is often not immediately available. We used a self-made device consisting of a three-way stopcock connected between a G-15 transtracheal airway catheter and an oxygen supply in a simulated 'cannot intubate, cannot ventilate' scenario and tested the hypothesis that the effectiveness of ...

BACKGROUND: Varying effects of pancuronium on neonatal pulmonary mechanics have been documented, including a decrease in pulmonary compliance or no significant change in compliance; but measurements of respiratory mechanics or quantification of episodes of hypoxemia in preterm newborns receiving vecuronium (Norcuron, Bedford Labs, Bedford, OH, USA) have not been reported. ...

OBJECTIVE: Noninvasive positive pressure ventilation (NIPPV) has been shown to decrease the need for invasive mechanical ventilation (MV) in patients presenting with acute respiratory failure (ARF). We conducted a prospective study to assess if NIPPV use, in a developing country, was associated with clinical and physiological improvements. DESIGN: Prospective observational ...

OBJECTIVE: Although critical illness neuromyopathy might interfere with weaning from mechanical ventilation, its respiratory component has not been investigated. We designed a study to assess the level of respiratory muscle weakness emerging during the intensive care unit stay in mechanically ventilated patients and to examine the correlation between respiratory and ...

BACKGROUND: Heme oxygenase produces carbon monoxide (CO) during the breakdown of heme molecules. A variety of stressors upregulate this enzymatic activity and can increase exhaled CO levels. Recently, exhaled CO levels have been reported to increase in critically ill patients and after anesthesia and surgery. To use this measurement during ...

OBJECTIVE: To evaluate the applicability, tolerance, and efficacy of a closed-loop protocol to wean children from mechanical ventilation. DESIGN: Prospective single-center pilot study. SETTING: Tertiary care university hospital. PATIENTS: Twenty mechanically ventilated children aged between 1 and 17 yrs, with a body weight > or =10 kg, no inotropes, and ...

Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and ...

STUDY OBJECTIVE: Sudden death after a conducted electrical weapon exposure has not been well studied. We examine the effects of a single Taser exposure on markers of physiologic stress in healthy humans. METHODS: This is a prospective trial investigating the effects of a single Taser exposure. As part of their ...

BACKGROUND: Undetected malpositioned or dislodged ventilation tubes during cardiac arrest have fatal consequences, and no single method can detect the tube position reliably during such low-flow states. We wanted to test the ability of impedance changes as measured across the chest via the standard defibrillation pads to distinguish between oesophageal ...

OBJECTIVE: Measurement of functional residual capacity (FRC) during controlled and especially during assisted ventilation remains a challenge in the physiological evaluation of ventilated patients. To validate a bag-in-box closed helium dilution technique allowing measurements both during pressure-controlled (PCV) and pressure-support ventilation (PSV). DESIGN AND SETTING: Experimental study on lung models ...

OBJECTIVE: To evaluate the safety and efficacy of high-frequency jet ventilation for transporting critically ill hypoxic neonates to an extracorporeal membrane oxygenation (ECMO) center. STUDY DESIGN: We conducted a retrospective cohort study of 38 transported neonates. Safety was assessed by the comparison of cardiopulmonary variables before and after transport from ...

BACKGROUND: During volume guarantee (VG) ventilation the peak inflating pressure (PIP) for each ventilator inflation is adjusted to ensure the expired tidal volume (V(Te)) is close to the set V(Te). Differences in the PIP between inflations triggered by the infant's inspirations and untriggered inflations are seen. AIM: To investigate the ...

BACKGROUND: The aim was to determine the effectiveness of continuous aminophylline infusion on refractory bronchospasm in long-term mechanically ventilated neonates. CASE REPORT: Presented are seven newborns with gestational ages from 24 to 38 weeks and mean age at treatment of 29.7 days. All were mechanically ventilated from birth because of ...

BACKGROUND: The optimum timing for denture removal in edentulous patients before anesthesia and surgery is uncertain. METHODS: We conducted a prospective, randomized, controlled trial to evaluate the effect of leaving dentures in during bag-mask ventilation at induction of general anesthesia. One hundred sixty-six edentulous patients were randomized to two groups. ...

BACKGROUND: Noninvasive ventilation (NIV) is being increasingly used in hypercapnic chronic obstructive pulmonary disease (COPD) patients but the most appropriate ventilation mode is still not known. OBJECTIVES: The aim of this study was to investigate if assisted pressure-controlled ventilation (APCV) can be a better alternative to pressure-support ventilation (PSV) for ...

