Stratégie ventilatoire pendant la RCP Pr Jean-Christophe M Richard Pôle SAMU 74 Urgence et Réanimation Centre Hospitalier Annecy Genevois
CONFLICTS OF INTEREST - Air Liquide Medical Systems (part time) Financial support for research (Genève /Annecy/Angers) -VYGON (personal fee for lectures) -SHILLER -MAQUET (NAVA) -COVIDIEN (PAV+) (personal fee for lectures) -DRAGER (SmartCare) -GE (FRC)
Classical interpretation of CPR physiology Circulation Ventilation
ETI + curarised subjects Manual CC generates 156mL of V T (0 to 390mL) ETT + cardiac arrest subjects Manual CC generates no V T
Change in lung volume: Vt and FRC e f FRC b ml c f a. Ressort b. Soufflet c. Seringue d. Prise de pression dans le soufflet a d e. Entré d air f. Stylet et Papier millimétrique Pressure transmitted into the thoracic compartment
Paw Flow Volume Cordioli et al. J Appl Reduction in lung volume below FRC induced by Chest compressions FRC Lung volume reduction below FRC
Thoracic airways closure limiting inspiratory flow during Chest compressions Flow limitation at PEEP 0 PEEP 3 cmh20 PEEP 0 cmh20 Cordioli et al. J Appl
oxygenation Impact of thoracic airway closure on gas exchanges CO2 elimination Cordioli et al. Curent Op Crit Care (submitted)
For similar chest compressions, thoracic airways closure limits both Paw transmission and ventilation. As results, thoracic airways closure may affect capnogram and therefore be
Volume (L) Risks associated with 30:2 bag mask CPR: Gastric Inflation Accumulated gastric volume inflated after each minute of chest compressions regarding 3 different strategies of bag mask ventilation (5 thiel cadavers - median with interquartile range) 10 1 ICC 30:2 10 CCC 30:2 CCC 10/min 10 1 0, 8 8 0 6, 6 8 6 8 6 0, 8 0, 6 0, 4 4 0, 2 2 4 2 4 2 0, 4 0, 2 0 1 2 3 4 5 6 0 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 0 Time (min)
Volume (L) Risks associated with 30:2 bag mask CPR: Gastric Inflation 1.0 1 Vti and Vte at each minute during chest compression regarding 3 different strategies of bag mask ventilation (5 thiel cadavers mean with standard deviation) ICC 30:2 1.0 CCC 30:2 1.0 CCC 10/min 0, 8 0.8 0.8 0.8 0, 6 0.6 0.6 0.6 0, 4 0.4 0.4 0.4 0, 2 0.2 0.2 0.2 0.0 0 1 2 3 4 5 6 0.0 1 2 3 4 5 6 1 2 3 4 5 6 0.0 Time (min)
ERC Guidelines 2015 on EtCO 2 monitoring 1. To check proper placement of tracheal tube 2. To monitor respiratory rate to avoid hyperventilation 3. To assess quality of chest compressions 4. To detect ROSC without interrupting chest compressions Our Lack of confidence in the accuracy of EtCO 5. To predict outcome at 20 min 2 measurement during CPR, and the need of advance airway to measure EtCO2 reliably, limits our confidence in its use for prognostication.
CO2 depends on ventilation and circulation Both depend on chest compression
The median Vt per compression : 41.5 ml (33.0-62.1 ml) which was considerably less than measured dead space
Accidental observation: Periodic variation of EtCO 2 during CPR P aw CO 2 Capnogram (EtCO2 waveform) during CPR varies periodically with chest compressions and ventilation.
Capnograms obtained during chest compressions in OHCA CO 2
Capnograms obtained during chest compressions in OHCA CO 2
Leturiondo M et al.
CO2 CO2 ITP P-P aw Thiel cadaver model with CO2 (CAVIAR lab) CO2 Airways opening measurements Intra thoracic measurements
Thiel cadaver model with CO2 (CAVIAR lab) Full Airway patency: PEEP 10 cmh 2 O Partial and complete airway closure: PEEP < P closing Cordioli et al. Curent Op Crit Care (submitted)
CO2 Production L/min Bench model with CO2 (Toronto Lab) ROSC CO2 Time (s)
Bench Model of CPR with additional CO2 Partial airway closure: PEEP 0 cmh 2 O Full Airway patency: PEEP 5 cmh 2 O D Luca Grieco et al. AJRCCM (Epub ahead of print)
How to interpret capnogram during chest compressions? Insufflation from the ventilator Alveolar CO2 CO2 Wash out by fresh gas Insufflation from the ventilator
Airway Opening Index : AOI CO2max CO2 AOI = CO2 CO2max = 75% CO2min Time AOI = 85% AOI = 5% The AOI permits to characterize and quantify oscillations on capnogram that is correlated with alveolar ventilation
CLINICAL OBSERVATIONAL STUDY : 100 OHCA patients: D Luca Grieco et al. AJRCCM (Epub ahead of print)
CO2 CO2 ITP P-P aw Thiel cadaver model with CO2 (CAVIAR lab) CO2 Airways opening measurements Intra thoracic measurements
Maximal EtCO2 value is the best surrogate of alveolar CO2 CLINICAL OBSERVATIONAL STUDY : 100 OHCA patients: 100 OHCA N=90 Patients 75 CO2 (mmhg) 50 25 0 Patients D Luca Grieco et al. AJRCCM (Epub ahead of print)
Thiel cadaver model with CO2 (CAVIAR lab) D Luca Grieco et al. AJRCCM (Epub ahead of print)
Thiel cadaver model with CO2 (CAVIAR lab) D Luca Grieco et al. AJRCCM (Epub ahead of print)
Clinical implications: CLINICAL OBSERVATIONAL STUDY : 100 OHCA patients: D Luca Grieco, et al. AJRCCM (Epub ahead of print)
Annecy CPR Round Table : Two phase time sensitive model to OHCA ETCO 2 guided therapy Airway Closure? guided therapy SURVIVAL High Quality CPR Early Defibrillation Cardiac Pump Goal Directed Optimization Cardiac and Thoracic Pump Consider ECMO 4 7 10 TIME Brain perfusion guided therapy
Ventilation during CPR should be revisited to be adapted to this specific context Thoracic airways closure may impair oxygenation and CO2 elimination during CPR. Only maximal value of exhaled CO2 during CPR reflect alveolar CO2 Capnogram oscillations reflect thoracic airways patency and ventilation quality during CPR EtCO2 monitoring during CPR is highly recommended but not adapted to CPR
Thiel cadaver model with CO2 (CAVIAR lab) Full Airway patency: PEEP 10 cmh 2 O Partial airway closure: PEEP 5 cmh 2 O P aw CO 2 By decreasing PEEP from above to below thoracic closing pressure, CO2 changed from oscillating to non oscillating pattern
CONCLUSIONS Ventilation during CPR should be revisited to be adapted to this specific context Protective ventilation compliant with continuous chest compression is the priority Thoracic airways closure may impair oxygenation and CO2 elimination during CPR. EtCO2 monitoring during CPR is highly recommended but not adapted to CPR Only maximal value of exhaled CO2 during CPR reflect alveolar CO2 Capnogram oscillations reflect thoracic airways patency and ventilation quality during CPR