OBJECTIVE: To report the use of high frequency oscillatory ventilation (HFOV) in two children with severe traumatic brain injury and concurrent lung pathology where conventional mechanical ventilation was ineffective. DESIGN:: Case report. SETTING: Regional intensive care unit in a pediatric teaching hospital. PATIENTS: Two severely head-injured children (both with postresuscitation ...

BACKGROUND: Severe diaphragmatic dysfunction can prolong mechanical ventilation after cardiac surgery. An ultrasonographic criterion for diagnosing severe diaphragmatic dysfunction defined by a reference technique such as transdiaphragmatic pressure measurements has never been determined. METHODS: Twenty-eight patients requiring mechanical ventilation > 7 days postoperatively were studied. Esophageal and gastric pressures were ...

Acute lung injury (ALI), as occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation. Here, we systematically tested a murine model of ALI by using pressure-controlled ventilation to induce ventilator-induced lung injury. For ...

The aim of this study was to assess whether postoperative cardiac troponin T levels could predict ventilation requirements in infants undergoing the arterial switch operation. Cardiac troponin T was measured 6 hours after aortic cross clamping and prior to tracheal extubation in 20 consecutive patients; 10 had simple and 10 ...

OBJECTIVE: To evaluate transcutaneously measured P(CO(2)) (P(tcCO(2))) values during ventilator weaning and during bronchoscopies on ventilated patients, and to compare P(tcCO(2)) values to P(aCO(2)) values from arterial blood analysis and end-tidal P(CO(2)) (P(ETCO(2))) values from capnography. METHODS: In our specialized weaning unit we measured P(tcCO(2)) in tracheostomized patients with prolonged ...

Noninvasive positive pressure ventilation (NPPV) is becoming more commonplace, both in the ICU and also in the Emergency Department. This article addresses the rationale and mechanism of action for NPPV. A review of the indications for using NPPV and a discussion detailing the initiation of NPPV follows. NPPV has been ...

BACKGROUND: Mechanical ventilation with small tidal volumes reduces the development of ventilator-induced lung injury and mortality, but may increase PaCO2. It is not clear whether the beneficial effect of a lung-protective strategy results from reduced ventilation pressures/tidal volumes or is mediated by the effects of hypercapnic acidosis on the inflammatory ...

OBJECTIVE: The objective of this study was to identify the definitional criteria for the pressure-limited and time-cycled modes: airway pressure release ventilation (APRV) and biphasic positive airway pressure (BIPAP) available in the published literature. DESIGN: Systematic review. METHODS: Medline, PubMed, Cochrane, and CINAHL databases (1982-2006) were searched using the following ...

OBJECTIVE: Neurally adjusted ventilatory assist (NAVA) is a new mode wherein the assistance is provided in proportion to diaphragm electrical activity (EAdi). We assessed the physiologic response to varying levels of NAVA and pressure support ventilation (PSV). SETTING: ICU of a University Hospital. PATIENTS: Fourteen intubated and mechanically ventilated patients. ...

Ventilated patients frequently require transport by air in a hypobaric environment. Previous studies have demonstrated significant changes in the performance of ventilators with changes in cabin pressure (altitude) but no studies have been published on the function of modem ventilators at altitude. This experiment set out to evaluate ventilatory parameters ...

BACKGROUND: Adaptive-support ventilation (ASV) is a minute ventilation-controlled mode governed by a closed-loop algorithm. With ASV, tidal volume and respiratory rate are automatically adjusted to minimize work of breathing. Studies indicate that ventilation in ASV enables more rapid weaning. The authors conducted a randomized controlled trial to determine whether ventilation ...

Subcutaneous emphysema is a physical finding that itself is usually perceived as benign yet rarely may, in and of itself, be life-threatening. We present an unusual case of a 67-year-old woman who developed delayed severe subcutaneous emphysema and tension pneumothorax from a rib fracture subsequent to a fall. We review ...

