Lung Ultrasound Predicts Well Extravascular Lung Water but Is of Limited Usefulness in the Prediction of Wedge Pressure

Lung ultrasound among Expert operator'S: ScOring and iNter-rater reliability analysis (LESSON study) a secondary COWS study analysis from ITALUS group

BACKGROUND

Lung ultrasonography (LUS) is a non-invasive imaging method used to diagnose and monitor conditions such as pulmonary edema, pneumonia, and pneumothorax. It is precious where other imaging techniques like CT scan or chest X-rays are of limited access, especially in low- and middle-income countries with reduced resources. Furthermore, LUS reduces radiation exposure and its related blood cancer adverse events, which is particularly relevant in children and young subjects. The score obtained with LUS allows semi-quantification of regional loss of aeration, and it can provide a valuable and reliable assessment of the severity of most respiratory diseases. However, inter-observer reliability of the score has never been systematically assessed. This study aims to assess experienced LUS operators' agreement on a sample of video clips showing predefined findings.

METHODS

Twenty-five anonymized video clips comprehensively depicting the different values of LUS score were shown to renowned LUS experts blinded to patients' clinical data and the study's aims using an online form. Clips were acquired from five different ultrasound machines. Fleiss-Cohen weighted kappa was used to evaluate experts' agreement.

RESULTS

Over a period of 3 months, 20 experienced operators completed the assessment. Most worked in the ICU (10), ED (6), HDU (2), cardiology ward (1), or obstetric/gynecology department (1). The proportional LUS score mean was 15.3 (SD 1.6). Inter-rater agreement varied: 6 clips had full agreement, 3 had 19 out of 20 raters agreeing, and 3 had 18 agreeing, while the remaining 13 had 17 or fewer people agreeing on the assigned score. Scores 0 and score 3 were more reproducible than scores 1 and 2. Fleiss' Kappa for overall answers was 0.87 (95% CI 0.815-0.931, p < 0.001).

CONCLUSIONS

The inter-rater agreement between experienced LUS operators is very high, although not perfect. The strong agreement and the small variance enable us to say that a 20% tolerance around a measured value of a LUS score is a reliable estimate of the patient's true LUS score, resulting in reduced variability in score interpretation and greater confidence in its clinical use.

Complex Heart-Lung Ventilator Emergencies in the CICU

This review aims to enhance the comprehension and management of cardiopulmonary interactions in critically ill patients with cardiovascular disease undergoing mechanical ventilation. Highlighting the significance of maintaining a delicate balance, this article emphasizes the crucial role of adjusting ventilation parameters based on both invasive and noninvasive monitoring. It provides recommendations for the induction and liberation from mechanical ventilation. Special attention is given to the identification of auto-PEEP (positive end-expiratory pressure) and other situations that may impact hemodynamics and patients' outcomes.

The role of lung and cardiac ultrasound for cardiovascular hemodynamic assessment of women with preeclampsia

Preeclampsia remains the leading cause of maternal morbidity and mortality and is associated with abnormal body fluid homeostasis and cardiovascular dysfunction. Moreover, 2 distinct hemodynamic phenotypes have been described in preeclampsia, which might require different therapeutic approaches. Fluid restriction is mandatory in women at risk of pulmonary edema, whereas additional fluid administration may be required to correct tissue hypoperfusion in women with intravascular volume depletion. As clinical examination alone cannot discriminate among different hemodynamic patterns, optimal management of women with preeclampsia remains challenging. Noninvasive bedside ultrasound has become an important diagnostic and monitoring tool in critically ill patients, and it has been demonstrated that it can also be used in the monitoring of women with preeclampsia. Echocardiography in combination with lung ultrasound provides information on hemodynamic status, cardiac function, lung congestion, and fluid responsiveness and, therefore, could help clinicians identify women at higher risk of life-threatening complications. This review describes the cardiovascular changes in preeclampsia and provides an overview of the ultrasound methodologies that could be efficiently used for better hemodynamic assessment and management of women with preeclampsia.

