Heat strain† and volume depletion‡ by AKI categories
| Total sample (n=283) | Males (n=182) | Females (n=101) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| KDIGO§ stage | KDIGO§ stage | KDIGO§ stage | |||||||||||||
| No injury | Stage 1¶ | Stage 2** | No AKI¶ | AKI | No injury | Stage 1** | Stage 2 | No AKI¶ | AKI | No injury | Stage 1** | Stage 2 | No AKI¶ | AKI | |
| n (%) | 248 (87.6) | 31 (11.0) | 4 (1.3) | 248 (87.6) | 35 (12.4) | 160 (87.9) | 20 (10.9) | 2 (1.1) | 160 (87.9) | 22 (12.1) | 88 (87.1) | 11 (10.9) | 2 (2.0) | 88 (87.1) | 13 (12.9) |
| Heat strain† | |||||||||||||||
| No heat strain | 241 (88.3) | 28 (10.3) | 4 (1.5) | 241 (88.3) | 32 (11.7) | 153 (89.0) | 17 (9.9) | 2 (1.2) | 153 (89.0) | 19 (11.0) | 88 (87.1) | 11 (10.9) | 2 (2.0) | 88 | 13 |
| Heat strain | 7 (70) | 3 (30) | 0 | 7 (70) | 3 (30) | 7 (70.0) | 3 (30.0) | 0 | 7 (70.0) | 3 (30.0) | 0 | 0 | 0 | 0 | 0 |
| Volume depletion | ** | ||||||||||||||
| No body mass change | 9 (90) | 1 (10) | 0 | 9 (90) | 1 (10) | 2 (66.7) | 1 (33.3) | 0 | 2 (66.7) | 1 (33.3) | 7 (100.0) | 0 | 0 | 7 (100.0) | 0 |
| Gained any body mass | 70 (88.6) | 7 (8.9) | 2 (2.5) | 70 (88.6) | 9 (11.4) | 36 (90.0) | 4 (10.0) | 0 | 36 (90.0) | 4 (10.0) | 34 (87.2) | 3 (7.7) | 2 (5.1) | 34 (87.2) | 5 (12.8) |
| Lost <1.5% body mass | 151 (89.3) | 16 (9.5) | 2 (1.1) | 151 (89.3) | 18 (10.7) | 104 (89.7) | 10 (8.6) | 2 (1.7) | 104 (89.7) | 12 (10.3) | 47 (88.7) | 6 (11.3) | 0 | 47 (88.7) | 6 (11.3) |
| Lost ≥1.5% body mass | 18 (72) | 7 (28) | 0 | 18 (72) | 7 (28) | 18 (78.3) | 5 (21.7) | 0 | 18 (78.2) | 5 (21.7) | 0 | 2 (100.0) | 0 | 0 | 2 (100.0) |
*p Value <0.05 based on χ2 tests, comparing categories within stratification.
†Heat strain estimated by PSI=5×(peak core temperature−base core temperature)/(39.5−base core temperature)+5×(peak hr−base hr)/(220−age)−base hr).
‡Volume depletion estimated by per cent change in body mass (postshift weight−preshift weight)×100/preshift weight.
§Kidney Disease Improving Global Outcomes.
¶AKI as dichotomous variable (stage 1 or 2 vs no injury).
**Stage 1 classified based on meeting at least one of the criteria.
AKI, acute kidney injury; hr, heart rate; PSI, physiological strain index.