1. PATRICK GERARD L. MORAL, M.D.

3. T OPICS Arterial Blood GasArterial Blood Gas Ventilatory SupportVentilatory Support Arterial Blood GasArterial Blood Gas Ventilatory SupportVentilatory Support

4. A BG Acid - base statusAcid - base status ventilatory statusventilatory status oxygenation statusoxygenation status Acid - base statusAcid - base status ventilatory statusventilatory status oxygenation statusoxygenation status

5. N ORMAL VALUES pH7.35 - 7.45 pH7.35 - 7.45 paCO2 35 - 45 paCO2 35 - 45 paO2 80 - 100 paO2 80 - 100 HCO3 22 - 26 HCO3 22 - 26 O2 sat > 95%O2 sat > 95% pH7.35 - 7.45 pH7.35 - 7.45 paCO2 35 - 45 paCO2 35 - 45 paO2 80 - 100 paO2 80 - 100 HCO3 22 - 26 HCO3 22 - 26 O2 sat > 95%O2 sat > 95%

6. A CID BASE STATUS < 7.35 - acidosis < 7.35 - acidosis – increased CO2- respiratory – decreased HCO3- metabolic > 7.45 - alkalosis > 7.45 - alkalosis – decreased CO2-respiratory – increased HCO3 -metabolic < 7.35 - acidosis < 7.35 - acidosis – increased CO2- respiratory – decreased HCO3- metabolic > 7.45 - alkalosis > 7.45 - alkalosis – decreased CO2-respiratory – increased HCO3 -metabolic

7. V ENTILATION increased CO2 - hypoventialtion increased CO2 - hypoventialtion decreased CO2 - hyperventilation decreased CO2 - hyperventilation increased CO2 - hypoventialtion increased CO2 - hypoventialtion decreased CO2 - hyperventilation decreased CO2 - hyperventilation

8. C OMPENSATION Acidosis Acidosis – respiratory acidosis (inc. CO2) - inc HCO3 – metabolic acidosis (dec. HCO3) - dec CO2 Alkalosis Alkalosis – respiratory alkalosis (dec. CO2) - dec. HCO3 – metabolic alkalosis (inc. HCO3) - inc. CO2 Acidosis Acidosis – respiratory acidosis (inc. CO2) - inc HCO3 – metabolic acidosis (dec. HCO3) - dec CO2 Alkalosis Alkalosis – respiratory alkalosis (dec. CO2) - dec. HCO3 – metabolic alkalosis (inc. HCO3) - inc. CO2

9. C OMPENSATION PartiallyPartially – the pH does not return to normal FullyFully –the pH returns to the normal range PartiallyPartially – the pH does not return to normal FullyFully –the pH returns to the normal range

10. pH 7.45 ACIDOSISNORMAL or COMPENSATED ALKALOSIS PaCO 2 35 - 45 < 35 >45 Uncompensated Metabolic Acidosis Partly Compensated Metabolic Acidosis Respiratory HCO 3 22 - 26 Uncompensated Respiratory Acidosis > 26 < 22 Partly Compensated Respiratory Acidosis Combined Respiratory and Metabolic Acidosis PaCO 2 35 - 45 > 45 < 35 Uncompensated Metabolic Alkalosis Partly Compensated Metabolic Alkalosis Respiratory HCO 3 22 - 26 > 26 < 22 Uncompensated Respiratory Alkalosis Partly Compensated Respiratory Alkalosis Combined Respiratory and Metabolic Alkalosis pH 7.4 Normal or Compensated Acidosis Normal or Compensated Alkalosis PaCO 2 < 35 > 45 35 - 45 Normal Acid-Base Compensated Respiratory Acidosis Compensated Metabolic Acidosis Compensated Respiratory Alkalosis Compensated Metabolic Alkalosis Figure 1. Summary Algorithm for Acid-Base Interpretation

11. O XYGENATION at room air at room air – < 80 mmHg -hypoxemic – 80 - 100-normal oxygenation with supplemental oxygenation with supplemental oxygenation – < 80 mm Hg-inadequate – 80 - 100 mmHg-adequate – > 100 mmHg-more than adequate at room air at room air – < 80 mmHg -hypoxemic – 80 - 100-normal oxygenation with supplemental oxygenation with supplemental oxygenation – < 80 mm Hg-inadequate – 80 - 100 mmHg-adequate – > 100 mmHg-more than adequate

12. I NTUBATION Prevention of upper airway obstructionPrevention of upper airway obstruction Protection against aspirationProtection against aspiration Facilitating tracheobronchial toiletFacilitating tracheobronchial toilet Providing a closed system for mechanical ventilationProviding a closed system for mechanical ventilation Prevention of upper airway obstructionPrevention of upper airway obstruction Protection against aspirationProtection against aspiration Facilitating tracheobronchial toiletFacilitating tracheobronchial toilet Providing a closed system for mechanical ventilationProviding a closed system for mechanical ventilation

