1. Mechanical Ventilation Circuit Errors For RET 2264C-12 Dr. J.B. Elsberry Prof. J. M. Newberry

2. Historically Ventilator Circuit Problems were Limited to: Circuit Disconnections Circuit Disconnections Fluid pooling in circuit Fluid pooling in circuit Fluid pooling in filter Fluid pooling in filter Kinking of circuit Kinking of circuit Endotracheal tube obstruction Endotracheal tube obstruction

3. Additional Issues: as circuits have become more complex: Multiple devices at the Wye Multiple devices at the Wye HHME resistance HHME resistance Nebulizer and MDI placement Nebulizer and MDI placement Inadequate Humidification in Adult Circuits Inadequate Humidification in Adult Circuits NO injection NO injection Heliox Injection Heliox Injection

4. Air Leak Volume (ml) Time (sec) Air Leak What goes in Fails to Come Out…

5. Failure to Identify the source of a Circuit Leak What goes in Fails to Come Out… What goes in Fails to Come Out… Gas leaks in the Circuit due to: Gas leaks in the Circuit due to: 1. Patient disconnection 1. Patient disconnection 2. Circuit leaks 2. Circuit leaks 3. Airway leaks 3. Airway leaks 4. Chest tube leaks 4. Chest tube leaks

6. Process of Elimination Isolating Leak: Isolating Leak: Ventilator or Circuit Exhalation Valve Ventilator or Circuit Exhalation Valve Circuit Connections at the Patient wye Circuit Connections at the Patient wye ETT Cuff and Pilot Valve leaks ETT Cuff and Pilot Valve leaks Chest Tube Leaks and Sensitivity Chest Tube Leaks and Sensitivity

7. Aerosol Therapy and Humidification What works and How much?

8. Airway clearance (after suppression of the muco-ciliary escalator) Humidification of Inspired Air Humidification of Inspired Air Cough Stimulation Cough Stimulation Suctioning Suctioning Open Systems Open Systems Closed Systems Closed Systems Chest Oscillation Chest Oscillation

9. Which Nebulizers will work best? SVN SVN USN USN MDI MDI Vibrating Mesh Vibrating Mesh

10. HME/MDI Use in Mechanical Ventilation Where do you put the spacer? Where do you put the spacer? Crit Care. 2000; 4(4): 227–234. Crit Care. 2000; 4(4): 227–234.

11. When do you depress the MDI? “Synchronization of aerosol delivery with the beginning of inspiration, large tidal volume, low inspiratory flow and long duty cycle (T I /T TOT ) are also associated with greater aerosol deposition…” “Synchronization of aerosol delivery with the beginning of inspiration, large tidal volume, low inspiratory flow and long duty cycle (T I /T TOT ) are also associated with greater aerosol deposition…” Am J Respir Crit Care Med. 1999;159:63–68.

12. ETT Tube Resistance “It is generally accepted that larger endotracheal tubes (> size 7) permit better aerosol administration” (for adults) Ahrens RC, Ries RA, Popendorf W, et al: The delivery of therapeutic aerosols through endotracheal tubes, Pediatric Pulmonol 2:19, 1986.

13. Placement of the SVN AARC Practice Guidelines suggest placement of the continuous flow SVN on the inspiratory side of the circuit 30 cm from the ETT junction AARC Practice Guidelines suggest placement of the continuous flow SVN on the inspiratory side of the circuit 30 cm from the ETT junction

14. ETT Lavage & Suctioning No advantage to the instillation of Normal Saline into the ETT prior to suctioning has been established. No advantage to the instillation of Normal Saline into the ETT prior to suctioning has been established. Respiratory Care--October 2007 Vol. 33 No.10 Beware the Biofilm!

15. Humidification HME vs. HHT HMEs have become popular for several reasons: They have no moving parts They do not require electricity If they are changed only once every 24 to 48 hours, they can be a less expensive method for providing an acceptable level of humidity to invasively ventilated patients HMEs have become popular for several reasons: They have no moving parts They do not require electricity If they are changed only once every 24 to 48 hours, they can be a less expensive method for providing an acceptable level of humidity to invasively ventilated patients Grzeskowiak, M.: Resp.Therapy August 2005

16. Humidity Deficit? Ideal is 44 mg/L H 2 O content Ideal is 44 mg/L H 2 O content HCH (hygroscopic condenser humidifier) HCH (hygroscopic condenser humidifier) 22 mg to 34 mg/L H 2 O 22 mg to 34 mg/L H 2 O HME (layered aluminum inside a low-compliance case) HME (layered aluminum inside a low-compliance case) 14-30 mg/L H 2 O 14-30 mg/L H 2 O [AARC guidelines call for 30mg/L or > H 2 O] [AARC guidelines call for 30mg/L or > H 2 O] HHT (designed to produce maximum H 2 O content) HHT (designed to produce maximum H 2 O content) Some studies with poor temp. control yielded only 20 mg/L H 2 0 Some studies with poor temp. control yielded only 20 mg/L H 2 0