BACKGROUND: The effects of pressure-controlled (PC) ventilation on the ventilatory and haemodynamic parameters during laparoscopy procedures had not been carefully assessed. This prospective cross-over study was undertaken to compare how volume-controlled (VC) and PC modes could affect pulmonary mechanics, gas exchange, and cardiac function in patients undergoing laparoscopy. METHODS: Twenty-one ...

OBJECTIVE: Imperfect patient-ventilator interaction is common during assisted ventilation, and the detection of clinically relevant mismatching requires visual monitoring of the ventilator screen. We have assessed the feasibility, sensitivity and specificity of an algorithm embedded in a ventilator system that is able to automatically detect the occurrence of ineffective triggering ...

OBJECTIVE: To compare subjective experience of comfort associated with various commonly used supportive modes of mechanical ventilation for weaning in the intensive care unit (ICU). SUBJECTS AND METHODS: The study was carried out in general ICU of a community-based teaching hospital in 30 healthy adult Nepalese volunteers of either sex ...

BACKGROUND: A reduction in the incidence of posttraumatic Acute Respiratory Distress Syndrome (ARDS) has been demonstrated. It is hypothesized that ventilation strategies and restrictive transfusion policies are contributory. The purpose of this study is to examine the changes in ventilation and transfusion parameters over time and their associations with late ...

OBJECTIVES: To investigate the effect of 90 degrees lateral positioning on oxygenation, respiratory mechanics, and hemodynamics in ventilated intensive care patients. METHODS: Thirty-four subjects (mean age = 46.1 +/- 17.3 years) with no, unilateral, or bilateral pulmonary infiltrates on chest radiograph participated. Arterial blood gas, respiratory mechanic, and hemodynamic data ...

OBJECTIVE: Mechanical ventilation can be lifesaving for status asthmaticus, but how best to accomplish mechanical ventilation is unclear. Biologically variable ventilation (mechanical ventilation that emulates healthy variation) and conventional control mode ventilation (monotonously regular) were compared in an animal model of bronchospasm to determine which approach yields better gas exchange ...

INTRODUCTION: To describe ventilator management using a high-frequency percussive ventilator (HFPV), after other modes of mechanical ventilation failed. DESIGN: Case series. SETTING: Pediatric intensive care unit. PATIENTS: Previously healthy 11-month-old male with severe aspiration pneumonitis from mineral oil. INTERVENTIONS: The patient was initially placed on a conventional ventilator in a ...

OBJECTIVE: Ventilator settings typically used for high-frequency oscillatory ventilation (HFO) in adults provide acceptable gas exchange but may not take best advantage of its lung-protective aspects. We provide guidelines for HFO in adults with acute respiratory distress syndrome that should optimize the lung-protective characteristics of this ventilation mode. DESIGN: Roundtable ...

Electrical impedance tomography (EIT) has the potential to become a new tool for bedside monitoring of regional lung ventilation. The aim of our study was to assess the reproducibility of regional lung ventilation distribution determined by EIT during mechanical ventilation under identical ventilator settings. The experiments were performed on 10 ...

BACKGROUND: The delay between changes in end-expired sevoflurane concentrations and bispectral index (BIS) may be characterized by a 'rate constant' (ke0). A smaller ke0 reflects a longer delay. Values for ke0 vary substantially among studies. The question arises how ke0 depends on experimental conditions, including ventilation and apparatus. METHODS: Increasing ...

BACKGROUND AND OBJECTIVE: Thoracic surgery requires immobilization of the operating area. Usually, this is achieved with one-lung ventilation (OLV), however this may still lead to some movement. High-frequency jet ventilation (HFJV) may be an alternative way of ventilation in thoracic surgery. The purpose of this study was to determine the ...

STUDY OBJECTIVE: The primary objective of this study was to test whether an elevated systolic pulmonary artery (PA) pressure or an elevated pulmonary dead space fraction (Vd/Vt) in early acute lung injury (ALI) is associated with poor clinical outcomes in the era of lung-protective ventilation. DESIGN: Prospective observational cohort study. ...

OBJECTIVE: Noninvasive ventilation (NIV) is often applied with ICU ventilators. However, leaks at the patient-ventilator interface interfere with several key ventilator functions. Many ICU ventilators feature an NIV-specific mode dedicated to preventing these problems. The present bench model study aimed to evaluate the performance of these modes. DESIGN AND SETTING: ...

A large number of ventilation strategies are now available for the neonate. This review has focused on new information, that is, studies published since 2000 and the implication of their results for current clinical practice. Meta-analysis of randomised trials has demonstrated that assist control and synchronous intermittent mandatory ventilation (SIMV) ...

