1. What is I:E Ratio?

The I:E ratio (Inspiratory to Expiratory ratio) is a measurement used in mechanical ventilation that compares the duration of inspiration to expiration. It's a crucial parameter in setting and evaluating ventilator modes.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Inspiratory Time — Duration of inhalation in seconds
• Expiratory Time — Duration of exhalation in seconds

Explanation: The ratio is typically expressed both as a decimal value and in the conventional "1:x" format used in clinical settings.

3. Importance of I:E Ratio

Details: The I:E ratio affects oxygenation, ventilation, and patient comfort. Abnormal ratios can lead to air trapping (auto-PEEP), hemodynamic compromise, or patient-ventilator dyssynchrony.

4. Using the Calculator

Tips: Enter both inspiratory and expiratory times in seconds. Typical values range from 0.2-0.5 seconds for inspiratory time and 0.5-2.0 seconds for expiratory time in mechanical ventilation.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal I:E ratio?
A: In spontaneous breathing, the normal I:E ratio is about 1:2 (0.5). In mechanical ventilation, ratios typically range from 1:1 to 1:4 depending on the clinical situation.

Q2: When would you use an inverse I:E ratio?
A: Inverse ratios (I:E > 1) are sometimes used in ARDS management to improve oxygenation, but require careful monitoring for complications.

Q3: How does I:E ratio affect CO2 elimination?
A: Longer expiratory times (lower I:E ratios) generally improve CO2 elimination by allowing more complete exhalation.

Q4: What's the relationship between I:E ratio and respiratory rate?
A: For a given respiratory rate, changing the I:E ratio alters the absolute inspiratory and expiratory times.

Q5: How is I:E ratio different in obstructive vs restrictive disease?
A: Obstructive diseases often require lower I:E ratios (longer expiration), while restrictive diseases may tolerate higher ratios.