Table 3. Subgroup analyses of the changes in respiratory mechanics and PaO₂/FiO₂ in patients with right or left lung ventilation under different PEEP levels.

Ventilated side	Group	n	DLV	OLV 0.5 h	OLV 1 h	DLV-End of operation
PaO2/FiO2
Right	PEEP5	18	314.0+112.1	208.7+92.0	232.3+88.9	368.7+133.2
	PEEPEIT	15	389.8+75.9	274.1+119.9a	336.0+106.2a	476.4+113.3a
Left	PEEP5	35	329.0+112.1	182.3+75.0	212.9+63.5	322.7+123.5
	PEEPEIT	32	343.5+101.3	243.9+99.6b	302.9+98.5 b	433.2+137.2b
Cdyn
Right	PEEP5	18	24.0+5.5	14.9+3.8	16.1+4.6	24.7+6.1
	PEEPEIT	15	28.2+7.8	19.7+5.9 a	20.8+7.3a	27.9+8.0
Left	PEEP5	35	27.3+7.2	14.1+2.8	15.4+2.6	27.3+7.7
	PEEPEIT	32	24.4+5.6	17.9+5.5b	19.9+6.7b	26.1+5.9
ΔP
Right	PEEP5	18	13.7+3.2	20.5+2.6	20.4+3.2	15.8+2.6
	PEEPEIT	15	14.3+5.0	16.5+4.2a	16.7+4.1a	14.6+4.5
Left	PEEP5	35	14.7+3.1	18.2+3.8	19.1+3.5	14.7+3.0
	PEEPEIT	32	13.1+3.7	14.0+2.4b	13.5+2.3b	13.7+3.5

^a, P<0.05, comparation between the PEEP_EIT and PEEP₅ in the right lung ventilation subgroup; ^b, P<0.05, comparation between the PEEP_EIT and PEEP₅ in the left lung ventilation subgroup.