Table 2.
Population PK parameters of imipenem in 51 ICU patients
| Basic model | Final model | ||||||
|---|---|---|---|---|---|---|---|
| Value | RSE (%) | Value | RSE (%) | P value* | Median of bootstrap† | 95% Confidence interval of bootstrap† | |
| Fixed effects | |||||||
| CL (l h−1) | 13.0 | 6 | 13.2 | 5 | – | 13.2 | 11.4–15.3 |
| βCrCL4h (log l h−1) | – | – | 0.2 | 19 | 6.4 × 10−5 | 0.25 | 0.1–0.4 |
| V1 (l) | 22.4 | 9 | 20.4 | 7 | – | 19.8 | 14.9–25.4 |
| βWeight (log l) | – | – | 1.3 | 17 | 1.3 × 10−4 | 1.2 | 0.6–2.2 |
| βSerum albumin (log l) | – | – | −1.1 | 18 | 1.8 × 10−4 | −1.0 | −1.8 to −0.5 |
| Q (l h−1) | 10.1 | 28 | 12.2 | 25 | – | 12.3 | 4.7–20.3 |
| V2 (l) | 9.9 | 14 | 9.8 | 13 | – | 10.5 | 6.9–13.7 |
| Between-subject variability | |||||||
| ωCL (%) | 48 | 10 | 38 | 13 | – | 36 | 26–49 |
| ωV1 (%) | 48 | 15 | 31 | 18 | – | 22 | 1–45 |
| Correlation | – | ||||||
|
0.48 | 29 | 0.51 | 28 | – | 0.79 | −1 to 1 |
| Residual variability | |||||||
| σ (%) | 33 | 4 | 33 | 3 | – | 34 | 26–41 |
| BIC | 1595 | – | 1560 | – | – | – | – |
Abbreviations are as follows: BIC, Bayesian information criterion; ICU, intensive care unit; PK, pharmacokinetics; RSE, relative standard error.
*
Likelihood ratio test;
†
from 1000 bootstrap resampling.
Final population PK covariate model is as follows:
.