The effect of polymyxin B hemoperfusion on modulation of human leukocyte antigen DR in severe sepsis patients

BACKGROUND

Recent randomized trials have not found that polymyxin B hemoperfusion (PMX-HP) improves outcomes for patients with sepsis. However, it remains unclear whether the therapy could provide benefit for highly selected patients. Monocyte human leukocyte antigen (mHLA-DR) expression, a critical step in the immune response, is decreased during sepsis and leads to worsening sepsis outcomes. One recent study found that PMX-HP increased mHLA-DR expression while another found that the treatment removed HLA-DR-positive cells.

METHODS

We conducted a randomized controlled trial in patients with blood endotoxin activity assay (EAA) level ≥ 0.6. Patients in the PMX-HP group received a 2-h PMX-HP treatment plus standard treatment for 2 consecutive days. Patients in the non-PMX-HP group received only standard treatment. The primary outcome compared the groups on median change in mHLA-DR expression between day 3 and baseline. Secondary outcomes compared the groups on the mean or median change in CD11b expression, neutrophil chemotaxis, presepsin, cardiovascular Sequential Organ Failure Assessment (CVS SOFA) score, vasopressor dose, and EAA level between day 3 and baseline. We further compared the groups on mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and major adverse kidney events (MAKE 28), measured on day 28.

RESULTS

Fifty-nine patients were randomized to PMX-HP (n = 29) and non-PMX-HP (n = 30) groups. At baseline, mHLA-DR expression, CD11b, neutrophil chemotaxis, and clinical parameters were comparable between groups. The median change in mHLA-DR expression between day 3 and baseline was higher in PMX-HP patients than in patients receiving standard therapy alone (P = 0.027). The mean change in CD11b between day 3 and baseline was significantly lower in the PMX-HP group than in the non-PMX-HP group (P = 0.002). There were no significant changes from baseline in neutrophil chemotaxis, presepsin, CVS SOFA scores, vasopressor doses, or EAA level between groups. On day 28 after enrollment, mortality, ICU-free days, ventilator-free days, dialysis dependence status, renal recovery, serum creatinine, vasopressor-free days, and MAKE 28 were comparable between groups.

CONCLUSION

PMX-HP improved mHLA-DR expression in severe sepsis patients. Future studies should examine the potential benefit of PMX-HP in patients with low mHLA-DR expression.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02413541 . Registered on 3 March 2015.

Impact of a high loading dose of amikacin in patients with severe sepsis or septic shock

BACKGROUND

The therapeutic effect of aminoglycosides is highest and optimal when the peak plasma concentration (C _max)/minimal inhibitory concentration (MIC) ratio is between 8 and 10. The French guidelines recommend to use high doses of aminoglycosides for empiric antibiotic therapy in patients suffering from severe sepsis or septic shock. In clinical practice, the recommended target is an amikacin C _max between 60 and 80 mg/L, which corresponds to approximately 8 times the MIC breakpoint, as defined by the European Committee on Antimicrobial Susceptibility Testing. The aim of this study was to assess the incidence and impact on mortality of an amikacin concentration between 60 and 80 mg/L in patients suffering from severe sepsis or septic shock.

METHODS

This was a prospective observational cohort study conducted in two intensive care units (ICU). Patients receiving amikacin at a loading dose of 30 mg/kg for severe sepsis or septic shock were enrolled in the cohort. The target C _max for amikacin was between 60 and 80 mg/L, as recommended by French guidelines (i.e. C _max/MIC breakpoint = 8-10).

RESULTS

Over the study period, the amikacin C _max was <60 mg/L, between 60 and 80 mg/L, and >80 mg/L in 20 (18.2%), 46 (41.8%) and 44 (40%) of the 110 selected patients, respectively. Mortality rate was 40, 28.3 and 56.8% in the groups of patients with C _max < 60 mg/L, 60 mg/L < C _max < 80 mg/L and C _max > 80 mg/L, respectively. Following multivariate analysis, mortality rate was significantly lower in the group of patients with amikacin C _max between 60 and 80 mg/L than in the group of patients with amikacin C _max > 80 mg/L (P = 0.004). The multivariate analysis also revealed that the factors independently associated with a higher in-ICU mortality rate were age (P = 0.02) and norepinephrine dose (P = 0.0001).

CONCLUSIONS

With a loading dose of 30 mg/kg of amikacin, concentration was potentially suboptimal (C _max < 60 mg/L) in only 18.2% of patients. The pharmacodynamic target (60 mg/L < C _max < 80 mg/L) recommended by French guidelines was reached in 41.8% of patients and was associated with reduced in-ICU mortality. But amikacin overexposure (i.e. C _max > 80 mg/L) was frequent and potentially associated with increased mortality.

Assessment of the National French recommendations regarding the dosing regimen of 8mg/kg of gentamicin in patients hospitalised in intensive care units

INTRODUCTION

To assess the French National Agency for Medicines and Health Products Safety (ANSM) guidelines concerning the peak plasma concentration (Cmax) of gentamicin when using a loading dose of 8mg/kg administered in patients hospitalised in the intensive care unit (ICU).

PATIENTS AND METHODS

A prospective observational cohort study conducted in one ICU.

RESULTS

During the study period, 34 patients with a median simplified acute physiology score 2 of 54 [44-70] received a median dose of 8 [7.9-8.1] mg/kg of gentamicin. The median Cmax was 17.5 [15.4-20.7] mg/L and no patient had a Cmax>30mg/L. Twenty-four of 34 patients (71%) had a Cmax>16mg/L. Following multivariate analysis, the only factor associated with Cmax<16mg/L was a positive fluid balance 24hours before gentamicin administration (per 1000mL increment) (OR: 0.37, 95% CI: 0.18-0.77, P=0.008).

CONCLUSIONS

These results suggest that a Cmax>30mg/L [which corresponds to approximately 8 times the minimal inhibiting concentrations (MIC) breakpoints for Pseudomonas aeruginosa and Enterobacteriaceae with intermediate sensitivity] of gentamicin as recommended by ANSM guidelines seems impossible to obtain with a loading dose of 8mg/kg in the ICU. A loading dose of 8mg/kg should probably not be used in the empiric antibiotic treatment of infection due to non-fermenting Gram-negative bacilli and Enterobacteriaceae with intermediate sensitivity whose MIC breakpoint is 4mg/L. A Cmax>16mg/L was not reached in almost 30% of patients, particularly in the group with a positive fluid balance who require higher doses than currently recommended.