Table 3. Renal function variables (mean ± standard deviation or median with range [minimum, maximum]) in six Beagle dogs before (baseline: BL) and during an infusion of saline as control (C), remifentanil at incremented doses of 0.15 (T1), 0.60 (T2) and 2.40 (T3) μg/kg/min (R), dexmedetomidine at 0.5 μg/kg/hr (D), or the combination of remifentanil and dexmedetomidine (RD) under sevoflurane anesthesia equipotent to 1.5 times of minimum alveolar concentration.
| Variable | Treatment | BL | T1 | T2 | T3 |
|---|---|---|---|---|---|
| UO (ml/min/kg) | C | 0.015 (0.010, 0.022) | 0.021 (0.011, 0.045) | 0.017 (0.012, 0.032) | 0.020 (0.013, 0.052) |
| R | 0.014 (0.011, 0.032) | 0.015 (0.010, 0.019) | 0.014 (0.010, 0.030)d) | 0.017 (0.014, 0.040) | |
| D | 0.015 (0.009, 0.020) | 0.024 (0.017, 0.126) | 0.035 (0.019, 0.228)ac) | 0.054 (0.024, 0.264)a) | |
| RD | 0.015 (0.012, 0.027) | 0.024 (0.015, 0.060) | 0.018 (0.012, 0.070) | 0.017 (0.013, 0.029)d) | |
| USG | C | 1.041 ± 0.009 | 1.037 ± 0.014 | 1.041 ± 0.013 | 1.036 ± 0.014d) |
| R | 1.038 ± 0.012 | 1.046 ± 0.009d) | 1.044 ± 0.010d) | 1.037 ± 0.009d) | |
| D | 1.039 ± 0.009 | 1.025 ± 0.012c) | 1.019 ± 0.011abc) | 1.017 ± 0.010abc) | |
| RD | 1.038 ± 0.010 | 1.030 ± 0.010 | 1.034 ± 0.014 | 1.040 ± 0.010d) | |
| UOsm (mOsm/kg H2O) | C | 1,051 ± 179 | 1,013 ± 270 | 1,068 ± 192 | 964 ± 272 |
| R | 1,018 ± 231 | 1,093 ± 199d) | 1,120 ± 132d) | 1,021 ± 210d) | |
| D | 996 ± 156 | 698 ± 240c) | 574 ± 231abc) | 510 ± 201abc) | |
| RD | 996 ± 203 | 732 ± 206 | 854 ± 331 | 1,054 ± 201d) | |
| POsm (mOsm/kg H2O) | C | 295.3 ± 5.4 | 294.4 ± 3.3 | 295.1 ± 5.2 | 294.6 ± 4.2 |
| R | 294.9 ± 4.7 | 291.8 ± 2.4 | 289.0 ± 3.2 | 289.0 ± 3.6 | |
| D | 294.2 ± 2.4 | 293.3 ± 2.2 | 290.6 ± 3.6 | 289.8 ± 3.1 | |
| RD | 292.7 ± 2.9 | 291.0 ± 2.3 | 292.1 ± 3.2 | 290.8 ± 3.7 | |
| CLOsm (ml/min/kg) | C | 0.056 (0.044, 0.066) | 0.064 (0.051, 0.093) | 0.060 (0.048, 0.090) | 0.070 (0.054, 0.083) |
| R | 0.052 (0.048, 0.071) | 0.055 (0.044, 0.066) | 0.056 (0.042, 0.099) | 0.063 (0.052, 0.106) | |
| D | 0.051 (0.041, 0.059) | 0.069 (0.044, 0.176) | 0.075 (0.047, 0.245)a) | 0.104 (0.057, 0.275)a) | |
| RD | 0.050 (0.042, 0.075) | 0.059 (0.045, 0.081) | 0.055 (0.042, 0.073) | 0.058 (0.048, 0.075) | |
| CLH2O (ml/min/kg) | C | –0.037 (−0.047, −0.034) | –0.046 (−0.058, −0.039) | –0.042 (−0.058, −0.036) | –0.044 (−0.054, −0.031) |
| R | –0.037 (−0.047, −0.037) | –0.041 (−0.047, −0.027) | –0.042 (−0.070, −0.031) | –0.048 (−0.066, −0.036) | |
| D | –0.034 (−0.041, −0.025) | –0.042 (−0.055, −0.025) | –0.030 (−0.055, −0.017) | –0.029 (−0.074, −0.010) | |
