Adaptive Support and Pressure Support Ventilation Behavior in Response to Increased Ventilatory Demand

Background:Dual-control modes of ventilation adapt the pressure delivery to keep a volume target in response to changes in respiratory mechanics, but they may respond poorly to changes in ventilatory demand. Adaptive support ventilation (ASV), a complex minute volume-targeted pressure-regulated ventilation, was compared to adaptive pressure ventilation (APV), a dual-mode in which the pressure level is adjusted to deliver a preset tidal volume, and to pressure support ventilation (PSV) when facing an increase in ventilatory demand. Methods:A total of 14 intensive care unit patients being weaned off mechanical ventilation were included in this randomized crossover study. The effect of adding a heat-and-moisture exchanger to augment circuit dead space was assessed with a same fixed level of ASV, PSV, and APV. Results:Arterial blood gases, ventilator response, and patient respiratory effort parameters were evaluated at the end of the six periods. Adding dead space significantly increased minute ventilation and Paco 2 values with the three modes. Indexes of respiratory effort (pressure-time index of respiratory muscles and work of breathing) increased with all ventilatory modes after dead-space augmentation. This increase was significantly greater with APV than with PSV or ASV (P < 0.05). The assistance delivered during APV decreased significantly with dead-space from 12.7 ± 2.6 to 6.7 ± 1.4 cm H2O, whereas no change occurred with ASV and PSV. Conclusions:ASV and PSV behaved differently but ended up with similar pressure level facing acute changes in ventilatory demand, by contrast to APV (a simple volume-guaranteed pressure-control mode), in which an increase in ventilatory demand results in a decrease in the pressure support provided by the ventilator.

[1]  H RAHN,et al.  Mechanics of breathing in man. , 1950, Journal of applied physiology.

[2]  W A Zin,et al.  A simple method for assessing the validity of the esophageal balloon technique. , 2015, The American review of respiratory disease.

[3]  I. Grossbach-Landis,et al.  Weaning from mechanical ventilation , 2005, ERS practical Handbook of Invasive Mechanical Ventilation.

[4]  W. Sanborn.  Inspiratory pressure support prevents diaphragmatic fatigue during weaning from mechanical ventilation. , 1989, The American review of respiratory disease.

[5]  T. Similowski,et al.  Clinically relevant diaphragmatic dysfunction after cardiac operations. , 1994, The Journal of thoracic and cardiovascular surgery.

[6]  J. Brunner,et al.  Automatic selection of tidal volume, respiratory frequency and minute ventilation in intubated ICU patients as startup procedure for closed-loop controlled ventilation , 1994, International journal of clinical monitoring and computing.

[7]  G. Iotti,et al.  Simple method to measure total expiratory time constant based on the passive expiratory flow-volume curve. , 1995, Critical care medicine.

[8]  N. Weiler,et al.  [Adaptive lung ventilation (AVL). Evaluation of new closed loop regulated respiration algorithm for operation in the hyperextended lateral position]. , 1996, Der Anaesthesist.

[9]  V. Ranieri,et al.  Patient-ventilator interaction during acute hypercapnia: pressure-support vs. proportional-assist ventilation. , 1996, Journal of applied physiology.

[10]  V. Ranieri.  Optimization of patient-ventilator interactions: closed-loop technology to turn the century , 1997, Intensive Care Medicine.

[11]  S. Jaber,et al.  Noninvasive ventilation with helium-oxygen in acute exacerbations of chronic obstructive pulmonary disease. , 2000, American journal of respiratory and critical care medicine.

[12]  M. S. Lourens,et al.  Expiratory time constants in mechanically ventilated patients with and without COPD , 2000, Intensive Care Medicine.

[13]  J. Revelly,et al.  Adaptive Support Ventilation for Fast Tracheal Extubation after Cardiac Surgery: A Randomized Controlled Study , 2001, Anesthesiology.

[14]  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.

[15]  R. Branson,et al.  Adaptive support ventilation. , 2001, Respiratory care clinics of North America.

[16]  Patient-ventilator interactions during volume-support ventilation: asynchrony and tidal volume instability--a report of three cases. , 2001, Respiratory care.

[17]  L. Brochard.  When ventilator and patient's end of inspiration don't coincide: what's the matter? , 2002, American journal of respiratory and critical care medicine.

[18]  G. Iotti,et al.  Adaptive Support Ventilation (ASV). , 2002, Minerva anestesiologica.

[19]  D. Tassaux,et al.  Patient-ventilator interactions during partial ventilatory support: A preliminary study comparing the effects of adaptive support ventilation with synchronized intermittent mandatory ventilation plus inspiratory pressure support , 2002, Critical care medicine.

[20]  J. Revelly,et al.  Clinical experience with adaptive support ventilation for fast-track cardiac surgery. , 2003, Journal of cardiothoracic and vascular anesthesia.

[21]  N. Weiler,et al.  Adaptive Lung Ventilation (ALV) during Anesthesia for Pulmonary Surgery: Automatic Response to Transitions to and from One-Lung Ventilation , 1998, Journal of Clinical Monitoring and Computing.

[22]  Robert Babuška,et al.  Estimation of Expiratory Time Constants via Fuzzy Clustering , 2004, Journal of Clinical Monitoring and Computing.

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

[24]  R. Branson,et al.  What is the evidence base for the newer ventilation modes? , 2004, Respiratory care.

[25]  R. Branson.  Understanding and implementing advances in ventilator capabilities , 2004, Current opinion in critical care.

[26]  Michel Dojat,et al.  Computer-driven management of prolonged mechanical ventilation and weaning: a pilot study , 2005, Intensive Care Medicine.

[27]  M. Sebbane,et al.  Volume-guaranteed pressure-support ventilation facing acute changes in ventilatory demand , 2005, Intensive Care Medicine.

[28]  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.

[29]  M. Dojat,et al.  A multicenter randomized trial of computer-driven protocolized weaning from mechanical ventilation. , 2006, American journal of respiratory and critical care medicine.

[30]  M. Underwood,et al.  Randomized Controlled Trial Comparing Adaptive-support Ventilation with Pressure-regulated Volume-controlled Ventilation with Automode in Weaning Patients after Cardiac Surgery , 2008, Anesthesiology.