A total of 140 patients were assessed for eligibility, and 124 subjects were enrolled in the study. The remaining 16 patients were excluded because either they did not meet the inclusion criteria (n=10) or they refused to participate (n=6). Thirty-one patients were allocated to each group. Due to protocol violation, 1 patient were excluded from group D2. Therefore, 31 patients in group D1, 30 patients in group D2, 31 patients in group D3, and 31 patients in group C were analyzed (Figure 1).
There were no significant differences of the demographics among the four groups (Table 1). Compared with group C, urine volume increased significantly in groups D2 and D3 (P=0.004 and 0.039, respectively), while other intraoperative data were similar among the four groups (Table 2).
3.1 Potassium and lactate
Compared with the basic serum potassium values, the concentrations at T11 increased significantly in groups D1, D2 and C (P=0.003, 0.002, and ˂0.001, respectively), while increased significantly at T7 (P=0.008), T10 (P=0.015) and T11 (P˂0.001) in group D3. Compared with group C, the serum potassium concentration in group D2 decreased significantly at T11 (P=0.032). Compared with group D2, the serum potassium concentration in group D3 increased significantly at T7 (P=0.036).
Compared with the basic serum lactate values, the concentrations decreased significantly at T6 in groups D2 and D3 (P=0.002 and 0.003, respectively). Compared with group D2, the serum lactate concentrations in group D3 decreased significantly at T10 (P=0.033) (Table 3).
3.2 Hemodynamic results
Repeated-measures analysis of variance revealed significant variation in HR and MAP over time within each group (Table 4, 5).
Compared with T1, HR decreased significantly at T2 (P=0.002), T3 (P=0.001), T4 (P ˂0.001), T5 (P ˂0.001), T6 (P=0.003) and T7 (P=0.033) in group D1, at T3 (P˂0.001), T4 (P˂0.001), T5 (P˂0.001), T6 (P˂0.001), T7 (P˂0.001), T8 (P=0.030), T9 (P=0.037) and T10 (P˂0.001) in group D2, at T2 (P=0.025), T3 (P=0.001), T4 (P˂0.001), T5 (P˂0.001), T6 (P˂0.001), T7 (P˂0.001), T8 (P=0.024), T9 (P=0.022) and T10 (P˂0.001) in group D3, and at T4 (P=0.023) in group C. Compared with group C, HR decreased significantly in group D2 at T5 (P=0.010), T7 (P=0.017), T8 (P=0.005), T9 (P=0.030) and T10 (P=0.011) and in group D3 at T5 (P=0.042), T7 (P=0.002), T8 (P=0.007), T9 (P=0.034) and T10 (P=0.019).
Compared with T1, MAP at T4 (P=0.002), T5 (P=0.007), T6 (P˂0.001), T7 (P˂0.001), T8 (P=0.047) and T9 (P=0.048) decreased significantly in group D1, at T10 (P=0.029) in group D2, and at T6 (P=0.006) and T10 (P=0.002) in group D3, while decreased significantly at T3 (P=0.007) and T6 (P=0.002) and increased significantly at T8 (P=0.015) in group C. Compared with group C, MAP increased significantly at T2 (P=0.040) and decreased significantly at T5 (P=0.045), T7 (P=0.018), T8 (P=0.001) and T9 (P=0.030) in group D1, decreased significantly at T8 (P=0.002), T9 (P=0.049) and T10 (P=0.037) in group D2, and at T8 (P=0.033) and T9 (P=0.013) in group D3.
3.3 Perioperative drug use
Significantly, less dosage of propofol was required (P=0.011) in group D2 as compared to Group C. Again, dose of remifentanil was significantly lower in groups D1, D2 and D3 (P=0.039, 0.004 and 0.042, respectively) than group C. More patients in group C received ephedrine to treat intraoperative hypotension (P=0.048) than the other groups.
3.4 Postoperative recovery indicators
The activity of plasma alanine aminotransferase (ALT) was significantly higher at T11 than T1 in all groups (P=0.030, ˂0.001, 0.005 and 0.011 in groups D1, D2, D3 and C, respectively), and plasma aspartate aminotransferase (AST) activities increased significantly at T11 than T1 in groups D2, D3 and C (P=0.037, 0.034 and 0.031, respectively). There was no significant difference in serum creatinine. Additionally, patients in group D1 had significantly higher blood urea nitrogen at T11 than T1 (P=0.014) (Table 6). There were no significant differences in length of hospital stay, intraperitoneal drainage volume and pulmonary infection incidence at 24 h postoperatively among the four groups.