Abstract
Introduction
Bloodstream infections remain a major cause of morbidity and mortality for infants admitted to neonatal intensive care units (NICUs), with central venous catheter use representing one of the principal risk factors. Among the strategies developed to prevent and manage catheter-related bloodstream infections (CRBSIs) and central line-associated bloodstream infections (CLABSIs), catheter-lock therapy (CLT) has emerged as a particularly promising approach. CLT is defined as the instillation of antimicrobial or antibiotic solutions into the catheter lumen, which are then left in place for a defined period, and has been adopted in adult and paediatric populations with satisfactory results. However, evidence supporting CLT efficacy and safety in newborns is still limited and fragmented. A rigorous synthesis of the available data is therefore critically needed.
Methods and analysis
This systematic review will follow the methodological recommendations of the Cochrane Collaboration, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcome will be the frequency of CRBSI and CLABSI in newborns receiving CLT in NICUs, compared with those receiving placebo or no lock therapy. Secondary outcomes will include mortality, duration of NICU stay, catheter survival rate and catheter dwell time, antibiotic exposure and safety profiles. A Population, Intervention, Comparison, and Outcome framework will be used to guide the inclusion criteria. A comprehensive search strategy has been developed across the most relevant electronic databases, together with grey literature. Search queries have been tailored for each specific database. Backward and forward citation strategies will be used. No restrictions regarding language or publication period will be applied. The systematic search will be conducted on 1 May 2026. All study designs presenting original data will be considered for inclusion—randomised controlled trials, cohort studies, case-control studies, case reports and surveys. Studies without original data will be excluded; however, the reference list of relevant reviews will be screened manually. Two reviewers will independently screen titles and abstracts, extract data and assess the risk of bias of each included study using standardised tools. In the event of disagreement, a third reviewer will be consulted. The quantitative synthesis will involve aggregation of comparable data, with results presented in tabular and graphical form. The effects of CLT will be evaluated separately according to its use as prophylaxis or as treatment. A subgroup analysis will be conducted according to the type of locking solution employed. Where at least two studies are judged sufficiently homogeneous, a meta-analysis will be performed. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach will be applied to assess the certainty of the evidence for clinically relevant outcomes.
Ethics and dissemination
As this protocol pertains to a systematic review based on secondary data from published studies, formal ethical approval is not required. We anticipate completing the systematic review within 6 months. On conclusion, the findings will be submitted for publication in peer-reviewed journals indexed in PubMed. This systematic review protocol has been registered in PROSPERO (International Prospective Register of Systematic Reviews) under registration number: CRD420251176308.