Vancomycin pharmacokinetics during high-volume continuous venovenous hemofiltration in critically ill septic patients.

AIMS: To assess the influence of continuous venovenous hemofiltration (CVVH) at a filtration rate of 45 mL/kg/h on vancomycin pharmacokinetics in critically ill septic patients with acute kidney injury (AKI). METHODS: Seventeen adult septic patients with acute kidney injury treated with CVVH and vancomycin were included. All patients received first dose of 1.0 g intravenously followed by 1.0 g/12 h if not adjusted. In sixteen patients vancomycin was introduced on the day of the start of CRRT therapy. Blood samples and ultrafiltrates were obtained before and 0.5, 1, 6 and 12 h after vancomycin administration. RESULTS: On the first day, the median total vancomycin clearance (Cltot) was 0.89 mL/min/kg (range 0.31 - 2.16). CRRT clearance accounted for around 50-60% of the total clearance of vancomycin found in a population with normal renal function (0.97 mL/min/kg). Vancomycin serum concentrations after the first dose were below the required target of 10 mg/L as early as 6 h in 10 patients, AUC0-24/MIC ≥ 400 ratio was achieved in 10 patients on the first day. CONCLUSIONS: CVVH at a filtration rate of 45 mL/kg/h leads to high and rapid extracorporeal removal of vancomycin in critically ill patients. Due to the rapid change in patient clinical status it was impossible to predict a fixed dosage regimen. We recommend blood sampling as early as 6 h after first vancomycin dose with maintenance dose based on vancomycin serum level monitoring.

Vancomycin removal during low-flux and high-flux extended daily hemodialysis in critically ill septic patients.

AIMS: To determine the extent of vancomycin removal and vancomycin pharmacokinetics in septic patients with AKI using daily hemodialysis with polysulphone high-flux and low-flux membrane. METHODS: Five patients received 6 h daily dialysis with low-flux polysulphone membrane, four patients with high-flux polysulphone membrane. Vancomycin was administered over the last hour of dialysis. The maintenance dose was adjusted based on pre-hemodialysis serum concentrations. Patients were followed up for two days. RESULTS: Median percentage of vancomycin removal by low-flux membrane dialysis was 17% (8-38%) and by high-flux membrane dialysis was 31% (13-43%). Vancomycin clearance was only moderately higher in high-flux membrane dialysis (median 3.01 L/h, range 2.34-3.5 L/h) compared to low-flux dialysis (median 2.48 L/h, range 0.53-5.68 L/h) in the first day of the study. About two-fold higher vancomycin clearance in high-flux dialysis (median 3.62 L/h, range 1.37-5.07 L/h) was observed on the second day of the study than low-flux dialysis (median 1.74 L/h, range 0.75-30.94 L/h). CONCLUSIONS: Both high-flux and low-flux membrane dialysis remove considerable amounts of vancomycin in critically ill septic patients with AKI. Application of vancomycin after each dialysis was required to maintain therapeutic concentrations.

Gentamicin pharmacokinetics during continuous venovenous hemofiltration in critically ill septic patients.

OBJECTIVE: Current dosing recommendations for administration of gentamicin to septic patients with acute kidney injury (AKI) on continuous venovenous hemofiltration (CVVH) at a filtration rate of 45 ml/kg/h are missing. AIM: To describe gentamicin pharmacokinetics and to find an optimal dosing regimen in patients on CVVH. METHODS: Seven adult patients were included. Patients received loading dose of 240 mg followed by application of maintenance dose every 24 hours. Maintenance dose was adjusted according to gentamicin C(max)/MIC ratio and drug levels simulation using a pharmacokinetic programme. RESULTS: Median total clearance (0.59-0.79 ml/min/kg) was similar to patients with normal renal function; median volume of distribution was higher than observed in non-septic patients (about 0.5 l/kg versus 0.25 l/kg). Patients with diuresis required an increase of gentamicin dose to reach C(max)/MIC ratio. CONCLUSION: Septic patients with AKI on CVVH (45 ml/kg/h) require a loading dose of 240 mg, followed by therapeutic drug monitoring to optimize maintenance dose.

Improvement of cardiovascular risk factors and cosmetic side effects in kidney transplant recipients after conversion to tacrolimus.

