2. Mechanical Ventilation: A Primer (How to save a life when I’m alone in the middle of the night) Nick Mohr, MD Assistant Professor Department of Emergency Medicine Division of Critical Care, Department of Anesthesia University of Iowa Carver College of Medicine

3. Objectives To review basic mechanical ventilation theory and terminology To define an algorithmic approach to mechanical ventilation in the emergency department To explore algorithms for troubleshooting ventilation and oxygenation problems To discuss specific clinical scenarios requiring specialized ventilation strategies

4. Conflicts of Interest This speaker has no financial relationships to disclose. Topics discussed in this lecture are a component of the University of Iowa Visiting Professor Program Conference Series. The content of this lecture was developed following an extensive literature search and contains up-to- date, evidence-based information.

5. Basic Mechanical Ventilation Ventilation Mechanics: Inflection Points, Loops, Synchrony Advanced Strategies: Triggering, PRVC/VC+ Ventilation Adjuncts: Proning, Inhaled Vasodilators, Heliox Rescue Modes: APRV, HFOV % Patients Ventilated Safely Education 90%

6. What is the goal of mechanical ventilation?

7. Definitions

8. Modes of Ventilation Assist-Control (A/C) –Volume Control (VC) –Pressure Control (PC) –Pressure Regulated Volume Control (PRVC/VC+) Synchronized Intermittent Mandatory Ventilation (SIMV) Pressure Support Ventilation (PSV) Definitions

9. Ventilator Terminology PEEP p t Definitions

10. Ventilator Terminology PEEP Tidal Volume FiO 2 Respiratory Rate –Set vs. actual Peak Pressure Plateau Pressure p t peak plateau Definitions

11. Tidal Volume Respiratory Rate FiO 2 PEEP “Lung Protection” “Ventilation” “Oxygenation” Definitions

12. Determann RM. et al. Crit Care 2010;14:R1 Algorithm

13. Mascia L. et al. JAMA 2010;304:2620-7. Algorithm

14. Ventilation Algorithm Courtesy Scott Weingart, MD Algorithm

15. Successful Intubation Lung Protection StrategyObstructive Lung Disease 1. Select ventilation strategy Algorithm

16. Successful Intubation Lung Protection StrategyObstructive Lung Disease 1. Select ventilation strategy Algorithm

17. IBW male (kg) = 50 + (2.3 x h (over 5 ft) (in)) IBW female (kg) = 45.5 + (2.3 x h (over 5 ft) (in)) 2. Calculate ideal tidal volume Goal volume 6 mL/kg Algorithm

18. Image courtesy JustPressPlay ® HeightMaleFemale 5 ft 2 in350 5 ft 5 in400 5 ft 8 in450 5 ft 11 in500 6 ft 2 in550500 6 ft 5 in600550 6 ft 8 in650600 Algorithm

19. How well do we practice low tidal volume ventilation in the ED? Fuller BM. et al. Acad Emerg Med 2013;20:659-69.

20. 3. Select respiratory rate Try to match required minute ventilation Usually start at 14-18 breaths/minute Check a blood gas Algorithm

21. 4. Select oxygenation parameters Start all ventilated patients at FiO 2 = 100% Wean aggressively Algorithm

22. Why add PEEP? Algorithm

23. Volume Pressure Algorithm

24. Volume Pressure PEEP Algorithm

25. Volume Pressure PEEP Algorithm

26. Bendixen HH. et al. N Engl J Med 1963;269:961-6 AIR Pulmonary artery Pulmonary vein SHUNT Algorithm

27. Slutsky AS. et al. NEJM 2006;354:1839-41 Algorithm

28. Why add PEEP? Decrease shunt Prevent atelectasis Increase mean airway pressure FiO 2 PEEP 30%5 40%5 8 50%8 10 60%10 70%10 70%12 70%14 80%14 90%14 90%16 90%18 100%18-24 Brower RG. et al. N Engl J Med 2000;342:1301-8 Algorithm

