Clinical measurements obtained from point-of-care ultrasound images to assess acquisition skills.

BACKGROUND: Current methods of assessing competence in acquiring point-of-care ultrasound images are inadequate. They rely upon cumbersome rating systems that do not depend on the actual outcome measured and lack evidence of validity. We describe a new method that uses a rigorous statistical model to assess performance of individual trainees based on the actual task, image acquisition. Measurements obtained from the images acquired (the actual desired outcome) are themselves used to validate effective training and competence acquiring ultrasound images. We enrolled a convenience sample of 21 spontaneously breathing adults from a general medicine ward. In random order, two trainees (A and B) and an instructor contemporaneously acquired point-of-care ultrasound images of the inferior vena cava and the right internal jugular vein from the same patients. Blinded diameter measurements from each ultrasound were analyzed quantitatively using a multilevel model. Consistent mean differences between each trainee's and the instructor's images were ascribed to systematic acquisition errors, indicative of poor measurement technique and a need for further training. Wider variances were attributed to sporadic errors, indicative of inconsistent application of measurement technique across patients. In addition, the instructor recorded qualitative observations of each trainee's performance during image acquisition. RESULTS: For all four diameters, the means and variances of measurements from trainee A's images differed significantly from the instructor's, whereas those from trainee B's images were comparable. Techniques directly observed by the instructor supported these model-derived findings. For example, mean anteroposterior diameters of the internal jugular vein obtained from trainee A's images were 3.8 mm (90% CI 2.3-5.4) smaller than from the instructor's; this model-derived finding matched the instructor's observation that trainee A compressed the vein during acquisition. Instructor summative assessments agreed with model-derived findings, providing internal validation of the descriptive and quantitative assessments of competence acquiring ultrasound images. CONCLUSIONS: Clinical measurements obtained from point-of-care ultrasound images acquired contemporaneously by trainees and an instructor can be used to quantitatively assess the image acquisition competence of specific trainees. This method may obviate resource-intensive qualitative rating systems that are based on ultrasound image quality and direct observation, while also helping instructors guide remediation.

Limited agreement between two noninvasive measurements of blood volume during fluid removal: ultrasound of inferior vena cava and finger-clip spectrophotometry of hemoglobin concentration.

OBJECTIVE: Plots of blood volume measurements over time (profiles) may identify euvolemia during fluid removal for acute heart failure. We assessed agreement between two noninvasive measurements of blood volume profiles during mechanical fluid removal, which exemplifies the interstitial fluid shifts that occur during diuretic-induced fluid removal. APPROACH: During hemodialysis we compared change in maximum diameter of the inferior vena cava by ultrasound ([Formula: see text]) to change in relative blood volume derived from capillary hemoglobin concentration from finger-clip spectrophotometry (RBVSpHb). We grouped profiles of these measurements into three distinct shapes using an unbiased, data-driven modeling technique. METHODS: Fifty patients who were not in acute heart failure underwent a mean of five paired measurements while an average of 1.3 liters of fluid was removed over 2 h during single hemodialysis sessions. [Formula: see text] changed -1.0 mm (95% CI -1.9 to -0.2 mm) and the RBVSpHb changed -1.1% (95% CI -2.7 to +0.5%), but these changes were not correlated (r -0.04, 95% CI -0.32 to +0.24). Nor was there agreement between categorization of profiles of change in the two measurements (kappa -0.1, 95% CI -0.3 to +0.1). SIGNIFICANCE: [Formula: see text] and RBVSpHb estimates of blood volume do not agree during mechanical fluid removal, likely because regional changes in blood flow and pressure modify IVC dimensions as well as changes total blood volume.

Reproducibility of point-of-care ultrasonography for central vein diameter measurement: Separating image acquisition from interpretation.

PURPOSE: Central vein point-of-care ultrasonography must be reproducible to detect intravascular volume changes. We sought to determine which measurement step, image acquisition or interpretation, could be more compromising for reproducibility. METHODS: Three investigators each acquired inferior vena cava (IVC) and internal jugular (IJV) vein ultrasonographic sequences (US) from a convenience sample of 21 hospitalized general medicine participants and then interpreted each US three separate times. We partitioned the random errors of acquisition and interpretation, attributing wider dispersions of each to larger reductions in reproducibility. RESULTS: We analyzed 351 interpretations of 39 IVC and 432 interpretations of 48 IJV US. Reproducibility of the maximum (standard error of measurement 3.3 mm [95% confidence interval, CI 2.7-4.2 mm]) and minimum (4.8 mm [3.9-6.3 mm]) IVC diameter measurements were worse than that of the mediolateral (2.5 mm [2.0-3.2 mm]) and anteroposterior (2.5 mm [2.0-3.1 mm]) IJV diameters. The dispersions of random measurement errors were wider among acquisitions than interpretations. CONCLUSIONS: Among our investigators, central vein diameter measurements obtained by point-of-care ultrasonography are not sufficiently reproducible to distinguish clinically meaningful intravascular volume changes from measurement errors. Reproducibility could be most effectively improved by reducing the random measurement errors of acquisition. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:488-496, 2017.

