Integrating lung ultrasound in the hemodynamic evaluation of acute circulatory failure (the fluid administration limited by lung sonography protocol)

Volume Status Assessment by Lung Ultrasound in End-Stage Kidney Disease: A Systematic Review

Purpose of review

Lung ultrasound is a noninvasive bedside technique that can accurately assess pulmonary congestion by evaluating extravascular lung water. This technique is expanding and is easily available. Our primary outcome was to compare the efficacy of volume status assessment by lung ultrasound with clinical evaluation, echocardiography, bioimpedance, or biomarkers. The secondary outcomes were all-cause mortality and cardiovascular events.

Sources of information

We conducted a MEDLINE literature search for observational and randomized studies with lung ultrasound in patients on maintenance dialysis.

Methods

From a total of 2363 articles, we included 28 studies (25 observational and 3 randomized). The correlation coefficients were pooled for each variable of interest using the generic inverse variance method with a random effects model. Among the clinical parameters, New York Heart Association Functional Classification of Heart Failure status and lung auscultation showed the highest correlation with the number of B-lines on ultrasound, with a pooled r correlation coefficient of .57 and .36, respectively. Among echocardiographic parameters, left ventricular ejection fraction and inferior vena cava index had the strongest correlation with the number of B-lines, with a pooled r coefficient of .35 and .31, respectively. Three randomized studies compared a lung ultrasound-guided approach with standard of care on hard clinical endpoints. Although patients in the lung ultrasound group achieved better decongestion and blood pressure control, there was no difference between the 2 management strategies with respect to death from any cause or major adverse cardiovascular events.

Key findings

Lung ultrasound may be considered for the identification of patients with subclinical volume overload. Trials did not show differences in clinically important outcomes. The number of studies was small and many were of suboptimal quality.

Limitations

The included studies were heterogeneous and of relatively limited quality.

Impact of bedside ultrasound to reduce the incidence of acute renal injury in high-risk surgical patients: a randomized clinical trial

PURPOSE

This study aimed to determine whether performing bedside ultrasound impacts the occurrence of acute kidney injury (AKI) in the immediate postoperative period (POP) of high-risk surgery patients.

METHODS

POP patients were randomly assigned to two groups: (i) ultrasound (US) group, in which hemodynamic management was guided with clinical parameters supplemented with the bedside US findings; (ii) control group, hemodynamic management based solely on clinical parameters. Two exams were performed in the first 24 h of admission.

RESULTS

Fifty-one patients were randomized to the US group and 60 to the control group. There was no significant difference for incidence of AKI in both groups assessed 12 h (31.4% vs 35.0%, P = 0.84), 24 h (27.5% vs 23.3%, P = 0.66), or 7 days (17.6 vs 8.3%, P = 0.16) after surgery. No difference was found in the amounts of volume administered over the first 12 h (1000 [500-2000] vs. 1000 [500-1500], P = 0.72) and 24 h (1000 [0-1500] vs. 1000 [0-1500], P = 0.95) between the groups. Patients without AKI in the control group received higher amounts of volume during the ICU stay.

CONCLUSION

The use of bedside US in the immediate postoperative period of high-risk surgery did not show benefits in reducing AKI incidence.

Transesophageal Echocardiography in Patients in Cardiac Arrest: The Heart and Beyond

Point of care ultrasound involves different ultrasound modalities and is useful to assist management in emergent clinical situations such as cardiac arrest. The use of point of care ultrasound in cardiac arrest has mainly been described using transthoracic echocardiography as a diagnostic and as a prognostic tool. However, cardiac evaluation using transthoracic echocardiography might be challenging because of patient-related or technical factors. Furthermore, its use during pulse check pauses has been associated with delays in chest compression resumption. Transesophageal echocardiography (TEE) overcomes these limitations by providing reliable and continuous imaging of the heart without interfering with cardiopulmonary resuscitation. In this narrative review we describe the role of TEE during cardiopulmonary resuscitation in 4 different applications: (1) chest compression quality feedback; (2) rhythm characterization; (3) diagnosis of reversible causes; and (4) procedural guidance. Considering its limitations, we propose an algorithm for the integration of TEE in patients with cardiac arrest with a focus on these 4 applications and extend its use to extracardiac applications.

Characterization of Cardiopulmonary Interactions and Exploring Their Prognostic Value in Acute Bronchiolitis: A Prospective Cardiopulmonary Ultrasound Study

We aimed to delineate cardiopulmonary interactions in acute bronchiolitis and to evaluate the capacity of a combined cardiopulmonary ultrasonography to predict the need for respiratory support. This was a prospective observational single-center study that includes infants <12 month of age admitted to a hospital due to acute bronchiolitis. All the included patients underwent clinical, laboratory and cardiopulmonary ultrasonographic evaluation at the same time point within 24 h of hospital admission. The existence of significant correlation between cardiac and respiratory parameters was the primary outcome. The association of different cardiopulmonary variables with the need of respiratory support higher than O₂, the length of stay hospitalization, the PICU stay and the duration of respiratory support were a secondary outcome. We enrolled 112 infants (median age 1 (0.5–3) months; 62% males) hospitalized with acute bronchiolitis. Increased values of the pulmonary variables (BROSJOD score, pCO₂ and LUS) showed moderate correlations with NT-proBNP and all echocardiographic parameters indicative of pulmonary hypertension and myocardial dysfunction (Tei index). Up to 36 (32%) infants required respiratory support during the hospitalization. This group presented with higher lung ultrasound score (p < 0.001) and increased values of NT-proBNP (p < 0.001), the Tei index (p < 0.001) and pulmonary artery pressures (p < 0.001). All the analyzed respiratory and cardiac variables showed moderate-to-strong correlations with the LOS of hospitalization and the time of respiratory support. Lung ultrasound and echocardiography showed a moderate-to-strong predictive accuracy for the need of respiratory support in the ROC analysis, with the AUC varying from 0.74 to 0.87. Those cases of bronchiolitis with a worse pulmonary status presented with a more impaired cardiac status. Cardiopulmonary ultrasonography could be a useful tool to easily identify high-risk populations for complicated acute bronchiolitis hospitalization.