Coexistence of a fluid responsive state and venous congestion signals in critically ill patients: a multicenter observational proof-of-concept study

BACKGROUND

Current recommendations support guiding fluid resuscitation through the assessment of fluid responsiveness. Recently, the concept of fluid tolerance and the prevention of venous congestion (VC) have emerged as relevant aspects to be considered to avoid potentially deleterious side effects of fluid resuscitation. However, there is paucity of data on the relationship of fluid responsiveness and VC. This study aims to compare the prevalence of venous congestion in fluid responsive and fluid unresponsive critically ill patients after intensive care (ICU) admission.

METHODS

Multicenter, prospective cross-sectional observational study conducted in three medical-surgical ICUs in Chile. Consecutive mechanically ventilated patients that required vasopressors and admitted < 24 h to ICU were included between November 2022 and June 2023. Patients were assessed simultaneously for fluid responsiveness and VC at a single timepoint. Fluid responsiveness status, VC signals such as central venous pressure, estimation of left ventricular filling pressures, lung, and abdominal ultrasound congestion indexes and relevant clinical data were collected.

RESULTS

Ninety patients were included. Median age was 63 [45-71] years old, and median SOFA score was 9 [7-11]. Thirty-eight percent of the patients were fluid responsive (FR+), while 62% were fluid unresponsive (FR-). The most prevalent diagnosis was sepsis (41%) followed by respiratory failure (22%). The prevalence of at least one VC signal was not significantly different between FR+ and FR- groups (53% vs. 57%, p = 0.69), as well as the proportion of patients with 2 or 3 VC signals (15% vs. 21%, p = 0.4). We found no association between fluid balance, CRT status, or diagnostic group and the presence of VC signals.

CONCLUSIONS

Venous congestion signals were prevalent in both fluid responsive and unresponsive critically ill patients. The presence of venous congestion was not associated with fluid balance or diagnostic group. Further studies should assess the clinical relevance of these results and their potential impact on resuscitation and monitoring practices.

Lung ultrasound and supine chest X-ray use in modern adult intensive care: mapping 30 years of advancement (1993-2023)

In critically ill patients with acute respiratory failure, thoracic images are essential for evaluating the nature, extent and progression of the disease, and for clinical management decisions. For this purpose, computed tomography (CT) is the gold standard. However, transporting patients to the radiology suite and exposure to ionized radiation limit its use. Furthermore, a CT scan is a static diagnostic exam for the thorax, not allowing, for example, appreciation of "lung sliding". Its use is also unsuitable when it is necessary to adapt or decide to modify mechanical ventilation parameters at the bedside in real-time. Therefore, chest X-ray and lung ultrasound are today's contenders for shared second place on the podium to acquire a thoracic image, with their specific strengths and limitations. Finally, electrical impedance tomography (EIT) could soon have a role, however, its assessment is outside the scope of this review. Thus, we aim to carry out the following points: (1) analyze the advancement in knowledge of lung ultrasound use and the related main protocols adopted in intensive care units (ICUs) over the latest 30 years, reporting the principal publications along the way, (2) discuss how and when lung ultrasound should be used in a modern ICU and (3) illustrate the possible future development of LUS.

Current and Future Role of Ultrasonography in the Cardiac Intensive Care Unit

The contemporary practice of ultrasonography in the cardiac intensive care unit integrates the principles of echocardiography with whole-body imaging to create a more expansive paradigm of critical care ultrasonography (CCUS). This article will review the use of CCUS for diagnostic assessment, monitoring, therapeutic guidance, and prognosis.

The "CHEOPS" bundle for the management of Left Ventricular Diastolic Dysfunction in critically ill patients: an experts' opinion

The impact of left ventricular (LV) diastolic dysfunction (DD) on the outcome of patients with heart failure was established over three decades ago. Nevertheless, the relevance of LVDD for critically ill patients admitted to the intensive care unit has seen growing interest recently, and LVDD is associated with poor prognosis. Whilst an assessment of LV diastolic function is desirable in critically ill patients, treatment options for LVDD are very limited, and pharmacological possibilities to rapidly optimize diastolic function have not been found yet. Hence, a proactive approach might have a substantial role in improving the outcomes of these patients. Recalling historical Egyptian parallelism suggesting that Doppler echocardiography has been the "Rosetta stone" to decipher the study of LV diastolic function, we developed a potentially useful acronym for physicians at the bedside to optimize the management of critically ill patients with LVDD with the application of the bundle. We summarized the bundle under the acronym of the famous ancient Egyptian pharaoh CHEOPS: Chest Ultrasound, combining information from echocardiography and lung ultrasound; HEmodynamics assessment, with careful evaluation of heart rate and rhythm, as well as afterload and vasoactive drugs; OPtimization of mechanical ventilation and pulmonary circulation, considering the effects of positive end-expiratory pressure on both right and left heart function; Stabilization, with cautious fluid administration and prompt fluid removal whenever judged safe and valuable. Notably, the CHEOPS bundle represents experts' opinion and are not targeted at the initial resuscitation phase but rather for the optimization and subsequent period of critical illness.

