TABLE 1.
Baseline characteristics of the cohort
| Characteristica | Standard infusion (n = 160) | Extended infusion (n = 160) | P value |
|---|---|---|---|
| Age (mean ± SD) (yr) | 53.8 ± 17.4 | 55.8 ± 16.5 | 0.30 |
| Women | 73 (46) | 77 (48) | 0.66 |
| African-American | 97 (61) | 107 (67) | 0.11 |
| Admission source | <0.01 | ||
| Home | 149 (93) | 130 (81) | |
| Nursing home | 7 (4) | 27 (17) | |
| Other hospital | 4 (3) | 3 (2) | |
| Ht (mean ± SD) (cm) | 170 ± 11 | 171 ± 11 | 0.38 |
| Wt (median [IQR]) (kg) | 79.3 (63.6–97.6) | 78.4 (69.0–95.0) | 0.87 |
| BMI (median [IQR]) (kg/m2) | 26.7 (22.3–33.0) | 26.8 (22.8–31.6) | 0.88 |
| Comorbid conditions | |||
| Peripheral vascular disease | 24 (15) | 8 (5) | <0.01 |
| Chronic pulmonary disease | 45 (28) | 52 (33) | 0.40 |
| Diabetes mellitus | 50 (31) | 30 (19) | 0.01 |
| Charlson comorbidity index (median [IQR]) | 1 (0–3) | 1 (0–2.5) | 0.59 |
| Hospital and infection-related variables | |||
| No sepsis | 29 (18) | 27 (17) | 0.95 |
| Sepsis | 88 (55) | 90 (56) | |
| Severe sepsis | 31 (19) | 33 (21) | |
| Septic shock | 12 (8) | 10 (6) | |
| ICU stay | 34 (21) | 33 (21) | 0.89 |
| Mechanical ventilation | 24 (15) | 25 (16) | 0.88 |
| WBC count at start day of combination therapy (median [IQR]) | 10.6 (7.2–14.4) | 11.6 (8.0–15.5) | 0.14 |
| Baseline creatinine (mean ± SD) (mg/dl) | 0.88 ± 0.21 | 0.84 ± 0.23 | |
| Length of stay before combination therapy (median [IQR]) (days) | 1.0 (1.0–3.5) | 1.0 (1.0–3.0) | 0.14 |
| Infection type and diagnosis | |||
| Physician diagnosis with positive culture | 57 (36) | 49 (31) | 0.34 |
| Pneumonia | 4 (3) | 11 (7) | 0.07 |
| Endocarditis | 4 (3) | 1 (1) | 0.21 |
| Intra-abdominal infection | 5 (3) | 4 (3) | 0.73 |
| Skin/soft tissue infection | 25 (16) | 15 (9) | 0.10 |
| Bone/joint infection | 15 (9) | 7 (4) | 0.09 |
| Urinary tract infection | 1 (1) | 7 (4) | 0.06 |
| Catheter-associated infection | 1 (1) | 2 (1) | 0.57 |
| Other/unknown | 2 (1) | 2 (1) | 1.00 |
| Bacteremia | 18 (11) | 12 (8) | 0.25 |
| Polymicrobial infection | 27 (17) | 19 (12) | 0.27 |
| Pathogens | |||
| Gram-positive bacteria | 45 (28) | 30 (19) | 0.04 |
| Gram-negative bacteria | 21 (13) | 26 (16) | 0.43 |
| MRSA | 8 (5) | 12 (8) | 0.35 |
| MSSA | 14 (9) | 4 (3) | 0.02 |
| Nephrotoxic agent | |||
| No. of nephrotoxins (mean ± SD) | 0.96 ± 0.96 | 0.94 ± 0.90 | 0.81 |
| No. (%) of nephrotoxins | |||
| 0 | 64 (40) | 61 (38) | 0.91 |
| 1 | 49 (31) | 56 (35) | |
| 2 | 38 (24) | 36 (23) | |
| 3 | 7 (4) | 6 (4) | |
| 4 | 2 (1) | 1 (1) | |
| Vasopressors | 10 (6) | 10 (6) | 1.00 |
| Aminoglycoside | 12 (8) | 6 (4) | 0.15 |
| Colistin | 3 (2) | 1 (1) | 0.33 |
| ACEI/ARB | 42 (26) | 40 (25) | 0.79 |
| Diuretics | 42 (26) | 48 (30) | 0.45 |
| Contrast | 45 (28) | 45 (28) | 1.00 |
| Any nephrotoxins | 96 (60) | 99 (62) | 0.73 |
| Vancomycin administration | |||
| Loading doses given (n [%]) | 135 (84) | 134 (84) | 0.87 |
| Loading dose (mg/day) (mean ± SD) | 1,968 ± 498 | 1,896 ± 431 | 0.20 |
| First maintenance dose (mg/day)(mean ± SD) | 3,092 ± 1,409 | 2,945 ± 1,267 | 0.25 |
| Median trough concn (mg/liter [IQR]) (n) | 18.1 (14.1–22.9) (138) | 17.5 (13.1–21.9) (135) | 0.36 |
| Duration of combination therapy (median [IQR]) (days) | 4.0 (3.0–6.0) | 4.0 (3.0–6.0) | 0.89 |
a
IQR, interquartile range; BMI, body mass index; ICU, intensive care unit; WBC, white blood cell; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible S. aureus; ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin II receptor blocker. Unless otherwise indicated, data are presented as no. (%).