BACKGROUND: Pressure-support ventilation (PSV) is more comfortable than volume controlled-continuous mandatory ventilation (VC-CMV) in acute hypercapnic respiratory failure, in patients undergoing noninvasive ventilation. Physiologic measurements of patient status have been compared in PSV and VC-CMV in endotracheally intubated patients, but patient perception of comfort has not been measured in this ...

Term and near-term infants with pulmonary hypertension are frequently treated with inhaled nitric oxide. This therapy can be delivered with high-frequency ventilation, but there has been limited study of the relative effectiveness of high-frequency jet ventilation and high-frequency oscillatory ventilation. OBJECTIVE: To compare short-term clinical outcomes of neonates with pulmonary ...

BACKGROUND: We compared spontaneous and positive-pressure ventilation in patients undergoing general anaesthesia for the treatment of extrathoracic, intralumenal laryngotracheal stenosis to assess the best method of ventilation in this patient group. METHODS: Records of 30 patients with laryngotracheal stenosis, but not with a tracheostomy, undergoing lumen-restoring surgery were prospectively reviewed. ...

AIM: The importance of ventilatory support during cardiac arrest and basic life support is controversial. This experimental study used dynamic computed tomography (CT) to assess the effects of chest compressions only during cardiopulmonary resuscitation (CCO-CPR) on alveolar recruitment and haemodynamic parameters in porcine model of ventricular fibrillation. MATERIALS AND METHODS: ...

During sleep changes in central and peripheral neurological pathways and muscle tone result in unique vulnerabilities in the respiratory system. Abnormalities of the respiratory system that are not apparent in wakefulness can become evident during particular sleep states, making overnight polysomnography (PSG) a valuable diagnostic indicator of the source as ...

BACKGROUND: The authors hypothesized that nasal mask ventilation may be more effective than combined oral-nasal mask ventilation during induction of general anesthesia. They tested this hypothesis by comparing the volume of carbon dioxide removed per breath with nasal versus combined oral-nasal mask ventilation in nonparalyzed, apneic, adult subjects during induction ...

Pressurized metered-dose inhalers (pMDIs) and nebulizers are employed routinely for aerosol delivery to ventilator-supported patients, but the ventilator circuit and artificial airway previously were thought to be major barriers to effective delivery of aerosols to patients receiving mechanical ventilation. In the past two decades, several investigators have shown that careful ...

Lung protective ventilatory strategies using conventional ventilators have resulted in decreased mortality in adult patients who have acute lung injury and acute respiratory distress syndrome. Conceptually, high frequency oscillatory ventilation and airway pressure release ventilation appear not only able to fulfill the goals of lung protection, but also to offer ...

OBJECTIVE: Dynamic ventilation (3)He-MRI is a new method to assess pulmonary gas inflow. As differing airway diameters throughout the ventilatory cycle can influence gas inflow this study intends to investigate the influence of volume and timing of a He gas bolus with respect to the beginning of the tidal volume ...

The standard of care for mechanical ventilation of the patient who has acute lung injury remains volume control ventilation at 6 mL/kg. Despite this fact, clinicians often employ pressure control ventilation and adaptive pressure control ventilation in an attempt to improve synchrony and limit the possibility for overdistension. Adaptive pressure ...

OBJECTIVE: Patient-ventilator synchrony during non-invasive pressure support ventilation with the helmet device is often compromised when conventional pneumatic triggering and cycling-off were used. A possible solution to this shortcoming is to replace the pneumatic triggering with neural triggering and cycling-off-using the diaphragm electrical activity (EA(di)). This signal is insensitive to ...

The cyclic appearance of dynamic left ventricular outflow tract obstruction during mechanical ventilation, according to the phasic changes in preload, is described in this article. Hemodialysis-induced fluid removal resulted in preload dependence as evidenced by the pulse pressure variation in a 56-year-old critically ill patient. The clinical picture was suggestive ...

