Effect of two tourniquet techniques on peripheral intravenous cannulation success: A randomized controlled trial.

OBJECTIVES: Peripheral intravenous (IV) cannulation is the most common procedure performed in the emergency department (ED). Elastic tourniquets (ETs) and blood pressure cuffs (BPCs) are frequently used for venodilation. Although BPCs lead to increased venodilation and decreased compressibility, it is unclear whether this translates into a meaningful patient-centered outcome. This study aimed to determine whether one method is superior for success on the first attempt. METHODS: This was a prospective, single-blinded, randomized controlled trial in the ED of a tertiary care center. A convenience sample of adult patients was randomly assigned to an ET or BPC with a cover concealing the type of tourniquet. The primary outcome was success rate on the first attempt. Secondary outcomes were number of attempts, number of providers, and rate of rescue techniques. RESULTS: Of the 121 patients enrolled, 119 qualified for analysis. In the ET group, 42 of 59 patients (71%) had successful IV cannulation on first attempt compared with 43 of 60 (72%) in the BPC group (P = .95). The number of attempts (P = .87), number of nurses (P = .67), and use of rescue techniques (P = .32) did not differ significantly. A history of difficult IV access and site other than the antecubital vein were associated with decreased success. CONCLUSIONS: ETs and BPCs performed similarly in providing venodilation for successful peripheral IV cannulation. History of difficult IV access and IV site are important factors in determining the likelihood of success.

Effect of Intranasal Vasoconstrictors on Blood Pressure: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Treatment for epistaxis includes application of intranasal vasoconstrictors. These medications have a precaution against use in patients with hypertension. Given that many patients who present with epistaxis are hypertensive, these warnings are commonly overridden by clinical necessity. OBJECTIVE: Our aim was to determine the effects of intranasal vasoconstrictors on blood pressure. METHODS: We conducted a single-center, randomized, double-blind, placebo-controlled trial from November 2014 through July 2016. Adult patients being discharged from the emergency department (ED) at Mayo Clinic (Rochester, Minnesota) were recruited. Patients were ineligible if they had a contraindication to study medications, had a history of hypertension, were currently taking antihypertensive or antidysrhythmic medications, or had nasal abnormalities, such as epistaxis. Subjects were randomized to one of four study arms (phenylephrine 0.25%; oxymetazoline 0.05%; lidocaine 1% with epinephrine 1:100,000; or bacteriostatic 0.9% sodium chloride [saline]). Blood pressure and heart rate were measured every 5 min for 30 min. RESULTS: Sixty-eight patients were enrolled in the study; of these, 63 patients completed the study (oxymetazoline, n = 15; phenylephrine, n = 20; lidocaine with epinephrine, n = 11; saline, n = 17). We did not observe any significant differences in mean arterial pressure over time between phenylephrine and saline, oxymetazoline and saline, or lidocaine with epinephrine and saline. The mean greatest increases from baseline in mean arterial pressure, systolic and diastolic blood pressure, and heart rate for each treatment group were also not significantly different from the saline group. CONCLUSIONS: Intranasal vasoconstrictors did not significantly increase blood pressure in patients without a history of hypertension. Our findings reinforce the practice of administering these medications to patients who present to the ED with epistaxis, regardless of high blood pressure.

Vps4 stimulatory element of the cofactor Vta1 contacts the ATPase Vps4 α7 and α9 to stimulate ATP hydrolysis.

The endosomal sorting complexes required for transport (ESCRTs) function in a variety of membrane remodeling processes including multivesicular body sorting, abscission during cytokinesis, budding of enveloped viruses, and repair of the plasma membrane. Vps4 ATPase activity modulates ESCRT function and is itself modulated by its cofactor Vta1 and its substrate ESCRT-III. The carboxyl-terminal Vta1/SBP-1/Lip5 (VSL) domain of Vta1 binds to the Vps4 ß-domain to promote Vps4 oligomerization-dependent ATP hydrolysis. Additionally, the Vps4 stimulatory element (VSE) of Vta1 contributes to enhancing Vps4 oligomer ATP hydrolysis. The VSE is also required for Vta1-dependent stimulation of Vps4 by ESCRT-III subunits. However, the manner by which the Vta1 VSE contributes to Vps4 activation is unknown. Existing structural data were used to generate a model of the Vta1 VSE in complex with Vps4. This model implicated residues within the small ATPase associated with various activities (AAA) domain, specifically α-helices 7 and 9, as relevant contact sites. Rational generation of Vps4 mutants defective for VSE-mediated stimulation, as well as intergenic compensatory mutations, support the validity of this model. These findings have uncovered the Vps4 surface responsible for coordinating ESCRT-III-stimulated Vta1 input during ESCRT function and identified a novel mechanism of Vps4 stimulation.