1. What is the I/T Ratio?

The I/T (Immature to Total neutrophil) ratio is a hematologic parameter used in the evaluation of neonatal sepsis. It compares the number of immature neutrophils to the total neutrophil count in a newborn's blood sample.

2. How Does the Calculator Work?

The calculator uses the I/T ratio formula:

Where:

• \( Immature\_neutrophils \) — Count of immature neutrophils (bands and earlier forms)
• \( Total\_neutrophils \) — Count of all neutrophils (mature + immature)

Explanation: The ratio helps identify an increased proportion of immature neutrophils, which suggests an acute bacterial infection in neonates.

3. Importance of I/T Ratio in Neonatal Sepsis

Details: An I/T ratio ≥0.2 is considered abnormal and suggests neonatal sepsis, especially when combined with other clinical findings. It's part of the sepsis scoring systems for newborns.

4. Using the Calculator

Tips: Enter the absolute counts of immature neutrophils and total neutrophils from a complete blood count with differential. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal I/T ratio in newborns?
A: In healthy term infants, the I/T ratio is typically <0.2. Values ≥0.2 suggest infection.

Q2: How sensitive is the I/T ratio for neonatal sepsis?
A: Sensitivity ranges from 60-90% depending on the study. It's more specific than sensitive.

Q3: Does the I/T ratio change with gestational age?
A: Yes, preterm infants may have slightly higher normal ranges. Always consider gestational age when interpreting results.

Q4: When should the I/T ratio be measured?
A: When sepsis is suspected based on clinical signs (temperature instability, respiratory distress, feeding intolerance).

Q5: Are there limitations to the I/T ratio?
A: The ratio can be affected by stress, maternal hypertension, and other non-infectious conditions. Always interpret in clinical context.