Table 1 Demographics and clinical characteristics of patients with or without atelectasis
Characteristics | Overall n = 1,941 | Atelectasis group n = 373 | Non-atelectasis group n = 1,568 | P-value |
|---|---|---|---|---|
Demographics | ||||
 Age, yr | 60.2 ± 15.8 | 63.3 ± 13.3 | 59.5 ± 16.3 |  < 0.001 |
 Sex (% male) | 778 (40.1) | 158 (42.4) | 620 (39.5) | 0.318 |
 BMI, kg/m2 | 24.6 ± 4.4 | 25.6 ± 4.3 | 24.4 ± 4.4 |  < 0.001 |
Medical comorbidities | ||||
 Asthma | 54 (2.8) | 9 (2.4) | 45 (2.9) | 0.630 |
 COPD | 32 (1.6) | 7 (1.9) | 25 (1.6) | 0.700 |
 Hypertension | 888 (45.7) | 202 (54.2) | 686 (43.8) |  < 0.001 |
 Heart failure | 72 (3.7) | 16 (4.3) | 56 (3.6) | 0.510 |
 Diabetes mellitus | 442 (22.8) | 110 (29.5) | 332 (21.2) | 0.001 |
 Anemia (hemoglobin < 10 g/dL) | 168 (8.7) | 36 (9.7) | 132 (8.4) | 0.447 |
 Hypoalbuminemia (serum albumin < 3.5 g/dL) | 182 (9.4) | 34 (9.1) | 148 (9.4) | 0.847 |
 Smoking history | 340 (17.5) | 77 (20.6) | 263 (16.8) | 0.077 |
 Preoperative CXR abnormality | 189 (9.7) | 35 (9.4) | 154 (9.8) | 0.798 |
ASA physical status | Â | Â | Â | 0.070 |
 I | 83 (4.3) | 6 (1.6) | 77 (4.9) |  |
 II | 1364 (70.3) | 265 (71.0) | 1099 (70.1) |  |
 III | 450 (23.2) | 93 (24.9) | 357 (22.8) |  |
 IV | 44 (2.3) | 9 (2.4) | 35 (2.2) |  |
Type of surgery |  |  |  |  < 0.001 |
 Brain surgery | 55 (2.8) | 12 (3.2) | 43 (2.7) |  |
 Back and spine surgery | 308 (15.9) | 44 (11.8) | 264 (16.8) |  |
 Upper abdominal surgery | 330 (17.0) | 106 (28.4) | 224 (14.3) |  |
 Lower abdominal surgery | 744 (38.3) | 170 (45.6) | 574 (36.6) |  |
 Orthopedic surgery | 416 (21.4) | 33 (8.8) | 383 (24.4) |  |
 Other surgeries | 88 (4.5) | 8 (2.1) | 80 (5.1) |  |
Anesthesia time, min | 195.8 ± 105.9 | 234.3 ± 113.2 | 186.6 ± 102.0 |  < 0.001 |
Type of reversal agents |  |  |  |  < 0.001 |
 Pyridostigmine | 848 (43.7) | 108 (29.0) | 740 (47.2) |  |
 Sugammadex | 1071 (55.2) | 263 (70.5) | 808 (51.5) |  |
 None | 22 (1.1) | 2 (0.5) | 20 (1.3) |  |
Postoperative pneumonia | 63 (3.2) | 19 (5.1) | 44 (2.8) | 0.025 |
ICU admission | 147 (7.6) | 45 (12.1) | 102 (6.5) |  < 0.001 |
Postoperative LOS, days | 6 [4-8] | 7 [5-10] | 6 [3-8] |  < 0.001 |
30-day mortality | 5 (0.3) | 0 (0.0) | 5 (0.3) | 0.275 |