Table 2.
Group-level differences in sociodemographic and treatment characteristics
| Characteristics | PS (N = 23) Mean (SD) |
MS (N = 27) Mean (SD) |
MK (N = 24) Mean (SD) |
PK (N = 30) Mean (SD) |
p-value | |
|---|---|---|---|---|---|---|
| Preoperative | Age (year) | 60.78 (11.33) | 54.63 (12.75) | 58.04 (13.54) | 52.83 (12.12) | 0.11 |
| Height (cm) | 169.3 (9.22) | 167.07 (10.46) | 166.0 (9.38) | 167.73 (8.18) | 0.698 | |
| Weight (kg) | 75.27 (13.02) | 69.77 (14.07) | 68.5 (10.76) | 71.96 (11.86) | 0.309 | |
| Postoperative | ICU stay (day) | 1.74 (1.10) | 1.67 (2.06) | 1.71 (1.12) | 2.30 (2.73) | 0.572 |
| Ward stay (day) | 6.65 (2.89) | 6.04 (3.07) | 6.62 (5.66) | 5.6 (2.03) | 0.661 | |
| Total stay (day) | 8.39 (2.93) | 7.70 (2.32) | 8.33 (5.36) | 7.90 (3.38) | 0.886 | |
| Start of oral feeding (day) | 3.14 (1.15) | 3.41 (1.40) | 3.00 (0.89) | 2.70 (1.10) | 0.199 | |
| Ambulation (day) | 2.15 (0.81) | 2.52 (1.12) | 2.16 (0.50) | 2.46 (2.71) | 0.826 | |
| Intraoperative | Duration (min) | 220.24 (77.14) | 177.63 (53.68) | 202.88 (51.48) | 234.83 (77.56) | 0.033 |
| Mean MAP (mmHg) | 98.90 (11.30) | 100.74 (11.11) | 93.57 (14.28) | 94.60 (14.28) | 0.224 | |
| Maximum MAP (mmHg) | 122.85 (16.83) | 122.47 (12.88) | 117.43 (20.24) | 116.79 (18.01) | 0.515 | |
| Minimum MAP (mmHg) | 75.90 (11.54) | 81.32 (12.53) | 74.76 (13.83) | 78.50 (17.08) | 0.477 | |
| Surgery BIS | 49.86 (3.69) | 48.84 (4.19) | 50.50 (5.12) | 49.60 (4.41) | 0.675 | |
| Blood loss (cc) | 171.43 (116.80) | 124.74 (88.90) | 147.50 (58.48) | 174.67 (91.04) | 0.231 | |
| Urine output (cc) | 466.71 (314.30) | 436.84 (229.64) | 600.00 (558.20) | 436.28 (228.56) | 0.351 | |
| Preoperative MOCA | Total (out of 30) | 18.57 (7.55) | 19.59 (6.68) | 19.00 (7.44) | 22.9 (5.75) | 0.085 |
| Visuospatial (out of 5) | 2.39 (1.78) | 2.52 (1.81) | 2.21 (1.91) | 3.34 (1.78) | 0.106 | |
| Naming (out of 3) | 2.26 (0.81) | 2.48 (0.89) | 2.25 (0.94) | 2.52 (0.63) | 0.517 | |
| Attention (out of 6) | 3.91 (2.45) | 4.00 (1.80) | 4.12 (1.96) | 4.79 (1.37) | 0.307 | |
| Language (out of 3) | 1.30 (1.18) | 1.41 (1.15) | 1.21 (1.25) | 1.86 (1.16) | 0.645 | |
| Abstraction (out of 2) | 0.87 (0.87) | 0.96 (0.94) | 0.96 (1.00) | 1.45 (0.83) | 0.083 | |
| Memory (out of 5) | 2.35 (1.58) | 2.81 (1.62) | 2.83 (1.55) | 3.07 (1.67) | 0.456 | |
| Orientation (out of 6) | 5.22 (1.31) | 5.40 (1.12) | 5.46 (1.06) | 5.86 (0.58) | 0.144 | |
| Surgery night | CAM-ICU-7 | 1.74 (2.36) | 1.89 (1.87) | 1.42 (1.84) | 1.57 (1.98) | 0.849 |
