Table 1 Baseline characteristics of participants with and without postoperative ultrasound
covariate | no postoperative ultrasound | postoperative ultrasound | X2 | P value |
|---|---|---|---|---|
n = 154 | n = 895 | |||
Gender, no.(%) | ||||
 Male | 69 (44.81) | 354 (39.55) | 1.506 | 0.22 |
 Female | 85 (55.19) | 541 (60.45) |  |  |
Drinking history, no.(%) | ||||
 No | 116 (75.32) | 69 (77.09) | 0.231 | 0.631 |
 Yes | 38 (24.68) | 205 (22.91) |  |  |
Smoking history, no.(%) | ||||
 No | 125 (81.17) | 722 (80.67) | 0.021 | 0.885 |
 Yes | 29 (18.83) | 173 (19.33) |  |  |
BMI (kg/m2), no.(%) | ||||
  ≤ 18 | 12 (7.79) | 108 (12.17) | 2.832 | 0.243 |
 18–25 | 118 (76.62) | 631 (70.50) |  |  |
 >25 | 24 (15.59) | 148 (16.53) |  |  |
Cerebral infarction, no.(%) | ||||
 No | 137 (88.96) | 774 (86.48) | 0.708 | 0.4 |
 Yes | 17 (11.04) | 121 (13.52) |  |  |
Diabetes, no.(%) | ||||
 No | 121 (78.57) | 728 (81.34) | 0.653 | 0.419 |
 Yes | 33 (21.43) | 167 (18.66) |  |  |
Coronary heart disease, no.(%) | ||||
 No | 137 (88.96) | 798 (89.16) | 0.005 | 0.941 |
 Yes | 17 (11.04) | 97 (10.84) |  |  |
Hypertension, no.(%) | ||||
 No | 101 (65.58) | 613 (68.49) | 0.511 | 0.475 |
 Yes | 53 (34.42) | 282 (31.51) |  |  |
Hyperlipidemia, no.(%) | ||||
 No | 145 (94.16) | 859 (95.98) | 1.062 | 0.303 |
 Yes | 9 (5.84) | 36 (4.02) |  |  |
Pulmonary diseases, no.(%) | ||||
 No | 145 (94.16) | 774 (86.48) | 7.13 | 0.008 |
 Yes | 9 (5.84) | 121 (13.52) |  |  |
Hepatic diseases | ||||
 No | 135 (87.66) | 777 (86.82) | 0.083 | 0.773 |
 Yes | 19 (12.34) | 118 (13.18) |  |  |
Renal diseases, no.(%) | ||||
 Yes | 144 (93.51) | 791 (88.38) | 0 | 0.983 |
 No | 10 (6.49) | 104 (11.62) |  |  |
Malignant tumor, no.(%) | ||||
 No | 145 (94.16) | 825 (92.18) | 0.738 | 0.39 |
 Yes | 9 (5.84) | 70 (7.82) |  |  |
ASA classification, no.(%) | ||||
  ≤ 2 | 58 (37.66) | 208 (23.24) | 14.439 | <0.001 |
 >2 | 96 (62.34) | 687 (76.76) |  |  |
Lung infection, no.(%) | ||||
 No | 142 (92.21) | 797 (89.05) | 1.396 | 0.237 |
 Yes | 12 (7.79) | 98 (10.95) |  |  |
Osteoporosis, no.(%) | ||||
 No | 100 (64.94) | 567 (63.35) | 0.142 | 0.706 |
 Yes | 54 (35.06) | 328 (36.65) |  |  |
Chronic obstructive pulmonary disease, no.(%) | ||||
 No | 141 (91.56%) | 779 (87.04) | 2.488 | 0.115 |
 Yes | 13 (8.44) | 116 (13.96) |  |  |
Anticoagulation, no.(%) | ||||
 No | 11 (7.14) | 37 (4.13) | 2.724 | 0.099 |
 yes | 143 (92.06) | 858 (95.07%) |  |  |