Objectives: The objective was to determine whether serial bedside visual estimates of left ventricular systolic function (LVF) and respiratory variation of the inferior vena cava (IVC) diameter would agree with quantitative measurements of LVF and caval index in hypotensive emergency department (ED) patients during fluid challenges. The authors hypothesized that there would be moderate inter-rater agreement on the visual estimates.Methods: This prospective observational study was performed at an urban, regional ED. Patients were eligible for enrollment if they were hypotensive in the ED as defined by a systolic blood pressure (sBP) of <100 mm Hg or mean arterial pressure of £65 mm Hg, exhibited signs or symptoms of shock, and the treating physician intended to administer intravenous (IV) fluid boluses for resuscitation. Sonologists performed a sequence of echocardiographic assessments at the beginning, during, and toward the end of fluid challenge. Both caval index and LVF were determined by the sonologist in qualitative then quantitative manners. Deidentified digital video clips of two-dimensional IVC and LVF assessments were later presented, in random order, to an ultrasound (US) fellowship-trained emergency physician using a standardized rating system for review. Statistical analysis included both descriptive statistics and correlation analysis.Results: Twenty-four patients were enrolled and yielded 72 caval index and LVF videos that were scored at the bedside prior to any measurements and then reviewed later. Visual estimates of caval index compared to measured caval index yielded a correlation of 0.81 (p < 0.0001). Visual estimates of LVF compared to fractional shortening yielded a correlation of 0.84 (p < 0.0001). Inter-rater agreement of respiratory variation of IVC diameter and LVF scores had simple kappa values of 0.70 (95% confidence interval [CI] = 0.56 to 0.85) and 0.46 (95% CI = 0.29 to 0.63), respectively. Significant differences in mean values between time 0 and time 2 were found for caval index measurements, the visual scores of IVC diameter variation, and both maximum and minimum IVC diameters.Conclusions: This study showed that serial visual estimations of the respiratory variation of IVC diameter and LVF agreed with bedside measurements of caval index and LVF during early fluid challenges to symptomatic hypotensive ED patients. There was moderate inter-rater agreement in both visual estimates. In addition, acute volume loading was associated with detectable acute changes in IVC measurements.ACADEMIC EMERGENCY MEDICINE 2011; 18:912-921 ª

BackgroundUltrasound (US) vascular guidance is traditionally performed in transverse (T) and longitudinal (L) axes, each with drawbacks. We hypothesized that the introduction of a novel oblique (O) approach would improve the success of US-guided peripheral venous access. We examined emergency physician (EP) performance using the O approach in a gel US phantom.MethodsIn a prospective, case control study, EPs were enrolled from four levels of physician experience including postgraduate years one to three (PGY1, PGY2, PGY3) and attending physicians. After a brief training session, each participant attempted vessel aspiration using a linear probe in T, L, and O axes on a gel US phantom. Time to aspiration and number of attempts to aspiration were recorded. The approach order was randomized, and descriptive statistics were used.ResultsTwenty-four physicians participated. The first-attempt success rate was lower for O, 45.83%, versus 70.83% for T (p = 0.03) and 83.33% for L (p = 0.01). The average time to aspiration was 12.5 s (O) compared with 9.47 s (T) and 9.74 s (L), respectively. There were no significant differences between all four groups in regard to total amount of time and number of aspiration attempts; however, a trend appeared revealing that PGY3 and attending physicians tended to aspirate in less time and by fewer attempts in all three orientations when compared with the PGY2 and PGY1 physicians.ConclusionIn this pilot study, US-guided simulated peripheral venous access using a phantom gel model in a mixed user group showed that the novel oblique approach was not initially more successful versus T and L techniques.

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