Lung ultrasonography derived B-line scores as predictors of left ventricular end-diastolic pressure and pulmonary artery wedge pressure

BACKGROUND

Non-invasive assessment of elevated left ventricular end-diastolic pressure (LVEDP) and pulmonary artery wedge pressure (PAWP) in patients with heart diseases is challenging. Lung ultrasonography (LUS) is a promising modality for predicting LVEDP and PAWP.

METHODS

Fifty-seven stable ambulatory patients who underwent right and left heart catheterization were included. Following the procedures, LUS was performed in twenty-eight ultrasonographic zones, and the correlation between five different LUS derived B-line scores with LVEDP and PAWP was examined.

RESULTS

The B-line index correlated with LVEDP and PAWP, with coefficients of 0.45 (p = 0.006) and 0.30 (p = 0.03), respectively. B-line index showed an AUC of 0.76 for identifying LVEDP > 15 mmHg (p = 0.01) and an AUC of 0.73 for identifying PAWP > 15 mmHg (p = 0.008). Overall, scores performances were similar in predicting LVEDP or PAWP > 15 mmHg. A B-line index ≥ 28 was significantly associated with LVEDP > 15 mmHg (OR: 9.97) and PAWP > 15 mmHg (OR: 6.61), adjusted for age and indication for heart catheterization.

CONCLUSIONS

LUS derived B-line scores are moderately correlated with PAWP and LVEDP in patients with heart diseases. A B-line index ≥ 28 can be used to predict elevated LVEDP and PAWP with high specificity.

Noninvasive Imaging Methods for Quantification of Pulmonary Edema and Congestion: A Systematic Review

Quantification of pulmonary edema and congestion is important to guide diagnosis and risk stratification, and to objectively evaluate new therapies in heart failure. Herein, we review the validation, diagnostic performance, and clinical utility of noninvasive imaging modalities in this setting, including chest x-ray, lung ultrasound (LUS), computed tomography (CT), nuclear medicine imaging methods (positron emission tomography [PET], single photon emission CT), and magnetic resonance imaging (MRI). LUS is a clinically useful bedside modality, and fully quantitative methods (CT, MRI, PET) are likely to be important contributors to a more accurate and precise evaluation of new heart failure therapies and for clinical use in conjunction with cardiac imaging. There are only a limited number of studies evaluating pulmonary congestion during stress. Taken together, noninvasive imaging of pulmonary congestion provides utility for both clinical and research assessment, and continued refinement of methodologic accuracy, validation, and workflow has the potential to increase broader clinical adoption.

Objective Methods of Assessing Fluid Status to Optimize Volume Management in Kidney Disease and Hypertension: The Importance of Ultrasound

Fluid overload, a prevalent complication in patients with renal disease and hypertension, significantly impacts patient morbidity and mortality. The daily clinical challenges that clinicians face include how to identify fluid overload early enough in the course of the disease to prevent adverse outcomes and to guide and potentially reduce the intensity of the diuresis. Traditional methods for evaluating fluid status, such as pitting edema, pulmonary crackles, or chest radiography primarily assess extracellular fluid and do not accurately reflect intravascular volume status or venous congestion. This review explores the rationale, mechanism, and evidence behind more recent methods used to assess volume status, namely, lung ultrasound, inferior vena cava (IVC) ultrasound, venous excess ultrasound score, and basic and advanced cardiac echocardiographic techniques. These methods offer a more accurate and objective assessment of fluid status, providing real-time, non-invasive measures of intravascular volume and venous congestion. The methods we discuss are primarily used in inpatient settings, but, given the increased pervasiveness of ultrasound technology, some could soon expand to the outpatient setting.

