Demographic characteristics and AKI risk factors of the all T&O patients undergoing an elective or emergency operation between 1 June 2020 and 31 December 2020 (inclusive) in terms of those who had a postoperative AKI and those who did not
| Variable | All N (%) | Postoperative AKI N (%) | No postoperative AKI N (%) | P value |
| Total number and type of T&O operations | 928 | 19 | 909 | |
| Elective | 241 (26.0) | 3 (15.8) | 238 (26.2) | 0.430 |
| Emergency | 687 (74.0) | 16 (84.2) | 671 (73.8) | |
| Median age (IQR) | 52 (29–74) | 84 (70–89) | 51 (28–74) | <0.001 |
| Sex | 0.028 | |||
| Male | 500 (53.9) | 5 (26.3) | 495 (54.5) | |
| Female | 428 (46.1) | 14 (73.7) | 414 (45.5) | |
| ASA grade | <0.001 | |||
| 1 or 2 | 645 (69.5) | 6 (31.6) | 639 (70.3) | |
| 3 or 4 | 242 (26.1) | 13 (68.4) | 229 (25.2) | |
| Missing | 41 (4.4) | 0 (0.0) | 41 (4.5) | |
| Hypotension/Hypovolaemia | 0.592 | |||
| Hypotension occurred during admission | 408 (44.0) | 10 (52.6) | 398 (43.8) | |
| Hypotension did not occur during admission | 520 (56.0) | 9 (47.4) | 511 (56.2) | |
| NSAIDs | 0.678 | |||
| Received | 259 (27.9) | 4 (21.1) | 255 (28.1) | |
| Not received | 669 (72.1) | 15 (78.9) | 654 (71.9) | |
| Gentamicin | 0.006 | |||
| Received | 185 (19.9) | 9 (47.4) | 176 (19.4) | |
| Not received | 743 (80.1) | 10 (52.6) | 733 (80.6) | |
| ACEi/ARB | 0.014 | |||
| Received | 104 (11.2) | 6 (31.6) | 98 (10.8) | |
| Not received | 824 (88.8) | 13 (68.4) | 811 (89.2) | |
| Diuretic | <0.001 | |||
| Received | 87 (9.4) | 9 (47.4) | 78 (8.6) | |
| Not received | 841 (90.6) | 10 (52.6) | 831 (91.4) | |
| Number of risk factor drug classes received | <0.001 | |||
| 0 | 428 (46.1) | 4 (21.1) | 424 (46.6) | |
| 1 | 382 (41.2) | 4 (21.1) | 378 (41.6) | |
| 2 | 101 (10.9) | 9 (47.4) | 92 (10.1) | |
| 3 | 17 (1.83) | 2 (10.5) | 15 (1.7) | |
| Median length of stay in days (IQR) | 1 (1–4) | 10 (5.5–15.5) | 1 (1–4) | <0.001 |
| 1-year postoperative mortality | <0.001 | |||
| Died within 1 year postoperatively | 85 (9.2) | 9 (47.4) | 76 (8.4) | |
| Did not die within 1 year postoperatively | 843 (90.8) | 10 (52.6) | 833 (91.6) |
P values for the χ2 tests are presented except for age and length of stay where a Kruskal-Wallis test was conducted. Missing values were excluded from χ2 calculations. Fisher’s exact test was used for the type of operation, gentamicin, ACEi, diuretics, number of high-risk drugs received, 1-year postoperative mortality variables.
ACEi, ACE inhibitor; AKI, acute kidney injury; ARB, angiotensin receptor blocker; ASA, American Society of Anaesthesiologists; NSAID, non-steroidal anti-inflammatory drug; T&O, trauma and orthopaedics.