Non-invasive ventilation (NIV) refers to the delivery of mechanical ventilation to the lungs using techniques that do not require an endotracheal airway. Essentially, there are two modalities: continuous positive airway pressure (CPAP) and pressure support ventilation (NIPSV). In acute pulmonary edema (APE) both modalities have shown a faster improvement in ...

High-frequency oscillatory ventilation (HFOV) is characterized by the rapid delivery of small tidal volumes (Vts) of gas and the application of high mean airway pressures (mPaws). These characteristics make HFOV conceptually attractive as an ideal lung-protective ventilatory mode for the management of ARDS, as the high mPaws prevent cyclical derecruitment ...

OBJECTIVE: a) Characterize how ventilator and patient variables affect tidal volume during high-frequency oscillatory ventilation; and b) measure tidal volumes in adults with acute respiratory distress syndrome during high-frequency oscillatory ventilation. DESIGN: Observational study. SETTING: Research laboratory and medical intensive care unit. PATIENTS: Test lung and patients with acute respiratory ...

BACKGROUND: Numerous mechanical ventilators are designed and marketed for use in patient transport. The complexity of these ventilators differs considerably, but very few data exist to compare their operational capabilities. METHODS: Using bench and animal models, we studied 15 currently available transport ventilators with regard to their physical characteristics, gas ...

INTRODUCTION: The need for rescue breaths in bystander CPR has been questioned after several studies have shown that omitting ventilation does not worsen outcome. Chest compression may produce passive tidal volumes large enough to provide adequate ventilation in animal studies, but no recent clinical studies have examined this phenomenon. We ...

High-frequency ventilation is the application of mechanical ventilation with a respiratory rate > 100 breaths/min. High-frequency oscillatory ventilation (HFOV) is the form of high-frequency ventilation most widely used in adult critical care. The principles of lung-protective ventilation have matured in parallel with the technology for HFOV. The 2 basic principles ...

BACKGROUND: Pressure-controlled ventilation (PCV) has been suggested as a tool to improve oxygenation during one-lung ventilation (OLV) for patients undergoing thoracic surgery. In this study we investigated whether PCV results in improved arterial oxygenation compared with volume-controlled ventilation (VCV) during OLV. METHODS: Fifty-eight patients with good preoperative pulmonary function scheduled ...

Airway pressure release ventilation and biphasic positive airway pressure ventilation are being used increasingly as alternative strategies to conventional assist control ventilation for patients with acute respiratory distress syndrome (ARDS) and acute lung injury. By permitting spontaneous breathing throughout the ventilatory cycle, these modes offer several advantages over conventional strategies ...

The patient with acute heart failure may present with acute cardiogenic pulmonary edema (ACPE), a condition accompanied by severe respiratory distress, with crackles over the lung and orthopnea, and an O2 saturation usually < 90% on room air, prior to treatment. Non-invasive ventilation is the delivery of assisted ventilation without ...

Although the accumulation of gas is the most common cause of an expanding interpleural space, the presence of other structures or substances (hydrothorax, gastrothorax, hemothorax, urohemothorax, pyothorax, and chylothorax) under pressure may be sufficient to cause hemodynamic and respiratory compromise. We present two pediatric patients that developed hemodynamic and respiratory ...

OBJECTIVE: In ventilated neonates, only the applied pressure of the ventilator is adjusted and monitored. When an endotracheal tube leaks, intratracheal pressure decreases depending on the size of the endotracheal tube and of the leak. Furthermore, an increase in resistance and/or compliance might delay the increase of intratracheal pressure during ...

Programmed diaphragmatic pacing using implanted neuromodulators represents an emerging method for providing pulmonary support using negative pressure ventilation. The implantable, rechargeable, programmable and miniaturized nature of diaphragmatic pacers may obviate many of the management issues associated with noninvasive positive pressure ventilation devices. Closed loop systems may facilitate the implementation of ...

This chapter addresses the use of long-term non-invasive positive pressure ventilation (NIPPV) (to the exclusion of continuous positive airway pressure) in the different clinical settings in which it is currently proposed: principally in diseases responsible for hypoventilation characterized by elevated PaCO(2). Nasal masks are predominantly used, followed by nasal pillow ...

OBJECTIVE: Noninvasive partial CO2 rebreathing (NICO; Novametrix Medical Systems, Inc, Wallingford, CT) is a relatively new alternative to thermodilution (TDCO) for measurement of cardiac output. This study compares the 2 methods during thoracic surgery and one-lung ventilation. DESIGN: A prospective, observational study. SETTING: A tertiary hospital. PARTICIPANTS: Twelve adult patients ...