Alexander Levitov

Guidelines for the Appropriate Use of Bedside General and Cardiac Ultrasonography in the Evaluation of Critically Ill Patients-Part I: General Ultrasonography.

Objective: To establish evidence-based guidelines for the use of bedside ultrasound by intensivists and specialists in the ICU and equivalent care sites for diagnostic and therapeutic purposes for organs of the chest, abdomen, pelvis, neck, and extremities. Methods: The Grading of Recommendations, Assessment, Development and Evaluation system was used to determine the strength of recommendations as either strong or conditional/weak and to rank the “levels” of quality of evidence into high (A), moderate (B), or low (C) and thus generating six “grades” of recommendation (1A-1B-1C-2A-2B-2C). Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for all questions with clinically relevant outcomes. RAND appropriateness method, incorporating modified Delphi technique, was used in steps of GRADE that required panel judgment and for those based purely on expert consensus. The process was conducted by teleconference and electronic-based discussion, following clear rules for establishing consensus and agreement/disagreement. Individual panel members provided full disclosure and were judged to be free of any commercial bias. The process was conducted independent of industry funding. Results: Twenty-four statements regarding the use of ultrasound were considered—three did not achieve agreement and nine were approved as conditional recommendations (strength class 2). The remaining 12 statements were approved as strong recommendations (strength class 1). Each recommendation was also linked to its level of quality of evidence. Key strong recommendations included the use of ultrasonography for ruling-in pleural effusion and assisting its drainage, ascites drainage, ruling-in pneumothorax, central venous cannulation, particularly for internal jugular and femoral sites, and for diagnosis of deep venous thrombosis. Conditional recommendations were given to the use of ultrasound by the intensivist for diagnosis of acalculous cholecystitis, renal failure, and interstitial and parenchymal lung diseases. No recommendations were made regarding static (vs dynamic) ultrasound guidance of vascular access or the use of needle guide devices. Conclusions: There was strong agreement among a large cohort of international experts regarding several recommendations for the use of ultrasound in the ICU. Evidence-based recommendations regarding the appropriate use of this technology are a step toward improving patient outcomes in relevant patients.

Shear Wave Elastography for Evaluation of Liver Fibrosis

The prognosis and management of chronic viral hepatitis mainly depend on the extent of liver fibrosis, particularly in chronic hepatitis C. Liver histologic analysis is still considered the reference standard in the assessment of liver fibrosis despite the interobserver and interobserver variability in staging and some morbidity and mortality risks. Thus, noninvasive methods for assessing liver fibrosis are of great clinical interest. In the last decade, ultrasound‐based techniques to estimate the stage of liver fibrosis have become commercially available. They all have the capability to noninvasively evaluate differences in the elastic properties of soft tissues by measuring tissue behavior when a mechanical stress is applied. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push. This article reviews the results that have been obtained with shear wave elastography for assessment of liver fibrosis.

Echocardiographic Assessment of Preload Responsiveness in Critically Ill Patients

Fluid challenges are considered the cornerstone of resuscitation in critically ill patients. However, clinical studies have demonstrated that only about 50% of hemodynamically unstable patients are volume responsive. Furthermore, increasing evidence suggests that excess fluid resuscitation is associated with increased mortality. It therefore becomes vital to assess a patients fluid responsiveness prior to embarking on fluid loading. Static pressure (CVP, PAOP) and echocardiographic (IVC diameter, LVEDA) parameters fails to predict volume responsiveness. However, a number of dynamic echocardiographic parameters which are based on changes in vena-caval dimensions or cardiac function induce by positive pressure ventilation or passive leg raising appear to be highly predictive of volume responsiveness.

Volume Responsiveness in Critically Ill Patients Use of Sonography to Guide Management

odern resuscitation has changed since the advent of goaldirected therapy. Today, practitioners providing fluid resuscitation are cognizant of the danger associated with volume depletion while being aware of the morbidity of volume overload.1 Thus, fluid resuscitation must be rapid, precise, and individually tailored to each patient based on reliable data.2 Critically ill patients have a mixture of intravascular volume depletion, low systemic vascular resistance, and decreased cardiac output, which makes responses to attempts at volume resuscitation difficult to predict. As a result, despite initial attempts at fluid resuscitation, persistent hypotension is common and poses the dilemma of whether the patient should receive additional fluid boluses, a vasopressor, or a positive inotropic agent. Traditionally, resuscitation was guided by static measurements, such as central venous pressure, which was thought to determine the patient’s “intravascular volume.”1 These static measurements have been shown to be unreliable predictors of a patient’s ability to positively respond to volume expansion.3 Clinicians have increasingly relied on fluid responsiveness, defined as an increase in cardiac output by 15% following a 500-mL fluid bolus given over 10 minutes, to guide the resuscitation process. Several minimally invasive methods have been used to determine whether a patient is fluid responsive, including pulse counter analysis,4 transpulmonary thermodilution,5 and reactance.6 All of these methods have shown promise in evaluation of the volume status of septic patients; however, bedside sonography has also emerged as a useful tool for evaluating cardiac function in critically ill patients.7 The echocardiographic methods described below are entirely noninvasive, provide real-time data, can be taught reasonably quickly, and can be repeated frequently until desirable clinical outcomes are achieved. This article will review 3 methods aimed at predicting volume responsiveness in critical ill patients: (1) measurement of the caval index; (2) measurement of cardiac output with passive leg raising; and (3) measurement of common carotid artery (CCA) blood flow with passive leg raising.8–10 These latter techniques enable bedside clinicians to determine changes in blood flow in the left ventricular outflow tract (LVOT) and aorta in response to manipulations of right ventricular preload by passive leg raising, thus predicting the response to a fluid bolus without exposing the patient to potentially harmful hypervolemia.11 David Evans, MD, Giovanna Ferraioli, MD, John Snellings, MD, Alexander Levitov, MD

Thyroid and parathyroid ultrasound examination

These guidelines are an educational tool designed to assist practitioners in providing appropriate radiologic care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the American College of Radiology cautions against the use of these guidelines in litigation in which the clinical decisions of a practitioner are called into question.