Point-of-Care Lung Ultrasound to Diagnose the Etiology of Acute Respiratory Failure at Admission to the PICU

OBJECTIVES

Determine the sensitivity and specificity of point-of-care lung ultrasound in identifying the etiology of acute respiratory failure at admission to the PICU.

DESIGN

Prospective observational study.

SETTING

Tertiary PICU.

PATIENTS

Children older than 37 weeks gestational age and less than or equal to 18 years old admitted to the PICU with acute respiratory failure from December 2018 to February 2020.

INTERVENTION

Point-of-care lung ultrasound performed within 14 hours of admission to the PICU by physicians blinded to patient history and clinical course. Two physicians, blinded to all clinical information, independently interpreted the point-of-care lung ultrasound and then established a consensus diagnosis (ultrasound diagnosis). The ultrasound diagnosis was compared with an independent, standardized review of the medical record following hospital discharge (final diagnosis).

MEASUREMENTS AND RESULTS

Eighty-eight patients were enrolled in the study. Forty-eight patients had a final diagnosis of bronchiolitis/viral pneumonitis (55%), 29 had pneumonia (33%), 10 had status asthmaticus (11%), and one was excluded because of an inability to differentiate the final diagnosis. Point-of-care lung ultrasound correctly identified the etiology of acute respiratory failure in 56% of patients (49/87; 95% CI, 46-66%). It identified bronchiolitis/viral pneumonitis with 44% sensitivity (95% CI, 0.31-0.58) and 74% specificity (95% CI, 0.59-0.85), pneumonia with 76% sensitivity (95% CI, 0.58-0.88) and 67% specificity (95% CI 0.54-0.78), and status asthmaticus with 60% sensitivity (95% CI, 0.31-0.83) and 88% specificity (95% CI, 0.79-0.94).

CONCLUSIONS

In contrast to literature demonstrating high utility differentiating the cause of acute respiratory failure in adults, blinded point-of-care lung ultrasound demonstrates moderate sensitivity and specificity in identifying the etiology of pediatric acute respiratory failure at admission to the PICU among children with bronchiolitis, pneumonia, and status asthmaticus.

Outcomes of end-stage renal disease patients in the PROCESS trial

OBJECTIVE

Intravenous fluid administration is a main component of sepsis therapy, but physicians are cautious about giving fluids to end-stage renal disease (ESRD) patients out of concern for causing volume overload. We compared the outcomes of septic shock patients with and without ESRD and evaluated the association between early intravenous fluid administration and outcomes.

METHODS

We analyzed patients enrolled in the Protocolized Care for Early Septic Shock (PROCESS) trial, which studied different resuscitation strategies for early septic shock. Stratifying for ESRD, we compared patient characteristics, course of care, and outcomes between ESRD and non-ESRD. Using multivariable logistic regression, we determined the association between 6-hour total fluid volume (> = 30 mL/kg vs < 30 mL/kg) from preenrollment and outcomes.

RESULTS

There were 84 ESRD and 1257 non-ESRD patients. ESRD patients had a higher median Charlson Comorbidity score (5 vs 2, P < .001), higher median acute physiology and chronic health evaluation (APACHE) II score (26.5 vs 20.0, P < .001), and lower 6-hour intravenous fluid administration (54.7 vs 68.3 mL/kg, P < .001). Ninety-day mortality (33.3% vs 29.3%, P = .43) and intubation rate (31.0% vs 33.4%, P = .64) did not differ between groups. Fewer ESRD received > = 30 mL/kg (66.6% vs 86.7% P < .001). For ESRD, receipt of > = 30 mL/kg intravenous fluid did not alter any outcome. For non-ESRD patients, receiving   ≥30 mL/kg of intravenous fluid was associated with increased 90-day mortality (adjusted odds ratio = 1.64; 95% confidence interval, 1.03-2.61).

CONCLUSIONS

In the PROCESS trial, ESRD patients had similar outcomes to non-ESRD patients. Although ESRD patients received less intravenous fluid administration, most received over 30 mL/kg in the first 6 hours. In contrast to non-ESRD patients, receiving  ≥30 mL/kg of intravenous fluid was not associated with worse outcomes in ESRD.

It’s Not All about Echocardiography. Open the Lung Window for the Cardiac Emergencies

In the acute cardiac care setting, undifferentiated clinical presentations such as dyspnea, chest pain, shock, and cardiac arrest are common diagnostic challenges for the clinician. Lung ultrasonography is a well-established diagnostic tool which can be integrated in simplified decision making algorithms during the initial approach of the patient, in order to differentiate accurately cardiac from non-cardiac causes and improve the management of time-sensitive cardiovascular emergencies.

Assessment of extravascular lung water by measuring the number of pulmonary ultrasound B-lines before and after CBP in patients with MODS

To determine whether the change in the number of pulmonary ultrasound B-line can accurately assess the extravascular lung water (EVLW) before and after continuous bedside blood purification (CBP) in patients with multiple organ dysfunction syndrome (MODS).Seventy-six patients with MODS who underwent CBP were examined within 24 hours before and after CBP using pulmonary ultrasound to detect the number of ultrasound B-line or using pulse indicator continuous cardiac output method to examine extravascular lung water, blood oxygenation index, and B-type natriuretic peptide (BNP) content. The correlation of the change in the number of B lines before and after CBP treatment with the negative balance of 24 hours liquid, the change of oxygenation index, and BNP content were analyzed.In the 76 patients, CBP treatment significantly decreased EVLW, the number of B-line, and BNP (P < .05 for all), while it significantly increased the oxygenation index (P < .05). Correlation analysis showed that the decrease in B-line number after CBP treatment was positively correlated with the 24 hours negative lung fluid balance, decrease of EVLW, oxygenation index improvement, and decreased BNP content. The change in the numbers of pulmonary ultrasound B-line can accurately assess the change of EVLW before and after CBP treatment and reflect the efficiency of ventilation in the lungs and the risk of heart failure.Thus, it can replace pulse indicator continuous cardiac output as an indicator for evaluating EVLW in patients with MODS treated with CBP.

