Ultrasound-guided radial artery catheterization at different sites: a prospective and randomized study.

OBJECTIVE: Herein, we aimed to compare ultrasound (US)-guided radial artery catheterization at the wrist joint and mid-forearm level to evaluate the success rate of US-guided radial artery catheterization at the mid-forearm level. PATIENTS AND METHODS: This prospective randomized controlled study included 240 consecutive patients who were admitted to the intensive care unit of Taizhou Hospital of Integrated Traditional Chinese and Western Medicine and underwent radial artery catheterization between January 1, 2019, and October 1, 2021. All patients were randomly allocated to the mid-forearm and wrist groups, with 120 patients in each group. Patients in the mid-forearm and wrist groups underwent out-of-plane US-guided radial artery catheterization at wrist and mid-forearm levels, respectively. The overall success rate, first-attempt success rate, and related complications were recorded and compared between the two groups. RESULTS: The first-attempt success rate and overall success rate of radial artery catheterization were significantly higher in the mid-forearm group than in the wrist group (75.0% vs. 60.0%, p=0.013; 90.8% vs. 80.8, p =0.026, respectively). The incidence of hematoma was significantly lower in the mid-forearm group than in the wrist group (9.2% vs. 28.3%, p <0.001). CONCLUSIONS: US-guided radial artery catheterization at the mid-forearm level increased the first-attempt success rate and overall success rate, decreased the incidence of hematoma during puncture, and improved nurse satisfaction. This puncture site may afford a new choice to replace the traditional wrist site.

Contribution of stratified extracellular polymeric substances to the gel-like and fractal structures of activated sludge.

The gel-like and fractal structures of activated sludge (AS) before and after extracellular polymeric substances (EPS) extraction as well as different EPS fractions were investigated. The contributions of individual components in different EPS fractions to the gel-like behavior of sludge samples by enzyme treatment were examined as well. The centrifugation and ultrasound method was employed to stratify the EPS into slime, loosely and tightly bound EPS (LB- and TB-EPS). It was observed that all samples behaved as weak gels with weak-link. TB-EPS and AS after LB-EPS extraction showed the strongest elasticity in higher concentrations and highest mass fractal dimension, which may indicate the key role of TB-EPS in the gel-like and fractal structures of the sludge. Effects of protease or amylase on the gel-like property of sludge samples differed in the presence of different EPS fractions.