Remote multiparametric monitoring and management of heart failure patients through cardiac implantable electronic devices

In this review we focus on heart failure (HF) which, as known, is associated with a substantial risk of hospitalizations and adverse cardiovascular outcomes, including death. In recent years, systems to monitor cardiac function and patient parameters have been developed with the aim to detect subclinical pathophysiological changes that precede worsening HF. Several patient-specific parameters can be remotely monitored through cardiac implantable electronic devices (CIED) and can be combined in multiparametric scores predicting patients' risk of worsening HF with good sensitivity and moderate specificity. Early patient management at the time of pre-clinical alerts remotely transmitted by CIEDs to physicians might prevent hospitalizations. However, it is not clear yet which is the best diagnostic pathway for HF patients after a CIED alert, which kind of medications should be changed or escalated, and in which case in-hospital visits or in-hospital admissions are required. Finally, the specific role of healthcare professionals involved in HF patient management under remote monitoring is still matter of definition. We analyzed recent data on multiparametric monitoring of patients with HF through CIEDs. We provided practical insights on how to timely manage CIED alarms with the aim to prevent worsening HF. We also discussed the role of biomarkers and thoracic echo in this context, and potential organizational models including multidisciplinary teams for remote care of HF patients with CIEDs.

Heart failure diagnosis in the general community - Who, how and when? A clinical consensus statement of the Heart Failure Association (HFA) of the European Society of Cardiology (ESC)

A significant proportion of patients experience delays in the diagnosis of heart failure due to the non-specific signs and symptoms of the syndrome. Diagnostic tools such as measurement of natriuretic peptide concentrations are fundamentally important when screening for heart failure, yet are frequently under-utilized. This clinical consensus statement provides a diagnostic framework for general practitioners and non-cardiology community-based physicians to recognize, investigate and risk-stratify patients presenting in the community with possible heart failure.

Individual Changes in Respiratory Compliance Upon Immersion May Predict Susceptibility to Immersion Pulmonary Edema

BACKGROUND

Immersion pulmonary edema (IPE) is a frequent diving accident, and it is the primary cause of hospitalization for young military divers during training. The objective of this study was to identify immersion-induced parameters predicting individual susceptibility to IPE.

METHODS

Eighteen experienced male divers having completed at least 100 dives were recruited. Eight divers had previously been hospitalized for IPE (IPE), and the other ten had never developed IPE (non-IPE). The two groups were matched for age, BMI, and number of dives performed. Ventilatory function and overall compliance of the respiratory system (Crs) were measured on land and during head-out-of-water immersion. Subjects also performed 30 min of fin swimming in a channel at 33 m min^-1. Following this exercise, the presence of extravascular lung water, revealed by ultrasound lung comets (ULC), was assessed.

RESULTS

In the whole group, the decrease in Crs upon immersion correlated with the immersion-induced alterations to expiratory reserve volume, ERV (r² = 0.91; p < 0.001), inspiratory reserve volume, IRV (r² = 0.94; p < 0.001), and tidal volume, Vt, changes (r² = 0.43; p < 0.003). The number of ULC correlated strongly with immersion-induced changes in ventilatory function (r² = 0.818; p < 0.001 for ERV, r² = 0.849; p < 0.001 for IRV, r² = 0.304; p = 0.0164 for Vt) and reduced Crs (r² = 0.19; p < 0.001). The variations of ERV, IRV, and Crs at rest induced by head-out-of-water immersion and the number of ULC measured after swimming for 30 min were significantly greater in IPE subjects.

CONCLUSION

In the face of similar immersion stresses, the extent of alterations to ventilatory function and the number of ULCs were very different between individuals but remained statistically correlated. These parameters were significantly greater in divers with a history of IPE. Alterations to pulmonary function and, in particular, to pulmonary compliance induced by head-out-of-water immersion, through their effects on work of breathing appear to allow the identification of divers with a greater susceptibility to developing IPE. Measurement of these parameters could therefore be proposed as a predictive test for the risk of developing IPE.

