Dose Adjustments of Beta-lactam Antibiotics in Critically Ill Patients with AKI
Overview
This scoping review evaluated evidence on beta-lactam antibiotic dose adjustments in critically ill patients experiencing acute kidney injury (AKI). It highlights the challenges of dosing due to unreliable kidney function markers and dynamic patient physiology, and the limited high-quality data guiding dose reduction practices.
Background
Acute kidney injury is a frequent complication in critically ill patients, with incidences reported between 20% and 75%. Beta-lactam antibiotics, commonly used in ICU infections, are primarily renally cleared, necessitating dose adjustments based on kidney function. However, estimated glomerular filtration rate (eGFR) is often unreliable in critical illness, and most dosing guidelines derive from chronic kidney disease populations rather than AKI. Early antibiotic therapy is crucial for survival, yet underdosing is common due to concerns about renal impairment and delayed markers of kidney function.
Data Highlights
A comprehensive literature search identified 2,098 records, with 1,436 unique articles screened after duplicates removal. Inclusion criteria focused on primary studies involving critically ill adults with AKI receiving beta-lactam antibiotics, excluding chronic kidney disease and renal replacement therapy patients. Outcomes assessed included mortality, treatment failure, adverse events, length of stay, and pharmacodynamic target attainment. Risk of bias was evaluated using ROB-2 and ROBINS-E tools.
Key Findings
AKI diagnosis relies on serum creatinine and urine output, but creatinine is a delayed and imprecise marker, complicating early dosing decisions.
Beta-lactam antibiotics have a broad therapeutic window, and many AKI cases resolve within 24 to 48 hours, suggesting initial dose reductions may be unnecessary.
Pharmacodynamic targets are frequently not achieved in ICU patients, indicating common underdosing despite kidney dysfunction.
Existing dosing guidelines are mostly extrapolated from chronic kidney disease data and expert opinion, lacking robust evidence specific to AKI.
Some narrative reviews recommend postponing dose reductions until 48 hours after therapy initiation to better assess renal function trajectory.
There is a paucity of high-quality studies systematically evaluating clinical outcomes and pharmacodynamic target attainment related to beta-lactam dose adjustments in AKI.
Clinical Implications
Clinicians should be cautious when reducing beta-lactam doses solely based on early AKI diagnosis due to the potential for transient kidney dysfunction and the broad therapeutic window of these antibiotics. Monitoring and reassessment within the first 48 hours are critical to optimize dosing and avoid underexposure. Individualized dosing strategies considering dynamic renal function and infection severity are recommended until more definitive evidence emerges.
Conclusion
Current evidence on beta-lactam dose adjustments in critically ill patients with AKI is limited and largely based on expert opinion. Further high-quality research is needed to guide optimal dosing strategies that balance efficacy and safety in this vulnerable population.
References
Hirsch et al. 2025 -- Dose Adjustments of Beta-lactam Antibiotics in Critically Ill Patients Experiencing Acute Kidney Injury: A Scoping Review
