Table 1 Scheme for calculating the fluid retention index (FRI), which is the mean of the dehydration scores for 4 urinary indexes of fluid retention
From: Preoperative fluid retention increases blood loss during major open abdominal surgery
Fluid retention score | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
Specific gravity | ≤ 1.005 | 1.010 | 1.015 | 1.020 | 1.025 | 1.030 |
Osmolality (mOsmol/kg) | < 250 | 250–450 | 450–600 | 600–800 | 800–1000 | > 1000 |
Creatinine(mmol/l) | < 4 | 4–7 | 7–12 | 12–17 | 17–25 | > 25 |
Colour (shade) | 1 | 2 | 3 | 4 | 5 | 6 |