2. Mechanical Ventilation Management RC 270

3. Flowrate Check and adjust (if necessary) on each vent check Meet patient’s inspiratory demand while maintaining I:E Ratio Optimize V/Q Decrease W.O.B. Don’t be afraid to increase flowrate!

4. Managing PCO2 Math Mechanical Deadspace IMV

5. Math Management of PCO2 Ve and PaCO2 are inversely proportional When one changes, the other changes in the opposite direction

6. Mathematical Method Current (Ve x PaCO2) =Desired(Ve X PaCO2) Use algebra to solve for desired variable

7. Desired PaCO2 Usually the one that normalizes ph Use Siggard-Andersen Nomogram

9. Setting New Ve If increasing Ve, increase Vt or rate Increasing Vt is best If decreasing Ve, decrease Vt or rate If possible, decrease rate before Vt (why?)

10. Example A patient is on A/C CMV with the following settings: FIO2=40%, Vt=600ml, rate =16. ABGs on these settings are: ph= 7.49 PaCO2=30mmhg, PO2=80mmhg, HCO3=23 Find the Ve that will increase PaCO2 and bring the ph to 7.40 1. Find desired PaCO2 using Siggard-Andersen nomogram. 2. Calculate present Ve. 3. Use the formula to determine the new Ve.

11. Mechanical Deadspace Patient rebreathes exhaled CO2 Corrugated flex tubing is added between the ventilator wye and the patient’s airway connection

12. Intermittent Mandatory Ventilation (IMV) is an excellent way to control PaCO2 The Ve from the ventilator can be titrated with the patient’s spontaneous Ve to achieved a desired PaCO2

13. Managing PaO2 Use a-A ratios to predict new PaO2 and new FIO2 If increasing the FIO2 is not increasing the PaO2, it may be time for CPAP/PEEP

14. Lets boogie!

15. Note: Vd/VT does not change rapidly. Except: Pulmonary embolism