3/5/14. Disclosures. Background. None. No discussion of non FDA approved products

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1 Disclosures None No discussion of non FDA approved products Background Who are the patients at risk for severe hypoxemic respiratory failure? ú Acute Lung Injury (ALI) PaO 2 /FIO ú Acute Respiratory Distress Syndrome (ARDS) PaO 2 /FIO ú Severe hypoxemic respiratory failure PaO 2 /FIO

2 Background CT-CHEST of ARDS Patient Problems Encountered: 1. Volutrauma 2 o over-stretching or over-distension of normal lung 2. Atelectrauma 2 o shearing forces as alveoli open and close 3. Barotrauma 2 o stiff lungs resulting in elevated lung pressures Background ú Approximately 16% of deaths in patients with ARDS results from severe hypoxemic respiratory failure. 1 ú Degree of respiratory failure may be a direct predictor of poor prognosis. 2 ú ARDS patients on lung-protective mechanical ventilation who improve in oxygenation and disease severity in 24h 3, % mortality ú ARDS patients who don t improve in PaO 2 /FIO 2 ratio in the first 24h of lung-protective ventilation 3, % mortality 1. Montgomery AB, et al. Am Rev Respir Dis 1985; 132: Luhr OR, et al. Am J Respir Crit Care Med 1999; 159: Villar J, et al. Intensive Care Med. 1999; 25 (9): Ferguson ND, et al. Intensive Care Med. 2004; 30 (6): Rationale Background ú The accumulating body of evidence suggests that volutrauma and barotrauma contribute to the development and worsening of ALI and ARDS Normal Lungs 2. After 5 min of ventilation at a peak airway pressure of 45 cmh 2 O 3. After 20 min of ventilation at a peak airway pressure of 45 cmh 2 O Malhorta A. NEJM 2007; 357 (11):

3 Background High Frequency Percussive Ventilation (HFPV) Developed 30 years ago by Dr. Forest Bird Volumetric Diffusive Respirator (VDR) ú Flow-regulated, pressure-limited, and time-cycled ú Combination of high-frequency oscillatory ventilation (HFOV) and conventional pressure-limited breathing cycles ú Currently utilized as a rescue mode in patients failing conventional ventilation (CV) Lucangelo U, et al. Minerva Anestesiol 2003; 69 (11): Esan A, et al. Chest 2010; 137 (5): ALI / ARDS consequences REDUCED SURFACTANT PRODUCTION DUE TO TYPE II CELL INJURY. SURFACTANT INACTIVATION BY PLASMA PROTEINS INCREASED SURFACE TENSION: * MICROATELECTASIS * SMALL AIRWAY COLLAPSE MECHANICAL VENTILATION AND ALI/ARDS BECAUSE LUNG INJURY IS NON-HOMOGENOUS, VENTILATION IS DISTRIBUTED UNEVENLY. VENTILATION IS DISTRIBUTED TO THE REGIONS OF GREATEST COMPLIANCE AND THE LEAST RESISTANCE OR THE PREFERENTIAL AIRWAY. WHEN THIS MAL-DISTRIBUTION OF VENTILATION DOES FURTHER LUNG DAMAGE THIS IS KNOWN AS (VILI). 3

4 BAROTRAUMA Injury due to Airway Pressure VOLUTRAT TRAUMA Injury due to Lug Volume ATELECTRAUMA Injury due to Cyclical Opening & Closing of lung units V.A.L.I V.I.L.I. BIOTRAUMA Activation & Release of Inflammatory mediators (Cytokine, Neutrophil.) High Frequency Percussive Ventilation Volumetric Diffusive Respirator Definition ú Flow- regulated, pressure- limited and time- cycled ventilation ú Delivers a series of high- frequency small volumes in a successive stepwise stacking pattern resulting in formation of low- frequency convective pressure- limited breathing cycles Volumetric Diffusive Respirator Gently recruits alveoli Keeps alveoli patent Mobilizes secre5ons Well tolerated by pa5ents No need for paralysis or seda5on No known contraindica5ons 4

5 Can be applied ARDS with severe hypoxia and/or hypercarbia Severe unilateral lung injury Persistent lobar collapse due to secretions Refractory bronchopleural fistula Inhalation injury or airway debris ú in burn patients Cystic Fibrosis Neuromuscular weakness ú Post surgical patients VDR- Characteristics n Pneumatically powered n Combines regular breath cycle with high frequency flow interruption during that cycle n Respiratory rate 2-30 cycles/min n Inspiratory and expiratory oscillation o Range of frequency cycles/min VDR - Characteristics n Flow regulated n see chest vibration n Pressure limited Delivery of tidal volume (Vt) is completed when the peak inspiratory pressure is reached n Fluctuation in flow will effect Vt and peak pressure n Time cycled Can take spontaneous breaths at any point n Exhalation is passive n Step wise deflation of the lung to CPAP level 5