| RD | –0.036 (−0.049, −0.026) | –0.035 (−0.044, −0.020) | –0.037 (−0.050, 0.017) | –0.044 (−0.050, −0.035) | |
| GFR (ml/min/kg) | C | 3.39 (2.82, 4.12) | 2.84 (2.64, 4.27) | 3.06 (2.78, 4.39) | 3.19 (2.40, 5.52) |
| R | 3.56 (2.26, 4.42) | 3.18 (2.60, 3.79) | 2.90 (2.47, 4.50) | 3.14 (2.10, 3.54) | |
| D | 3.72 (2.63, 3.96) | 3.18 (2.48, 4.57) | 3.20 (2.65, 4.03) | 3.37 (2.43, 4.72) | |
| RD | 3.32 (2.73, 3.93) | 3.45 (2.75, 4.20) | 3.08 (2.63, 4.37) | 3.39 (3.09, 4.30) | |
| RBF (ml/min/kg) | C | 12.4 (9.6, 19.8) | 16.6 (10.6, 26.3) | 19.6 (11.4, 26.3) | 15.0 (11.0, 19.0) |
| R | 14.8 (7.4, 19.7) | 12.6 (8.6, 15.1) | 13.3 (10.3, 21.7) | 17.0 (11.7, 25.5) | |
| D | 11.7 (10.7, 19.8) | 16.3 (10.2, 26.8) | 18.0 (9.3, 19.7) | 19.4 (14.5, 29.6) | |
| RD | 12.0 (9.6, 15.9) | 19.7 (9.3, 24.8) | 19.5 (8.4, 22.6) | 14.1 (10.0, 25.6) | |
| FENa (%) | C | 0.32 (0.15, 0.48) | 0.77 (0.16, 0.98) | 0.38 (0.11, 1.58) | 0.67 (0.12, 1.43) |
| R | 0.27 (0.13, 0.41) | 0.21 (0.16, 0.30) | 0.25 (0.11, 0.42) | 0.32 (0.17, 0.88) | |
| D | 0.22 (0.16, 0.32) | 0.34 (0.14, 3.73) | 0.66 (0.24, 5.86)a) | 0.93 (0.28, 10.18)a) | |
| RD | 0.24 (0.15, 0.52) | 0.27 (0.16, 0.36) | 0.31 (0.10, 0.44) | 0.29 (0.17, 0.61) | |
| FEK (%) | C | 27.6 (22.3, 56.0) | 37.6 (28.4, 51.5) | 31.9 (15.4, 38.7) | 32.5 (9.2, 47.5) |
| R | 37.3 (18.9, 55.5) | 28.8 (16.5, 40.3) | 36.0 (12.5, 42.0) | 41.7 (17.9, 47.2) | |
| D | 27.9 (19.5, 41.0) | 38.1 (15.7, 74.4) | 33.7 (21.1, 44.4) | 43.4 (16.5, 69.6) | |
| RD | 33.5 (18.3, 57.2) | 27.3 (16.1, 32.5) | 26.6 (17.2, 57.1) | 28.6 (21.5, 44.8) | |
| FECl (%) | C | 0.66 (0.27, 0.95) | 0.92 (0.57, 1.30) | 0.58 (0.33, 1.97) | 0.89 (0.18, 1.92) |
| R | 0.54 (0.29, 1.40) | 0.48 (0.40, 0.76) | 0.54 (0.30, 1.50) | 0.86 (0.39, 2.28) | |
| D | 0.50 (0.25, 0.89) | 0.75 (0.16, 3.39) | 0.67 (0.51, 6.05) | 1.26 (0.32, 10.17) | |
| RD | 0.53 (0.28, 1.97) | 0.34 (0.20, 0.74)b) | 0.58 (0.088, 1.69) | 0.92 (0.48, 1.71) | |
UO, urine output; USG, urine specific gravity; UOsm, urine osmolality; POsm, plasma osmolality; CLOsm, osmolar clearance; CLH2O, free-water clearance; GFR, glomerular filtration rate; RBF, renal blood flow; FENa, fractional clearance of sodium; FEK, fractional clearance of potassium; FECl, fractional clearance of chloride. a) Significantly differ from respective baseline value (P<0.05); b) significantly differ from C treatment at this time point (P<0.05); c) significantly differ from R treatment at this time point (P<0.05); d) significantly differ from D treatment at this time point (P<0.05).