Q: All of the following increase the Rapid Shallow Breathing Index (RSBI) except?

A) size of endotracheal tube (ETT) 
B) male gender
C) sepsis
D) supine position
E) suctioning


Answer: B

 It is an usual clinical practice to insert lower sized diameter ETT in females - and both these factors may falsely give high RSBI, independent of the weaning outcome. Another common bedside mistake is to measure RSBI right after suctioning, which may also falsely increase RSBI.


References: 

1.  Epstein SK, Ciubotaru RL. Influence of gender and endotracheal tube size on preextubation breathing pattern. Am J Respir Crit Care Med 1996; 154:1647. 

2. Seymour CW, Cross BJ, Cooke CR, et al. Physiologic impact of closed-system endotracheal suctioning in spontaneously breathing patients receiving mechanical ventilation. Respir Care 2009; 54:367.