High success rates of ultrasound-guided distal internal jugular vein and axillary vein approaches for central venous catheterization: A randomized controlled open-label pilot trial

BACKGROUND

Ultrasound (US)-guided axillary vein (AV) catheterization has been considered as the preferred site of insertion to minimize catheter-related infections. Given its difficulty of realization, internal jugular vein (IJV) access remains, thus, the first choice of catheter insertion site. This descriptive study was aimed to assess the success and complication rates of in-plane short axis approach of IJV in the lower neck and the AV approach under US-guidance.

METHODS

In a prospective randomized controlled open-label pilot trial, all patients requiring central venous catheterization (CVC) in intensive care unit or operating room were randomly assigned to low IJV or AV groups. The primary objective was to estimate the overall success rate of both approaches. The secondary objectives were immediate complication rates, procedure durations, success rate after the first puncture, late complication rates (i.e., thrombosis, catheter colonization, and catheter-related infections), and nurse satisfaction regarding insertion site dressings.

RESULTS

One hundred and seventy-three out of two hundred and ten included patients were fully analyzed (90 and 83 in the IJV and AV approach groups, respectively). Overall success rates for IJV and AV sites were 96% (95% confidence interval (CI) [90-99]) and 89% (95% CI [81-94]) respectively. First puncture success rates were 90% and 80% respectively. The median overall procedure duration from US pre-procedural screening to guidewire insertion was 8 and 10 min in IJV and AV groups. Overall immediate complications rates for IJV and AV sites were 11.6% and 14.6%, respectively. Incidence of catheter colonization were 7.9% and 6.8% and catheter-related infection rate were 2.6% and 0%, respectively.

CONCLUSION

In this pilot study, US-guided low IJV and AV approaches are safe and efficient techniques for CVC insertion associated with high success and low complications rates. Duration for guidewire insertion seemed to be shorter in the short axis in-plane IJV approach. It provides the basis for a future randomized trial comparing these two approaches.

Complex regulatory network controls initial adhesion and biofilm formation in Escherichia coli via regulation of the csgD gene

The Escherichia coli OmpR/EnvZ two-component regulatory system, which senses environmental osmolarity, also regulates biofilm formation. Up mutations in the ompR gene, such as the ompR234 mutation, stimulate laboratory strains of E. coli to grow as a biofilm community rather than in a planktonic state. In this report, we show that the OmpR234 protein promotes biofilm formation by binding the csgD promoter region and stimulating its transcription. The csgD gene encodes the transcription regulator CsgD, which in turn activates transcription of the csgBA operon encoding curli, extracellular structures involved in bacterial adhesion. Consistent with the role of the ompR gene as part of an osmolarity-sensing regulatory system, we also show that the formation of biofilm by E. coli is inhibited by increasing osmolarity in the growth medium. The ompR234 mutation counteracts adhesion inhibition by high medium osmolarity; we provide evidence that the ompR234 mutation promotes biofilm formation by strongly increasing the initial adhesion of bacteria to an abiotic surface. This increase in initial adhesion is stationary phase dependent, but it is negatively regulated by the stationary-phase-specific sigma factor RpoS. We propose that this negative regulation takes place via rpoS-dependent transcription of the transcription regulator cpxR; cpxR-mediated repression of csgB and csgD promoters is also triggered by osmolarity and by curli overproduction, in a feedback regulation loop.