Antimicrobial treatment decision-making for carbapenem-resistant Klebsiella pneumoniae bacteraemia in critically ill patients: a qualitative study

Abstract

Abstract Background Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) bacteraemia is associated with high mortality in critically ill patients and poses major therapeutic challenges due to limited antimicrobial options, diagnostic uncertainty and toxicity concerns. While quantitative studies have evaluated antimicrobial efficacy, little is known about how clinicians navigate real-world decision making when managing CR-Kp bacteraemia. Methods We conducted a qualitative study using semi-structured interviews with physicians involved in the management of critically ill patients with CR-Kp bacteraemia. Participants were purposively sampled across multiple specialities. Interviews explored antimicrobial selection, dosing strategies, use of diagnostics, stewardship influences, and system-level constraints. Data were analysed using a constructivist grounded theory approach involving iterative coding, constant comparison, theme development and investigator triangulation, supported by ATLAS.ti software. Reporting adhered to the COREQ checklist. Results Fifteen physicians participated. Inductive analysis identified seven themes and fifteen subthemes. Across these themes, antimicrobial decision-making emerged as an iterative clinical decision-making process of balancing the urgency of early effective treatment against evolving microbiological evidence, patient-specific toxicity and pharmacokinetics considerations, stewardship expectations and resource constraints. Clinicians initially prioritized clinical risk and urgency, often before microbiological confirmation, and subsequently modified therapy as diagnostic information and clinical response evolved. Antimicrobial selection and dosing therefore involved continuous reassessment of efficacy, toxicity and feasibility. Although microbiological and molecular diagnostics were valued, their influence was constrained by turnaround times and interpretative challenges, while cost, drug availability and communication gaps further limited optimal therapy. Outcomes evaluation and experiential learning subsequently informed future treatment decisions. Conclusion Antimicrobial management of CR-Kp bacteraemia extends beyond drug choice to encompass clinical urgency, diagnostic integration, pharmacokinetic uncertainty, stewardship dynamics and structural constraints. Optimizing care requires context-appropriate decision-support tools, timely diagnostics, strengthened multidisciplinary stewardship, and system-level interventions, understanding clinician decision-making processes is essential for designing effective strategies to improve outcomes in CR-Kp bacteraemia.