Volume 17, Number 6—June 2011
Dispatch
High Vancomycin MIC and Complicated Methicillin-Susceptible Staphylococcus aureus Bacteremia
Table 2
Comparative analysis of 99 patients with complicated vs. noncomplicated MSSA bacteremia, Hospital 12 de Octubre, Madrid, Spain, January 2002–December 2004*
Variable | Noncomplicated MSSA, n = 71 | Complicated MSSA, n = 28 | p value |
---|---|---|---|
Mean age, y (SD) | 63.9 (17.4) | 62 (16) | 0.6 |
M/F, % | 69/31 | 60.7/39.3 | 0.8 |
Co-morbidity Charlson Index, mean (SD) |
2.92 (2.4) |
2.93 (3.5) |
0.9 |
Previous valvular prosthesis | 1 (1.4) | 2 (7.1) | 0.39 |
Other previous endovascular prosthesis | 4 (5.6) | 1 (3.6) | 0.9 |
Previous ostheoarticular prosthesis | 2 (2.8) | 1 (3.6) | 0.8 |
Previous renal failure requiring hemodyalisis |
8 (11.3) |
3 (10.7) |
0.8 |
Type of IV catheter as the source of bacteremia | |||
Peripheral line | 32 (45.1) | 11 (39.3) | 0.7 |
Transitory central catheter | 30 (42.2) | 14 (50) | 0.8 |
Permanent central catheter |
9 (12.7) |
3 (10.7) |
0.9 |
Vancomycin MIC for the first MSSA isolate, median (range) | 1.2 (0.5–1.7) | 1.5 (1.0–1.7) | <0.0001 |
Vancomycin MIC >1.5 µg/mL for the first MSSA isolate |
5 (7) |
18 (64.3) |
<0.0001 |
Initial treatment with glycopeptides | 41 (57.7) | 23 (82.1) | 0.042 |
Initial treatment with antistaphylococcal β-lactams† | 20 (28.2) | 5 (17.9) | 0.42 |
Initial treatment with non–β-lactam antistaphylococcal agents‡ | 7 (9.9) | 0 | 0.19 |
Delay in initiation of active antibiotic treatment, d,§ mean (SD) | 0.92 (1.3) | 1.07 (1) | 0.8 |
Delay >24 h at the start of effective antibiotics§ | 28 (39.4) | 14 (53.6) | 0.2 |
Duration of antibiotic treatment, d, mean (SD) |
12.77 (8) |
19.39 (11.4) |
0.002 |
Prompt IV catheter removal¶ | 58 (81.7) | 21 (75) | 0.65 |
Conservative IV catheter management# |
5 (7) |
1 (3.6) |
0.8 |
Development of severe sepsis/septic shock |
9 (12.7) |
7 (25) |
0.23 |
Days of follow-up, mean (SD) | 502 (441) | 462 (463) | 0.77 |
Crude 30-day death rate | 9 (12.7) | 5 (17.9) | 0.9 |
Attributable death rate | 3 (4.2) | 4 (14.3) | 0.18 |
*Values are no. (%) except as indicated. MSSA, methicillin-susceptible Staphylococcus aureus; IV, intravenous.
†Antistaphylococcal β-lactams refer to parenteral cloxacillin, cefazolin, amoxicillin-clavulanate, piperacillin-tazobactam, or imipenem/meropenem.
‡Including non–β-lactam antibiotics with in vitro activity against MSSA (mostly levofloxacin, moxifloxacin, or clindamycin).
§Delay since isolation of MSSA in blood cultures.
¶Removal of catheter in the first 48 h since isolation of MSSA in blood cultures.
#Catheter kept at least 7 days since isolation of MSSA in blood cultures.