29. peak plateau P P alveoli ventilator 5. Limit plateau pressure Algorithm

30. 6. Check blood gas, reassess Check ABG/VBG at 15-30 minutes Correlate with EtCO 2 Algorithm

31. Volume Pressure Plateau Pressure ≤ 30 cm H 2 0 Tidal volume 6 – 8 mL/kg PEEP set to limit atelectasis and shunt (PEEP table) Minimize FiO 2 Lung Protective Ventilation Algorithm

32. Goal-Directed Ventilation MAP ≥ 65 pH ≥ 7.15 FiO 2 ≤ 60% V T < 8 mL/kg p plateau < 30 pO 2 ≥ 60 Comfort Sedation Pain Control Algorithm

33. Lung Protective Ventilation 1.Start with A/C (VC), sedation/pain control 2.Set tidal volume (6 – 8 mL/kg IBW) 3.Adjust respiratory rate for ventilation 4.Set FiO 2 at 100% and wean aggressively –Titrate PEEP to necessary FiO 2 (table) 5.Check plateau pressure (goal < 30) 6.Check blood gas and titrate Algorithm

34. How does ventilation differ in patients with obstructive lung disease? Algorithm

35. P Flow Flow does not return to zero Peak pressure rises “Air trapping” Algorithm Normal lungs Obstructive Lung Disease

36. Algorithm Marini. et al. Critical Care Medicine: The Essentials, 1997

37. NormalAbnormal Flow “Rest” “No Silence” Algorithm

38. Tidal Volume Respiratory Rate FiO 2 PEEP “Lung Protection” “Ventilation” “Oxygenation” Protection Algorithm

39. Successful Intubation Lung Protection StrategyObstructive Lung Disease 1. Select ventilation strategy Algorithm

40. IBW male (kg) = 50 + (2.3 x h (over 5 ft) (in)) IBW female (kg) = 45.5 + (2.3 x h (over 5 ft) (in)) 2. Calculate ideal tidal volume Goal volume 8 mL/kg Algorithm

41. 3. Select respiratory rate Try to meet ventilatory demands Start at 8 breaths per minute Reassess at bedside – look at flow loop T HIS IS THE MOST EFFECTIVE WAY TO KILL A SEVERE ASTHMATIC WITH THE VENTILATOR Algorithm

42. 4. Select oxygenation parameters Start all ventilated patients at FiO 2 = 100% Wean aggressively These patients probably will not require high FiO 2 levels Algorithm

43. 5. Set PEEP Start low (PEEP 0 okay) Keep it low Algorithm

44. peak plateau P P alveoli ventilator 6. Limit plateau pressure Recheck frequently Algorithm

45. 7. Check blood gas, reassess Check ABG/VBG at 15-30 minutes Correlate with EtCO 2 pH ≥ 7.10 – 7.15 is good enough in most circumstances Algorithm

46. Goal-Directed Ventilation MAP ≥ 65 pH ≥ 7.15 FiO 2 ≤ 60% V T < 8 mL/kg p plateau < 30 pO 2 ≥ 60 Comfort Sedation Pain Control Algorithm

47. Obstructive Lung Disease Ventilation 1.Start with A/C (VC), sedation/pain control (deep) 2.Set tidal volume (8 mL/kg IBW), higher for ventilation 3.Keep respiratory rate low 4.Set FiO 2 at 100% and wean aggressively –Use PEEP 0 - 5 5.Check plateau pressure (goal < 30), no air trapping 6.Check blood gas and titrate Algorithm

48. Troubleshooting the Ventilator Troubleshooting

49. Failures of Mechanical Ventilation HypoxiaHemodynamic Instability Troubleshooting

50. Hypoxia on the Ventilator islodgement D O P E EtCO 2 Direct Visualization Fiberoptic Bronchoscopy Troubleshooting

51. Hypoxia on the Ventilator islodgement bstruction DOPEDOPE Pass suction catheter Lavage Replace ETT Troubleshooting

52. Hypoxia on the Ventilator islodgement bstruction neumothorax DOPEDOPE Bilateral breath sounds Tracheal deviation Ventilator peak pressures Troubleshooting

