Table 1 Patient characteristics, details of surgery, laboratory investigation, and prognostic outcomes
|  | Delirium (n = 162) | Non delirium (n = 4288) | P |
|---|---|---|---|
Variables | Â | Â | Â |
 Age (year) mean ± SD | 65.3 ± 15.6 | 61.8 ± 17.3 | 0.013 |
  <40 (n, %) | 11 (6.8) | 537 (12.5) |  |
  40–70 (n, %) | 76 (47.0) | 2175 (50.7) |  |
  >70 (n, %) | 75 (46.2) | 1576 (36.8) |  |
 Male (n, %) | 102 (63.0) | 2505 (58.4) | 0.249 |
 Body mass index (kg/m2) (mean ± SD) | 22.0 ± 4.6 | 23.0 ± 5.7 | 0.031 |
 ASA PS (n, %) |  |  | <0.001 |
  I–II | 26 (23.6) | 1291(39.0) |  |
  III | 58 (52.7) | 1620 (49.0) |  |
  IV–VI | 26 (23.6) | 392 (12.0) |  |
 Comorbidity (n, %) |  |  |  |
  Hypertension | 75 (46.3) | 2130 (49.7) | 0.399 |
  Diabetes mellitus | 33 (20.4) | 946 (22.1) | 0.610 |
  Coronary artery disease | 15 (9.4) | 433 (10.1) | 0.728 |
  Congestive heart failure | 11 (6.8) | 93 (2.2) | <0.001 |
  COPD | 21 (12.9) | 184 (4.3) | <0.001 |
  Chronic renal failure | 25 (15.4) | 406 (9.5) | 0.012 |
 Smoking history (n, %) |  |  | <0.001 |
  Current smokers | 32 (19.7) | 498 (11.6) |  |
  Ex-smokers | 50 (30.8) | 1054 (24.6) |  |
  Non smokers | 80 (49.4) | 2736 (63.8) |  |
 Numbers of pack years median (P25–75) | 15.5( 10–25) | 15 (6–30) | 0.631 |
 Numbers of operative patients (n, %) | 119 (73.5) | 3377 (79.8) | 0.118 |
 Sites of SICU (n, %) |  |  | <0.001 |
  Site A (incidence 1.9 %) | 18 (11.1) | 922 (21.5) |  |
  Site B (incidence 1.2 %) | 5 (3.1) | 404 (9.4) |  |
  Site C (incidence 2.7 %) | 15 (9.3) | 545 (12.7) |  |
  Site D (incidence 1.9 %) | 8 (5.0) | 402 (9.3) |  |
  Site E (incidence 0.8 %) | 3 (1.8) | 390 (9.1) |  |
  Site F (incidence 0 %) | 0 | 139 (3.2) |  |
  Site G (incidence 13.9 %) | 109 (67.3) | 675 (15.7) |  |
  Site H (incidence 0.8 %) | 3 (1.8) | 368 (8.6) |  |
  Site I (incidence 0.2 %) | 1 (0.6) | 443 (10.5) |  |
 Emergency surgery (n, %) | 79 (66.4) | 987 (29.2) | <0.001 |
 Site of surgery (n, %) |  |  |  |
  Upper abdomen | 56 (34.6) | 1182 (27.6) | 0.051 |
  Lower abdomen | 43 (26.5) | 1178 (27.5) | 0.795 |
  Thoracic | 15 (9.8) | 162 (3.8) | <0.001 |
  Vascular | 5 (3.1) | 134 (3.1) | 0.978 |
  Extremities | 14 (8.6) | 371 (8.3) | 0.883 |
  Anus | 1 (0.62) | 52 (1.2) | 0.493 |
  Other surgeries | 28 (17.2) | 1209 (28.2) | 0.001 |
 Duration of surgery (min) median (P25–75) | 180 (105–275) | 240 (150–360) | <0.001 |
 Amount of PRC transfusion (ml) median (P25–75) | 100 (0–635) | 0 (0–511) | 0.274 |
 Amount of FFP transfusion (ml) median (P25–75) | 0 (0–780) | 0 (0–0) | <0.001 |
 APACHE II median (P25–75) | 16 (12–23) | 10 (7–15) | <0.001 |
 SOFA median (P25–75) | 5 (2–8) | 2 (1–5) | <0.001 |
 Sepsis (n, %) | 109 (67.3) | 779 (18.2) | <0.001 |
 Mechanical ventilation (n, %) | 141 (87.0) | 2635 (61.8) | <0.001 |
 Albumin (g/dl) (mean ± SD) | 2.4 ± 0.85 | 2.8 ± 0.80 | <0.001 |
 Hemoglobin (g/dl) (mean ± SD) | 9.7 ± 2.6 | 10.6 ± 2.1 | <0.001 |
 Blood sugar (mg%) (mean ± SD) | 144.0 ± 72.0 | 164.1 ± 68.8 | 0.013 |
 PaO2 (mmHg) (mean ± SD) | 144.0 ± 72.1 | 164.1 ± 0.81 | 0.013 |
 Exposure to sedative drugs (n, %) | 110 (67.9) | 932 (21.7) | <0.001 |
 Exposure to analgesic drugs (n, %) | 134(82.7) | 3683 (85.9) | 0.256 |
 ICU admission diagnosis (n, %) |  |  | 0.005 |
  Abdominal | 71 (43.8) | 1728 (40.3) |  |
  Cardiovascular | 31 (19.1) | 662 (15.4) |  |
  Respiratory | 17 (10.5) | 335 (7.8) |  |
  Renal | 10 (6.2) | 356 (8.3) |  |
  Other | 33 (20.4) | 1207 (28.2) |  |
Prognostic outcomes | Â | Â | Â |
 Ventilator days (days) median (P25–75) | 7 (4–17) | 2 (1–4) | <0.001 |
 Length of ICU stay (days) median (P25–75) | 8 (5–19) | 2 (1–4) | <0.001 |
 Duration of hospital stay (days) median(P25–75) | 22 (14–34) | 15 (9–26) | <0.001 |
 ICU mortality (n, %) | 38 (23.5) | 349 (8.1) | <0.001 |
 28-day mortality (n, %) | 45 (27.8) | 534 (12.4) | <0.001 |