TEAM C SURVIVAL GUIDE: Answer to Question #7

7.       Your patient is ventilator dependent.  Current settings are SIMV 16 PIP 20  PEEP 5 and FiO2 40%.  His nurse tells you he has been fussy all morning w/more frequent desaturations.  You ask for an arterial blood gas.  On the above settings it is 7.21/70/50/26.  What does this mean for your patient, and how can you correct it?  

This blood gas is suggestive of respiratory acidosis.  You want the patient to blow off CO2.  Since he is ventilator dependent, you will need to do this for him.  By increasing the rate or increasing the PIP you can try to achieve these goals.  (Please see reading material re: mechanical ventilation for physiology details.)