Comparison of Single-Dose and Extended-Duration Empiric Aminoglycoside Combination Therapy in Patients With Septic Shock

Background: Empiric combination antimicrobial therapy is often used in patients with decompensating septic shock. However, the optimal duration of combination therapy is unknown.

Study question: The goal of this study was to compare the clinical effects of a single dose of an aminoglycoside to an extended duration of aminoglycosides for combination therapy in patients with septic shock without renal dysfunction.

Study design: Retrospective, single-center evaluation of patients with septic shock who received empiric combination therapy with an aminoglycoside.

Measures and outcomes: Two patient cohorts were evaluated: those who received a single dose of an aminoglycoside and those who received more than 1 dose of an aminoglycoside. The primary outcome was shock-free days at day 14. Secondary outcomes included mortality, length of stay, clinical cure, and nephrotoxicity. A post hoc subgroup analysis including only patients who received more than 2 doses of an aminoglycoside compared with a single dose was conducted.

Results: One hundred fifty-one patients were included in this evaluation, 94 in the single-dose aminoglycoside group and 57 in the extended duration group. There was no difference in shock-free days at day 14 between patients who received a single dose of an aminoglycoside or those who received an extended duration (12.0 vs. 11.6 days; P = 0.56). There were no differences in mortality, length of stay, clinical cure rates, or rates of nephrotoxicity between groups (28% for single dose vs. 26% for extended duration; P = 0.86). No differences in outcomes were detected when evaluating patients who received more than 2 doses of an aminoglycoside compared with a single dose.

Conclusions: Patients with septic shock and normal renal function who received a single dose of an aminoglycoside for combination antimicrobial therapy had no differences detected in shock duration or nephrotoxicity development compared with those who received an extended duration of aminoglycoside combination therapy.