Table 3.
Potential impact of multiplex PCR on antibiotic therapy
| Initial antibiotic therapy (after Gram stain results) | n | Appropriate changes | No change | Inappropriate changes | ||||
|---|---|---|---|---|---|---|---|---|
| Adequacy | De-escalation | Optimization | Inadequacy | Escalation | De-optimization | |||
| Carbapenem + others | 17 | 0 | 10 | 0 | 6 | 1 | 0 | 0 |
| Piperacillin-tazobactam ± aminoglycosides | 27 | 2 | 15 | 3 | 7 | 0 | 0 | 0 |
| Fourth-generation cephalosporin ± aminoglycosides | 16 | 1 | 7 | 0 | 6 | 0 | 0 | 2 |
| Third-generation cephalosporin ± aminoglycosides | 11 | 5 | 2 | 0 | 4 | 0 | 0 | 0 |
| Amoxicillin-clavulanate | 5 | 0 | 1 | 0 | 4 | 0 | 0 | 0 |
| Others* | 5 | 2 | 2 | 0 | 1 | 0 | 0 | 0 |
| No treatment | 14 | 10 | 0 | 0 | 4 | 0 | 0 | 0 |
| Total (%) | 95 | 20 (21) | 37 (39) | 3 (3) | 32 (34) | 1 (1) | 0 | 2 (2) |
Only bacteria that were superior to diagnostic thresholds (104 CFU/ml for BAL and 103 CFU/ml for PTC) were considered
*Others included cefazolin switched to piperacillin-tazobactam (adequacy), addition of levofloxacin + rifampicin for a L. pneumophila (adequacy), colistin switched to cefotaxime (de-escalation), vancomycin switched to oxacillin (de-escalation), unchanged cefazolin