Global Ultrasound Check for the Critically lll (GUCCI)-a new systematized protocol unifying point-of-care ultrasound in critically ill patients based on clinical presentation

Ultrasound technology is an essential tool in the management of critically ill patients. Point-of-care ultrasonography (POCUS) enables data collection from different anatomic areas to achieve the most probable diagnosis and administer the right therapy at the right time. Despite the increasing utilization of POCUS, there is still a lack of standards to establish how to use different bedside ultrasound protocols, and it is imperative to develop a unifying protocol. Thus, the aim of this paper is to establish a new systematized approach that can be adopted by all physicians to implement POCUS for critically ill patient management. To achieve this, we propose a new systematized approach—Global Ultrasound Check for the Critically Ill (GUCCI)—that integrates multiple protocols. This protocol is organized based on three syndromes (acute respiratory failure, shock, and cardiac arrest) and includes ultrasound-guided procedures.

Effect of Fluid Bolus Therapy on Extravascular Lung Water Measured by Lung Ultrasound in Children With a Presumptive Clinical Diagnosis of Sepsis

OBJECTIVES

Fluid bolus therapy for the treatment of sepsis may lead to the accumulation of extravascular lung water (EVLW) and result in respiratory dysfunction. We aimed to assess changes in EVLW using lung ultrasound (US) in children with a presumptive clinical diagnosis of sepsis after fluid bolus therapy and correlate these changes with respiratory signs.

METHODS

This work was a prospective observational study set in the emergency department of the Royal Children's Hospital. Children meeting international consensus criteria for sepsis receiving fluid bolus therapy were included. Respiratory signs were recorded, and lung US examinations were performed immediately before, 5 minutes after, and 60 minutes after fluid bolus therapy. A pediatric emergency physician blinded to the participants' identities and timing of US calculated an EVLW score from lung US. Results-Fifty fluid boluses were recorded in 41 children. The lung US score (range, 0-8) increased over the study period: median, 1 (interquartile range, 0-2) before fluid bolus therapy, 1 (interquartile range, 0-3) 5 minutes after fluid bolus therapy, and 3 (interquartile range, 1-4) 60 minutes after fluid bolus therapy. Respiratory effort, but not the respiratory rate or the presence of rales, increased over the study period and was correlated with the lung US score (ρ = 0.33; P = .02).

CONCLUSIONS

Extravascular lung water as measured by lung US increased after fluid bolus therapy in septic children and was correlated with an increase in the respiratory distress score. The respiratory rate and the presence of rales did not change over the study period. The role of lung US for titrating fluid bolus therapy in sepsis warrants further investigation.

Point-of-Care Ultrasound in the Intensive Care Unit

Spreading beyond the realm of tertiary academic medical centers, point-of-care ultrasound in the intensive care unit is an important diagnostic tool. The real-time feedback garnered can lead to critical and clinically relevant changes in management and decrease potential complications. Bedside ultrasound evaluation in the intensive care setting with a small, portable equipment is well-suited for placement of central lines, lumbar puncture, thoracentesis or other bedside ICU procedures and in the evaluation of cardiac activity, pleural and abdominal cavity and the overall fluid volume. Formalized curriculums centering on point-of-care ultrasound are emerging that will enhance its applicability and relevance.

Point-of-Care Ultrasound in Established Settings

The original and most widely accepted applications for point-of-care ultrasound (POCUS) are in the settings of trauma, shock, and bedside procedures. Trauma was the original setting for the introduction of POCUS and has been standardized under the four-plus view examination called the Focused Assessment with Sonography in Trauma (FAST). This examination was found to be especially practice changing for achieving rapid diagnoses in critically ill patients who are too unstable for the delays and transportation inherent in more advanced imaging with computed tomography. This application was broadened from the critically ill trauma patient to any critically ill patient, particularly the patient in undifferentiated shock. Although the Focused Assessment with Sonography in Trauma examination originally focused on sources of hemorrhage causing hypovolemic shock, POCUS also can quickly differentiate cardiogenic, obstructive, and distributive shock and help identify the more specific etiology such as massive pulmonary emboli, pericardial tamponade, and pneumothoraces. By expediting diagnosis, POCUS facilitates faster definitive treatment of life-threatening conditions. In pursuing treatment, US continues to serve a role in the form of visually guiding many procedures that were previously done blindly. US guidance of procedures has improved the safety of central line insertion, thoracentesis, and paracentesis, and has an emerging role in lumbar puncture. Experience in bedside US is becoming a vital tool in the clinician's bedside assessment and management, filling a void between the stethoscope and the more advanced studies and interventions available through radiology. Understanding the strengths and limitations of US enables clinicians to identify the appropriate situations in which they can apply this tool confidently.

The efficacy of bedside chest ultrasound: from accuracy to outcomes

For many respiratory physicians, point-of-care chest ultrasound is now an integral part of clinical practice. The diagnostic accuracy of ultrasound to detect abnormalities of the pleura, the lung parenchyma and the thoracic musculoskeletal system is well described. However, the efficacy of a test extends beyond just diagnostic accuracy. The true value of a test depends on the degree to which diagnostic accuracy efficacy influences decision-making efficacy, and the subsequent extent to which this impacts health outcome efficacy. We therefore reviewed the demonstrable levels of test efficacy for bedside ultrasound of the pleura, lung parenchyma and thoracic musculoskeletal system.For bedside ultrasound of the pleura, there is evidence supporting diagnostic accuracy efficacy, decision-making efficacy and health outcome efficacy, predominantly in guiding pleural interventions. For the lung parenchyma, chest ultrasound has an impact on diagnostic accuracy and decision-making for patients presenting with acute respiratory failure or breathlessness, but there are no data as yet on actual health outcomes. For ultrasound of the thoracic musculoskeletal system, there is robust evidence only for diagnostic accuracy efficacy.We therefore outline avenues to further validate bedside chest ultrasound beyond diagnostic accuracy, with an emphasis on confirming enhanced health outcomes.