The Haiti Medical Education Project: development and analysis of a competency based continuing medical education course in Haiti through distance learning.

BACKGROUND: Recent calls for reform in healthcare training emphasize using competency-based curricula and information technology-empowered learning. Continuing Medical Education programs are essential in maintaining physician accreditation. Haitian physicians have expressed a lack access to these activities. The Haiti Medical Education Project works in alliance with Haitian medical leadership, faculty and students to support the Country's medical education system. We present the creation, delivery and evaluation of a competency-based continuing medical education curriculum for physicians in rural Haiti. METHODS: Real time lectures from local and international institutions were teleconferenced to physicians in remote Haitian sites using VidyoConferencing™ technology. With American Academy of Family Physicians (AAFP) and College of Family Physicians Canada (CFPC) guidelines as references, a competency-derived syllabus was created for a Haitian continuing medical education program. The resulting educational goals were reviewed by a committee of Haitian and North American physician/medical education practitioners to reflect local needs. All authors reviewed lectures and then conferred to establish agreement on competencies presented for each lecture. RESULTS: Sixty-seven lectures were delivered. Human immunodeficiency virus/Acquired Immunodeficiency Syndrome, ophthalmologic, infectious diseases, renal and endocrine competencies were well-represented, with more than 50 % of the joint AAFP and CFPC recommended competencies outlined. Areas under-represented included allergy and immunology, cardiology, surgery, pain management, gastroenterology, neurology, pulmonology, men's health and rheumatology; these topics accounted for less than 25 % of AAFP/CFPC recommended competencies. Areas not covered included geriatrics, nutrition, occupational health and women's health. Within practice-based lectures, only disaster medicine, health promotion and information management were included, but only partially covered. CONCLUSIONS: We identified teaching goals covered and competencies that were missing from a CME program for rural Haitian physicians. We aim to use this analysis to provide a competency-based CME lecture series that proportionally meets local needs while following recommendations of recognized national family medicine organizations.

Kidney care in Haiti--the role of partnerships.

Establishing a programme for the prevention and treatment of acute kidney injury, chronic kidney disease and end-stage renal disease in a developing country involves unique challenges. We became involved in a collaborative effort to improve nephrology care in Haiti after participating in the emergency response to the 2010 earthquake. The focus of this ongoing project is overcoming barriers to implementation with the goal of improving training and resources for Haitian health-care workers and developing programmes for renal disease prevention and treatment in a setting of limited resources. Here, we offer practical advice for nephrologists who would like to help to advance medical care in developing countries. Rather than technical issues related to the prevention and treatment of renal disease, we focus on collaboration, education and the building of partnerships.

Aspirin treatment is associated with a significantly decreased risk of Staphylococcus aureus bacteremia in hemodialysis patients with tunneled catheters.

BACKGROUND: Hemodialysis patients with tunneled catheters are at increased risk of bacteremic Staphylococcus aureus infections. In vitro and in vivo studies showed that aspirin has direct antistaphylococcal effects by inhibiting expression of alpha-toxin and matrix adhesion genes through activation of sigma factor B stress-induced operon. We hypothesized that long-term treatment with aspirin may decrease the frequency of S aureus bacteremia in such patients. METHODS: We retrospectively analyzed electronic medical records for a variety of clinical parameters, including catheter dwell times, blood culture results, and aspirin use in our dialysis population. RESULTS: A total of 4,722 blood cultures were performed in 872 patients during more than 476 patient-catheter-years. There was a lower rate of catheter-associated S aureus bacteremia in patients treated with aspirin versus those not treated with aspirin (0.17 versus 0.34 events/patient-catheter-year, P = 0.003), whereas no such difference was observed for other bacteria. This association was dose dependent, seen mostly with the 325-mg aspirin dose. Using the Cox proportional hazard method, risk to develop a first episode of S aureus bacteremia decreased by 54% in patients using aspirin (confidence interval, 24 to 72; P = 0.002). Aspirin was associated with decreased risk of: (1) a first episode of methicillin-resistant S aureus bacteremia and (2) metastatic complications during the first episode of catheter-related S aureus bacteremia. CONCLUSION: These data are consistent with our clinical hypothesis that aspirin has a clinically useful antistaphylococcal effect in the dialysis population.

Acid-base disturbances in the intensive care unit: metabolic acidosis.

This article will discuss metabolic acidosis and, to a lesser extent, metabolic alkalosis in the ICU setting. A classification and clinical approach will be the focus.

Electrolyte disturbances in the intensive care unit.

The development of many electrolyte disturbances in the ICU can be prevented by attention to the use of intravenous fluids and nutrition. Hyponatremia is a relative contraindication to the use of hypotonic intravenous fluids and hypernatremia calls for the administration of water. Formulae have been devised to guide the therapy of severe hyponatremia and hypernatremia. All formulae regard the patient as a closed system, and none takes into account ongoing fluid losses that are highly variable between patients. Thus, therapy of severe hyponatremia and hypernatremia must be closely monitored with serial electrolyte measurements. The significance of hypocalcemia in the critically ill is controversial. Hypokalemia, hypophosphatemia, and hypomagnesemia should be corrected.