1. What is I Time?

I Time (Inspiratory Time) is the duration of the inspiratory phase in a respiratory cycle. It's a critical parameter in mechanical ventilation that affects patient comfort and gas exchange.

2. How Does the Calculator Work?

The calculator uses the I Time formula:

Where:

• \( Total\ Cycle\ Time \) — Duration of one complete breath cycle (in seconds)
• \( I:E\ Ratio \) — Ratio of inspiratory time to expiratory time

Explanation: The equation calculates the inspiratory portion of the total breath cycle based on the set I:E ratio.

3. Importance of I Time Calculation

Details: Proper I Time setting is essential for adequate ventilation, patient-ventilator synchrony, and preventing auto-PEEP in mechanical ventilation.

4. Using the Calculator

Tips: Enter total cycle time in seconds and I:E ratio as a numerical value (e.g., 1:2 ratio is entered as 0.5). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical I:E ratio?
A: Normal spontaneous breathing has an I:E ratio of about 1:2. Mechanical ventilation often uses ratios between 1:1 and 1:3.

Q2: How does I Time affect ventilation?
A: Longer I Time increases mean airway pressure and may improve oxygenation but can cause hemodynamic compromise if too long.

Q3: What's the relationship between I Time and respiratory rate?
A: At a given respiratory rate, increasing I Time decreases expiratory time, which may lead to air trapping in patients with obstructive lung disease.

Q4: When would you use inverse ratio ventilation?
A: Inverse ratio (I:E > 1:1) may be used in ARDS to improve oxygenation, but requires heavy sedation/paralysis due to patient discomfort.

Q5: How is total cycle time calculated?
A: Total cycle time = 60 seconds / respiratory rate (in breaths per minute).