Practice Variation in Spontaneous Breathing Trial Performance and Reporting

Table 4

Measures of variance for physiologic variables (tidal volume, respiratory rate, heart rate, and O₂ saturation). Expressed as mean, standard deviation, coefficient of variation, and average range per spontaneous breathing trial (SBT).

Physiologic variable	Mean value	Stdev	Coefficient of variation	Average range/SBT
Tidal volume (mL)	461.9	176.1	0.38	87.4
Respiratory rate (breaths per min)	20.6	7.3	0.35	3.9
Heart rate (beats per min)	87.9	16.3	0.19	5.8
O2 saturation (%)	96.3	2.8	0.03	1.5