Table 2.
Baseline characteristics of patients, according to NLR level.
| Variable | Level | NLR ≤ 3.6 | NLR > 3.6 | P-value | |
|---|---|---|---|---|---|
| n | n | 111,792 | 245,55 | ||
| Sex [n (%)] | Men | 54,502 (48.8) | 14,650 (59.7) | < 0.001 | |
| Women | 57,274 (51.2) | 9,903 (40.3) | |||
| Age [median (IQR)] | 51.00 (40.00, 63.00) | 53.00 (42.00, 65.00) | < 0.001 | ||
| BMI [median (IQR)] | 23.00 (21.00, 26.00) | 23.00 (20.00, 25.00) | < 0.001 | ||
| Prognostic models | ASA-PS [n (%)] | I–II | 84,446 (75.6) | 12,229 (49.9) | < 0.001 |
| III | 26,765 (24.0) | 10,700 (43.6) | |||
| IV–V | 491 (0.4) | 1,591 (6.5) | |||
| CCI [n (%)] | ≤ 4 | 96,520 (86.3) | 20,615 (84.0) | < 0.001 | |
| 5–8 | 12,515 (11.2) | 3,075 (12.5) | |||
| ≥9 | 2,757 (2.5) | 865 (3.5) | |||
| RCRI [n (%)] | 0 | 59,908 (54.9) | 11,050 (46.5) | < 0.001 | |
| 1 | 43,896 (40.2) | 10,757 (45.2) | |||
| 2 | 4,842 (4.4) | 1,717 (7.2) | |||
| ≥3 | 511 (0.5) | 262 (1.1) | |||
| Excare [median (IQR)] | 13.22 (13.22, 17.47) | 19.88 (13.22, 22.58) | < 0.001 | ||
| Comorbidities [n (%)] | Ischemic heart disease | No | 108,712 (97.2) | 23,579 (96.0) | < 0.001 |
| Yes | 3,080 (2.8) | 976 (4.0) | |||
| Atrial fibrillation | No | 110,022 (98.4) | 23,940 (97.5) | < 0.001 | |
| Yes | 1,770 (1.6) | 615 (2.5) | |||
| Chronic heart failure or cardiomyopathy | No | 111,696 (99.9) | 24,468 (99.6) | < 0.001 | |
| Yes | 96 (0.1) | 87 (0.4) | |||
| Valvular disease | No | 107,108 (95.8) | 23,514 (95.8) | 0.739 | |
| Yes | 4,684 (4.2) | 1,041 (4.2) | |||
| Peripheral vascular disease or abdominal aorticaneurysm | No | 109,199 (97.7) | 23,800 (96.9) | < 0.001 | |
| Yes | 2,593 (2.3) | 755 (3.1) | |||
| Hypertension | No | 93,824 (83.9) | 18,271 (74.4) | < 0.001 | |
| Yes | 17,968 (16.1) | 6,284 (25.6) | |||
| Cerebrovascular disease | No | 111,191 (99.5) | 24,312 (99.0) | < 0.001 | |
| Yes | 601 (0.5) | 243 (1.0) | |||
| Hemiplegia paraplegia or paralytic syndrome | No | 111,538 (99.8) | 24,123 (98.2) | < 0.001 | |
| Yes | 254 (0.2) | 432 (1.8) | |||
| Chronic obstructive pulmonary disease | No | 107,378 (96.1) | 22,965 (93.5) | < 0.001 | |
| Yes | 4,414 (3.9) | 1,590 (6.5) | |||
| Diabetes | No | 104,560 (93.5) | 22,207 (90.4) | < 0.001 | |
| Yes | 7,232 (6.5) | 2,348 (9.6) | |||
| Cancer (including lymphoma and leukemi) | No | 78,385 (70.1) | 17,922 (73.0) | < 0.001 | |
| Yes | 33,407 (29.9) | 6,633 (27.0) | |||
| Childpugh grade | A | 90,442 (80.9) | 13,629 (55.5) | < 0.001 | |
| B | 21,349 (19.1) | 10,925 (44.5) | |||
| C | 102,541 (93.9) | 20,047 (84.3) | < 0.001 | ||
| Preoperative anemia | No | 6,616 (6.1) | 3,739 (15.7) | ||
| Yes | 111,094 (99.4) | 18,879 (76.9) | < 0.001 | ||
| Preoperative increased creatinine | No | 698 (0.6) | 5,676 (23.1) | ||
| Yes | 16,804 (96.0) | 3,186 (77.7) | < 0.001 | ||
| Preoperative leukocytosis (%) | No | 683 (3.9) | 835 (20.4) | ||
| Yes | 26 (0.1) | 80 (2.0) | |||
| Emergency case [n (%)] | Emergency | 108,817 (98.3) | 17,785 (73.0) | < 0.001 | |
