PMVF-ASMIC 2017 What s new and exciting for Pediatric Mechanical ventilation? Rujipat Samransamruajkit MD Professor of Pediatrics Chief of PICU KCMH, Faculty of Medicine Chulalongkorn U BKK, Thailand
Introduction of modes Branson, Johanningman et al 2004
History of ventilation Branson, Johanningman et al 2004
Introduction of Mode MV Closed loop ventilation/duomode PRVC/ASV/VS PRVC/SIMV/ATC VG INTELLIVENT 2000 Present Future DuoPAP NAVA+ SIMV PAV Physiologic monitoring
Overview
Mechanisms of gas transport Mechanical Ventilation Positive-Pressure Gradient produced by the ventilator Wood BR. Assisted Ventilation 2003, 4th Ed.
Why new modes? More safely assist patient Less likelihood of ventilator associated lung injury. Less hemodynamic compromise More effectively ventilate/oxygenate Improve patient - ventilator synchrony More rapid weaning
Evolution Where we are today? Volume control Pressure control/pressure support Dual control Algorithm based Knowledge/Evidence based
Goals of Mec ventilation
Ped ARDS
PALI study group 2015
pards MV support pards CV+PEEP titration APRV HFOV
Jain et al Intens Care Med Expr 2016 Demirkol D, et al Indian J Pediatr 2010
CV VS APRV
APRV VS HFOV
APRV Pressure wave form
Expiratory Flow
HFOV VS APRV Settings
Yehya N, et al Ped Pulmonary 2014
APRV Ped Summary Jain SV et al ICM Exp 2016
Neural adjusted ventilator assist A new way of ventilation
Neuro-Ventilatory Coupling Neural adjusted ventilator assist NAVA Central Nervous System Phrenic Nerve Diaphragm Excitation Diaphragm Contraction Chest Wall and Lung Expansion Airway Pressure, Flow and Volume Ideal Technology New Technology Current Technology Ventilator Unit
Conventional triggering Conventional ventilator technology uses a pressure drop or flow reversal to provide assistance to the patient. It is the last step of the signal chain leading to inhalation. This last step is subject to disturbances such as intrinsic PEEP, hyperinflation and leakage.
NAVA triggering The earliest signal that can be registered with a low degree of invasivity is the excitation of the diaphragm. The excitation of the diaphragm is independent of pneumatic influence and insensitive to the problems with pneumatic triggering technologies. By following diaphragm excitation and adjusting the support level in synchrony with the rise and fall of the electrical discharge, the ventilator and the diaphragm will work with the same signal input. In effect, this allows the ventilator to function as an extra muscle, unloading extra respiratory work induced by the disease process.
NAVA-Components
Catheters
NAVA Edi Catheter Esophagus
Catheter verification P and QRS waves are present on the top leads and the P-waves disappear on the lower leads and with a decrease of the QRSamplitude on the lower leads. When an Edi waveform is present, observe which leads are highlighted in blue. If the leads highlighted in blue are in the center (i.e. second and third leads), secure the Edi Catheter in this position. To finally verify correct positioning of the Edi Catheter press the Exp. Hold and keep the button depressed until a breathing effort is registered. A negative deflection in the pressure curve with a simultaneous positive inflection in the Edi curve verifies correct position of the Edi Catheter.
NAVA AND NIV NAVA Upper pressure limit indication 2013-12-05 MX-5804 Rev 01 ver. 01
Edi, the vital sign of respiration How to monitor patient ventilator asynchrony Edi identifies early spontaneous breathing efforts Edi allows for immediate identification of wasted efforts, delayed triggering and autotriggering Flat or low Edi signal are mostly caused by excessive sedation or too high assist levels P Edi Wasted effort Delayedtriggering Autotriggering MX-6289 version:01
Patient-ventilator synchrony with NAVA Length of stay - first outcome studies Pediatric (Kallio M, Pediatric Pulmol. 2014) Adult (Hadfield D, ISICEM. 2013) MX-6289 version:01
NAVA Literature review NAVA Feasibility and physiological effects of noninvasive neurally adjusted ventilatory assist in preterm infants. Gibu CK1, Cheng PY1, et al. Pediatr reserch 2017 Neurally adjusted ventilatory assist for infants under prolonged ventilation. Lee J1, Kim HS2, et al Pediatr Inter 2017 Effective Neurally Adjusted Ventilatory Assist (NAVA) Ventilation in a Child With Jeune Syndrome. Cosi G1, et al Pediatrics 2016
Adjunctive Rx
Prone position Kallet RH et al Resp Care 2015
Scholten et al Chest 2017
Prone position
Prone position protocol/meta-analysis
Minimized lung injury with new mode
Use the ideal BW Series of test breath Adaptive support ventilation(asv) If no spontaneous breath, then ventilator determine the appropriate RR, TV, pressure limit I:E and Ti optimized by the ventilator to prevent auto- PEEP If continue to have spontaneous breath, the ventilator decrease mandatory breath, switch to PS mode Automatic adjust pressure limit
The ability to set and deliver VG Volume Guarantee specific tidal volumes In a ventilator would reduce volume trauma and thus avoid lung injury The ventilator automatically adjusts the inspiratory pressure according to changes of compliance, resistance or respiratory drive to achieve a set tidal volume
Controlling of PIP during Volume Guarantee Any change in tidal volume leads to an automatic adjustment of PIP As tidal volume increases due to improving C after surfactant application the ventilator automatically drops PIP When patient effort changes and tidal volume changes, the PIP is automatically adapted to maintain the set tidal volume
Volume guarantee ventilation
VG adjust pressure
VG How to set up Klingenberge C, et al J perinatol 2011
Mechanical ventilation How to make it safe?
