Optimal antibiotic use in the intensive care unit

Antibiotic resistance has emerged as one of the most important factors influencing the outcomes of patients with life-threatening infections in the ICU. The increasing prevalence of antibiotic-resistant infections globally highlights the importance of this issue for all intensivists. Antibiotic utilization in the ICU should be optimized to ensure that timely appropriate treatment is administered in a way that minimizes the subsequent emergence of antibiotic resistance. Antibiotic strategies have been developed to assist clinicians in achieving this important balance. Familiarity with local ICU pathogens and their antibiotic susceptibilities is at the forefront of optimizing ICU antibiotic practices. Moreover, timely antibiotic administration along with pharmacokinetic/pharmacodynamic (PK/PD) optimization, including ideal dosing and infusion duration, should be key components of all ICU antibiotic strategies. Microbiologic testing to include conventional pathogen identification and susceptibility testing as well as use of microbiologic rapid diagnostic tests can confirm the antibiotic regimen that is required to treat the causative pathogens while allowing de-escalation to occur if possible. Similarly, biomarkers such as procalcitonin can aid with avoiding unnecessary antibiotic use in the ICU and shortening their overall duration. ICUs should routinely employ formal programs for reviewing and optimizing antibiotic practices. These programs can include directed input from pharmacists and microbiologists during ICU rounds, the use of specialized order sets focusing on duration of treatment with stop as well as dosing optimization guidance, use of computerized decision support tools, incorporated protocols for the prevention of nosocomial infections, and the appropriate use of antibiotic prophylaxis regimens to include selective digestive decontamination (SDD). Tracking antibiotic practices in the ICU, as well as changing patterns of pathogens and antibiotic susceptibilities, mandate regular modification and updating of these practices over time. Antibiotic combination regimens can also be employed in some circumstances to increase the likelihood of treatment success with an appropriate initial regimen while also reducing the propensity for resistance emergence. Additionally artificial intelligence/machine learning (AI/ML) methods will increasingly serve to enhance antibiotic decision making in the future. Antibiotic optimization strategies in the ICU should routinely be employed by a multi-specialty group including intensivists, microbiologists, pharmacists, infectious disease specialists, and infection control practitioners. Regular review and updating of ICU antibiotic practices will help to safeguard their long-term use to optimize patient outcomes while minimizing resistance emergence.