Table 2 Summary of differences in serum biochemistry between non-buffered and buffered fluid groups
Outcomes | Absolute effects | No. of participants (studies) | p | |
|---|---|---|---|---|
Outcome with non-buffered fluid (mean) | Outcome with buffered fluid (mean; mean difference with 95% CI) | |||
PaCO2 | 35.0 mmHg | 34.9 mmHg (MD 1 mmHg higher; 95% CI 0.15 to 1.94) | 446 (7 RCTs) | 0.02 |
Postoperative pH | 7.32 | 7.38 (MD 0.05 units higher; 95% CI 0.04 to 0.07) | 720 (12 RCTs) | < 0.0001 |
Base excess | − 5.0 | − 1.65 (MD 3.5 units higher; 95% CI 2.6 to 4.4) | 459 (9 RCTs) | < 0.0001 |
Serum bicarbonate | 18.6 mmol/L | 21.6 mmol/L (MD 3.14 mmol/L; 95% CI 2.3 to 4.0) | 478 (8 RCTs) | < 0.0001 |
Serum sodium—postoperative | 139.4 mmol/L | 137.3 mmol/L (MD 0.52 mmol/ L higher; 95% CI − 2.8 to − 1.7) | 447 (8 RCTs) | < 0.0001 |
Serum sodium—postoperative day 1 | 141.8 mmol/L | 140.6 mmol/L (MD 0.52 mmol/ L higher; 95% CI − 2.8 to −1.7) | 91 (2 RCTs) | 0.07 |
Serum potassium | 4.22 mmol/L | 4.13 mmol/L (MD 0.04 mmol/ L lower; 95% CI − 0.14 to 0.06) | 459 (7 RCTs) | 0.43 |
Serum chloride—postoperative | 114.3 mmol/L | 107.5 mmol/L (MD 6.77 mmol/ L lower; 95% CI − 3.38 to −10.17) | 530 (10 RCTs) | 0.0001 |
Serum chloride—postoperative day 1 | 114.4 mmol/L | 105.7 mmol/L (MD 8.48 mmol/ L lower; 95% CI − 15.88 to −1.08) | 258 (5 RCTs) | 0.02 |
Serum glucose | 6.0 mmol/L | 6.0 mmol/L (MD no difference; 95% CI − 0.29 to 0.29) | 145 (3 RCTs) | 0.99 |
Serum lactate | 1.6 mmol/L | 2.3 mmol/L (MD 0.52 mmol/ L higher; 95% CI − 0.04 to 1.1) | 199 (4 RCTs) | 0.067 |
Serum calcium | 1.6 mmol/L | 2.0 mmol/L | 47 (1 RCT) | 0.0001 |