Initiating Positive Pressure CMV

1. Initiating Positive Pressure CMV A generic approach!

2. Do these BEFORE attaching the patient • Assemble the ventilator circuit • Attach humidifier and fill with water • Attach high pressure O2 hose (may also need hose for air) • Plug ventilator in

3. Set the FIO2 • If no prior ABGs, start on 100%

4. Set desired Vt • 6-12 ml/kg

5. Set rate • Choose a rate that in conjunction with Vt, gives a minimum Ve of 6-8 LPM • ALWAYS THINK OF MINUTE VENTILATION WHEN SETTING RATE

6. Set flowrate • Start between 40-60 LPM • Make sure it meets patients inspiratory demand • Steady rise on manometer • Make sure it gives good I:E ratio • The larger the Vt, the faster the flowrate!

7. Set sigh parameters ( if using) • Sigh Vt = 1.5 x Vt • Sigh rate = 6-10 per hour

8. Set sensitivity • If pressure triggering, set for 1-2 cmH2O pressure drop • If flow triggering, usually set for 3-5 LPM drop in flow

9. Turn ventilator on and attach patient Note: make sure high pressure alarms are set at 50 cmH2O to start the patient on CMV

10. Set high pressure alarms • For Vt, set 5-10 cmH2O greater than peak pressure for Vt • For sigh, set 5-10 cmH2O greater than peak pressure for sigh

11. Set low exhaled volume alarm • Set 100 ml less than Vt

12. Set low pressure alarm • Set 5-10 cmH2O less than peak pressure for Vt

13. Alarms and Monitors What they mean and what to do

14. Assist Light • Shows patient triggered the breath • If patient is not triggering and light is on, then ventilator is too sensitive • autocycling

15. Pressure Light • Shows ventilator pressure limited the breath • Also has audible alarm

16. Pressure limiting may be caused by: • Secretions • Water in the tubing • Physical obstruction or a kink in tubing • Change in patient position • ET tube in right main stem bronchus • Pneumothorax • Maladjusted control

17. Indicates increased resistance Also a decrease in compliance

18. Remember: Flow =pressure/resistance

19. Ratio Light • Indicates inverse I:E • Inspiration is as long or longer than expiration • Increase flow!!!!!

20. Oxygen Lights • Red = FIO2 set to greater than 21% but not hooked up to source of O2 • Usually has audible too • Green = FIO2 is greater than 21% • Many ventilators only check for pressure on the O2 line

21. Low exhaled Vt/Low pressure • Indicates a leak between ventilator and patient • The closer the leak is to the ventilator, the lower the manometer pressure

22. Low exhaled Vt/pressure causes: • Patient disconnect • Leaking humidifier (very common) • Leak in exhalation valve • Loose nebulizer • Loose tubing connection • Leak in ET tube • Alarm maladjustment

23. Tubing compliance • Tubing expands as it is pressurized • Some of Vt from ventilator is lost to tubing expansion • Nondisposable circuit compliance is about 3 ml/cmH2O

24. To figure out how much Vt is lost to tubing expansion: • Multiply peak pressure by tubing compliance (usually 3 ml/cmH2O) • Subtract this number (tubing expansion volume) from the set Vt • The difference is known as effective or corrected Vt • Effective or corrected Vt is the Vt the patient actually gets!

25. Flow sheet • Accumulated data • Makes sure patient is being ventilated effectively • Allows trend analysis to aid in decisions about ventilator management • Filled out periodically, eg every 2 hours

26. Time to Rock and Roll!