Integrative Cardiopulmonary Ultrasound for Interstitial Lung Disease Assessment: Correlation between Lung Ultrasound Performance and Cardiac Involvement

The aims of this study were to apply integrative cardiopulmonary ultrasound (thoracic ultrasound) to the evaluation of patients with interstitial lung disease (ILD) and to determine the relationship between lung ultrasound signs and echocardiographic parameters such as systolic pulmonary artery pressure (SPAP) and various right ventricular parameters. ILD patients and healthy controls underwent lung ultrasound (LUS) and echocardiographic tests. In addition to traditional echocardiographic parameters, right ventricular free wall longitudinal strain (RVLS_FW) was measured using 2-D speckle-tracking echocardiography. The degree of pulmonary fibrosis or the disease severity of each ILD patient was scored with a semiquantitative scoring method, taking into account multiple LUS signs. Statistical analyses were performed to compare various parameters between ILD patients with and those without pulmonary hypertension. Correlations between the different parameters were then evaluated, and the LUS scores were used to predict pulmonary hypertension using a receiver operating characteristic curve analysis. Among the 90 patients who qualified for entry into this study, 30% (n = 27) had pulmonary hypertension. The patients with pulmonary hypertension had larger right ventricular dimensions, lower RVLS_FW and higher LUS scores. An effective correlation was found between ILD LUS scores and echocardiographic parameters, especially SPAP (r = 0.735, p < 0.001). The groups were comparable with respect to most echocardiographic parameters, with mild, moderate and severe pulmonary fibrosis, whereas SPAP was significantly higher in the moderate and severe groups. RVLS_FW was obviously reduced in the group with severe pulmonary fibrosis. Although RVLS_FW in the mild pulmonary fibrosis group was in the normal range, it was slightly reduced compared with that of the controls. A cutoff of more than 16 LUS points had 85.2% sensitivity and 80.3% specificity in predicting elevated SPAP (>36 mm Hg). Thoracic ultrasound is useful in the assessment of ILD. As ILD progresses, the structure or function of the right ventricle gradually deteriorates. LUS not only detects lung conditions in ILD, but also indirectly reflects SPAP and right ventricular function. Integrated use of LUS and echocardiography will provide an invaluable point-of-care imaging modality to facilitate the diagnosis, management and treatment of patients with ILD.

Point-of-Care Ultrasonography for Primary Care Physicians and General Internists

Point-of-care ultrasonography (POCUS) is a safe and rapidly evolving diagnostic modality that is now utilized by health care professionals from nearly all specialties. Technological advances have improved the portability of equipment, enabling ultrasound imaging to be executed at the bedside and thereby allowing internists to make timely diagnoses and perform ultrasound-guided procedures. We reviewed the literature on the POCUS applications most relevant to the practice of internal medicine. The use of POCUS can immediately narrow differential diagnoses by building on the clinical information revealed by the traditional physical examination and refining clinical decision making for further management. We describe 2 common patient scenarios (heart failure and sepsis) to highlight the impact of POCUS performed by internists on efficiency, diagnostic accuracy, resource utilization, and radiation exposure. Using POCUS to guide procedures has been found to reduce procedure-related complications, along with costs and lengths of stay associated with these complications. Despite several undisputed advantages of POCUS, barriers to implementation must be considered. Most importantly, the utility of POCUS depends on the experience and skills of the operator, which are affected by the availability of training and the cost of ultrasound devices. Additional system barriers include availability of templates for documentation, electronic storage for image archiving, and policies and procedures for quality assurance and billing. Integration of POCUS into the practice of internal medicine is an inevitable change that will empower internists to improve the care of their patients at the bedside.

An observational study using ultrasound to assess physiological changes following fluid bolus administration in paediatric sepsis in the emergency department

Background

Fluid bolus administration is widely recommended as part of the initial treatment of paediatric sepsis, though the physiological benefits and harms are unclear. The primary aim of this study is to determine the effect of fluid bolus administration on cardiac index (CI). Secondary aims are to determine the effect of fluid bolus administration on extra-vascular lung water (EVLW), whether fluid responsiveness can be predicted by inferior vena cava (IVC) collapsibility, and whether fluid responsiveness correlates with changes in vital signs.

Methods/design

A prospective observational study of children presenting to the Emergency Department of The Royal Children’s Hospital with clinically diagnosed sepsis requiring fluid bolus administration. Prior to fluid bolus administration, an echocardiogram, lung ultrasound, and IVC ultrasound will be performed, and vital signs recorded. These will be repeated 5 min after and 60 min after fluid bolus administration. Recorded echocardiograms and lung/IVC ultrasound will be evaluated independently by a paediatric cardiologist and paediatric emergency physician, respectively, blinded to the patient identity and time of examination relative to time of fluid bolus administration. Fifty patients will be enrolled in the study based on a precision based sample size calculation. Results will be analysed for change in CI and change in EVLW 5 min after and 60 min after fluid bolus administration compared to baseline, IVC collapsibility as a predictor of fluid responsiveness, and the relationship between fluid responsiveness and changes in vital signs.

Discussion

This study will explore assumptions about the effect of fluid boluses on CI in children with sepsis, and will provide evidence for secondary effects on other organ systems. This may lead to novel methods for assessment and decision making in the initial resuscitation of paediatric sepsis in clinical and research settings, and will likely influence the design of future interventional studies in this arena.

Trial registration

The study is registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12614000824662; 04 August 2014).

Critical Care Ultrasound: A Review for Practicing Nephrologists

The use of point-of-care ultrasound in the intensive care unit, both for diagnostic and procedural purposes, has rapidly proliferated, and evidence supporting its use is growing. Conceptually, critical care ultrasound (CCUS) should be considered an extension of the physical examination and should not be considered a replacement for formal echocardiography or radiology-performed ultrasound. Several CCUS applications are of particular relevance to nephrologists, including focused renal ultrasound in patients at high risk for urinary tract obstruction, real-time ultrasound guidance and verification during the placement of central venous catheters, and ultrasound-augmented assessment of shock and volume status. Each of these applications has the capacity to improve outcomes in patients with acute kidney injury. Although robust evidence regarding long-term outcomes is lacking, existing data demonstrate that CCUS has the potential to improve diagnostic accuracy, expedite appropriate management, and increase safety for critically ill patients across a spectrum of pathologies.

