Blood Culture Utilization, Contamination Rates, Antibiotic Use, and Patient Outcomes in Intensive Care Units at a Tertiary Care Hospital in Western India: A Prospective Observational Study.

Background and objective Bloodstream infections present a severe clinical challenge in intensive care units (ICUs), making timely and accurate blood cultures (BCs) critical for diagnosis. However, pre-analytical errors frequently compromise results and drive unnecessary broad-spectrum antibiotic use. The objective of this study was to describe baseline BC utilization, contamination rates, antimicrobial resistance profiles, and patient outcomes across different ICUs at a tertiary care hospital. Methods A 12-month prospective observational study was conducted at a 1000-bedded tertiary hospital in Surat, India. BC utilization, contamination rates, pathogen profiles, and defined daily doses (DDDs) were analyzed for 1704 cultures. Clinical outcomes were followed for 142 culture-positive patients. Results Overall BC utilization was 62.3 per 1000 patient-days, peaking in the medical ICU (MICU; 107.12). Observed high utilization units also show a high contamination rate, which was highest in the MICU (27%) compared to the neonatal ICU (NICU; 21%) and pediatric ICU (PICU; 19%). Gram-negative bacteria predominated (>79% across wards), with Acinetobacter baumannii (33.8%) and Klebsiella pneumoniae (30.3%) as leading isolates. Meropenem showed the highest consumption (4.55 DDD/100 patient-days). Mortality was significantly higher in the NICU (63.3%) compared to the MICU (30.8%) and PICU (25%) (p = 0.000). Conclusions High BC utilization in adult ICUs is associated with excessive contamination rates, highlighting a gap in diagnostic stewardship. The high prevalence of multidrug-resistant organisms and significant neonatal mortality underscores the need for standardized collection bundles and unit-specific antimicrobial policies to improve clinical outcomes.