Translating Guidelines into Practical Practice: Point-of-Care Ultrasound for Pediatric Critical Care Clinicians

Point-of-care ultrasound (POCUS) is now transitioning from an emerging technology to a standard of care for critically ill children. POCUS can provide immediate answers to clinical questions impacting management and outcomes within this fragile population. Recently published international guidelines specific to POCUS use in neonatal and pediatric critical care populations now complement previous Society of Critical Care Medicine guidelines. The authors review consensus statements within guidelines, identify important limitations to statements, and provide considerations for the successful implementation of POCUS in the pediatric critical care setting.

Lung ultrasound in congestion assessment of patients with advanced heart failure referred for heart transplant: Correlations with right heart catheterization findings

Background

In advanced heart failure (HF), diagnostic performance of physical exam may be poor. Physical examination associated with lung ultrasound (LUS) may be an important tool to facilitate congestion screening.

Objective

To evaluate performance of LUS for congestion screening in advanced HF referred for transplant, as compared to findings of right heart catheterization (RHC).

Methods

Prospective study of 23 subjects with advanced HF referred for RHC. LUS was performed in association with clinical congestion score (CCS), analogue-visual dyspnea scale (AVDS) and presence of trepopnea/bendopnea prior to catheterization. Congestion was assessed by the number of B-lines in the LUS, and by findings of physical examination as well as by NT-proBNP serum values.

Results

Congestion was present in 43.4 % of patients by LUS (B-lines ≥ 15), as compared to 21.7 % by CCS (score greater than or equal to 5), 56.5 % by NT-proBNP (>1000 pg/ml), and 60.8 % by pulmonary capillary wedge pressure (PCWP) (>15 mm Hg). The number of B-lines was correlated to cardiac index (CI) (rho = -0.619; p 0.002), but not with PCWP (rho 0.190; p 0.386), RAP (rho -0.244; p 0.262), CCS (rho 0.198; p 0.36) and neither with NT-proBNP (rho 0.282; p 0.193). Otherwise, NT-proBNP was correlated with PCWP (rho = 0.636; p = 0.001) and with CI (rho -0.667 p 0.001).

Conclusions

In advanced HF patients referred for transplant, number of B-lines in LUS was not correlated with PCWP or RAP. Advanced HF patients seem to have increased filling pressures, but no interstitial pulmonary congestion that LUS could detect.

Association between B-lines on lung ultrasound, invasive haemodynamics, and prognosis in acute heart failure patients

AIMS

Increased left atrial pressure leads to pulmonary congestion. Although the B-lines in lung ultrasound (LUS) are useful in detecting pulmonary congestion, data regarding the association between B-lines and invasive haemodynamics are inconsistent. This study aimed to explore the correlation of the B-line count by LUS with pulmonary capillary wedge pressure (PCWP) stratified for preserved and reduced ejection fraction (EF) in acute heart failure patients.

METHODS AND RESULTS

We performed a prospective observational study on 116 hospitalized patients with acute heart failure (mean age, 75.2 ± 10.3 years), who underwent right heart catheterization before discharge. LUS was performed in eight zones within 4 h of right heart catheterization and compared with PCWP separately in each EF group. Cardiac events were recorded 1 year after discharge. PCWP revealed a clear pivot point at which the B-lines began to increase in the overall cohort and each EF. Specific thresholds of the increase in B-lines were identified at 19 and 25 mmHg for preserved and reduced EF, respectively. Residual congestion at discharge was defined as the presence of ≥6 B-lines. Patients with residual congestion had a higher risk for cardiac events than those without residual congestion (hazard ratio, 12.6; 95% confidence interval, 4.71-33.7; log-rank, P < 0.0001).

CONCLUSION

A clear pivot point was associated with increased B-lines count in PCWP at 19 and 25 mmHg for preserved and reduced EF, respectively. Moreover, the increased B-line count above the defined cut-off used to quantify residual congestion was associated with significantly worse outcomes.

Lack of Association Between a Quantified Lung Ultrasound Score and Illness Severity in Pediatric Emergency Department Patients With Acute Lower Respiratory Infections

OBJECTIVES

Lung ultrasound (LUS) may help determine illness severity in children with acute lower respiratory tract infections (LRTI) but limited pediatric studies exist. Our objective was to determine the association between LUS findings and illness severity in children with LRTI.

