Table 3 Comparison of postoperative risk factors in participants with and without delirium

Clinical characteristics

 The presence of atrial fibrillation (AF) rhythm, yes (%)

8 (1.9)

55 (11.3)

 < 0.001*

 Use of invasive arterial blood pressure (IABP), yes (%)

2 (0.5)

46 (9.4)

 < 0.001*

 Electroshock therapy, yes (%)

2 (0.5)

11 (2.3)

0.025*

 Acute tubular necrosis (ATN), yes (%)

22 (5.1)

241 (49.4)

 < 0.001*

 Need for hemodialysis, yes (%)

2 (0.5)

72 (14.8)

 < 0.001*

 Cerebral vascular accident (CVA), yes (%)

2 (0.5)

2 (0.4)

0.903

 Drainage data, median (IQR)

240 (180–320)

450 (320–660)

 < 0.001*

 Red-cell storage time, median (IQR)

0.001 (0.001–12)

18 (15–20)

 < 0.001*

 Sleep quality in first night after surgery, ≤ 270

97 (22.5)

378 (77.5)

 < 0.001*

 Sleep quality in second night after surgery, ≤ 240

37 (8.6)

201 (41.2)

 < 0.001*

 Use of physical restraint, yes (%)

423 (97.9)

478 (98)

0.971

 ICU-OH length of stay, ≥ 4 days

26 (6)

407 (83.4)

 < 0.001*

 Hospital length of stay, ≥ 9 days

50 (11.6)

393 (80.5)

 < 0.001*

Blood transfusion data

 Blood product, packed red blood cells (PRBC)

42 (9.7)

266 (54.5)

 < 0.001*

 Blood product, platelets

390 (90.3)

222 (45.5)

Environmental factors

 Lux measurement in the morning, ≥ 54 (%)

368 (85.2)

390 (79.9)

0.036*

 Lux measurement in the evening, ≥ 260 (%)

409 (94.7)

456 (93.4)

0.431

 Lux measurement in the night, ≥ 271 (%)

358 (82.9)

415 (85)

0.370

 Sound metrics in the morning, ≥ 41 (dB)

29 (6.7)

38 (7.8)

0.532

 Sound metrics in the evening, ≥ 65 (dB)

111 (25.7)

153 (31.4)

0.058

 Sound metrics in the night, ≥ 53 (dB)

90 (20.8)

124 (25.4)

0.101

 Temperature, ≥ 27 °C

260 (60.2)

311 (63.7)

0.269

 Humidity, ≥ 11%

284 (65.7)

322 (66)

0.938

 Bed position, natural light (NL) group, near to window

239 (55.3)

229 (46.9)

0.011*

Medication data

 Midazolam, ≥ 7 (%)

103 (23.8)

331 (67.8)

 < 0.001*

 Morphine, ≥ 9 (%)

72 (16.7)

213 (43.6)

 < 0.001*

 Fentanyl drip, ≥ 0.21 (%)

188 (43.5)

358 (73.4)

 < 0.001*

 Dexmedetomidine, ≥ 400 (%)

288 (66.7)

275 (56.4)

0.001*

 Dexamethasone, ≥ 9 (%)

145 (33.6)

128 (26.2)

0.015*

 Norepinephrine, ≥ 1 (%)

5 (1.2)

110 (22.5)

 < 0.001*

Laboratory data

 Sodium levels in first day, ≥ 140 (mEq/L)

235 (54.4)

260 (53.3)

0.734

 Sodium levels in second day, ≥ 140 (mEq/L)

196 (45.4)

255 (52.3)

0.037*

 Sodium levels in third day, ≥ 140 (mEq/L)

219 (50.7)

254 (52)

0.692

 Potassium levels in first day, ≥ 4.21 (mEq/L)

191 (44.2)

256 (52.5)

0.013*

 Potassium levels in second day, ≥ 4.21 (mEq/L)

185 (42.8)

276 (56.6)

 < 0.001*

 Potassium levels in third day, ≥ 4.21 (mEq/L)

201 (46.5)

291 (59.6)

 < 0.001*

 Hematocrit levels in first day, ≥ 26.11

282 (65.3)

171 (35)

 < 0.001*

 Hematocrit levels in second day, ≥ 27.61

283 (65.5)

182 (37.3)

 < 0.001*

 Hematocrit levels in third day, ≥ 29.21

282 (65.3)

186 (38.1)

 < 0.001*

 Minimum blood glucose in first day, ≤ 175 (mg/dL)

270 (62.5)

186 (38.1)

 < 0.001*

 Maximum blood glucose in first day, ≥ 242 (mg/dL)

164 (38)

312 (63.9)

 < 0.001*

 Minimum blood glucose in second day, ≤ 155 (mg/dL)

264 (61.1)

194 (39.8)

 < 0.001*

 Maximum blood glucose in second day, ≥217 (mg/dL)

152 (35.2)

309 (63.3)

<0.001*

 Minimum blood glucose in third day, ≤133 (mg/dL)

246 (56.9)

211 (43.2)

<0.001*

 Maximum blood glucose in third day, ≥176 (mg/dL)

161 (37.3)

304 (62.3)

<0.001*

 Lactate levels in first day, ≥4.71 (mmol/L)

129 (29.9)

331 (67.8)

<0.001*

 Lactate levels in second day, ≥3.1 (mmol/L)

136 (31.5)

343 (70.3)

<0.001

 Lactate levels in third day, ≥1.41 (mmol/L)

117 (27.1)

332 (68)

<0.001*