ABSTRACT
Background: Amikacin monotherapy is recommended for urinary tract infection (UTI) treatment with multi-resistant pathogens. Even though amikacin efficacy in the treatment of UTIs is dependent on its urinary concentration, there are no robust data proving that sufficiently high urinary concentration is reached in patients with reduced glomerular filtration rate (GFR). Methods: A prospective study to monitor amikacin penetration into urine of 70 patients [40 males, median (interquartile range) age 70 (65-79) years] with different levels of glomerular filtration decline, including patients treated by dialysis, was conducted. The bactericidal efficacy of amikacin in urine samples has been evaluated. Results: Patients with estimated GFR (eGFR) <30 mL/min had significantly lower median amikacin urinary concentration than patients with eGFR >30 mL/min (89.75 vs 186.0 mg/L, P < .0001; 200.5 vs 830.0 mg/L, P < .0001; and 126.0 vs 408.0 mg/L, P < .0001 for minimal, maximal and minimal together with maximal concentrations, respectively). The amount of amikacin eliminated in the first 10-13 h after dose administration was dependent on eGFR (r2 = 0.6144, P < .0001). The urinary concentration of amikacin in patients treated by dialysis was indirectly proportional to pH of urine. The plasma concentrations of amikacin did not correlate with urinary levels in patients in either of the GFR categories. Microbiological evaluation showed that the critical urinary concentration for efficacy of amikacin during UTI monotherapy in patients treated by dialysis is 100 mg/L. We found that 4 out of 11 patients treated by dialysis did not reach this level during the treatment. Conclusion: Systemic administration of amikacin monotherapy in patients treated by dialysis is questionable as the concentrations of amikacin in their urine are often below the threshold of effectivity. Amikacin plasma concentrations are not a major determinant of amikacin concentration in urine, therefore pulse dosing is neither necessary nor safe in patients treated by dialysis, and may cause undesirable toxicity.
ABSTRACT
The natural course of as-yet-untreated ANCA-associated vasculitis (AAV) or complications of immunosuppressive treatment may result in rapid clinical deterioration with the need of admission to an intensive care unit (ICU). The aim of this retrospective study was to assess the outcome of patients with renal AAV admitted to the ICU in a single center. We reviewed the medical records of all 218 patients with AAV followed in our department between January 2001 and December 2006 and selected those admitted to the ICU. To assess the severity of critical illness, the Acute Physiology and Chronic Health Evaluation (APACHE II) and Sequential Organ Failure Assessment (SOFA) score on the first ICU day were calculated. Birmingham Vasculitis Activity Score (BVAS) was calculated to represent the total disease activity. Thirty patients with AAV (11 women, 19 men; mean age 61.5 +/- 13.2 years; 20 x cANCA, 10 x pANCA positive) were included. The most common reasons for ICU admission were as follows: active vasculitis (13 patients, 43.3 %), infections (7 patients, 23.3%), and other causes (10 patients, 33.3%). The in-ICU mortality was 33.3% (10 patients). The most common cause of death was septic shock (in 5 patients). The APACHE II (33.5 vs. 23.8) and SOFA scores (11.9 vs. 6.6), but not BVAS (11.5 vs. 16.1), were statistically significantly higher in non-survivors than in survivors (p < 0.01). In conclusion, the in-ICU mortality in AAV patients may be predicted by APACHE II and SOFA scores. While active vasculitis is the most frequent reason for ICU admission, the mortality rate is highest in patients with infectious complications.
