TABLE 2.
Bivariate analysis of predictors for acute kidney injury in the total population who received vancomycin and piperacillin-tazobactam combination therapya
| Variableb | Non-AKI (n = 215) | AKI (n = 105) | P value |
|---|---|---|---|
| Age (mean ± SD) (yr) | 56.4 ± 16.6 | 51.6 ± 17.4 | 0.02 |
| Women | 97 (45.1) | 53 (50.5) | 0.40 |
| Race | |||
| White | 76 (35.4) | 27 (25.7) | 0.08 |
| Black | 133 (61.9) | 71 (67.6) | |
| Other | 6 (2.8) | 7 (6.7) | |
| Admission source | |||
| Home | 185 (86.1) | 94 (89.5) | 0.68 |
| Nursing home | 25 (11.6) | 9 (8.6) | |
| Other hospital | 5 (2.3) | 2 (1.9) | |
| Ht (mean ± SD) (cm) | 171.3 ± 11.2 | 170.1 ± 11.5 | 0.36 |
| Wt (median [IQR]) (kg) | 79.4 (66.0–95.0) | 79.0 (66.0–97.0) | 0.62 |
| BMI (median [IQR]) (kg/m2) | 26.9 (22.4–32.4) | 26.8 (23.0–32.9) | 0.42 |
| Comorbid conditions | |||
| AIDS | 3 (1.4) | 0 (0) | 0.55 |
| Myocardial infarction | 13 (6.1) | 2 (1.9) | 0.16 |
| Congestive heart failure | 28 (13.0) | 9 (8.6) | 0.27 |
| Peripheral vascular disease | 24 (11.2) | 8 (7.6) | 0.43 |
| Dementia | 18 (8.4) | 7 (6.7) | 0.66 |
| Chronic pulmonary disease | 66 (30.7) | 31 (29.5) | 0.90 |
| Connective tissue disease | 8 (3.7) | 4 (3.8) | 1.00 |
| Peptic ulcer disease | 3 (1.4) | 0 (0) | 0.55 |
| Chronic kidney disease | 5 (2.3) | 1 (1.0) | 0.67 |
| Leukemia | 2 (0.9) | 1 (1.0) | 1.00 |
| Lymphoma | 1 (0.5) | 0 (0) | 1.00 |
| Malignant solid tumor | 29 (13.5) | 14 (13.3) | 1.00 |
| Cerebrovascular disease | 20 (9.3) | 11 (10.5) | 0.84 |
| Liver disease | 11 (5.1) | 6 (5.7) | 0.80 |
| Diabetes mellitus | 57 (26.5) | 23 (21.9) | 0.41 |
| Hypertension | 125 (58.1) | 44 (41.9) | 0.01 |
| Charlson comorbidity index (median [IQR]) | 1.0 (0.0–3.0) | 1.0 (0.0–2.0) | 0.09 |
| Score >0 | 155 (72.1) | 64 (61.0) | 0.055 |
| Hospital and infection-related variables | |||
| No sepsis | 43 (20.0) | 13 (12.4) | 0.15 |
| Sepsis | 117 (54.4) | 61 (58.1) | |
| Severe sepsis | 38 (17.7) | 26 (24.8) | |
| Septic shock | 17 (7.9) | 5 (4.8) | |
| Any sepsis | 172 (80.0) | 92 (87.6) | 0.12 |
| Severe sepsis/septic shock | 55 (25.6) | 31 (29.5) | 0.50 |
| ICU stay | 47 (21.9) | 20 (19.1) | 0.66 |
| Mechanical ventilation | 34 (15.8) | 15 (14.3) | 0.87 |
| Length of stay before combination therapy (median [IQR]) (days) | 1.0 (1.0–3.0) | 1.0 (1.0–4.0) | 0.09 |
| Infection type and diagnosis | |||
| Physician diagnosis in combination with positive culture | 63 (29.3) | 43 (41.0) | 0.04 |
| Pneumonia | 8 (3.7) | 7 (6.7) | 0.27 |
| Endocarditis | 2 (0.9) | 3 (2.9) | 0.34 |
| Intra-abdominal infection | 6 (2.8) | 3 (2.9) | 1.00 |
| Skin/soft tissue infection | 27 (12.6) | 13 (12.4) | 1.00 |
| Bone/joint infection | 11 (5.1) | 11 (10.5) | 0.10 |
| Urinary tract infection | 6 (2.8) | 2 (1.9) | 1.00 |
| Catheter-associated infection | 2 (0.9) | 1 (1.0) | 1.00 |
| Other/unknown | 1 (0.5) | 3 (2.9) | 0.11 |
| Invasive infectionc | 21 (9.8) | 21 (20.0) | 0.01 |
| Bacteremia | 17 (7.9) | 13 (12.4) | 0.22 |
| Polymicrobial infection | 27 (12.6) | 19 (18.1) | 0.23 |
| Gram-positive bacteria | 41 (19.1) | 34 (32.4) | 0.01 |
| MRSA | 10 (4.7) | 10 (9.5) | 0.14 |
| MSSA | 10 (4.7) | 8 (7.6) | 0.31 |
| Gram-negative bacteria | 31 (14.4) | 16 (15.2) | 0.87 |
| Pseudomonas aeruginosa | 11 (5.1) | 3 (2.9) | 0.56 |
| Enterobacteriaceae | 18 (8.4) | 8 (7.6) | 1.00 |
| Any nephrotoxins | 120 (55.8) | 75 (71.4) | 0.007 |
| Vasopressors | 17 (7.9) | 3 (2.9) | 0.09 |
| Aminoglycoside | 10 (4.7) | 8 (7.6) | 0.31 |
| Colistin | 2 (0.9) | 2 (1.9) | 0.60 |
| ACEI/ARB | 57 (26.5) | 25 (23.8) | 0.68 |
| Diuretics | 54 (25.1) | 36 (34.3) | 0.11 |
| Contrast | 54 (25.1) | 36 (34.3) | 0.11 |
| Vancomycin administration | |||
| Loading doses given (n [%]) | 176 (81.9) | 93 (88.6) | 0.14 |
| Loading dose (mg/day) (mean ± SD) | 1,932.2 ± 477.1 | 1,933.5 ± 449.3 | 0.98 |
| Mean first maintenance dose (mg/day) (mean ± SD) | 2,992.6 ± 1,285.0 | 3,071.4 ± 1,451.0 | 0.64 |
| Median trough concnd (mg/liter [IQR]) | 17.1 (12.4–21.3) | 17.9 (13.7–23.2) | 0.07 |
| No. (%) of patients with median trough concn (mg/liter) of: | |||
| 0–10 | 24 (11.2) | 5 (4.8) | |
| 10–15 | 37 (17.2) | 23 (21.9) | 0.05 |
| 15–20 | 55 (25.6) | 17 (16.2) | 0.49 |
| >20 | 58 (27.0) | 16 (15.2) | 0.62 |
All cases received vancomycin and piperacillin-tazobactam as empirical therapy. The criteria for AKI were those for RIFLE.
IQR, interquartile range; BMI, body mass index; ICU, intensive care unit; 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. (%).
Combination of pneumonia, bone/joint infection, and/or endocarditis.
Vancomycin troughs were only considered if they were obtained prior to AKI development. Patients without vancomycin troughs obtained at all during treatment (n = 47 [15%], 41 [19%] patients in the non-AKI group, and 6 [6%] patients in the AKI group) and those who had no troughs obtained prior to AKI (n = 38, all in AKI group [36% of patients in AKI group]) were excluded from trough analyses.