Table 2

Weaning parameters

Weaning index	Number	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
Weaning parameters for the PS 5/5 group
Δtdi%	36	96	64	86	88
Δtdi%×V_T	36	96	64	86	88
tdi at end-expiration	36	84	18	70	33
Weaning parameters for the SB trial group
Δtdi%	27	75	100	100	67
Δtdi%×V_T	27	78	100	100	38
RSBI	26	87	33	91	25
tdi at end-expiration	27	96	33	92	50

Threshold for RSBI=105 (min/L).
NPV, negative predictive value; PPV, positive predictive value; PS, pressure support; RSBI, rapid shallow breathing index; SB, spontaneous breathing; V_T, tidal volume.