Clinical characteristics
The 174,9 patients were divided into an ERAS group (n= 691) and a routine group (n= 1,058). Clinical data including age, sex, comorbidities, pathologic stage and type, pulmonary function, and amount of bleeding during the operation were compared between groups (Table 2). Compared with the routine pathway group, the ERAS group was found to have a higher proportion of VATS (74.2% vs. 65.3%), shorter postoperative in-hospital LOS (4.0 (2.0, 6.0) vs. 6.0 (4.0, 9.0)), shorter total LOS (10.0 (7.0, 13.0) vs. 13.0 (10.0, 16.0) days), and lower total in-hospital costs, including material and drug expenses, all with significant differences (all P<0.001). With regard to drainage, a lower drainage volume (540.0 (275.0, 1170.5) vs. 700.0 (150, 1710) ml) and a shorter duration of drainage (3.0 (2.0, 5.0) vs. 5.0 (4.0, 7.0) days) were observed in the ERAS group (both P<0.001).
Table 2 clinical characteristic between two groups
|
ERAS group
n=691
|
Routine group
n=1058
|
P
|
Basic clinical characteristics
|
|
|
|
Age (Year) *
|
61.0 (56.0, 67.0)
|
61.0 (53.0, 68.0)
|
0.688
|
Sex(M/F)
|
351/340
|
527/531
|
0.687
|
Comorbidities
|
|
|
|
Hypertension(Y/N)
|
111/580
|
151/907
|
0.305
|
COPD(Y/N)
|
71/620
|
97/961
|
0.443
|
Diabetes mellitus(Y/N)
|
62/629
|
88/970
|
0.633
|
Smoking status (Y/N)
|
182/509
|
249/809
|
0.595
|
Pulmonary function
|
|
|
|
FEV1 (L) *
|
2.29 (1.71, 2.73)
|
2.28 (2.12, 2.44)
|
0.807
|
FVC (L) *
|
3.26 (2.72, 3.71)
|
3.20 (2.94, 3.48)
|
0.169
|
Surgical approach (n%)
|
|
|
|
VATS
|
513 (74.2)
|
691 (65.3)
|
<0.001
|
Open
|
178 (25.8)
|
367 (34.7)
|
|
Amount of bleeding in operation*
|
50.0 (20.0, 70.0)
|
180.0 (140.0, 220.0)
|
0.628
|
Surgery time*
|
90.0 (70.0, 120.0)
|
120.0 (90.0, 150.0)
|
<0.001
|
Postoperative LOS*
|
4.0 (2.0,6.0)
|
6.0 (4.0, 9.0)
|
<0.001
|
Total LOS*
|
10.0 (7.0, 13.0)
|
13.0 (10.0, 16.0)
|
<0.001
|
Pathological stage, (n%)
|
|
|
|
Stage I
|
313 (45.3)
|
506 (47.8)
|
0.589
|
Stage II
|
292 (42.3)
|
421 (39.8)
|
|
Stage III
|
75 (10.9)
|
119 (11.2)
|
|
Stage IV
|
11 (1.6)
|
12 (1.1)
|
|
Pathological type (n%)
|
|
|
|
Adenocarcinoma
|
473 (68.5)
|
740 (69.9)
|
0.799
|
Squamous cell carcinoma
|
192 (27.8)
|
281 (26.6)
|
|
Other
|
26 (3.8)
|
37 (3.5)
|
|
In-hospital expense, ¥
|
|
|
|
Total*
|
46047.7 (39068.7, 52733.8 )
|
47583.0 (43761.6, 51839.6)
|
<0.001
|
Material cost*
|
23742.6 (19588.2, 27844.8)
|
25040.4 (21439.5,29871.5)
|
<0.001
|
Drug cost*
|
7633.5 (5537.0, 10100.3)
|
8157.6 (6453.2, 11665.5 )
|
<0.001
|
Drainage volume*
|
540.0 (275.0, 1170.5)
|
700.0 (150, 1710)
|
<0.001
|
Duration of drainage*
|
3.0 (2.0, 5.0)
|
5.0 (4.0, 7.0)
|
<0.001
|
*Non-normal distribution variables described as median (interquartile)
ERAS: enhanced recovery after surgery; COPD, chronic obstructive pulmonary disease defined as FEV1/FVC <70% and FEV1 <80% of predicted; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; VATS: video assisted thoracic surgery; LOS: length of stay.
Table 3 Postoperative pulmonary complications between the two groups.
|
ERAS group
n=691
|
Routine group
n=1058
|
P value
|
PPCs rate, (n %)
|
105 (15.2)
|
206 (19.5)
|
0.022
|
Pneumonia
|
58 (8.4)
|
150 (14.2)
|
<0.001
|
Atelectasis
|
41 (5.9)
|
104 (9.8)
|
0.004
|
Pulmonary embolism
|
2 (0.3)
|
4 (0.4)
|
1.000
|
Respiratory/heart failure or ADRS
|
11 (1.6)
|
12 (1.1)
|
0.411
|
Bronchopleural fistula
|
6 (0.9)
|
10 (0.9)
|
0.869
|
mechanical ventilation>48h
|
18 (2.6)
|
35 (3.3)
|
0.239
|
empyema
|
4 (0.6)
|
11 (1.0)
|
0.307
|
Air leak
|
35 (5.1)
|
78 (7.4)
|
0.055
|
Back to ICU
|
7 (1.0)
|
11 (1.0)
|
0.957
|
Death
|
4 (0.6)
|
6 (0.6)
|
1.000
|
PPCs: postoperative pulmonary complications; ERAS: enhanced recovery after surgery
Occurrence of PPCs
Compared with the routine pathway group, the ERAS group presented with a lower occurrence of PPCs (15.2%, 105/691 vs. 19.5%, 206/1058, P=0.022) and a significantly lower occurrence of pneumonia (8.4%, 58/691 vs. 14.2%, 150/1058, P<0.001) or atelectasis (5.9%, 41/691 vs. 9.8%, 104/1058, P=0.004).