13. VENTILATORY FAILURE REDUCED CENTRAL DRIVE IMPAIRED INSPIRATORY MUSCLE PERFORMANCE EXCESSIVE RESPIRATORY WORKLOAD

14. O BJECTIVES To support pulmonary gas exchangeTo support pulmonary gas exchange –alveolar ventilation –arterial oxygenation To increase lung volumeTo increase lung volume To reduce or manipulate work of breathingTo reduce or manipulate work of breathing To support pulmonary gas exchangeTo support pulmonary gas exchange –alveolar ventilation –arterial oxygenation To increase lung volumeTo increase lung volume To reduce or manipulate work of breathingTo reduce or manipulate work of breathing P HYSIOLOGICAL

15. O BJECTIVES To reverse hypoxemiaTo reverse hypoxemia To reverse acute respiratory acidosisTo reverse acute respiratory acidosis To relieve respiratory distressTo relieve respiratory distress To prevent / reverse atelectasisTo prevent / reverse atelectasis To reverse ventilatory muscle fatigueTo reverse ventilatory muscle fatigue To permit sedation / neuromuscular blockadeTo permit sedation / neuromuscular blockade To decrease myocardial oxygen consumptionTo decrease myocardial oxygen consumption To reduce intracranial pressureTo reduce intracranial pressure To stabilize chest wallTo stabilize chest wall To reverse hypoxemiaTo reverse hypoxemia To reverse acute respiratory acidosisTo reverse acute respiratory acidosis To relieve respiratory distressTo relieve respiratory distress To prevent / reverse atelectasisTo prevent / reverse atelectasis To reverse ventilatory muscle fatigueTo reverse ventilatory muscle fatigue To permit sedation / neuromuscular blockadeTo permit sedation / neuromuscular blockade To decrease myocardial oxygen consumptionTo decrease myocardial oxygen consumption To reduce intracranial pressureTo reduce intracranial pressure To stabilize chest wallTo stabilize chest wall C LINICAL

16. 700 - 900 mL700 - 900 mL 15 LPM (self-inflating)15 LPM (self-inflating) augment VTaugment VT 700 - 900 mL700 - 900 mL 15 LPM (self-inflating)15 LPM (self-inflating) augment VTaugment VT A MBUBAG VENTILATION

17. M ODES Assist - ControlAssist - Control SIMVSIMV PSVPSV CPAPCPAP Servo-controlledServo-controlled Assist - ControlAssist - Control SIMVSIMV PSVPSV CPAPCPAP Servo-controlledServo-controlled

18. B ASIC V A = V T - V D V A = V E - V D V A = V T - V D V A = V E - V D VAVA VAVA VTVT VTVT

19. Hook to mechanical ventilator with the following set-up:Hook to mechanical ventilator with the following set-up: – mode: assist - control – VT: 500 mL – BUR: 15/ minute – FiO2: 100 % ABG 30 minutes after hooking to MVABG 30 minutes after hooking to MV In-line nebulization q 6In-line nebulization q 6 Hook to mechanical ventilator with the following set-up:Hook to mechanical ventilator with the following set-up: – mode: assist - control – VT: 500 mL – BUR: 15/ minute – FiO2: 100 % ABG 30 minutes after hooking to MVABG 30 minutes after hooking to MV In-line nebulization q 6In-line nebulization q 6 O RDERS

20. FiO2FiO2 100 %100 % dependent on target PaO2, hemodynamic status, MAP, PEEP leveldependent on target PaO2, hemodynamic status, MAP, PEEP level 100 %100 % dependent on target PaO2, hemodynamic status, MAP, PEEP leveldependent on target PaO2, hemodynamic status, MAP, PEEP level

21. O XYGEN CONTENT CaO2 = 1.34 mL x Hgb x SaO2 +.OO3 mL O2 x PaO2 1.34 mL x Hgb x SaO2 +.OO3 mL O2 x PaO2 CaO2 = 1.34 mL x Hgb x SaO2 +.OO3 mL O2 x PaO2 1.34 mL x Hgb x SaO2 +.OO3 mL O2 x PaO2

22. T IDAL VOLUME Physiologic: 5 - 7 mL / KgPhysiologic: 5 - 7 mL / Kg MV: 10 - 15 mL / KgMV: 10 - 15 mL / Kg alveolar distending pressure: 35 cm H 2 Oalveolar distending pressure: 35 cm H 2 O Physiologic: 5 - 7 mL / KgPhysiologic: 5 - 7 mL / Kg MV: 10 - 15 mL / KgMV: 10 - 15 mL / Kg alveolar distending pressure: 35 cm H 2 Oalveolar distending pressure: 35 cm H 2 O