METHODS

We conducted a prospective study of patients <20 years with LRTI. Trained investigators performed standardized LUS examinations of 12 regions. Blinded sonologists reviewed examinations for individual pathologic features and also calculated a Quantified Lung Ultrasound Score (QLUS). We defined focal severity as QLUS of ≥2 in ≥1 region, and diffuse severity as QLUS of ≥1 in ≥3 regions. The primary outcome was the Respiratory component of the Pediatric Early Warning Score (RPEWS), a 14-item scale measuring respiratory illness severity. Secondary outcomes included hospital admission, length of stay, supplemental oxygen, and antibiotic use.

RESULTS

We enrolled 85 patients with LRTIs, 46 (54%) whom were hospitalized (5.4% intensive care). Median RPEWS was 1 (interquartile range 2). Neither individual features on ultrasound nor total QLUS were associated with RPEWS, hospitalization, length of stay, or oxygen use. Mean RPEWS was similar for participants regardless of focal (1.46 versus 1.26, P = .57) or diffuse (1.47 versus 1.21, P = .47) severity findings, but those with focal or diffuse severity, or isolated consolidation, had greater antibiotic administration (P < .001).

CONCLUSIONS

In children with LRTI, neither individual features nor QLUS were associated with illness severity. Antibiotics were more likely in patients with either focal or diffuse severity or presence of consolidation on ultrasound.

Fluid management in acute kidney injury: from evaluating fluid responsiveness towards assessment of fluid tolerance

Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.

Lung ultrasound to quantitatively evaluate extravascular lung water content and its clinical significance

BACKGROUND

As we all know, pulmonary edema can be diagnosed by lung ultrasound (LUS), but how to accurately and quantitatively evaluate lung water content by ultrasound is a difficult problem that needs to be solved urgently. B-line assessment with LUS has recently been proposed as a reliable, noninvasive semiquantitative tool for evaluating extravascular lung water (EVLW). To date, however, there has been no easy quantitative method to evaluate EVLW by LUS.

OBJECTIVE

(1) To explore the feasibility of establishing a rabbit model with increased EVLW by injecting warm normal saline (NS) into the lungs via the endotracheal tube. (2) To establish a simple, accurate and clinically operable method for quantitative assessment of EVLW using LUS. (3) To develop LUS into a resource for guiding the clinical treatment of patients with increased EVLW.

METHODS

Forty-five New Zealand rabbits were randomized into nine groups (n = 5). After anesthesia, each group of rabbits was injected with different amounts of warm sterile NS (0 ml/kg, 2 ml/kg, 4 ml/kg, 6 ml/kg, 8 ml/kg, 10 ml/kg, 15 ml/kg, 20 ml/kg, 30 ml/kg) via the endotracheal tube. Each rabbit was examined by LUS before and after NS injection. At the same time, the spontaneous respiratory rate (RR, breaths per minute), heart rate (HR, bpm) and arterial blood gas (ABG) of the rabbits were recorded. Then, both lungs were dissected to obtain the wet and dry weight and conduct a complete histological examination.

RESULTS

Injecting NS into the lungs through a tracheal tube can successfully establish a rabbit model with increased EVLW. The extent of EVLW increase is related to the volume of NS injected into the lungs. As the EVLW increases, three different types of B-lines can be seen in the LUS. When the NS injection volume is 2-6 ml/kg, comet-tail artifacts and B-lines are the main patterns found on LUS; as additional NS is injected into the lungs, the rabbits' RR gradually increases, while their HR gradually decreases, ABG remains normal or shows mild metabolic acidosis (MA). Confluent B-lines grow gradually but significantly, reaching a dominant position when the NS injection volume reaches 6-8 ml/kg and predominating almost entirely when the NS injection volume is 8-15 ml/kg; at that time, rabbits' RRs and HRs decrease sharply, and the ABG indicated type I respiratory failure (RF).Compact B-lines occur and predominate almost entirely when the NS injection volume reaches 10 ml/kg and 15-20 ml/kg, respectively. At that time, rabbits begin to enter cardiac and respiratory arrest, and ABG shows type II RF and MA.

CONCLUSION

In this study, the establishment of an animal model with increased EVLW confirmed that different lung water content had corresponding manifestations in ultrasound and was associated with different degrees of clinical symptoms, and the study results can be used to guide clinical practice.