OBJECTIVE: To report our experience of non-invasive ventilation (NIV) as primary ventilatory support strategy in infants admitted for severe bronchiolitis. DESIGN AND SETTING: Retrospective study in a paediatric intensive care unit of an university hospital. PATIENTS: Infants aged less than 12 months, admitted for bronchiolitis during 2003-2004 and 2004-2005 winter ...

In a physical model of a pediatric respiratory system we measured the pressure drop across ETTs of 3 and 4mm inner diameter (ID) when we varied frequency, mean airway pressure and pressure amplitude of high-frequency-oscillation-ventilation (HFOV). Depending on ventilator settings the relative loss of mean pressure amplitude caused by the ...

OBJECTIVE: Gastric inflation (GI) is a significant issue when ventilation is performed on unprotected airways. DESIGN: Experimental analysis on the respiratory effects of hose extended bag-valve ventilation devices designed to reduce inspiratory pressure and flow. SETTING: Laboratory with lung/oesophageal sphincter simulator and pressure-flow-volume analyser. Lung compliance: 300ml/kPa, airway resistance: 0.5kPa/l/s. ...

The effects of mechanical ventilation on the surface electrocardiogram (ECG) have not been systematically investigated and the anticipated changes such as rightward P and QRS axes shifts, reduced QRS voltage, and slow R-wave progression are not supported by definitive data. We sought to determine the effects of mechanical ventilation on ...

For disease states characterized by oscillatory ventilation, an ideal dynamic therapy would apply a counteracting oscillation in ventilation. Modulating respiratory gas transport through the circulation might allow this. We explore the ability of repetitive alternations in heart rate, using a cardiac pacemaker, to elicit oscillations in respiratory variables and discuss ...

OBJECTIVE: We examined whether additional helmet flow obtained by a single-circuit and a modified plateau valve applied at the helmet expiratory port (open-circuit ventilators) improves CO(2) wash-out by increasing helmet airflow. DESIGN AND SETTING: Randomized physiological study in a university research laboratory. PARTICIPANTS: Ten healthy volunteers. INTERVENTIONS: Helmet continuous positive ...

BACKGROUND: During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle ...

Hilly areas around Fairbanks, Alaska, are known to have elevated soil radon concentrations. Due to geological conditions, cold winters, and the resulting stack effect, houses in these areas are prone to higher indoor radon concentrations. Key variables with respect to radon mitigation were addressed in this paper by using a ...

We examined the pressures produced by a construction intended for emergency ventilation through a needle cricothyroidotomy. This construction consisted of a standard hospital wall oxygen supply, flowmeter, oxygen tubing and a three-way tap. We measured the flow achieved through a transtracheal catheter and compared the construction to a Manujet jet ...

BACKGROUND: We compared pressure and volume-controlled ventilation (PCV and VCV) in morbidly obese patients undergoing laparoscopic gastric banding surgery. METHODS: Thirty-six patients, BMI>35 kg m(-2), no major obstructive or restrictive respiratory disorder, and Pa(CO(2))<6.0 kPa, were randomized to receive either VCV or PCV during the surgery. Ventilation settings followed two ...

OBJECTIVE: To compare the triggering performance of mid-level ICU mechanical ventilators with a standard ICU mechanical ventilator. DESIGN: Experimental bench study. SETTING: The respiratory care laboratory of a university-affiliated teaching hospital. SUBJECT: A computerized mechanical lung model, the IngMar ASL5000. INTERVENTIONS: Ten mid-level ICU ventilators were compared to an ICU ...

OBJECTIVE: To identify ventilatory setting adjustments that improve patient-ventilator synchrony during pressure-support ventilation in ventilator-dependent patients by reducing ineffective triggering events without decreasing tolerance. DESIGN AND SETTING: Prospective physiological study in a 13-bed medical intensive care unit in a university hospital. PATIENTS AND PARTICIPANTS: Twelve intubated patients with more than ...