| Elective | 1,913 (1.7) | 6,566 (27.0) | |||
| Surgical category [n (%)] | General | 36,720 (32.8) | 8,136 (33.1) | ||
| Orthopedic | 16,825 (15.1) | 4,890 (19.9) | |||
| Urological | 15,452 (13.8) | 2,689 (11.0) | |||
| Neurosurgery | 8,398 (7.5) | 3,227 (13.1) | |||
| Otorhinolaryngology, head and neck | 10,057 (9.0) | 1,060 (4.3) | |||
| Thoracic | 9,335 (8.4) | 1,169 (4.8) | |||
| Cardiovascular | 7,539 (6.7) | 1,670 (6.8) | |||
| Burn and plastic | 3,041 (2.7) | 302 (1.2) | |||
| Other | 4,425 (4.0) | 1,412 (5.8) | |||
| General anesthesia [n (%)] | No | 6,177 (5.6) | 1,593 (6.5) | < 0.001 | |
| Yes | 105,101 (94.4) | 22,771 (93.5) | |||
| Intraoperative hypotension [n (%)] | MAP < 55 mmHg at any time | No | 96,948 (86.7) | 20,322 (82.8) | < 0.001 |
| Yes | 14,844 (13.3) | 4,233 (17.2) | |||
| Intraoperative mean heart rate [median (IQR)] | 67.62 (62.37, 74.27) | 72.48 (65.32, 82.55) | < 0.001 | ||
| Intraoperative transfusion [median (IQR)] | No | 109,120 (97.6) | 21,677 (88.3) | < 0.001 | |
| Yes | 2,672 (2.4) | 2,878 (11.7) | |||
| Duration of surgery [median (IQR)] | 89.00 (49.00, 151.00) | 114.00 (60.00, 195.00) | < 0.001 | ||
| Preoperative laboratory tests | Hb [median (IQR)] | 136.00 (126.00, 148.00) | 128.00 (110.00, 142.00) | < 0.001 | |
| BUN [median (IQR)] | 4.90 (4.00, 5.90) | 5.10 (4.00, 6.70) | < 0.001 | ||
| CRE [median (IQR)] | 67.00 (57.00, 80.00) | 69.00 (57.00, 86.00) | < 0.001 | ||
| eGFR [median (IQR)] | 98.99 (87.25, 109.78) | 97.01 (79.90, 110.15) | < 0.001 | ||
| TBil [median (IQR)] | 11.30 (8.70, 14.90) | 12.00 (8.50, 17.20) | < 0.001 | ||
| ALB [median (IQR)] | 44.40 (41.70, 47.00) | 41.90 (37.40, 45.70) | < 0.001 | ||
| ALT [median (IQR)] | 18.00 (13.00, 28.00) | 19.00 (13.00, 31.00) | < 0.001 | ||
| LDH [median (IQR)] | 162.00 (143.00, 187.00) | 179.00 (152.00, 219.00) | < 0.001 | ||
| ALP [median (IQR)] | 74.00 (61.00, 91.00) | 80.00 (64.00, 102.00) | < 0.001 | ||
| G [median (IQR)] | 4.97 (4.62, 5.44) | 5.57 (4.89, 6.89) | < 0.001 | ||
| NLR [median (IQR)] | 1.88 (1.44, 2.43) | 5.40 (4.23, 8.71) | < 0.001 | ||
| Outcomes | ICU admission (%) | No | 102,662 (91.8) | 19,904 (81.1) | < 0.001 |
| Yes | 9,130 (8.2) | 4,651 (18.9) | |||
| PMI (%) | No | 110,700 (99.0) | 24,096 (98.1) | < 0.001 | |
| Yes | 1,092 (1.0) | 459 (1.9) | |||
| Length of hospital stay [median (IQR)] | 7.00 (4.00, 9.00) | 9.00 (5.00, 15.00) | < 0.001 | ||
| Death (%) | No | 111,337 (99.6) | 23,532 (95.8) | < 0.001 | |
| Yes | 455 (0.4) | 1,023 (4.2) | |||
NLR, neutrophil to lymphocyte ratio; BMI, body mass index; ASA-PS, American Society of Anesthesiologists Physical Status; CCI, Charlson Comorbidity Index; RCRI, Revised Cardiac Risk Index; Ex-care, Ex-Care model; MAP, mean arterial pressure; Hb, Hemoglobin; BUN, Blood urea nitrogen; CRE, Creatinine; eGFR, Estimated glomerular filtration rate; TBil, Total bilirubin; ALB, Albumin; ALT, Alanine transaminase; LDH, Lactate dehydrogenase; ALP, Alkaline phosphatase; G, Blood glucose; PMI, perioperative myocardial injury.