Table 1.
Characteristics of the patients.
| Variables | All (n = 138) | Acute kidney injury |
p | |
|---|---|---|---|---|
| No (n = 105) | Yes (n = 33) | |||
| Baseline characteristics | ||||
| Age (years) | 65.26 ± 14.84 | 66.46 ± 14.57 | 61.45 ± 15.26 | .068 |
| Female, n (%) | 55 (39.86) | 42 (40.00) | 13 (39.39) | .951 |
| Comorbidities, n (%) | ||||
| Diabetes | 9 (6.52) | 5 (4.76) | 4 (12.12) | .135 |
| Chronic cardiovascular disease | 40 (28.99) | 31 (29.52) | 9 (27.27) | .977 |
| Mental disorder | 14 (10.14) | 10 (9.52) | 4 (12.12) | .666 |
| Dementia | 5 (3.62) | 4 (3.81) | 1 (3.03) | .834 |
| Institution, n (%) | .030 | |||
| 1 | 47 (34.0) | 40 (38.10) | 7 (21.21) | |
| 2 | 19 (13.77) | 13 (12.38) | 6 (18.18) | |
| 3 | 22 (15.94) | 17 (16.19) | 5 (15.15) | |
| 4 | 15 (10.87) | 14 (13.33) | 1 (3.03) | |
| 5 | 22 (15.94) | 15 (14.29) | 7 (21.21) | |
| 6 | 13 (9.42) | 6 (5.71) | 7 (21.21) | |
| Type of heat stroke, n (%) | .555 | |||
| Classic | 52 (37.68) | 41 (39.05) | 11 (33.33) | |
| Exertional | 86 (62.32) | 64 (60.95) | 22 (66.67) | |
| Chief complaints, n (%) | ||||
| Coma | 113 (81.88) | 82 (78.10) | 31 (93.94) | .039 |
| Epileptic seizure | 19 (13.77) | 12 (11.43) | 7 (21.21) | .155 |
| Onset time (h) | 1.00 (1.00–3.00) | 1.50 (1.00–3.00) | 1.00 (1.00–3.00) | .470 |
| Monitoring parameters at admission | ||||
| Temperature (°C) | 40.80 ± 0.81 | 40.77 ± 0.77 | 40.89 ± 0.95 | .452 |
| Heart rate (beat/min) | 128.57 ± 24.08 | 124.41 ± 23.64 | 141.82 ± 20.68 | <.001 |
| Systolic pressure (mmHg) | 126.62 ± 31.54 | 130.30 ± 31.42 | 114.94 ± 29.44 | .014 |
| Glasgow Coma Scale | 8.80 ± 4.19 | 9.50 ± 4.29 | 6.58 ± 2.94 | <.001 |
| NEWS | 12.51 ± 3.59 | 11.93 ± 3.69 | 14.36 ± 2.55 | <.001 |
| Body temperature after cooling (°C) | ||||
| Temperature (0.5 h) | 39.50 ± 0.99 | 39.32 ± 0.93 | 40.01 ± 0.90 | <.001 |
| Temperature (2 h) | 37.92 ± 1.00 | 37.73 ± 0.91 | 38.49 ± 1.05 | <.001 |
| Blood test at admission | ||||
| C-reactive protein (mg/L) | 0.62 (0.30–4.40) | 0.70 (0.30–5.80) | 0.30 (0.30–2.0) | .458 |
| Potassium (mmol/L) | 3.64 ± 0.63 | 3.58 ± 0.60 | 3.83 ± 0.70 | .053 |
| Sodium (mmol/L) | 130.46 ± 13.07 | 130.86 ± 7.67 | 129.21 ± 23.19 | .529 |
| Chloride (mmol/L) | 97.54 ± 9.06 | 97.11 ± 8.93 | 98.89 ± 9.49 | .329 |
| Blood glucose (mmol/L) | 11.35 ± 4.87 | 10.90 ± 4.80 | 12.70 ± 4.90 | .065 |
| Alanine aminotransferase (IU/L) | 23 (16.25–35.00) | 22.50 (16.25–35) | 23 (17.00–32.58) | .620 |
| Creatinine (mmol/L) | 98.11 ± 23.35 | 93.45 ± 23.26 | 112.92 ± 16.72 | <.001 |
| Blood urea nitrogen (mmol/L) | 6.86 ± 2.73 | 6.88 ± 2.82 | 6.80 ± 2.45 | .882 |
| Creatine kinase (U/L) | 265.50 (141.80–703.75) | 256.00 (133.20–546.55) | 395.00(159.50–930.00) | .656 |
| Troponin I (ng/mL) | 0.03 (0.01–0.07) | 0.02 (0.01–0.06) | 0.04 (0.02–0.15) | .061 |
| Prothrombin time (s) | 13.25 ± 2.01 | 13.29 ± 1.90 | 13.12 ± 2.37 | .681 |
| Lactic acid (mmol/L) | 3.42 ± 2.00 | 3.18 ± 2.08 | 4.15 ± 1.53 | .016 |
| White blood cell count (1 × 109/L) | 10.24 ± 4.71 | 10.25 ± 4.70 | 10.23 ± 4.82 | .983 |
| Platelet (1 × 109/L) | 197.01 ± 71.15 | 194.94 ± 69.07 | 203.55 ± 78.12 | .547 |
| Serum chlorine after normal saline infusion (mmol/L) | 107.67 ± 6.96 | 106.30 ± 6.53 | 110.83 ± 6.99 | .008 |
| Volume of normal saline infusion in ED (L) | 3.02 ± 1.45 | 2.82 ± 1.34 | 3.66 ± 1.61 | .006 |
| Total infusion volume (L) | 3.69 ± 1.99 | 3.48 ± 1.82 | 4.36 ± 2.19 | .043 |
| Use of vasoactive drugs, n (%) | 28 (20.29) | 13 (12.38) | 15 (45.45) | <.001 |
| Length of stay in ED (h) | 10.00 (4.50–19.88) | 10.00 (4.50–22.00) | 8.00 (4.00–16.50 | .160 |
| Outcomes | ||||
| RRT, n (%) | 7 (5.07) | 2 (1.90) | 5 (15.15) | .002 |
| Admitted to ICU, n (%) | 52 (37.68) | 25 (23.81) | 27 (81.82) | <.001 |
| Length of stay in hospital (d) | 5.00 (2.00–8.00) | 5.00 (0.00–7.00) | 7.00 (5.00–12.00) | .005 |
| Length of stay in ICU (d) | 0.00 (0.00–4.00) | 0.00 (0.00–0.00) | 5.00 (3.00–8.00) | <.001 |
| Coagulation impairment, n (%) | 20 (14.49) | 6 (5.71) | 14 (42.42) | <.001 |
| Rhabdomyolysis, n (%) | 8 (5.80) | 6 (5.71) | 2 (6.06) | .941 |
| Mortality, n (%) | 10 (7.25) | 5 (4.76) | 5 (15.15) | .045 |
| Central nervous system damage at discharge, n (%) | 16 (11.59) | 9 (8.57) | 7 (21.21) | .048 |
NEWS: National Early Warning Score; ED: emergency department; ICU: intensive care unit; RRT: renal replacement therapy.