AIMS: Tacrolimus and Cyclosporine A (CyA) are cornerstones in immunosuppressive therapy. Cyclosporine side eff ects include hypertension and hypercholesterolemia both of which may increase the risk of cardiovascular mortality, gingival hyperplasia and hirsutism are known to reduce quality of life. The aim of this prospective study was to evaluate changes in cardiovascular risk profile and cosmetic side eff ects after conversion from CyA to tacrolimus. METHODS: 25 stable kidney transplant recipients (9 male, 16 female) were converted from a CyA to a tacrolimus--based regimen. Mean age was 45.7 +/- 13.5 years. Time to switch following transplantation was 4.7+/-1.7 years. Reasons for conversion were multiple: arterial hypertension (9), hypertrichosis (3), gingival hyperplasia (3), hyperlipidemia (14). RESULTS: 19/25 patients completed the one year study period. One patient died, two returned to hemodialysis, two were switched back to CyA and one patient was lost to follow-up. There were statistically significant changes (p = < 0.05) in systolic and diastolic pressure and antihypertensive medication could be reduced in 13 patients. The dose of lipid-lowering agents could be reduced in the majority of the recipients and a complete withdrawal was achieved in 7 patients. Hypertrichosis and gingival hyperplasia resolved in all patients. Further, there was a significant improvement (p = <0.05) in urea and serum creatinine levels. Adverse events were consistent with the established safety profile for tacrolimus. CONCLUSIONS: Conversion to a tacrolimus-based regimen led to an improvement in the cardiovascular risk profile. Further, cosmetic side eff ects which may lead to non-compliance, resolved after the switch.

Ghrelin variants influence development of body mass index and plasma levels of total cholesterol in dialyzed patients.

BACKGROUND: Ghrelin is an endogenous hormone expressed predominantly in the stomach. Ghrelin controls growth hormone secretion and also affects the body's energy balance. We analyzed the association of ghrelin variants with body mass index (BMI), albumin as a marker of malnutrition and plasma lipids as risk factors for atherosclerosis in hemodialyzed patients, in whom malnutrition and accelerated atherosclerosis are common complications. METHODS: Ghrelin variants Arg51>Gln and Leu72> Met were analyzed by PCR-RFLP in 210 hemodialyzed patients, prospectively followed up for 15 months. Changes in body mass index, triglycerides, total cholesterol and albumin over time (after 3, 6, 9, 12 and 15 months of dialysis) were analyzed in subgroups divided according to ghrelin genotypes. RESULTS: Carriers of at least one of the Gln51 and Met72 alleles lost body weight more quickly than Arg51Arg/Leu72Leu homozygotes (p<0.01). Carriers of the Gln51 allele were at higher risk of developing high cholesterol levels (p<0.01). CONCLUSIONS: Common ghrelin variants may have an effect on changes in biochemical and anthropometric parameters in hemodialyzed patients over time and could be used in the future to plan individualized therapy.

Endogenous erythropoietin levels and anemia in long-term renal transplant recipients.

BACKGROUND/AIM: Although anemia is a common complication after renal transplantation (RT), data concerning endogenous erythropoietin (EPO) levels in long-term RT recipients are rare. The goal of this study was to evaluate the prevalence of anemia within 6 months to 5 years after RT and to assess the relationship between the serum concentrations of endogenous EPO, graft function and grade of improvement of anemia. METHODS: 140 patients who had undergone RT were included in the group: 89 males (63.6%) and 51 females (36.4%), with an average age 46.8 +/- 12.8 years. The serum concentrations of EPO and creatinine (Cr) were tested in all the individuals and the values of the red blood component of blood count, serum ferritin (SF), plasma iron concentration, plasma total iron-binding capacity (TIBC), transferrin saturation (TS), folic acid and vitamin B(12) levels in the serum were determined. A statistical analysis of the results was performed using the correlation analysis, Mann-Whitney U test and Duncan's multiple range test. RESULTS: Normal blood count values were found in 91 patients (65%), and a mild grade of anemia with a mean hemoglobin (Hb) 114.4 +/- 11.9 g/l was observed in 45 patients (32.1%), and 4 patients (2.9%) fulfilled the diagnostic criteria for post-transplantation erythrocytosis. Individuals with normal Hb values had a mean EPO serum concentration of 39.3 +/- 12.3 mU/ml (median 37.2) and the mean Cr was 133.8 +/- 36.9 micromol/l (median 122). Patients with anemia (Hb <120 g/l in females, Hb <130 g/l in males) had a mean EPO value of 47.0 +/- 26.6 mU/ml (median 36.0) and a mean Cr of 203.8 +/- 108.9 micromol/l (median 181). The difference in the Cr values was statistically significant (p < 0.0001), while the difference between the EPO concentrations was not significant. No relation of EPO serum concentration with regard to graft function was found in the analysis. A lack of storage iron (SF <10 microg/l in females, SF <22 microg/l in males) was found in 16 patients (11.4%), and a lack of functional iron (TS <20%) was found in 27 patients (19.3%). CONCLUSIONS: Theprevalence of anemia in patients after transplantation was 32.1%. The most common cause of anemia is insufficient graft function development. The achieved values of the red component of blood count have no relation to the endogenous EPO serum concentrations.

Dialysis activity of the Hemodialysis (HD) Center at University Hospital Olomouc in the past decade.

The paper presents a summary of dialysis statistics at the Olomouc Hemodialysis Center during the period 1991-2001. The number of individual treatments, patient structure, mortality and survival of patients on dialysis are featured, along with a comparison of state norms in some instances.