Rr/Vt Ratio - GE iVent 201 Series User's Reference Manual

Appendix F: Hold Function and Static Mechanics Measurements

RR/VT RATIO

Clinicians are always looking for uncomplicated methods of determining if
patients are capable of sustaining their own respiratory drive and being
successfully "weaned" from mechanical ventilation. One of the most popular and
easiest methods of predicting this success is through the use of the RR/Vt ratio or
Rapid Shallow Breathing Index (RSBI). It is the relationship between the patients
spontaneous breathing rate with the exhaled tidal volume. Literature suggests
there is a strong relationship between fast and shallow breathing (high RR/Vt
indexes) with patients that fail spontaneous breathing trials and subsequent
extubation.
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