6 Resonant Frequency The ventilator frequency at which there is the least amount of impedance to gas flow into and out of the lungs ú Using the least amount of force (pressure) for the maximum amount of penetration (volume delivery) This ideal frequency would be when maximum CO 2 removal is achieved for a given tidal volume This is achieved by the functional properties of the phasitron HFPV Static Waveform VDR A" Pulsatile flow during inspiration at 655cycles/min B" Convective pressure-limited breath with low frequency cycle C" Demand CPAP D" Oscillatory CPAP E" Single percussive breath F" Periodic programmed interruptions signifying end of inspiration and onset of exhalation A B B D C E F Action of the phasitron during obstruction Based on the sliding venturi principle ú Sliding ventury will entrain less gas ú Total flow output will decrease 6

7 Response to obstruction Vibration of the chest is diminished Force of the pulsation of the phasitron is reduced ú Flow is reduced Vt is decreased With ongoing pulsation of the phasitron ú small opening is created in the airways ú achieves full opening/ventilation Similar principle as in clearing the secretions Advantages No termination of the ventilation No high peak airway pressure No shearing forces No ventilation induced lung injury Able to gently reopen the airways Considerations Need to monitor the patient ú See the decrease in chest vibrations Partially deflate the cuff to evacuate secretions Suction the secretions May consider bronchoscopy to facilitate the clearing of the secretions 7

8 Setting up the VDR Set up the following; Pulsatile Flow Rate, Oscillatory CPAP, Convective Rate, Percussive Rate, Convective I:E Ratio, Percussive I:E Ratio and FiO2. Demand CPAP if necessary, Convective Pressure Rise if necessary. Don t set the Vt Monitor ú O2 Saturation ú Patient s Chest Vibrations ú Chest X- rays ú ABG s High- frequency percussive ventilation and low tidal volume ventilation in burns: A randomized controlled trial* Objectives: In select burn intensive care units, high-frequency percussive ventilation is preferentially used to provide mechanical ventilation in support of patients with acute lung injury, acute respiratory distress syndrome, and inhalation injury. However, we found an absence of prospective studies comparing high frequency percussive ventilation with contemporary low-tidal volume ventilation strategies. The purpose of this study was to prospectively compare the two ventilator modalities in a burn intensive care unit setting.design: Single-center, prospective, randomized, controlled clinical trial, comparing high-frequency percussive ventilation with low-tidal volume ventilation in patients admitted to our burn intensive care unit with respiratory failure.setting: A 16-bed burn intensive care unit at a tertiary military teaching hospital. Interventions : Subjects were randomly assigned to receive mechanical ventilation through a high-frequency percussive ven- tilation-based strategy (n! 31) or a low-tidal volume ventilation- based strategy (n! 31). Conclusions: A high-frequency percussive ventilation-based strategy resulted in similar clinical outcomes when compared with a low-tidal volume ventilation-based strategy in burn patients with respiratory failure. However, the low-tidal volume ventilation strategy failed to achieve ventilation and oxygenation goals in a higher percentage necessitating rescue ventilation Kevin K. Chung, MD; Steven E. Wolf, MD; Evan M. Renz, MD; Patrick F. Allan, MD; James K. Aden, PhD; Gerald A. Merrill, PhD; Mehdi C. Shelhamer, DO; Booker T. King, MD; Christopher E. White, MD; David G. Bell, MD; Martin G. Schwacha, PhD; Sandra M. Wanek, MD; Charles E. Wade, PhD; John B. Holcomb, MD; Lorne H. Blackbourne, MD; Leopoldo C. Cancio, MD. (CritCareMed 2010;38: ) Severe Hypoxemic Respiratory Failure : Part 1!!Ventilatory Strategies Adebayo Esan, Dean R. Hess, Suhail Raoof, Liziamma George and Curtis N. Sessler Chest 2010;137; DOI /chest The online version of this article, along with updated information and services can be found online on the World Wide Web at: CHEST is the official journal of the American College of Chest Physicians. It has been published monthly since Copyright 2010 by the American College of Chest Physicians, 3300 Dundee Road, Northbrook, IL All rights reserved. No part of this article or PDF may be reproduced or distributed without the prior written permission of the copyright holder. ( ISSN:

9 Chest, May 2010 Summary Combination of regular breath cycles with high frequency flow interruption ú Achieves the properties of conventional and high frequency ventilations Well tolerated by the patients No need for sedation or paralytics Summary Allows to ú Gently open alveoli ú Keep them patent ú Reduce barotrauma/volutrauma in ARDS ú Mobilizes secretions ú Overcomes obstruction ú Can be used in any circumstances, which requires ventilation Invasive and non- invasive 9

10 PATIENT: "Doctor, doctor, will I be able to play the violin after the operation?" Doctor: "Yes, of course..." Patient: "Great! I never could before!" THANK YOU 10