CO 2 Injury The Balancing Act of One-Lung Ventilation O2O2

The essence of efficient gas exchange is Ventilation –Perfusion Matching

West.JB: Resp Physiology Multiple Inert Gas Elimination Technique

West.JB: Resp Physiology Multiple Inert Gas Elimination Technique HPV

West.JB: Resp Physiology Multiple Inert Gas Elimination Technique HPV Gravity

West.JB: Resp Physiology Multiple Inert Gas Elimination Technique HPV Gravity Anatomy

MIGET during OLV

HPV & Gravity

R/O Obstruction

CPAP

PEEP Recruit

Hypoxia During OLV  FiO 2 = 1.0  R/O Obstruction/Malposition  Reinflation  Recruit/PEEP to Dependent Lung  CPAP to Nondependent Lung  PA Crossclamp

Optimal PEEP ?

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Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

Choice of Agent & PaO 2 during OLV Pagel ‘98(humans)Desfl = Isofl Schwarzkopf ‘03 (pigs)Desfl = Isofl Wang ‘98 (humans)Isofl = Sevo Saito ‘00 (humans)Isofl = Sevo Shimizu ‘98 (humans)Isofl = Sevo Abe ‘98 (humans)Isofl = Sevo Slinger ‘95 (humans)Isofl > Enfl

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

Dose of Volatile Agents and PaO 2 during OLV Schwarzkopf, Anesth Analg, 93:1434, 2001

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

TIVA vs Volatile Anesthesia PaO 2 during OLV Reid ‘96 (30 Pts) Prop/Alf = Iso Karzai ‘98 (10 pigs) Prop > Des Abe ‘98 (20 Pts) Prop > Iso/Des Beck ‘01 (40 Pts) Prop = Sevo Dossow ‘01 (50 Pts) Prop/Fent > TEA/Iso Schwarzkopf ‘03 (30 pigs) Prop>Des/Iso Pruszkowski ‘07 (80 Pts)Prop=Sevo Schwarzkopf ‘09 (60 Pts)Prop=Sevo

PaCO 2 (mmHg) PaO 2 (mmHg) † PvO 2 (mmHg)40+ 5* Qs/Qt (%) RL Perfusion (%) CO (L/min)5.4+ 2§, ‡ Schwarzkopf K; J Cardiothoracic Vasc Anesth 2003;17(1):73 TIVA vs Volatile Agents PropDesfl Isofl

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

iNO and Oxygenation During OLV Reference nNO PPM PaO 2 Hartigan36 20No Change Anesthesiology 1996

iNO and Oxygenation During OLV Reference nNO PPM PaO 2 Hartigan36 20No Change Anesthesiology 1996 Wilson6 40No Change J. Cardioth Vasc Anesth 1997 Ismail – Zade12 3-5No Change J. Cardioth Vasc Anesth 1997 Moutafis20 20No Change Anesth Analg 1997 Fradj60 20No Change Br J Anaesth 1998 Schwarzkopf152 20No Change Anesth Analg 2001 Della Rocca30 40No Change J. Cardioth Vasc Anesth 2001

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode

PCV vs VCV for OLV Tugrul ’97PCV > VCV (n=48, Crossover, VT=10ml/kg) Heimberg ’06PCV = VCV (n=50, No Crossover, VT=10ml/kg) Unzuetta ’07PCV = VCV (n=57, Crossover, VT=9ml/kg)

Dose of Volatile Agents and PaO 2 during OLV Schwarzkopf, Anesth Analg, 93:1434, 2001  14 Pigs – Anesth / Para, OLV, LLD  Varied Dose of Isofl & Desfl (0.5 – 1.0 – 1.5 MAC)  Measured: Qs/Qt, CO, PvO2, PaO2, % Q-R-Lung

Schwarzkopf, Anesth Analg, 93:1434, 2001 Dose of Volatile Agents and PaO 2 during OLV

12 Pigs – Anesth / Para, OLV, LLD 12 Pigs – Anesth / Para, OLV, LLD Initially Remifent + N 2 O, then: Initially Remifent + N 2 O, then: Isoflurane 1 MAC Isoflurane 1 MAC Desflurane 1 MAC Desflurane 1 MAC Propofol - adjusted to equivalent BP/HR Propofol - adjusted to equivalent BP/HR Measurements: Measurements: Qs/Qt, PaO 2, P V O 2, %Q-R-Lung, Hemodyn. Qs/Qt, PaO 2, P V O 2, %Q-R-Lung, Hemodyn. TIVA vs Volatile Agents Schwarzkopf K; J Cardiothorac Vasc Anesth 17: 73, 2003

Advantages of PCV  Decelerating Flow Pattern  Improved Recruitment of Slow Alveoli  More Homogeneous Ventilation  Better V/Q Matching (?)  Lower PIP’s

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode  Position  Thoracic Epidural  Cardiac Output

Lateral > Prone > Supine PaO 2 during OLV: Effect of Position

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode  Position  Thoracic Epidural  Cardiac Output

Beyond CPAP & PEEP ?  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Inhaled Nitric Oxide  Ventilator Mode  Position  Thoracic Epidural  Cardiac Output

Effect of C.O. on PaO 2 during OLV PaO 2 Perfusion of Nondependent Lung P.A. Pressure Counteracts HPV Mixed Venous O 2

Qs/Qt = Cc´o 2 – Cao 2 Cc´o 2 – Cvo 2 Cao 2 = Cc´o 2 · (1 – Qs/Qt) + (Qs/Qt) · Cvo 2 Cvo 2 = Cao 2 – (Vo 2 /Qt) · Cao 2 = Cc´o 2 – (Vo 2 /Qt) · Qs/Qt 10 x (1 – Qs/Qt) () Shunt Fick Combined x · Levin AI. Anesth Analg 2005; 100:12

C.O. & CaO 2 : Effect of Shunt Levin AI, Anesth Analg 2005; 100:12-14 Qs/Qt=0.2, VO 2 = 150. Qs/Qt = 0.4

Optimizing PaO 2 during OLV: Beyond CPAP & PEEP ?  Inhaled Nitric Oxide  Choice of Volatile Agent  Dose of Volatile Agent  TIVA  Ventilator Mode  Position  Thoracic Epidural  Cardiac Output

THE END