2. Page  2  Introduction  Physiological Aspects  Monitoring Requirements

4. Page  4 Thoracic anesthesia is challenging PatientProcedure

6. Page  6  “V" - ventilation  “V" - ventilation - the air which reaches the lungs  "Q" - perfusion  "Q" - perfusion - the blood which reaches the lungs  Normal V is 4 L of air per minute.  Normal Q is 5L of blood per minute. Normal V/Q ratio is 4/5 or 0.8.  So Normal V/Q ratio is 4/5 or 0.8.  When the V/Q is higher than 0.8, it means ventilation exceeds perfusion.  When the V/Q is < 0.8, there is a VQ mismatch caused by poor ventilation

7. Page  7 "shunt."  An area with no ventilation (and thus a V/Q of zero) is termed "shunt." “dead space”  An area with no perfusion (and thus a V/Q of infinity) is termed “dead space”

8. Page  8  A change in volume divided by a change in transpulmonary pressure.  (CL = ΔV / ΔPL)  A typical value of compliance is 200 ml/cm H20

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11. Page  11 Pulmonary blood flow distribution relative to the alveolar pressure Perfusion Ventilation

12. Page  12 Patient awake spontaneously breathing The dependent lung is better Ventilated than the Nondependent lung, ˙V/˙ Q still is well matched.

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16. Page  16 principle physiologic change of O  The principle physiologic change of OLV is the redistribution of lung perfusion between the ventilated (dependent) and blocked (nondependent) lung hypoxic pulmonary vasoconstriction, HPV and gravity.  Many factors contribute to the lung perfusion, the major determinants of them are hypoxic pulmonary vasoconstriction, HPV and gravity.

17. Page  17 HPV is a widely conserved, homeostatic, vasomotor response of precapillary smooth muscle in the PAs to alveolar hypoxia. HPV mediates ˙V/˙Q matching and, by reducing shunt fraction, optimizes systemic pO 2.

18. Page  18 Reduces the surface area available for gas exchange Reduced arterial oxygen tension Maintaining oxygenation and and elimination of carbon dioxide is the greatest challenge

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20. Page  20 Use of Monitoring to Detect and Diagnose Intraoperative Events  Respiration  Oxygenation  Ventilation  Cardiovascular function

21. Page  21 Apnea, respiratory difficulty, rales Pattern, respiratory rate Wheezing, rhonchi, apnea, compliance Auscultation Obstruction, pneumothorax, bronchospasm,secretions Airway pressure

22. Page  22 Inadvertent hypoxia FiO2 analyzer Hypoxia, integrity of pulse Pulse oximetry Acidosis (metabolic, respiratory) Arterial blood gas

23. Page  23 Capnography Bronchospasm Hypoventilation and apnea Confirm endotracheal intubation Return of spontaneous ventilation during controlled ventilation

24. Page  24  Electrocardiography Arrhythmia, ischemia  Intraarterial catheter Hypotension or hypertension Arterial compression

25. Page  25  Pulmonary artery catheter Pulmonary hypertension, filling pressures, assess cardiac performance  SvO2 Adequacy of cardiac output

26. Page  26  Transesophageal Echocardiography Ischemia, volume status, right ventricular dysfunction

27. Page  27 Failure to check the equipment properly before induction of anesthesia is before induction of anesthesia is responsible for 22% of the responsible for 22% of the critical incidents that occur during anesthesia critical incidents that occur during anesthesia

28. Page  28 Healthy patients no special intraopertive conditions Healthy patients no special intraopertive conditions Sick patients special intraopertive conditions Sick patients special intraopertive conditions Tier I ProcedureProcedurePatientPatient

29. Page  29 Gas exchange Airway mechanics Endotracheal tube position PA pressures Cardiovascul- ar status Color of tissues and shed blood Spo 2, PETCO 2 Feel of the breathing bag, stethoscope, PIP, PETCO 2 EBBS Ballotable balloon in SSN, FOB after placed in LDP Not measuredNIBP, pulse oximeter waveform, ECG, PETco2 esophageal stethoscope, ± CVP, ± invasive arterial pressure monitoring

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31. Page  31 Healthy patients no special intraopertive conditions Healthy patients no special intraopertive conditions Sick patients special intraopertive conditions Sick patients special intraopertive conditions Tier II ProcedureProcedurePatientPatient

32. Page  32 Healthy patients no special intraopertive conditions Healthy patients no special intraopertive conditions Sick patients special intraopertive conditions Sick patients special intraopertive conditions Tier II ProcedureProcedurePatientPatient

33. Page  33 Gas exchange Airway mechanics Endotracheal tube position PA pressures Cardiovascul- ar status As above plus frequent ABG studies As above plus spirometry. Individual and whole-lung compliance FOB to verify tube position while in supine position, as well as in the LDP Measure Ppa if lobectomy or lung resection As above, plus invasive arterial pressure monitoring, + CVP, + PA catheter (if poor EF, PA, HTN), ± TEE

34. Page  34  Spirometry volume, pressure and flow  Spirometry is a non-invasive monitor device which measures volume, pressure and flow in the airway.  These measurements may be used to construct :  a pressure-volume curve (PV) and  a flow-volume curve (FV). peri-operative respiratory function.  The constructed curves will give important information about the peri-operative respiratory function.

35. Page  35 Healthy patients no special intraopertive conditions Healthy patients no special intraopertive conditions Sick patients special intraopertive conditions Sick patients special intraopertive conditions Tier III ProcedureProcedurePatientPatient

36. Page  36 Gas exchange Airway mechanics Endotracheal tube position PA pressures Cardiovascul- ar status As above plus Qs/Qt, VD/Vt frequent VBGs As above plus airway resistance As above plus frequent rechecks to verify position Measure PA,Q, PVR, SVR, Dao 2 – Dvo 2 As above plus PA, TEE

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38. Page  38 Measured values:  CVP  CVP: 1-6 mm Hg (reflects right atrial pressure).  PAP  PAP: Systolic 15-30mm Hg, Diastolic 6-12mm Hg.  PCWP  PCWP: 6 - 12mm Hg. Estimates left atrial heart pressure and left ventricular end diastolic pressure.  CO  CO: 3.5 - 7.5 L/min  Sv02:  Sv02: (70 - 75%). Drawn from the end of the pulmonary artery catheter. Used to calculate how well oxygen is extracted by the tissues.

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40. Page  40  the LDP is important with regard to pulmonary artery catheter monitoring in three situations  the LDP is important with regard to pulmonary artery catheter monitoring in three situations. decreased.  The catheter is in the nondependent collapsed lung, the measured cardiac output and mixed venous blood (pvo2) may be decreased., Ppaw may not equal Pla.  When the nondependent lung is ventilated with PEEP and the catheter is in the nondependent lung, Ppaw may not equal Pla. Ppaw will be a faithful index of Pla  When the catheter is in the dependent lung, Ppaw will be a faithful index of Pla, even if PEEP is used

41. Page  41 Monitors are useful adjuncts, But they alone cannot replace Careful observation by Anaesthesiologist Careful observation by Anaesthesiologist.