Ventilator User Interface - How to Survive the ICU

Ventilator User Interface

Rules for ventilator settings:

1. The physician decides the ventilator settings.
2. Respiratory therapists place patient on ventilator.
3. An ABG is checked once ventilator is in place.
4. Ventilator settings are adjusted to meet these goals:
- Pa 02 60-90 mm Hg
- Pa C02 40 mm Hg, patient normal baseline
- pH 7.35-7.45
- Inspiratory pressure < 35 cm H20
- Minimized work of breathing

Click on photo for an enlarged view and explanation of ventilator components

Ventilator User Interface and Settings

Mode: The way a breath is delivered.

Assist Control: A/C

Intermittent Mandatory Ventilation: IMV

Synchronized Intermittent Ventilation: SIMV

Pressure Support Ventilation: PSV

Rate: (f tot)
Usually set at 10 - 15 breaths per minute.

Tidal Volume: (Vte)
10 - 12 ml/kg which is roughly 800 ml per breath in a 70 kg person.

Fi02: Fraction of Inspired Oxygen.

Started at 100% usually & weaned down to 40% once ABG is normalized.

21% Oxygen-Room Air is mixed with 100% Oxygen to achieve 80-60-40%

Goal: To get a Pa02 of 60-90 mmHg on an
Fi02 of 40-60%. (0.4-0.6)

Positive End Expiratory Pressure:
Start 2.5 cm H20, maximum. 10 cm H20 Prevent collapse of small airways & alveoli at end expiration.
When is it indicated?

In highly hypoxemic patients. (ARDS)

When we want to decrease Fi02 to avoid
oxygen toxicity.