We also compared clinical characteristics between patients with (n= 311) and without PPCs (n= 1,438). Significant differences between groups were found in age, FEV1, amount of bleeding during the operation, COPD, total or postoperative LOS, total in-hospital costs, drug costs, duration of drainage (all P<0.001), FVC (P=0.043), and surgery time (P=0.021) (Table 4).
Table 4 Comparison between PPCs group and Non-PPCs group
|
PPCs group
n=311
|
Non-PPCs group
n=1438
|
P
|
Basic clinical characteristics
|
|
|
|
Age (Year) *
|
62.0 (56.0, 73.0)
|
60.0 (54.0, 66.0)
|
<0.001
|
Sex(M/F)
|
148/163
|
730/708
|
0.310
|
Comorbidities
|
|
|
|
Hypertension(Y/N)
|
48/263
|
214/1224
|
0.805
|
COPD(Y/N)
|
46/265
|
122/1316
|
0.001
|
Diabetes mellitus(Y/N)
|
27/284
|
123/1315
|
0.942
|
Smoking status (Y/N)
|
72/239
|
370/1068
|
0.343
|
ERAS program (Y/N)
|
105/206
|
852/586
|
0.022
|
Pathological stage I or 0, (Y/N)
|
140/171
|
679/759
|
0.480
|
VATS approach
|
203/108
|
431/1001
|
0.134
|
Pulmonary function
|
|
|
|
FEV1 (L) *
|
2.13 (1.90, 2.31)
|
2.32 (2.09, 2.52)
|
<0.001
|
FVC (L) *
|
3.20 (2.84, 3.44)
|
3.23 (2.87 3.56)
|
0.043
|
Amount of bleeding in operation*
|
150.0 (100.0, 200.0)
|
50.0 (150.0, 200.0)
|
0.022
|
Surgery time*
|
120.0 (90.0, 140.0)
|
110.0 (80.0, 140.0)
|
0.021
|
Postoperative LOS*
|
9.0 (6.0,12.0)
|
4.0 (3.0, 7.0)
|
<0.001
|
Total LOS*
|
16.0 (12.0, 19.0)
|
8.0 (11.0, 14.0)
|
<0.001
|
In-hospital expense, ¥
|
|
|
|
Total*
|
52649.6 (46815.1, 61097.0 )
|
46151.2 (41919.2, 50908.2)
|
<0.001
|
Material cost*
|
24567.0 (19886.2, 31942.8)
|
24486.5 (20925.8, 28342.1)
|
0.085
|
Drug cost*
|
14411.3 (11127.8, 16427.8)
|
7322.0 (5980.1, 9655.5 )
|
<0.001
|
Drainage volume*
|
700 (230.0, 1600.0)
|
590.0 (180, 1470)
|
0.095
|
Duration of drainage*
|
5.0 (3.0, 8.0)
|
4.0 (3.0, 6.0)
|
<0.001
|
*Non-normal distribution variables described as median (interquartile)
PPCs: postoperative pulmonary complications; ERAS: enhanced recovery after surgery; COPD, chronic obstructive pulmonary disease defined as FEV1/FVC <70% and FEV1 <80% of predicted; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; VATS: video assisted thoracic surgery; LOS: length of stay.
The relevant independent factors for PPCs, pneumonia or atelectasis were investigated via binary logistic regression. The variables analyzed included sex, age, smoking status, comorbidities, FEV1, FVC, surgical approach, amount of bleeding during the operation, surgery time, and the presence of early stage (stage I) cancer. The ERAS intervention was found to be an independent factor for the occurrence of PPCs (OR: 0.601, 95% CI: 0.434-0.824, P=0.002), pneumonia (OR: 0.371, 95% CI: 0.243-0.566, P<0.001), and atelectasis (OR: 0.431, 95% CI: 0.271-0.687, P<0.001) (Table 5).
Establishment of a nomogram that predicts the risk of PPCs
As listed in Table 5, ERAS intervention, age, COPD, and FEV1 were independent predictors for PPCs.
Table 5 Multivariable analysis (n= 101) of risk to postoperative pulmonary complications (PPCs)*, pneumonia and atelectasis.
Variables
|
OR (95% CI)
|
P value
|
PPCs
|
|
|
ERAS intervention
|
0.601 (0.434-0.824)
|
0.002
|
Age
|
1.032 (1.018-1.046)
|
<0.001
|
COPD
|
1.792 (1.196-2.686)
|
0.005
|
FEV1
|
0.318 (0.221-0.457)
|
<0.001
|
Pneumonia
|
|
|
ERAS intervention
|
0.371 (0.243-0.566)
|
<0.001
|
Age
|
1.039 (1.022-1.055)
|
<0.001
|
FEV1
|
0.205 (0.125-0.339)
|
<0.001
|
Atelectasis
|
|
|
ERAS intervention
|
0.431 (0.271-0.687)
|
<0.001
|
Early stage
|
0.676 (0.469-0.975)
|
0.036
|
FEV1
|
0.272(0.157-0.471)
|
<0.001
|
*the multivariable analysis was performed via binary logistic regression; PPCs: postoperative pulmonary complications