23. B ASIC V A = V T - V D V A = V E - V D V A = V T - V D V A = V E - V D VAVA VAVA VDVD VDVD mechanical anatomic alveolar

24. C ARDIAC OUTPUT hyperinflation Increased pulmonary vascular resistance Increased RV afterload Decreased RV output Decreased LV preload Decreased LV output

25. PPV

26. 4 to 20 / minute4 to 20 / minute 8 to 12 / minute8 to 12 / minute dependent on:dependent on: –delivered VT –metabolic rate –target PaCO2 –level of spontaneous ventilation 4 to 20 / minute4 to 20 / minute 8 to 12 / minute8 to 12 / minute dependent on:dependent on: –delivered VT –metabolic rate –target PaCO2 –level of spontaneous ventilation R ESPIRATORY RATE

27. 40 to 100 L/ minute40 to 100 L/ minute determined by level of spontaneous breathing effortdetermined by level of spontaneous breathing effort 40 to 100 L/ minute40 to 100 L/ minute determined by level of spontaneous breathing effortdetermined by level of spontaneous breathing effort F LOW RATE

28. Inspiratory time: 0.8 to 1.2 sInspiratory time: 0.8 to 1.2 s I:E 1:2 to 1:1.5I:E 1:2 to 1:1.5 Inspiratory time: 0.8 to 1.2 sInspiratory time: 0.8 to 1.2 s I:E 1:2 to 1:1.5I:E 1:2 to 1:1.5 I NSPIRATORY TIME / I:E RATIO

29. Respiratory rate: 20 / minute Respiratory rate: 20 / minute 60 seconds / 20 = 3 seconds = T tot at an I:E ratio of 1:2: T I = 1 second T E = 2 seconds Respiratory rate: 20 / minute Respiratory rate: 20 / minute 60 seconds / 20 = 3 seconds = T tot at an I:E ratio of 1:2: T I = 1 second T E = 2 seconds I NSPIRATORY TIME / I:E RATIO

30. Respiratory rate: 30 / minute Respiratory rate: 30 / minute 60 seconds / 30 = 2 seconds = T tot at an I:E ratio of 1:1: T I = 1 second T E = 1 second Respiratory rate: 30 / minute Respiratory rate: 30 / minute 60 seconds / 30 = 2 seconds = T tot at an I:E ratio of 1:1: T I = 1 second T E = 1 second I NSPIRATORY TIME / I:E RATIO

31. -0.5 to 1.5 cm H20-0.5 to 1.5 cm H20 most sensitive level that prevents self- cyclingmost sensitive level that prevents self- cycling -0.5 to 1.5 cm H20-0.5 to 1.5 cm H20 most sensitive level that prevents self- cyclingmost sensitive level that prevents self- cycling S ENSITIVITY

32. High pressureHigh pressure Low pressureLow pressure High pressureHigh pressure Low pressureLow pressure P RESSURE ALARMS

33. Low pressureLow pressure –check connections between tubings and patient –deflated cuff –extubation Low pressureLow pressure –check connections between tubings and patient –deflated cuff –extubation P RESSURE ALARMS

34. High pressureHigh pressure –bronchoconstriction –airway obstruction –barotrauma –right main bronchus obstruction –kinked endotracheal tube High pressureHigh pressure –bronchoconstriction –airway obstruction –barotrauma –right main bronchus obstruction –kinked endotracheal tube P RESSURE ALARMS

35. Cascade humidifierCascade humidifier heats carrier gas to 37 Cheats carrier gas to 37 C holds 44 mg H20 / L gasholds 44 mg H20 / L gas water replacementwater replacement increases volume and decreases viscosity of the sputumincreases volume and decreases viscosity of the sputum Cascade humidifierCascade humidifier heats carrier gas to 37 Cheats carrier gas to 37 C holds 44 mg H20 / L gasholds 44 mg H20 / L gas water replacementwater replacement increases volume and decreases viscosity of the sputumincreases volume and decreases viscosity of the sputum H UMIDIFICATION

36. Chest radiographChest radiograph Arterial blood gasArterial blood gas OximetryOximetry CapnographyCapnography Chest radiographChest radiograph Arterial blood gasArterial blood gas OximetryOximetry CapnographyCapnography A NCILLARY

37. BarotraumaBarotrauma Oxygen toxicityOxygen toxicity Patient-ventilator asynchronyPatient-ventilator asynchrony CardiovascularCardiovascular RenalRenal GastrointestinalGastrointestinal BarotraumaBarotrauma Oxygen toxicityOxygen toxicity Patient-ventilator asynchronyPatient-ventilator asynchrony CardiovascularCardiovascular RenalRenal GastrointestinalGastrointestinal C OMPLICATIONS