BRIPPED scan for evaluation of ED patients with shortness of breath

OBJECTIVE

The BRIPPED scan is an ultrasound evaluation of pulmonary B-lines, right ventricle size, inferior vena cava collapsibility, pleural and pericardial effusion, pneumothorax, left ventricle ejection fraction, and lower extremity deep venous thrombosis. The primary goal was to evaluate the effect of the BRIPPED scan on the physician's list of differential diagnoses for patients presenting with shortness of breath.

METHODS

This prospective randomized control trial was performed on patients presenting to the emergency department with shortness of breath. Primary data analysis was performed using an ordinal quasi-symmetry model to compare the magnitude of change in the differential diagnoses between 2 groups. Secondary outcome measures included changes in physician orders or interventions, time to disposition, time to perform the BRIPPED scan, and the interrater reliability of the interpretation of the scan.

RESULTS

A total of 104 patients and 24 physicians were enrolled in this study. Fifty-two patients were randomly assigned to each cohort. Among the BRIPPED cohort, there was significant movement of likelihood for several etiologies of shortness of breath on the physician differential. There was no significance in the change of differential diagnosis between the BRIPPED and control cohorts. The average (SD) time to perform the scan was 5.7 (1.3) minutes (95% confidence interval, 5.4-6 minutes).

CONCLUSION

The BRIPPED scan is a rapid ultrasound evaluation of shortness of breath in the emergency department. BRIPPED influenced physician differential diagnoses to the same degree as laboratory and radiographic testing. BRIPPED did not alter the final diagnosis in this patient population.

BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill

This review article describes two protocols adapted from lung ultrasound: the bedside lung ultrasound in emergency (BLUE)-protocol for the immediate diagnosis of acute respiratory failure and the fluid administration limited by lung sonography (FALLS)-protocol for the management of acute circulatory failure. These applications require the mastery of 10 signs indicating normal lung surface (bat sign, lung sliding, A-lines), pleural effusions (quad and sinusoid sign), lung consolidations (fractal and tissue-like sign), interstitial syndrome (lung rockets), and pneumothorax (stratosphere sign and the lung point). These signs have been assessed in adults, with diagnostic accuracies ranging from 90% to 100%, allowing consideration of ultrasound as a reasonable bedside gold standard. In the BLUE-protocol, profiles have been designed for the main diseases (pneumonia, congestive heart failure, COPD, asthma, pulmonary embolism, pneumothorax), with an accuracy &gt; 90%. In the FALLS-protocol, the change from A-lines to lung rockets appears at a threshold of 18 mm Hg of pulmonary artery occlusion pressure, providing a direct biomarker of clinical volemia. The FALLS-protocol sequentially rules out obstructive, then cardiogenic, then hypovolemic shock for expediting the diagnosis of distributive (usually septic) shock. These applications can be done using simple grayscale machines and one microconvex probe suitable for the whole body. Lung ultrasound is a multifaceted tool also useful for decreasing radiation doses (of interest in neonates where the lung signatures are similar to those in adults), from ARDS to trauma management, and from ICUs to points of care. If done in suitable centers, training is the least of the limitations for making use of this kind of visual medicine.

Detection of abnormalities in ultrasound lung image using multi-level RVM classification

The classification of abnormalities in ultrasound images is the monitoring tool of fluid to air passage in the lung. In this study, the adaptive median filtering technique is employed for the preprocessing step. The preprocessed image is then extracted the features by the convoluted local tetra pattern, histogram of oriented gradient, Haralick feature extraction and the complete local binary pattern. The extracted features are selected by applying particle swarm optimization and differential evolution feature selection. In the final stage, classifiers namely relevance vector machine (RVM), and multi-level RVM are employed to perform classification of the lung diseases. The diseases respiratory distress syndrome (RDS), transient tachypnea of the new born, meconium aspiration syndrome, pneumothorax, bronchiolitis, pneumonia, and lung cancer are used for training and testing. The experimental analysis exhibits better accuracy, sensitivity, specificity, pixel count and fitness value than the other existing methods. The classification accuracy of above 90% is accomplished by multi-level RVM classifier. The system has been tested with a number of ultrasound lung images and has achieved satisfactory results in classifying the lung diseases.

The diagnosis of right heart thrombus by focused cardiac ultrasound in a critically ill patient in compensated shock

Right heart thrombus (RHT) is a life-threatening diagnosis that is rarely made in the emergency department (ED), but with the increasing use of focused cardiac ultrasound (FocUS), more of these cases may be identified in a timely fashion. We present a case of an ill-appearing patient who had an immediate change in management due to the visualization of RHT soon after arrival to the ED. The diagnosis was confirmed after a cardiology-performed ultrasound (US). This case illustrates the value of the recognition of RHT on FocUS and how US protocols designed for the evaluation of shock and shortness of breath may potentially be expanded to patients in a 'compensated' or 'pre-shock' state to expedite the correct diagnosis and to facilitate more timely management.

Point-of-Care Cardiac Ultrasound: Feasibility of Performance by Noncardiologists

Cardiac ultrasound has been used for decades to assess a wide variety of structural and functional pathology, as well as to monitor response to therapy. It offers the advantages of noninvasive, real-time dynamic functional assessment without the risk of radiation. Cardiologists have traditionally employed this modality and have established robust guidelines on the use of echocardiography. However, other specialties such as emergency medicine and critical care have realized the benefit of cardiac ultrasound and have established specialty guidelines in its use. There is growing evidence for the benefit of cardiac ultrasound at the point of care on hospital wards, clinics, and even pre-hospital environments as well. The pervasive use of focused ultrasound is perhaps most evident in the advent of ultrasound training in undergraduate medical curricula. This paper reviews some of the key literature on the use of focused, point-of-care ultrasound by noncardiologists. Feasibility, clinical utility, and emerging trends are reviewed.

