Table 2.
Characteristics according to obstruction duration and AKI/APN
| Obstruction duration ≤7 days (group 1) | Obstruction duration >7 days (group 2) | |||||||
| APN−AKI− (n=504) |
APN−AKI+ (n=267) |
APN+AKI− (n=38) |
APN+AKI+ (n=103) |
APN−AKI− (n=413) |
APN−AKI+ (n=188) |
APN+AKI− (n=24) |
APN+AKI+ (n=69) |
|
| Male gender, n (%) | 287 (56.9) | 182 (68.2) | 13 (34.2) | 55 (53.4) | 251 (60.8) | 135 (71.8) | 10 (41.7) | 39 (56.5) |
| Age | 48.0 (37.0–58.0) | 55.0 (42.0–65.0) | 52.5 (39.0–69.0) | 60.0 (50.0–69.5) | 54.0 (43.0–63.0) | 59.0 (48.0–67.0) | 55.5 (40.5–67.5) | 67.0 (56.0–76.0) |
| Obstruction release procedure, n (%) | ||||||||
| Spontaneous release | 46 (9.1) | 16 (6.0) | 4 (10.5) | 5 (4.9) | 10 (2.3) | 4 (2.2) | 0 (0.0) | 3 (4.4) |
| Double-J stenting | 142 (28.2) | 78 (29.2) | 11 (29.0) | 38 (36.9) | 139 (33.7) | 63 (33.5) | 11 (45.8) | 23 (33.3) |
| PCN | 8 (1.6) | 6 (2.3) | 0 (0.0) | 17 (16.5) | 7 (1.7) | 8 (4.3) | 1 (4.2) | 5 (7.3) |
| Operation (stone removal) | 106 (21.0) | 66 (24.7) | 14 (36.8) | 20 (19.4) | 182 (44.1) | 78 (41.5) | 6 (25.0) | 22 (31.9) |
| ESWL | 202 (40.1) | 101 (37.8) | 9 (23.7) | 23 (22.3) | 75 (18.2) | 35 (18.6) | 6 (25.0) | 16 (23.2) |
| Obstruction duration | 3.0 (1.0–5.0) | 3.0 (1.5–4.0) | 4.0 (2.0–6.0) | 4.0 (2.0–5.0) | 21.0 (12.0–33.0) | 15.0 (10.0–30.0) | 16.0 (10.0–27.0) | 15.0 (10.0–27.0) |
| Hypertension, n (%) | 87 (17.3) | 85 (31.8) | 10 (26.3) | 38 (36.9) | 137 (33.2) | 88 (46.8) | 7 (29.2) | 41 (59.4) |
| Diabetes mellitus, n (%) | 37 (7.3) | 47 (17.6) | 4 (10.5) | 26 (25.2) | 67 (16.2) | 57 (30.3) | 4 (16.7) | 28 (40.6) |
| Chronic kidney disease, n (%) | 0 (0.0) | 7 (2.6) | 0 (0.0) | 7 (6.8) | 2 (0.5) | 7 (3.7) | 1 (4.2) | 6 (8.7) |
| Pain killer, n (%) | ||||||||
| No use | 59 (11.7) | 60 (22.5) | 9 (23.7) | 41 (39.8) | 58 (14.0) | 58 (30.9) | 7 (29.2) | 36 (52.2) |
| NSAIDs (old)* | 20 (4.0) | 19 (7.1) | 5 (13.2) | 18 (17.5) | 17 (4.1) | 10 (5.3) | 1 (4.2) | 9 (13.0) |
| NSAIDs (new)† | 251 (49.8) | 100 (37.5) | 17 (44.7) | 21 (20.4) | 214 (51.8) | 70 (37.2) | 9 (37.5) | 10 (14.5) |
| Narcotic analgesics | 174 (34.5) | 88 (33.0) | 7 (18.4) | 23 (22.3) | 124 (30.0) | 50 (26.6) | 7 (29.2) | 14 (20.3) |
| Baseline SCr (mg/dL) | 0.8 (0.7–0.9) | 0.8 (0.7–1.0) | 0.7 (0.5–0.8) | 0.8 (0.6–1.0) | 0.8 (0.7–1.0) | 0.8 (0.7–1.0) | 0.8 (0.6–1.0) | 0.9 (0.6–1.2) |
| Baseline eGFR (mL/min/1.73 m2)‡ |
96.6 (81.0–112.9) | 91.4 (74.5–113.8) | 105.2 (89.7–126.4) | 93.7 (73.4–111.3) | 94.0 (79.1–113.7) | 91.3 (68.7–114.9) | 92.4 (69.1–109.2) | 79.1 (59.6–103.4) |
