Pulmonary complications in patients with chronic obstructive pulmonary disease following transthoracic esophagectomy

Table 5 Comparison of PaCO₂ changes in the first postoperative week in patients with or without POPCs in COPD group (mean ± SD)

Time	POPCs	Non-POPCs	P
`1 preoperative day	42.85 ± 4.10	42.37 ± 6.03	0.766
1 postoperative day	44.42 ± 4.61	41.24 ± 4.93	< 0.05
2 postoperative day	45.35 ± 4.97	41.38 ± 5.19	< 0.05
3 postoperative day	46.02 ± 4.88	42.45 ± 5.62	< 0.05
4 postoperative day	46.01 ± 5.56	39.10 ± 3.59	< 0.001
5 postoperative day	44.63 ± 5.31	40.62 ± 5.44	< 0.05
6 postoperative day	45.95 ± 6.56	42.03 ± 5.60	< 0.05
7 postoperative day	45.18 ± 5.80	40.49 ± 6.13	< 0.05

PaCO₂= partial pressure of carbon dioxide.