CMV PC mode with Pplat < 28 cmh 2 O (29-32, reduce chest wall compliance) Recommend to use TV 3-6 cc/predicted body weight (poor lung compliance) 5-8 cc/kg ideal body weight for better lung compliance Use moderate PEEP, 10-15 cmh2o, titrated for better oxygenation Careful use recruitment maneuver by slow incremental and decremental step Ped ARDS PCCM 2015
Fifty Years of Research in ARDS. Respiratory Mechanics in Acute Respiratory Distress Syndrome Henderson WR et al AJRCCM 2017 The measurement and application of clinically applicable pulmonary mechanical concepts Plateau pressures, Driving pressure, Transpulmonary pressures (TPP) Stress index and measurement of strain.
Breathing requires the generation of a
Breathing Driving Pressure Spontaneous Breathing Mechanical Ventilation Transpulmonary Pressure (P atm - P alv ) PIP/P plat - PEEP Respiratory muscles Ventilator
Driving Pressure Represents the pressure change that generates a flow, which exceeds the elastic, resistive and inertial properties of the respiratory system, resulting in a change of volume in the lung.
The respiratory system is modelled as a linear mechanical system, which is defined by the following equation: Röhrer Equation P= V/C + RV + IV Driving pressure... In this relationship, the driving pressure (P) is the sum of elastic (V/C), resistive (RV), and Inertial (IV) components. The elastic component of pressure is proportional to volume (V) by a constant (1/C), where C represents the dynamic lung compliance. The resistive component of pressure is proportional to airflow by a constant R which represents the inelastic airway and tissue resistances. The inertial component of pressure is proportional to gas acceleration by the inertial constant (when inspiratory and expiratory flow rates are < 5 lt/min, the inertial term may be assumed to be negligible.
ARDS & driving pressure Amato et al NEJM 2015 Driving pressure (ΔP) can be calculated at the bedside as plateau pressure minus positive end-expiratory pressure (P plat PEEP) Ped ARDS
Ped ARDS Amato M, et al NEJM 2015
The Relationship of Pplat/dP Outcomes P Plat PEEP ΔP Mortality Rising same rising rising Rising rising same same Same rising falling falling Ped ARDS
TPP Monitoring Transpulmonary pressure (TPP) is the net distending pressure applied to the lung by contraction of the inspiratory muscles or by positivepressure ventilation TPP is the difference between alveolar pressure (Palv) and pleural pressure (Ppl); i.e. TPP = Palv Ppl Oesophageal pressure [Pes] is used as a surrogate for Ppl, so TPP can be measured by performing oesophageal manometry during an end-inspiratory or endexpiratory occlusion; i.e. TPP = Palv Pes Aim to fully recruit the lung but avoid excessive overdistension Target TPP of 25 cmh 2 O during recruitment Set PEEP to maintain TPP of 0 to 10 cmh 2 O at end expiration using an end-expiration occlusion Aim to limit stress applied to the lung Keep TPP at end-inspiration below 25 cmh 2 O Talmor et al, NEJM 2008 Akoumianaki E, et al. Am J Respir Crit Care Med. 2014
Transpulmonary pressure monitoring AVEA
Mechanical ventilation & Metabolic monitoring
SCCM and ASPEN 2016 Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Critically Ill Patient 1. IC should be used to determine energy requirements when available 2. Provide at least 80% of estimated or calculated goal energy and protein within 48-72 hours over the 1 st week of hospitalization 3. Pulmonary failure High fat low carbohydrate formulations designed to manipulate RQ and decrease CO 2 production are not recommended for use 4. Burn IC should be used to assess energy needs with weekly repeated measures 5. Obesity Target energy requirements should be measured by IC. Feed at 65-70% of target McClave SA et al. J Parenter Enteral Nutr 2016;40(2):1-53
Consequences of Under- or Overfeeding Underfeeding 1,2 Impairs regeneration of respiratory epithelium Contributes to muscle weakness and respiratory dysfunction Overfeeding 2-5 Worsens metabolic stress Increases the work of breathing (can lengthen ventilator dependence) 1 Askanazi J, et. al. Crit Care Med. 1982;10:163-172. 2 Kan M, et al. J Crit Care. 2003;7:108-115. 3 McClave SA. J Resp Care Pract. 1997;10:57-8,60,62-64. 4 Dark DS, et al. Chest. 1985;88:141-143. 5 Porter C. J Am Diet Assoc. 1996;96:49-54, 57.
And what is available today ~ 320 m 3 ~ 0.003 m 3
Indirect Calorimetry Measurement of metabolic needs: O2 consumption, CO2 production, respiratory exchange ratio (RQ), energy expenditure Calculation of cardiac output Calculation of dead space ventilation
Future Views Pressure bar graph always visible SBT FRC Spirometry Metabolics Calculations
What is coming for the future?
INTELLIVENT-ASV Automate-Close loop ventilation
Equipment factors may significantly contribute to the dead space ventilation in children Potential alternative Rx with mild to moderate ARDS with APRV mode. High frequency oscillator ventilation remains an option for severe refractory respiratory failure in Pediatrics. Addition of PRONE position may improve benefit in refractory ARDS. ARDS, Knowledge of functional lung size would allow the quantitative estimation of Stress/strain. (including TPP/Driving P monitoring) NAVA mode technology, while not routine use in Pediatrics, may benefit in select patients. Closed loop/smart ventilation Take home message
Questions & Discussion