Table 2

Gas exchange
	Group	T_baseline	T_ALI	T_{6 h}	T_{18 h}	T_{24 h}

PaO₂/FiO₂(torr)	PCV	592 (572–603)	70 (59–71)^a	62 (50–217)^a	120 (69–315)^a	208 (78–340)^a
	PCV+R	554 (519–569)^b	56 (52–63)^a	260 (245–278)^a-c	240 (227–265)^a,c	250 (244–269)^a,c
PaCO₂(torr)	PCV	39 (35–46)	49 (41–58)^a	62 (56–68)^a,c	61 (50–64)^a,c	64 (57–67)^a,c
	PCV+R	39 (37–42)	55 (50–71)^a	54 (40–64)^a	47 (44–62)^a	48 (45–54)^a,b

Data are presented as the median (interquartile range). ^aFriedman repeated measures analysis of variance on ranks with all pairwise multiple comparison procedures (Student-Newman-Keuls method): versus T_baseline(p < 0.05). ^bMann-Whitney rank sum test: p < 0.05 versus PCV. ^cFriedman repeated measures analysis of variance on ranks with all pairwise multiple comparison procedures (Student-Newman-Keuls method): versus T_ALI(p < 0.05). FiO₂, inspiratory fraction of oxygen; PaCO₂, arterial carbon dioxide tension; PaO₂, arterial oxygen tension; PCV, pressure-controlled ventilation; PCV+R, pressure-controlled ventilation with recruitment manoeuvre; T_{6 h}, time point 6 hours after randomisation; T_{18 h}, time point 18 hours after randomisation; T_{24 h}, time point 24 hours after randomisation; T_ALI, time point after lung injury; T_baseline, baseline time point.
Kredel et al. Critical Care 2007 11:R13 doi:10.1186/cc5674