Table 3. Multiple regression analysis to evaluate the effect of SCD and PaCO 2 on systemic acid–base balance (arterial pH) .
| Variables | VIF | Estimated partial regression coefficients | 95% confidence interval | p -Value | |
|---|---|---|---|---|---|
| Lower limit | Upper limit | ||||
| SCD (mEq/L) | 1.05 | 8.408 × 10 −3 | 7.144 × 10 −3 | 9.671 × 10 −3 | < 0.001 |
| PaCO 2 (mm Hg) | 1.05 | −7.540 × 10 −3 | −8.021 × 10 −3 | −7.057 × 10 −3 | < 0.001 |
| Delivered pH equation Adjusted R2 | |||||
| pH = 7.469 + (8.408 × 10 −3 × SCD) − (7.540 × 10 −3 × PaCO 2 ) 0.82 | |||||
Abbreviations: PaCO 2 , partial pressure of carbon dioxide; SCD, sodium chloride ion difference; VIF, variance inflation factor.