Efficacy of Ultrasound-Guided Peripheral Intravenous Cannulation versus Standard of Care: A Systematic Review and Meta-analysis.

Peripheral intravenous cannulation (PIV) is a common and necessary procedure in the emergency department (ED). Patients with PIV access encounter significant treatment delay. Ultrasound guidance for PIV (USGPIV) cannulation is a modality to reduce delay of care in such patients, but its efficacy, when compared with cannulation by the standard of care (SOC), the landmark and palpation method, has not been well established. We performed a random effects meta-analysis of available literature that compared USGPIV with SOC cannulation. We searched PubMed, Scopus and EMBASE until October 2020 for eligible studies in adult patients. We excluded non-English language, non-full-text studies. Our primary outcome was rate of first successful cannulation. Other outcomes were number of attempts and patient satisfaction. After identifying 284 studies and screening 74 studies, we included 10 studies. There were 1860 patients, 966 (52%) in the USGPIV group and 894 (48%) who received the SOC. Sixty-six percent of patients were female. USGPIV cannulation was associated with a two-times higher likelihood of first successful cannulation (odds ratio: 2.1, 95% confidence interval [CI]: 1.65-2.7, p < 0.001, I2 = 2.9%). While procedure length was similar in both groups, USGPIV was associated with a significantly smaller number of attempts (standardized mean difference [SMD]: -0.272, 95% CI: -0.539 to -0.004, p = 0.047) and significantly higher patient satisfaction (SMD: 1.467, 95% CI: 0.92-2.012, p < 0.001). There was low heterogeneity among our included studies, which were mostly randomized control trials. Our study confirmed that USGPIV cannulation offers a more effective modality, compared with SOC, to improve quality of care for patients with difficult PIV access.

Identification of a d-Arabinose-5-Phosphate Isomerase in the Gram-Positive Clostridium tetani.

d-Arabinose-5-phosphate (A5P) isomerases (APIs) catalyze the interconversion of d-ribulose-5-phosphate and d-arabinose-5-phosphate. Various Gram-negative bacteria, such as the uropathogenic Escherichia coli strain CFT073, contain multiple API paralogs (KdsD, GutQ, KpsF, and c3406) that have been assigned various cellular functions. The d-arabinose-5-phosphate formed by these enzymes seems to play important roles in the biosynthesis of lipopolysaccharide (LPS) and group 2 K-antigen capsules, as well as in the regulation of the cellular d-glucitol uptake and uropathogenic infectivity/virulence. The genome of a Gram-positive pathogenic bacterium, Clostridium tetani, contains a gene encoding a putative API, C. tetani API (CtAPI), even though C. tetani lacks both LPS and capsid biosynthetic genes. To better understand the physiological role of d-arabinose-5-phosphate in this Gram-positive organism, recombinant CtAPI was purified and characterized. CtAPI displays biochemical characteristics similar to those of APIs from Gram-negative organisms and complements the API deficiency of an E. coli API knockout strain. Thus, CtAPI represents the first d-arabinose-5-phosphate isomerase to be identified and characterized from a Gram-positive bacterium.IMPORTANCE The genome of Clostridium tetani, a pathogenic Gram-positive bacterium and the causative agent of tetanus, contains a gene (the CtAPI gene) that shares high sequence similarity with those of genes encoding d-arabinose-5-phosphate isomerases. APIs play an important role within Gram-negative bacteria in d-arabinose-5-phosphate production for lipopolysaccharide biosynthesis, capsule formation, and regulation of cellular d-glucitol uptake. The significance of our research is in identifying and characterizing CtAPI, the first Gram-positive API. Our findings show that CtAPI is specific to the interconversion of arabinose-5-phosphate and ribulose-5-phosphate while having no activity with the other sugars and sugar phosphates tested. We have speculated a regulatory role for this API in C. tetani, an organism that does not produce lipopolysaccharide.