This brief review centers on the multiple inert gas elimination technique (MIGET). This technique, developed in the 1970s, measures the pulmonary exchange of a set of six different inert gases dissolved together in saline (or dextrose) and infused intravenously. It then uses those measurements to compute the distribution of ventilation/perfusion ...

BACKGROUND: Propofol dosages required for upper GI endoscopy are often high enough to pose serious risks of respiratory depression. Stopping the procedure and bag ventilating a patient until the propofol wears off may be a safer management because traditional mask ventilation is not available. OBJECTIVE: We introduce the mask adaptor ...

BACKGROUND: Induced external hypothermia during ventricular fibrillation (VF) improves resuscitation outcomes. Our objectives were twofold (1) to determine if very rapid hypothermia could be achieved by intrapulmonary administration of cold perfluorocarbons (PFC), thereby using the lungs as a vehicle for targeted cardiopulmonary hypothermia, and (2) to determine if this improved ...

Sexual activity is an important component of quality of life in patients suffering from chronic illnesses. To our knowledge, the effects of sexual activity on gas exchange in patients with respiratory failure have not been yet studied. To such an extent, we evaluated the oxygen saturation (SaO2), by a pulse ...

Though often lifesaving, mechanical ventilation itself bears the risk of lung damage [ventilator-induced lung injury (VILI)]. The underlying molecular mechanisms have not been fully elucidated, but stress-induced mediators seem to play an important role in biotrauma related to VILI. Our purpose was to evaluate an animal model of VILI that ...

OBJECTIVE: To assess the feasibility of using respiratory frequencies up to 15 Hz during high-frequency oscillatory ventilation (HFO) of adults with acute respiratory distress syndrome (ARDS). DESIGN: Observational study. SETTING: Medical intensive care unit at a tertiary care university hospital. PATIENTS: Thirty adult patients receiving HFO at the discretion of ...

INTRODUCTION: Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE: To compare conventional and high frequency ventilation using the lower inflection point of the ...

In modern emergency and critical care, physicians tend to choose the mode of mechanical ventilation based on spontaneous breathing for the purpose of promoting discharge of pulmonary secretion and preventing atelectasis in patients with acute respiratory insufficiency. However, we often observe "differences in recovery" among patients treated using the same ...

INTRODUCTION: Professional rescuers only deliver chest compressions 39% of the available time before intubation during out-of-hospital cardiac arrest. In manikin-studies lay rescuers need approximately 15s to deliver two ventilations. It is not known how much time professional rescuers use for two ventilations and we hypothesised that the time used for ...

OBJECTIVE: The aim of this study was to evaluate the effects of respiratory rate (RR) at a constant PaCO2 and conventional tidal volume (VT) on the development of ventilator-induced lung injury in normal lungs. DESIGN: Prospective, randomized, experimental study. SETTING: University research laboratory. SUBJECTS: Adult male C57BL/6 mice. INTERVENTIONS: Four ...

Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors ...

High altitude pulmonary oedema (HAPE) is a well-known potential hazard of activities at high altitudes but not a common disease presentation that most emergency physicians have experience treating. The mainstay of treatment is intuitive--early recognition with immediate descent, rest and oxygen--but what does the emergency physician do when a patient ...

To describe anesthetic management of endoscopic electrosurgical removal of a bronchial carcinoma, partially blocking the right main stem bronchus in a Cocker Spaniel. Clinical case report. Dog with a bronchial carcinoma. To allow sufficient space for the endoscope and to avoid an oxygen-rich gas mixture in the trachea, which carries ...

PURPOSE OF REVIEW: To present recent data on the role of noninvasive ventilation in the respiratory management of newborn infants. RECENT FINDINGS: Noninvasive ventilation is growing in popularity but is applied using widely varying devices and settings. Although short-term physiological advantages were reported for bubble and variable-flow continuous positive airways ...