Rapid Shallow Breathing Index (RSBI) also known as Tobin Index is the ratio determined by the frequency (f) divided by the tidal volume (Vt) in liters during a Spontaneous Breathing Trail (SBT). The SBT is done while while the patient is intubated. An RSBI < 105 breaths/min/L has been widely accepted by healthcare professionals as a criteria for weaning to extubation. Whereas patients with RSBI > 105 will have a high chance of failure and require re-intubation.
As an example, a patient who has a respiratory rate of 20 breaths/min and a tidal volume of 400 mL/breath has an RSBI of (20 breaths/min)/(0.40 L) = 50 breaths/min/L.
How to Calculate Rapid Shallow Breathing Index (RSBI)
|Respiratory Rate (f):|
|Tidal Volume (Vt) in Liters:|
What does Rapid Shallow Breathing Index of less than 105 Mean? An RSBI score of less than 105 is generally considered as an indication of weaning readiness.
Once a patient passes a spontaneous breathing trail other considerations before extubation will need to be considered.
- Does the patient have a difficult airway?
- Is the patient able to clear secretions effectively?
- Is there a risk for post-extubation laryngeal edema?