Mandatory Settings in Control Mode: A Review
As previously stated, for all mechanical ventilation modes, the clinician will always set FiO2 and PEEP. You need to ensure the alveoli do not collapse since mechanical ventilation is bypassing the normal pleural pressures that keep them inflated (please review Chapter 1 if you need to). You also need to always set the oxygen concentration the patient is going to require to maintain their blood oxygenation, which should be SpO2 >92% (please review Chapter 2 if you need to).
In addition to FiO2 and PEEP, in control modes specifically, the ventilator is driving how big a breath or how often (at minimum) the patient will breathe, so you need to set a Respiratory Rate (RR). In addition to the breathing frequency (respiratory rate), the clinician must also direct the size of the patient’s breath in control modes. For volume control, this means setting a tidal volume while in pressure control, we set the pressure control applied to cause a volume.
Initial settings to be chosen by the clinician are as follows:
| Volume Control | Pressure Control |
|---|---|
| FIO2 | |
| PEEP | |
| Respiratory Rate (RR) | |
| Tidal Volume (VT) and Inspiratory Flow (V̇) | Pressure control (PC) and Inspiratory time (IT or ITime) |
There are other settings that you will see on the ventilator that are not listed here. One will be trigger sensitivity (i.e., sensing a patient-initiated breath), as well as some secondary cycling settings, or, potentially, flow of air if the clinician is in volume control. These settings are pre-programmed with mechanical ventilators to default to numbers that work the majority of the time.
Because mechanical ventilators will default to a sensitivity trigger that will work for 99.9% of patients, medical providers who are not skilled in mechanical ventilation should focus on determining the initial settings listed above, and do not adjust the trigger sensitivity. There are very rare times that adjustment is needed, but it is best to leave adjustments of trigger sensitivity to advanced clinicians. Inappropriate adjustments are far more harmful to the patient than sticking with the default settings.
Practice Makes Perfect
Remember, every ventilator is a little bit different. The initial settings are always there, but they will be labelled differently depending on the ventilator manufacturer. Challenge yourself by trying to locate the common initial settings (FiO2, PEEP, Respiratory Rate, Pressure Control and ITime) on the ventilator pictured below.
Tip: This exercise will only allow you to locate one setting at a time. After you have located a setting, if you would like to locate additional settings from the list in the activity instructions, please refresh your browser page to clear your results.