| RASS | − 0.7 (1.15) | − 0.89 (0.93) | − 0.54 (0.83) | − 0.73 (0.91) | 0.638 | |
| VAS | 2.77 (3.10) | 5.52 (3.98) | 4.62 (3.28) | 6.00 (3.79) | 0.012 | |
| 1 st day | CAM-ICU-7 | 0.43 (1.34) | 0.81 (1.49) | 0.67 (1.24) | 0.97 (1.27) | 0.534 |
| RASS | − 0.04 (0.47) | − 0.26 (0.59) | − 0.12 (0.34) | − 0.37 (0.67) | 0.151 | |
| VAS | 5.83 (3.24) | 5.46 (3.05) | 4.21 (3.6) | 5.13 (3.10) | 0.358 | |
| 1 st night | CAM-ICU-7 | 0.91 (1.86) | 0.63 (1.45) | 0.58 (0.97) | 0.4 (0.93) | 0.584 |
| RASS | − 0.39 (0.84) | − 0.26 (0.66) | − 0.08 (0.50) | − 0.17 (0.59) | 0.407 | |
| VAS | 3.78 (2.95) | 5.33 (3.22) | 4.29 (3.38) | 4.77 (3.01) | 0.348 | |
| 2nd day | CAM-ICU-7 | 0.52 (1.41) | 0.3 (0.91) | 0.5 (1.22) | 0.47 (0.90) | 0.881 |
| RASS | − 0.08 (0.51) | − 0.14 (0.36) | − 0.08 (0.28) | − 0.20 (0.40) | 0.668 | |
| VAS | 3.57 (2.90) | 4.37 (2.99) | 3.5 (2.83) | 4.07 (3.13) | 0.685 | |
| 2nd night | CAM-ICU-7 | 0.43 (1.34) | 0.26 (0.94) | 0.17 (0.56) | 0.2 (0.61) | 0.739 |
| RASS | 0.39 (1.90) | − 0.07 (0.38) | − 0.04 (0.20) | − 0.1 (0.31) | 0.218 | |
| VAS | 2.61 (2.08) | 3.26 (3.15) | 3.67 (2.97) | 3.43 (2.67) | 0.592 | |
| 3rd day | CAM-ICU-7 | 0.22 (1.04) | 0.48 (0.98) | 0.21 (0.72) | 0.23 (0.97) | 0.671 |
| RASS | − 0.09 (0.42) | − 0.22 (0.51) | − 0.04 (0.20) | − 0.07 (0.25) | 0.279 | |
| VAS | 3.17 (2.76) | 3.85 (3.03) | 3.08 (3.20) | 3.20 (2.71) | 0.764 | |
| 3rd night | CAM-ICU-7 | 0.17 (0.83) | 0.33 (0.83) | 0.17 (0.64) | 0.24 (0.74) | 0.853 |
| RASS | − 0.04 (0.21) | − 0.07 (0.38) | − 0.08 (0.41) | − 0.1 (0.31) | 0.937 | |
| VAS | 3.17 (2.62) | 3.48 (2.61) | 3.58 (3.11) | 3.59 (3.21) | 0.956 | |
| 4th day | CAM-ICU-7 | 0.39 (1.49) | 0.03 (0.19) | 0.16 (0.48) | 0.27 (1.16) | 0.609 |
| RASS | 0.17 (1.15) | 0.0 (0.0) | − 0.04 (0.2) | − 0.07 (0.26) | 0.450 | |
| VAS | 2.47 (2.74) | 2.62 (2.80) | 2.83 (2.46) | 2.55 (2.55) | 0.970 | |
| 4th night | CAM-ICU-7 | 0.17 (0.83) | 0.0 (0.0) | 0.08 (0.41) | 0.28 (1.16) | 0.569 |
| RASS | − 0.09 (0.42) | 0.0 (0.0) | − 0.04 (0.2) | − 0.07 (0.26) | 0.649 | |
| VAS | 3.35 (3.13) | 3.11 (2.42) | 3.04 (2.48) | 1.59 (1.92) | 0.041 | |
PS, placebo-saline; MS, melatonin-saline; MK, melatonin-ketamine; PK, placebo-saline; SD, standard deviation; ICU, intensive care unit; MAP, mean arterial pressure; BIS, bispectral index score; MoCA, Montreal Cognitive Assessment; CAM, Confusion Assessment Method; RASS, Richmond Agitation Sedation Scale; VAS, visual analogue scale