1. What is Hypopnea Index?

Hypopnea Index (HI) is a measure used in sleep medicine to quantify the number of hypopneas (partial reductions in breathing) per hour of sleep. It helps diagnose and assess the severity of sleep-disordered breathing conditions.

2. How Does the Calculator Work?

The calculator uses the Hypopnea Index formula:

Where:

• \( Hypopneas \) — Total number of hypopnea events during sleep
• \( Sleep Hours \) — Total hours of sleep recorded

Explanation: The formula calculates the average number of hypopnea events per hour of sleep, providing a standardized measure of breathing disturbances during sleep.

3. Importance of HI Calculation

Details: Hypopnea Index is a crucial component in diagnosing sleep apnea and other sleep-related breathing disorders. It helps determine the severity of the condition and guides treatment decisions.

4. Using the Calculator

Tips: Enter the total number of hypopneas observed during sleep study and the total hours of sleep recorded. Both values must be valid (hypopneas ≥ 0, sleep hours > 0).

5. Frequently Asked Questions (FAQ)

Q1: What is considered a normal Hypopnea Index?
A: Generally, HI < 5 events/hour is considered normal. HI between 5-15 indicates mild, 15-30 moderate, and >30 severe sleep-disordered breathing.

Q2: How is HI different from AHI?
A: AHI (Apnea-Hypopnea Index) includes both apneas and hypopneas, while HI focuses specifically on hypopnea events.

Q3: What defines a hypopnea event?
A: Typically, a hypopnea is defined as a 30% or greater reduction in airflow accompanied by a 3% or greater oxygen desaturation or an arousal from sleep.

Q4: When should HI be measured?
A: HI is measured during polysomnography (sleep study) to assess breathing patterns and diagnose sleep disorders.

Q5: Are there limitations to HI measurement?
A: Yes, different scoring criteria and equipment variations can affect HI results. Standardized protocols should be followed for accurate measurement.