Patient–ventilator asynchrony during non-invasive ventilation for acute respiratory failure: a multicenter study

ObjectiveTo determine the prevalence of patient–ventilator asynchrony in patients receiving non-invasive ventilation (NIV) for acute respiratory failure.DesignProspective multicenter observation study.SettingIntensive care units in three university hospitals.MethodsPatients consecutively admitted to ICU were included. NIV, performed with an ICU ventilator, was set by the clinician. Airway pressure, flow, and surface diaphragmatic electromyography were recorded continuously for 30 min. Asynchrony events and the asynchrony index (AI) were determined from visual inspection of the recordings and clinical observation.ResultsA total of 60 patients were included, 55% of whom were hypercapnic. Auto-triggering was present in 8 (13%) patients, double triggering in 9 (15%), ineffective breaths in 8 (13%), premature cycling 7 (12%) and late cycling in 14 (23%). An AI > 10%, indicating severe asynchrony, was present in 26 patients (43%), whose median (25–75 IQR) AI was 26 (15–54%). A significant correlation was found between the magnitude of leaks and the number of ineffective breaths and severity of delayed cycling. Multivariate analysis indicated that the level of pressure support and the magnitude of leaks were weakly, albeit significantly, associated with an AI > 10%. Patient comfort scale was higher in pts with an AI < 10%.ConclusionPatient–ventilator asynchrony is common in patients receiving NIV for acute respiratory failure. Our results suggest that leaks play a major role in generating patient–ventilator asynchrony and discomfort, and point the way to further research to determine if ventilator functions designed to cope with leaks can reduce asynchrony in the clinical setting.

[1]  Stefano Nava,et al.  Automatic detection of ineffective triggering and double triggering during mechanical ventilation , 2007, Intensive Care Medicine.

[2]  L. Brochard,et al.  Increased use of noninvasive ventilation in French intensive care units , 2006, Intensive Care Medicine.

[3]  D. Tassaux,et al.  Comparative bench study of triggering, pressurization, and cycling between the home ventilator VPAP II and three ICU ventilators , 2002, Intensive Care Medicine.

[4]  S. Nava,et al.  Effect of varying the pressurisation rate during noninvasive pressure support ventilation , 2004, European Respiratory Journal.

[5]  S. Nava,et al.  Respiratory response and inspiratory effort during pressure support ventilation in COPD patients , 1995, Intensive Care Medicine.

[6]  M. Aydoğdu,et al.  [Patient-ventilator interaction]. , 2009, Tuberkuloz ve toraks.

[7]  R. Kacmarek,et al.  Noninvasive positive-pressure ventilation in acute respiratory failure outside clinical trials: Experience at the Massachusetts General Hospital* , 2008, Critical care medicine.

[8]  C. Gregoretti,et al.  Patient-ventilator asynchrony during noninvasive ventilation: the role of expiratory trigger , 1999, Intensive Care Medicine.

[9]  N. Hill,et al.  Acute applications of noninvasive positive pressure ventilation. , 2003, Chest.

[10]  Marc Gainnier,et al.  Expiratory trigger setting in pressure support ventilation: From mathematical model to bedside , 2004, Critical care medicine.

[11]  A. Torres,et al.  Noninvasive ventilation in severe hypoxemic respiratory failure: a randomized clinical trial. , 2003, American journal of respiratory and critical care medicine.

[12]  M. Antonelli,et al.  Predictors of failure of noninvasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a multi-center study , 2001, Intensive Care Medicine.

[13]  G. Heldt,et al.  Airway leak size in neonates and autocycling of three flow-triggered ventilators. , 1995, Critical care medicine.

[14]  A. Clément,et al.  Performance of ventilators for noninvasive positive-pressure ventilation in children , 2008, European Respiratory Journal.

[15]  iorgio,et al.  NONINVASIVE VENTILATION FOR ACUTE EXACERBATIONS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE , 2000 .

[16]  Philippe Jolliet,et al.  Performance of noninvasive ventilation modes on ICU ventilators during pressure support: a bench model study , 2007, Intensive Care Medicine.

[17]  C. Carvalho,et al.  Mask mechanics and leak dynamics during noninvasive pressure support ventilation: a bench study , 2001, Intensive Care Medicine.

[18]  M. Vitacca,et al.  Assessment of physiologic variables and subjective comfort under different levels of pressure support ventilation. , 2004, Chest.

[19]  N. Ambrosino.  Noninvasive mechanical ventilation in acute respiratory failure. , 1996, The European respiratory journal.

[20]  M. Wysocki,et al.  Noninvasive versus conventional mechanical ventilation. An epidemiologic survey. , 2001, American journal of respiratory and critical care medicine.

[21]  François Lellouche,et al.  Patient-ventilator asynchrony during assisted mechanical ventilation , 2006, Intensive Care Medicine.

[22]  J. Moran,et al.  Noninvasive ventilation in acute respiratory failure--a meta-analysis update. , 2002, Critical care medicine.

[23]  Y. Nakamura,et al.  The Effect of Breath Termination Criterion on Breathing Patterns and the Work of Breathing During Pressure Support Ventilation , 2001, Anesthesia and Analgesia.

[24]  Marc Gainnier,et al.  Impact of expiratory trigger setting on delayed cycling and inspiratory muscle workload. , 2005, American journal of respiratory and critical care medicine.

[25]  L. Brochard,et al.  Effect of the humidification device on the work of breathing during noninvasive ventilation , 2002, Intensive Care Medicine.

[26]  S. Nava,et al.  Patient-ventilator interaction and inspiratory effort during pressure support ventilation in patients with different pathologies. , 1997, The European respiratory journal.

[27]  S. Nava,et al.  Noninvasive ventilation in acute respiratory failure , 2007, Critical care medicine.

[28]  M J Tobin,et al.  Comparison of assisted ventilator modes on triggering, patient effort, and dyspnea. , 1997, American journal of respiratory and critical care medicine.

[29]  M. Tobin,et al.  Patient-ventilator interaction. , 2001, American journal of respiratory and critical care medicine.

[30]  L. Brochard,et al.  Physiologic effects of noninvasive ventilation during acute lung injury. , 2005, American journal of respiratory and critical care medicine.