Antibiotic Dosing in the Critically Ill Septic Patient

• Current international guidelines recommend that intravenous antibiotics begin within one hour for those with severe sepsis and septic shock.
• Equally as important as choosing the right antimicrobial is choosing the correct dose at the right dosing schedule.
• In fact, there is evidence to suggest improved outcomes in patients given continous antimicrobial infusions (over hours) rather than intermittent bolus dosing (over minutes).
• An important cause of underdosing in critically ill patients, especially those with sepsis, is hypoalbuminemia.
• It is believed that by increasing the unbound fraction, hypoalbuminemia promotes more extensive distribution and greater renal clearance, thereby increasing the risk of underdosing.
• Take Home Point: Critically ill septic patients with hypoalbuminemia require higher dosages, or alternative regimens, to ensure appropriate antimicrobial coverage.

References

Pea F, Viale P. Bench to bedside review: Appropriate antibiotic therapy in severe sepsis and septic shock - does the dose matter? Crit Care 2009;13:214.