| SCr on admission (mg/dL) | 0.9 (0.7–1.0) | 1.2 (1.0–1.5) | 0.8 (0.7–1.0) | 1.4 (1.1–1.7) | 0.9 (0.7–1.0) | 1.2 (1.0–1.6) | 0.9 (0.7–1.1) | 1.6 (1.1–2.0) |
| eGFR on admission (mL/min/1.73 m2)‡ |
85.6 (73.7–99.7) | 58.0 (46.7–69.1) | 80.6 (68.6–100.2) | 48.4 (34.1–63.9) | 83.5 (71.8–100.7) | 57.6 (43.9–73.5) | 75.6 (59.5–91.9) | 40.9 (31.0–61.6) |
| Performed imaging modality for diagnosis, n (%) | ||||||||
| KUB | 3 (6.0) | 10 (3.8) | 1 (2.6) | 2 (1.9) | 47 (11.4) | 26 (13.8) | 0 (0.0) | 2 (2.9) |
| Kidney sonography | 8 (1.6) | 3 (1.1) | 0 (0.0) | 0 (0.0) | 4 (1.0) | 1 (0.5) | 0 (0.0) | 1 (1.5) |
| CT | 368 (73.0) | 198 (74.2) | 35 (92.1) | 94 (91.3) | 283 (68.5) | 128 (68.1) | 21 (87.5) | 61 (88.4) |
| IVP | 98 (19.4) | 56 (21.0) | 2 (5.3) | 7 (6.8) | 79 (19.1) | 33 (17.6) | 3 (12.5) | 5 (7.3) |
| Hydronephrosis grade, n (%) | ||||||||
| No hydronephrosis | 127 (25.2) | 37 (13.9) | 4 (10.5) | 11 (10.7) | 97 (23.5) | 28 (14.9) | 7 (29.2) | 9 (13.0) |
| Grade 1 | 116 (23.0) | 55 (20.6) | 12 (31.6) | 19 (18.5) | 65 (15.7) | 34 (18.1) | 3 (12.5) | 13 (18.8) |
| Grade 2 | 178 (35.3) | 120 (44.9) | 18 (47.4) | 48 (46.6) | 98 (23.7) | 48 (25.5) | 6 (25.0) | 20 (29.0) |
| Grade 3 | 39 (7.7) | 34 (12.7) | 3 (7.9) | 18 (17.5) | 66 (16.0) | 30 (16.0) | 6 (25.0) | 16 (23.2) |
| Grade 4 | 7 (1.4) | 5 (1.9) | 1 (2.6) | 4 (3.9) | 36 (8.7) | 22 (11.7) | 0 (0.0) | 8 (11.6) |
| Obstruction side, n (%) | ||||||||
| Left | 252 (50.4) | 132 (49.6) | 21 (55.3) | 50 (48.5) | 190 (46.3) | 92 (49.7) | 12 (50.0) | 34 (49.3%) |
| Right | 210 (42.0) | 121 (45.5) | 13 (34.2) | 49 (47.6) | 179 (43.7) | 76 (41.1) | 11 (45.8) | 34 (49.3) |
| Bilateral | 4 (0.8) | 5 (1.9) | 2 (5.3) | 3 (2.9) | 9 (2.2) | 4 (2.2) | 0 (0.0) | 0 (0.0) |
| Undefined | 19 (3.8) | 5 (1.9) | 0 (0.0) | 0 (0.0) | 23 (5.6) | 10 (5.4) | 1 (4.2) | 0 (0.0) |
| Stone size (mm) | 5.3 (4.1–7.34) | 6.0 (4.6–7.7) | 6.0 (4.8–6.9) | 6.1 (4.8–8.9) | 7.6 (5.6–10.7) | 8.4 (5.8–12.0) | 6.3 (4.1–9.4) | 8.2 (6.2–10.0) |
*Old NSAIDs: naproxen, aceclofenac and ketorolac.
†New NSAIDs: talniflumate.
‡eGFR was calculated using the Isotope Dilution Mass Spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) study equation (mL/min/1.73 m2).
AKI, acute kidney injury; APN, acute pyelonephritis; eGFR, estimated glomerular filtration rate; ESWL, extracorporeal shock wave lithotripsy; IVP, intravenous pyelogram; KUB, kidney ureter bladder X-ray;NSAIDs, non-steroidal anti-inflammatory drugs; PCN, percutaneous nephrostomy; SCr, serum creatinine.