Accuracy of early rapid ultrasound in shock (RUSH) examination performed by emergency physician for diagnosis of shock etiology in critically ill patients

Background:

Rapid Ultrasound in Shock (RUSH) is a recently reported emergency ultrasound protocol designed to help clinicians better recognize distinctive shock etiologies in a short time. We tried to evaluate the accuracy of early RUSH protocol performed by emergency physicians to predict the shock type in critically ill patients.

Materials and Methods:

Our prospective study was approved by the ethics committee of trauma research center, Baqiyatallah University of Medical Science, Iran. We enrolled 52 patients with shock state in the emergency department from April 2013 to October 2013. We performed early bed-side sonographic examination for participants based on RUSH protocol. Patients received all needed standard therapeutic and diagnostic interventions without delay and were followed to document their final diagnosis. Agreement (Kappa index) of initial impression provided by RUSH with final diagnosis, and also sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RUSH for diagnosis of each shock type were calculated.

Results:

Fifty-two patients were enrolled in our study. Kappa index was 0.7 (P value = 0.000), reflecting acceptable general agreement between initial impression and final diagnosis. For hypovolemic and obstructive shocks, the protocol had sensitivity of 100% but had lower PPV. For shocks with distributive or mixed etiology, RUSH showed PPV of 100% but had low sensitivity. For cardiogenic shocks, all reliability indices were above 90%.

Conclusion:

We highlight the role of RUSH examination in the hands of an emergency physician in making a rapid diagnosis of shock etiology, especially in ruling out obstructive, cardiogenic, and hypovolemic types.

Bedside ultrasonography (US), Echoscopy and US point of care as a new kind of stethoscope for Internal Medicine Departments: the training program of the Italian Internal Medicine Society (SIMI)

In recent years, thanks to the development of miniaturized ultrasound devices, comparable to personal computers, tablets and even to smart phones, we have seen an increasing use of bedside ultrasound in internal medicine departments as a novel kind of ultrasound stethoscope. The clinical ultrasound-assisted approach has proved to be particularly useful in assessing patients with nodules of the neck, dyspnoea, abdominal pain, and with limb edema. In several cases, it has allowed a simple, rapid and precise diagnosis. Since 2005, the Italian Society of Internal Medicine and its Ultrasound Study Group has been holding a Summer School and training courses in ultrasound for residents in internal medicine. A national network of schools in bedside ultrasound was then organized for internal medicine specialists who want to learn this technique. Because bedside ultrasound is a user-dependent diagnostic method, it is important to define the limits and advantages of different new ultrasound devices, to classify them (i.e. Echoscopy and Point of Care Ultrasound), to establish appropriate different levels of competence and to ensure their specific training. In this review, we describe the point of view of the Italian Internal Medicine Society on these topics.

Critical care ultrasonography

Resuscitative ultrasonography provides rapid, repeatable, and multisystem assessment to guide diagnosis and management of critically ill patients in the emergency department (ED). Cardiac ultrasonography offers new anatomic and hemodynamic information, previously unavailable in an ED setting, whereas other applications match or exceed the speed and utility of existing tests such as chest radiograph (thoracic ultrasonography) or central venous pressure determination (inferior vena cava ultrasonography). Evolving areas of resuscitative ultrasonography include neurologic applications and transesophageal echocardiography, which promise to further enhance the role of ultrasonography in managing critical illness in the ED.

The CORE scan: concentrated overview of resuscitative efforts

Critically ill patients require rapid, accurate assessments and appropriate therapeutic interventions to maximize their chances of recovery. Often the cause of a patient's decompensation is not readily apparent based solely on history and physical examination findings. The Concentrated Overview of Resuscitative Efforts (CORE scan) is a compilation of targeted bedside ultrasound exams that should be performed during the assessment and management of critically ill patients. The CORE scan can be used to help make critical diagnoses and guide resuscitation efforts in patients with undifferentiated deterioration.

Integrated cardiopulmonary sonography: a useful tool for assessment of acute pulmonary edema in the intensive care unit

OBJECTIVES

Bedside sonography has become a popular method of assessment of critically ill patients with shock and dyspnea. This study evaluated the usefulness of integrated cardiopulmonary sonography for assessment of acute pulmonary edema.

METHODS

A total of 128 intensive care unit (ICU) patients with acute pulmonary edema were randomly divided into 2 groups: a sonography group, which received standard treatment as well as cardiopulmonary sonography, and a control group, which received standard treatment only. All patients were treated according to the same therapeutic strategies and underwent chest radiography and central venous catheter placement. Serum myocardial injury marker levels and central venous/arterial blood gas parameters were measured 0, 24, and 72 hours after enrollment. The cumulative fluid infusion volume at 6, 12, 24, and 72 hours, the time to diagnosis of the pulmonary edema etiology by the attending physician, the lengths of ICU and hospital stays, and ICU mortality were recorded.

RESULTS

The sonography group had a shorter time to diagnosis and received a smaller fluid infusion volume than the control group. There were no significant differences in ICU mortality and lengths of ICU and hospital stays between the sonography and control groups. In patients with cardiogenic pulmonary edema, the sonography group had a significantly shorter ICU stay and a faster return to normal myocardial injury marker levels and perfusion parameters than the control group (P < .05).

CONCLUSIONS

Integrated cardiopulmonary sonography resulted in faster and better-informed clinical decision making, shortened the time to diagnosis of the pulmonary edema etiology, and decreased fluid use. However, the impact of this examination on prognoses requires further study. We propose that integrated cardiopulmonary sonography may be a useful bedside tool for treatment of ICU patients with acute pulmonary edema.

Ultrasonography for clinical decision-making and intervention in airway management: from the mouth to the lungs and pleurae

OBJECTIVES

To create a state-of-the-art overview of the new and expanding role of ultrasonography in clinical decision-making, intervention and management of the upper and lower airways, that is clinically relevant, up-to-date and practically useful for clinicians.