Inhaled nitric oxide as salvage therapy in massive pulmonary embolism: a case series.

Inhaled nitric oxide (INO) has been shown to preferentially lower resistance in the pulmonary vasculature. The relative selectiveness of INO in accomplishing this effect makes it an attractive drug to administer as salvage therapy in patients with acute right ventricular failure secondary to pulmonary embolism. We describe 4 cases in which INO was used as a temporizing agent to decrease right ventricular after-load following massive near-fatal pulmonary embolism. All 4 patients survived to hospital discharge.

Neonatal incubators: a toxic sound environment for the preterm infant?*.

Background: High sound pressure levels may be harmful to the maturing newborn. Current guidelines suggest that the sound pressure levels within a neonatal intensive care unit should not exceed 45 dB(A). It is likely that environmental noise as well as the noise generated by the incubator fan and respiratory equipment may contribute to the total sound pressure levels. Knowledge of the contribution of each component and source is important to develop effective strategies to reduce noise within the incubator. Aims: The objectives of this study were to determine the sound levels, sound spectra, and major sources of sound within a modern neonatal incubator (Giraffe Omnibed; GE Healthcare, Helsinki, Finland) using a sound simulation study to replicate the conditions of a preterm infant undergoing high-frequency jet ventilation (Life Pulse, Bunnell, UT). Methods: Using advanced sound data acquisition and signal processing equipment, we measured and analyzed the sound level at a dummy infant’s ear and at the head level outside the enclosure. The sound data time histories were digitally acquired and processed using a digital Fast Fourier Transform algorithm to provide spectra of the sound and cumulative sound pressure levels (dBA). The simulation was done with the incubator cooling fan and ventilator switched on or off. In addition, tests were carried out with the enclosure sides closed and hood down and then with the enclosure sides open and the hood up to determine the importance of interior incubator reverberance on the interior sound levels Results: With all the equipment off and the hood down, the sound pressure levels were 53 dB(A) inside the incubator. The sound pressure levels increased to 68 dB(A) with all equipment switched on (approximately 10 times louder than recommended). The sound intensity was 6.0 × 10–8 watts/m2; this sound level is roughly comparable with that generated by a kitchen exhaust fan on high. Turning the ventilator off reduced the overall sound pressure levels to 64 dB(A) and the sound pressure levels in the low-frequency band of 0 to 100 Hz were reduced by 10 dB(A). The incubator fan generated tones at 200, 400, and 600 Hz that raised the sound level by approximately 2 dB(A)–3 dB(A). Opening the enclosure (with all equipment turned on) reduced the sound levels above 50 Hz by reducing the revereberance within the enclosure. Conclusion: The sound levels, especially at low frequencies, within a modern incubator may reach levels that are likely to be harmful to the developing newborn. Much of the noise is at low frequencies and thus difficult to reduce by conventional means. Therefore, advanced forms of noise control are needed to address this issue.

Detection of Subcutaneous and Intramuscular Air With Sonography A Sensitive and Specific Modality

Soft tissue air may raise suspicion for several life‐threatening illnesses. Physical examination has limited sensitivity in detecting air, and computed tomography and magnetic resonance imaging are time‐consuming and expensive. Sonography can show soft tissue air, but the sensitivity and specificity in this setting are currently unknown. Therefore, the purpose of this study was to assess the performance characteristics of sonography in depicting the presence, amount, and affected tissue plane in a cadaver model of soft tissue air.

Native renal artery duplex sonography

The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use of ultrasound in medicine through professional and public education, research, development of guidelines, and accreditation. To promote this mission, the AIUM is pleased to publish, in conjunction with the American College of Radiology (ACR), the Society for Pediatric Radiology (SPR), and the Society of Radiologists in Ultrasound (SRU), this AIUM Practice Guideline for the Performance of Native Renal Artery Duplex Sonography. We are indebted to the many volunteers who contributed their time, knowledge, and energy to bringing this document to completion. The AIUM represents the entire range of clinical and basic science interests in medical diagnostic ultrasound, and, with hundreds of volunteers, the AIUM has promoted the safe and effective use of ultrasound in clinical medicine for more than 50 years. This document and others like it will continue to advance this mission. Practice guidelines of the AIUM are intended to provide the medical ultrasound community with guidelines for the performance and recording of high-quality ultrasound examinations. The guidelines reflect what the AIUM considers the minimum criteria for a complete examination in each area but are not intended to establish a legal standard of care. AIUM-accredited practices are expected to generally follow the guidelines with recognition that deviations from these guidelines will be needed in some cases, depending on patient needs and available equipment. Practices are encouraged to go beyond the guidelines to provide additional service and information as needed.

Extensive cerebral venous sinus thrombosis following a dose increase in eltrombopag in a patient with idiopathic thrombocytopenic purpura

A 55-year-old female with a history of chronic idiopathic thrombocytopenic purpura (ITP) presented in the spring of 2012 to the emergency department (ED) with a 1-day history of severegeneralizedheadache,nausea,andvomiting.Adiagnosis