What lock solution is recommended to reduce CRBSIs?

• A. Normal saline
• B. 70% ethanol
• C. Heparin
• D. Antibiotics lock solution

Answer: (B)

The concept here is using a lock solution that stays inside the catheter lumen between uses to prevent microbial colonization and biofilm formation, thereby reducing catheter-related bloodstream infections. A 70% ethanol lock provides broad-spectrum antimicrobial activity and quickly disrupts biofilms inside the lumen, which directly lowers CRBSI risk. This makes it more effective for infection prevention than simply flushing with normal saline or using heparin, which focus on patency rather than disinfection. While antibiotic lock solutions can also reduce infections, they carry a higher risk of promoting antibiotic resistance and other concerns; ethanol avoids those issues and has demonstrated infection-reduction benefits in many settings.