17. Hospital Costs, VAP and/or Occluded A/Ws? Condensate management with HHT Condensate management with HHT Wet Circuits Wet Circuits Circuit Life Circuit Life Equipment and Labor $’s Equipment and Labor $’s No Study has shown a real difference in VAP acquisition comparing both systems No Study has shown a real difference in VAP acquisition comparing both systems The risk of occluded HME and/or endotracheal tube from inspissated secretions is considerable The risk of occluded HME and/or endotracheal tube from inspissated secretions is considerable

18. What’s the Bottom Line? “In the M.V. patient with secretion management issues (thick or copious secretions) heated humidification is preferred.” “In the M.V. patient with secretion management issues (thick or copious secretions) heated humidification is preferred.” “When Mechanical Ventilation is expected to last greater than 96 hours, heated humidification should be used from the outset.” “When Mechanical Ventilation is expected to last greater than 96 hours, heated humidification should be used from the outset.” Respiratory Care--October 2007 Vol. 33 No.10

19. Nitric Oxide Injectors

20. Placement of the NO Injector Dedicated nitric oxide equipped ventilators are now available commercially but are not yet common in clinical practice… [In many cases]. the use of nitric oxide in conjunction with a simple time–cycled, pressure regulated, flow generating ventilator attached to a infant–sized lung. Dedicated nitric oxide equipped ventilators are now available commercially but are not yet common in clinical practice… [In many cases]. the use of nitric oxide in conjunction with a simple time–cycled, pressure regulated, flow generating ventilator attached to a infant–sized lung. Increasing minute ventilation lowered measured nitric oxide concentration exponentially. Mixing of gases improved when nitric oxide was infused closer to the ventilator. Acid contamination was found in water samples from humidifier, water trap and ventilator gas outlet. Acidification was reduced, without change in measured nitric oxide delivery, when infused prehumidifier. We recommend, when used as therapy, nitric oxide levels in inspired gases should always be measured. Increasing minute ventilation lowered measured nitric oxide concentration exponentially. Mixing of gases improved when nitric oxide was infused closer to the ventilator. Acid contamination was found in water samples from humidifier, water trap and ventilator gas outlet. Acidification was reduced, without change in measured nitric oxide delivery, when infused prehumidifier. We recommend, when used as therapy, nitric oxide levels in inspired gases should always be measured. European Journal of Anesthesiology (2000), 17: 160-167 Cambridge University Press

21. AARC Times 1999 Nitric Oxide Injection Issues

22. Differences in mixing NO: IMV vs. HFO When the NO concentrations measured at the Y piece were 1, 2, 5, 10, 20, 30 and 40 ppm, the NO 2 concentrations at the same place were simultaneously measured. The NO 2 concentrations in the combination of the HFOV/ID-4 were significantly higher than those in the combinations of the IMV/ID-4, the IMV/ID- 2 and the HFOV/ID-2 in all of the NO concentrations except 30 ppm and 40 ppm. This occurs because the back and forth movements of the gas generated by the oscillation had an influence on the mixing of the NO and oxygen gases in the NO administration line. When the NO concentrations measured at the Y piece were 1, 2, 5, 10, 20, 30 and 40 ppm, the NO 2 concentrations at the same place were simultaneously measured. The NO 2 concentrations in the combination of the HFOV/ID-4 were significantly higher than those in the combinations of the IMV/ID-4, the IMV/ID- 2 and the HFOV/ID-2 in all of the NO concentrations except 30 ppm and 40 ppm. This occurs because the back and forth movements of the gas generated by the oscillation had an influence on the mixing of the NO and oxygen gases in the NO administration line.http://www.med.nagoya-cu.ac.jp/NMJ/44-73.html

23. Recommendations: When a bias flow of NO is injected Dosing of short pulse of NO at beginning of inspiration is advantageous for Pulmonary Hypertension –so adjust T I for better distribution across the A/C membrane Dosing of short pulse of NO at beginning of inspiration is advantageous for Pulmonary Hypertension –so adjust T I for better distribution across the A/C membrane Dosing at end inspiration is optimal for Airways Reactive Diz.— Adjust the flow or T I to minimize Auto-PEEP Dosing at end inspiration is optimal for Airways Reactive Diz.— Adjust the flow or T I to minimize Auto-PEEP Always employ NO 2 Monitoring Always employ NO 2 Monitoring Always monitor Methemoglobinemia Always monitor Methemoglobinemia Include a one-way valve after the injector to minimize bias flow mixing when using an Oscillator Include a one-way valve after the injector to minimize bias flow mixing when using an Oscillator Include a mixing tube between the Ventilator and the injector in CMV and SIMV modes Include a mixing tube between the Ventilator and the injector in CMV and SIMV modes

24. VAP Issues are Next…

25. Questions