53. Hypoxia on the Ventilator islodgement bstruction neumothorax quipment failure DOPEDOPE Bag-valve on FiO2 100% Use PEEP valve Check ventilator Troubleshooting

54. Hypoxia on the Ventilator islodgement bstruction neumothorax quipment failure DOPEDOPE Troubleshooting

55. Failures of Mechanical Ventilation HypoxiaHemodynamic Instability Troubleshooting

56. Sudden Cardiovascular Collapse Post-Intubation Induction Loss of sympathetic tone Right heart dysfunction Volume depletion New Onset Tension PTX Breath stacking/Air trapping Excessive PEEP Hypoxia/vagal Image courtesy Department of Environmental Health, Pitkin County, Colorado Troubleshooting

57. Sudden Cardiovascular Collapse Post-Intubation Fluid bolus Vasopressor BV slowly, unless intubated for acidemia New Onset Disconnect the ventilator Look for tension PTX BV slowly, turn down PEEP Image courtesy Department of Environmental Health, Pitkin County, Colorado Troubleshooting

58. Cases

59. Case 1 84 y/o f (height 5’11”) with UTI presents with hypotension (BP70/30), tachycardia (P135), fever (T39.1 C), and unresponsiveness You decide to intubate. Ventilator settings? Cases

60. Lung Protective Ventilation 1.Start with A/C (VC), sedation/pain control 2.Set tidal volume (6 – 8 mL/kg IBW) 3.Adjust respiratory rate for ventilation 4.Set FiO 2 at 100% and wean aggressively –Titrate PEEP to necessary FiO 2 (table) 5.Check plateau pressure (goal < 30) 6.Check blood gas and titrate Cases

61. Case 2 29 y/o m (height 5’11”) with h/o asthma presents by ambulance after waking up unable to breath. He is no longer arousable. P160 BP180/110 RR52 FiO2 86% You decide to intubate. Ventilator settings? Cases

62. Obstructive Lung Disease Ventilation 1.Start with A/C (VC), sedation/pain control (deep) 2.Set tidal volume (8 mL/kg IBW), higher for ventilation 3.Keep respiratory rate low 4.Set FiO 2 at 100% and wean aggressively –Use PEEP 0 - 5 5.Check plateau pressure (goal < 30), no air trapping 6.Check blood gas and titrate Cases

63. Case 3 68 y/o m with h/o COPD was involved in MVC and was intubated on arrival. While he is returning from CT 25 minutes later, he becomes hypoxic to 60% and bradycardic. What is your intervention? Cases

64. Hypoxia on the Ventilator islodgement bstruction neumothorax quipment failure D O P E Cases

65. Case 4 49 y/o f intubated for severe COPD at OSH is transferred for ICU care. As EMS arrives, they are starting chest compressions. What is your intervention? Cases

66. Sudden Cardiovascular Collapse Post-Intubation Fluid bolus Vasopressor BV slowly, unless intubated for acidemia New Onset Disconnect the ventilator Look for tension PTX BV slowly, turn down PEEP Image courtesy Department of Environmental Health, Pitkin County, Colorado Cases

67. Summary Thou shalt not fear mechanical ventilation. Most problems in the ED can be resolved with sedation, respiratory rate, and FiO 2 Thou shalt not use injurious ventilatory strategies (low tidal volume) Thou shalt not code an asthmatic on the ventilator (low respiratory rate/air trapping) Maintain an algorithmic approach to critically ill patients, then think about the physiology

68. Mechanical Ventilation: A Primer Nick Mohr, MD Assistant Professor Department of Emergency Medicine Division of Critical Care, Department of Anesthesia University of Iowa Carver College of Medicine