rsbi_score: Rapid Shallow Breathing Index (RSBI)

In cliot: Clinical Indices and Outcomes Tools

Rapid Shallow Breathing Index (RSBI)

Description

Calculates the Rapid Shallow Breathing Index (RSBI), a prognostic tool used to predict the success of weaning a patient from mechanical ventilation. It is defined as the ratio of respiratory frequency to tidal volume (f/Vt). Scores less than 105 breaths/min/L suggest a high likelihood of successful extubation.

Usage

rsbi_score(respiratory_rate, tidal_volume, volume_units = "L")

Arguments

respiratory_rate	Numeric. Respiratory frequency in breaths per minute.
tidal_volume	Numeric. Tidal volume measured during spontaneous breathing.
volume_units	String. Units for tidal volume. Options: "L" (default) or "mL".

Value

A list containing:

RSBI_Score	The calculated index value (breaths/min/L).
Interpretation	Prognostic guidance based on the 105 threshold.

References

Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. N Engl J Med. 1991;324(21):1445-1450. doi:10.1056/NEJM199105233242101

Examples

# Example 1: Success Likely
# RR 20, Vt 0.4 L (400 mL)
# RSBI = 20 / 0.4 = 50
rsbi_score(20, 0.4)

# Example 2: Failure Likely
# RR 35, Vt 300 mL (0.3 L)
# RSBI = 35 / 0.3 = 116.7
rsbi_score(35, 300, "mL")

cliot documentation built on Dec. 1, 2025, 1:06 a.m.