1. Principles of Mechanical Ventilation Mazen Kherallah, M.D., FCCP Internal Medicine, Critical Care Medicine, and Infectious Diseases Initial Ventilatory Settings

2. Modes of Mechanical Ventilation Volume-Cycled Control Mode Ventilation

3. Indicated for patients who are unable to ventilate: –Drug intoxication –CNS disorders –Peripheral neurological disorders –Pharmacological Paralysis Limitations: –Patient-ventilator dysynchrony secondary to aborted ventilatory cycles when patient exhales during ventilator inspiratory cycle –Hypercapnea

4. Modes of Mechanical Ventilation Assist-Control Ventilation

5. Indications: – for patients who are awake, moderately sedated or paralyzed and able to initiates ventilation –increase metabolic demands: infection, burns, multisystem organ failure –Respiratory muscle strengthening and weaning Limitations: –patient-ventilator dysynchrony –ventilator assisted hyperventilation in agitated patients with increased inspiratory drive –auto-PEEP in COPD patients

6. Modes of Mechanical Ventilation Intermittent Mandatory Ventilation

7. Modes of Mechanical Ventilation Synchronized Intermittent Mandatory Ventilation

8. Indications: –patients with minimal spontaneous respiratory efforts –respiratory muscle conditioning –ventilator weaning Limitations: –patient-ventilator dysynchrony especially in agitated patients –nonphysiologic way of respiratory muscle conditioning

9. Modes of Mechanical Ventilation Pressure Support Ventilation

10. Indications: –weaning –more physiologic conditioning of respiratory muscles: low pressure-high volume load –improved patient- ventilator dysynchrony Limitations:

11. Modes of Mechanical Ventilation Inverse Ratio Ventilation

12. Distribution of Normal Ventilation-Perfusion Ratios 1 10 0.10

13. Oxygen-carbon dioxide diagram

14. The Effect of Increasing Ventilation-Perfusion Inequality on Arterial Po2 and Pco2

15. Ventilation-Perfusion Inequality Acute Exacerbation of COPD 0.01 0.1 1 10 100

16. Ventilation-Perfusion Inequality Asthma 0.01 0.1 1 10 100

17. Ventilation-Perfusion Inequality Pulmonary Embolism 0.01 0.1 1 10 100

18. Shunting Process ARDS 0.01 1 10 100

19. The effect of changing the inspired oxygen concentration on arterial Po2 for lung’s shunts of 10 to 50%

21. Pulmonary Mechanics Peak pressure Plateau pressure IE Airway Resistance

22. Static Pressure-volume curve in ARDS with PEEP of 0 and 12 12 PEEP 0 PEEP

23. Auto-PEEP

25. Normal Lung Mechanics and Gas Exchange

26. Severe Airflow Obstruction

27. Acute on Chronic Respiratory Failure

28. Acute Hypoxemic Respiratory Failure