METHODS

This is a narrative review combined with a structured Medline literature search.

RESULTS

Ultrasonography can be utilised to predict airway difficulty during induction of anaesthesia, evaluate if the stomach is empty or possesses gastric content that poses an aspiration risk, localise the essential cricothyroid membrane prior to difficult airway management, perform nerve blocks for awake intubation, confirm tracheal or oesophageal intubation and facilitate localisation of tracheal rings for tracheostomy. Ultrasonography is an excellent diagnostic tool in intraoperative and emergency diagnosis of pneumothorax. It also enables diagnosis and treatment of interstitial syndrome, lung consolidation, atelectasis, pleural effusion and differentiates causes of acute breathlessness during pregnancy. Patient safety can be enhanced by performing procedures under ultrasound guidance, e.g. thoracocentesis, vascular line access and help guide timing of removal of chest tubes by quantification of residual pneumothorax size.

CONCLUSIONS

Ultrasonography used in conjunction with hands-on management of the upper and lower airways has multiple advantages. There is a rapidly growing body of evidence showing its benefits.

TEACHING POINTS

• Ultrasonography is becoming essential in management of the upper and lower airways. • The tracheal structures can be identified by ultrasonography, even when unidentifiable by palpation. • Ultrasonography is the primary diagnostic approach in suspicion of intraoperative pneumothorax. • Point-of-care ultrasonography of the airways has a steep learning curve. • Lung ultrasonography allows treatment of interstitial syndrome, consolidation, atelectasis and effusion.

Lung Ultrasound Predicts Interstitial Syndrome and Hemodynamic Profile in Parturients with Severe Preeclampsia

Background:

The role of lung ultrasound has never been evaluated in parturients with severe preeclampsia. The authors’ first aim was to assess the ability of lung ultrasound to detect pulmonary edema in severe preeclampsia. The second aim was to highlight the relation between B-lines and increased left ventricular end-diastolic pressures.

Methods:

This prospective cohort study was conducted in a level-3 maternity during a 12-month period. Twenty parturients with severe preeclampsia were consecutively enrolled. Both lung and cardiac ultrasound examinations were performed before (n = 20) and after delivery (n = 20). Each parturient with severe preeclampsia was compared with a control healthy parturient. Pulmonary edema was determined using two scores: the B-pattern and the Echo Comet Score. Left ventricular end-diastolic pressures were assessed by transthoracic echocardiography.

Results:

Lung ultrasound detected interstitial edema in five parturients (25%) with severe preeclampsia. A B-pattern was associated to increased mitral valve early diastolic peak E (116 vs. 90 cm/s; P = 0.05) and to increased E/E’ ratio (9.9 vs. 6.6; P &lt; 0.001). An Echo Comet Score of greater than 25 predicted an increase in filling pressures (E/E’ ratio &gt;9.5) with a sensitivity and specificity of 1.00 (95% CI, 0.69 to 1.00) and 0.82 (95% CI, 0.66 to 0.92), respectively.

Conclusions:

In parturients with severe preeclampsia, lung ultrasound detects both pulmonary edema and increased left ventricular end-diastolic pressures. The finding of a B-pattern should restrict the use of fluid. However, these preliminary results are associations from a single sample. They need to be replicated in a larger, definitive study.

Usefulness of cardiothoracic chest ultrasound in the management of acute respiratory failure in critical care practice

BACKGROUND

This study investigated the clinical relevance of early general chest ultrasonography (ie, heart and lung recordings) in patients in the ICU with acute respiratory failure (ARF).

METHODS

We prospectively compared this diagnostic approach (ultrasound) to a routine evaluation established from clinical, radiologic, and biologic data (standard). Subjects were patients consecutively admitted to the ICU of a university teaching hospital during a 1-year period. Inclusion criteria were age ≥ 18 years and the presence of severe ARF criteria to justify ICU admission. We compared the diagnostic approaches and the final diagnosis determined by a panel of experts.

RESULTS

Seventy-eight patients were included (age, 70 ± 18 years; sex ratio, 1). Three patients given two or more simultaneous diagnoses were subsequently excluded. The ultrasound approach was more accurate than the standard approach (83% vs 63%, respectively; P &lt; .02). Receiver operating characteristic curve analysis showed greater diagnostic performance of ultrasound in cases of pneumonia (standard, 0.74 ± 0.12; ultrasound, 0.87 ± 0.14; P &lt; .02), acute hemodynamic pulmonary edema (standard, 0.79 ± 0.11; ultrasound, 0.93 ± 0.08; P &lt; .007), decompensated COPD (standard, 0.8 ± 0.09; ultrasound, 0.92 ± 0.15; P &lt; .05), and pulmonary embolism (standard, 0.65 ± 0.12; ultrasound, 0.81 ± 0.17; P &lt; .04). Furthermore, we found that the use of ultrasound data could have significantly improved the initial treatment.

CONCLUSIONS

The use of cardiothoracic ultrasound appears to be an attractive complementary diagnostic tool and seems able to contribute to an early therapeutic decision based on reproducible physiopathologic data.

Frequency and number of ultrasound lung rockets (B-lines) using a regionally based lung ultrasound examination named vet BLUE (veterinary bedside lung ultrasound exam) in dogs with radiographically normal lung findings

Lung ultrasound is superior to lung auscultation and supine chest radiography for many respiratory conditions in human patients. Ultrasound diagnoses are based on easily learned patterns of sonographic findings and artifacts in standardized images. By applying the wet lung (ultrasound lung rockets or B-lines, representing interstitial edema) versus dry lung (A-lines with a glide sign) concept many respiratory conditions can be diagnosed or excluded. The ultrasound probe can be used as a visual stethoscope for the evaluation of human lungs because dry artifacts (A-lines with a glide sign) predominate over wet artifacts (ultrasound lung rockets or B-lines). However, the frequency and number of wet lung ultrasound artifacts in dogs with radiographically normal lungs is unknown. Thus, the primary objective was to determine the baseline frequency and number of ultrasound lung rockets in dogs without clinical signs of respiratory disease and with radiographically normal lung findings using an 8-view novel regionally based lung ultrasound examination called Vet BLUE. Frequency of ultrasound lung rockets were statistically compared based on signalment, body condition score, investigator, and reasons for radiography. Ten left-sided heart failure dogs were similarly enrolled. Overall frequency of ultrasound lung rockets was 11% (95% confidence interval, 6-19%) in dogs without respiratory disease versus 100% (95% confidence interval, 74-100%) in those with left-sided heart failure. The low frequency and number of ultrasound lung rockets observed in dogs without respiratory disease and with radiographically normal lungs suggests that Vet BLUE will be clinically useful for the identification of canine respiratory conditions.

Lung ultrasound for the evaluation of pulmonary congestion in outpatients: a comparison with clinical assessment, natriuretic peptides, and echocardiography

OBJECTIVES

The aim of this study was to define the performance of lung ultrasound (LUS) compared with clinical assessment, natriuretic peptides, and echocardiography, to evaluate decompensation in patients with systolic heart failure (HF) in an outpatient clinic.

BACKGROUND

Evaluation of pulmonary congestion in chronic HF is challenging. LUS has been recently proposed as a reliable tool for the semiquantification of extravascular lung water through assessment of B-lines.

METHODS

This was a cohort study of patients with moderate to severe systolic HF. Receiver-operating characteristic (ROC) analyses were performed to compare LUS with a previously validated clinical congestion score (CCS), amino-terminal portion of B-type natriuretic peptide (NT-proBNP), E/e' ratio, chest x-ray, and 6-min walk test.

RESULTS

Ninety-seven patients were enrolled. Decompensation was present in 57.7% of patients when estimated by CCS, 68% by LUS, 53.6% by NT-proBNP, and 65.3% by E/e' ≥15. The number of B-lines was correlated to NT-proBNP (r = 0.72; p < 0.0001), E/e' (r = 0.68; p < 0.0001), and CCS (r = 0.43; p < 0.0001). In ROC analyses, considering as reference for decompensation a combined method (E/e' ≥ 15 and/or NT-proBNP >1,000 pg/ml), LUS yielded a C-statistic of 0.89 (95% confidence interval: 0.82 to 0.96), providing the best accuracy with a cutoff ≥ 15 B-lines (sensitivity 85%, specificity 83%). A systematic approach using CCS, E/e', NT-proBNP, chest x-ray, and 6-min walk test in different combinations as reference for decompensation also corroborated this cutoff and found a similar accuracy for LUS.

CONCLUSIONS

In an HF outpatient clinic, B-lines were significantly correlated with more established parameters of decompensation. A B-line ≥15 cutoff could be considered for a quick and reliable assessment of decompensation in outpatients with HF.

Point-of-care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department

PURPOSE

We analyzed the efficacy of a point-of-care ultrasonographic protocol, based on a focused multiorgan examination, for the diagnostic process of symptomatic, non-traumatic hypotensive patients in the emergency department.

METHODS

We prospectively enrolled 108 adult patients complaining of non-traumatic symptomatic hypotension of uncertain etiology. Patients received immediate point-of-care ultrasonography to determine cardiac function and right/left ventricle diameter rate, inferior vena cava diameter and collapsibility, pulmonary congestion, consolidations and sliding, abdominal free fluid and aortic aneurysm, and leg vein thrombosis. The organ-oriented diagnoses were combined to formulate an ultrasonographic hypothesis of the cause of hemodynamic instability. The ultrasonographic diagnosis was then compared with a final clinical diagnosis obtained by agreement of three independent expert physicians who performed a retrospective hospital chart review of each case.

RESULTS

Considering the whole population, concordance between the point-of-care ultrasonography diagnosis and the final clinical diagnosis was interpreted as good, with Cohen's k = 0.710 (95 % CI, 0.614-0.806), p < 0.0001 and raw agreement (Ra) = 0.768. By eliminating the 13 cases where the final clinical diagnosis was not agreed upon (indefinite), the concordance increased to almost perfect, with k = 0.971 (95 % CI, 0.932-1.000), p < 0.0001 and Ra = 0.978.

CONCLUSIONS

Emergency diagnostic judgments guided by point-of-care multiorgan ultrasonography in patients presenting with undifferentiated hypotension significantly agreed with a final clinical diagnosis obtained by retrospective chart review. The integration of an ultrasonographic multiorgan protocol in the diagnostic process of undifferentiated hypotension has great potential in guiding the first-line therapeutic approach.

Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol

Assessment of hemodynamic status in a shock state remains a challenging issue in Emergency Medicine and Critical Care. As the use of invasive hemodynamic monitoring declines, bedside-focused ultrasound has become a valuable tool in the evaluation and management of patients in shock. No longer a means to simply evaluate organ anatomy, ultrasound has expanded to become a rapid and noninvasive method for the assessment of patient physiology. Clinicians caring for critical patients should strongly consider integrating ultrasound into their resuscitation pathways.

Cardiopulmonary interactions and volume status assessment

Assessment of the hemodynamics and volume status is an important daily task for physicians caring for critically ill patients. There is growing consensus in the critical care community that the "traditional" methods-e.g., central venous pressure or pulmonary artery occlusion pressure-used to assess volume status and fluid responsiveness are not well supported by evidence and can be misleading. Our purpose is to provide here an overview of the knowledge needed by ICU physicians to take advantage of mechanical cardiopulmonary interactions to assess volume responsiveness. Although not perfect, such dynamic assessment of fluid responsiveness can be helpful particularly in the passively ventilated patients. We discuss the impact of phasic changes in lung volume and intrathoracic pressure on the pulmonary and systemic circulation and on the heart function. We review how respirophasic changes on the venous side (great veins geometry) and arterial side (e.g., stroke volume/systolic blood pressure and surrogate signals) can be used to detect fluid responsiveness or hemodynamic alterations commonly encountered in the ICU. We review the physiological limitations of this approach.