Prognostic Value of Lung Ultrasound in Aortic Stenosis

Background: Aortic stenosis (AS) is the most common primary valve lesion requiring intervention in Europe and North America. It has a prolonged subclinical period during which, as AS worsens, left ventricular adaptation becomes inadequate and impaired systolic and/or diastolic dysfunction may lead to overt heart failure (HF). The development of HF is an inflexion point in the natural history of AS. Pulmonary congestion is a cardinal feature in HF, and lung ultrasound (LUS) evaluation of B-lines has been proposed as a simple, noninvasive tool to assess pulmonary congestion.

Aim: To assess the presence and the prognostic value of sonographic pulmonary congestion in patients with moderate or severe AS.

Methods: 75 consecutive patients (39 women, mean age 73.85 ± 7.7 years) with moderate or severe AS were enrolled. All patients underwent comprehensive echocardiography and LUS with the 28 scanning-site assessment. Patients were followed-up for 13.4 ± 6 months to establish the prognostic value of LUS. A composite endpoint of death (of any cause), hospitalization for HF and intensification of loop diuretic therapy was considered.

Results: We found a severe degree of B-lines (≥30) in 29.33% of patients. The number of B-lines correlated with the estimated pulmonary artery systolic pressure (p < 0.001, r = 0.574) and increased along with NYHA class (p < 0.05, rho = 0.383). At multivariable analysis, B-lines ≥30, and mean gradient were the independent predictors of events [B-lines: 2.79 (CI 1.03–7.54), p = 0.04; mean gradient: 1.04 (CI 1.01–1.07), p = 0.004].

Conclusion: Evaluation of B-lines is a simple, highly feasible method to detect pulmonary congestion in AS. The number of B-lines correlates with the hemodynamic changes caused by AS and with the functional status of patients. A severe degree of sonographic pulmonary congestion is associated with an increased risk of adverse events.

Assessment of fluid unresponsiveness guided by lung ultrasound in abdominal surgery: a prospective cohort study

A fluid challenge can generate an infraclinical interstitial syndrome that may be detected by the appearance of B-lines by lung ultrasound. Our objective was to evaluate the appearance of B-lines as a diagnostic marker of preload unresponsiveness and postoperative complications in the operating theater. We conducted a prospective, bicentric, observational study. Adult patients undergoing abdominal surgery were included. Stroke volume (SV) was determined before and after a fluid challenge with 250 mL crystalloids (Delta-SV) using esophageal Doppler monitoring. Responders were defined by an increase of Delta-SV > 10% after fluid challenge. B-lines were collected at four bilateral predefined zones (right and left anterior and lateral). Delta-B-line was defined as the number of newly appearing B-lines after a fluid challenge. Postoperative pulmonary complications were prospectively recorded according to European guidelines. In total, 197 patients were analyzed. After a first fluid challenge, 67% of patients were responders and 33% were non-responders. Delta-B-line was significantly higher in non-responders than responders [4 (2–7) vs 1 (0–3), p < 0.0001]. Delta-B-line was able to diagnose fluid non-responders with an area under the curve of 0.74 (95% CI 0.67–0.80, p < 0.0001). The best threshold was two B-lines with a sensitivity of 80% and a specificity of 57%. The final Delta-B-line could predict postoperative pulmonary complications with an area under the curve of 0.74 (95% CI 0.67–0.80, p = 0.0004). Delta-B-line of two or more detected in four lung ultrasound zones can be considered to be a marker of preload unresponsiveness after a fluid challenge in abdominal surgery.

The objectives and procedures of the study were registered at Clinicaltrials.gov (NCT03502460; Principal investigator: Stéphane BAR, date of registration: April 18, 2018).

Hemodynamic consequences of respiratory interventions in preterm infants

Advances in perinatal management have led to improvements in survival rates for premature infants. It is known that the transitional period soon after birth, and the subsequent weeks, remain periods of rapid circulatory changes. Preterm infants, especially those born at the limits of viability, are susceptible to hemodynamic effects of routine respiratory care practices. In particular, the immature myocardium and cardiovascular system is developmentally vulnerable. Standard of care (but essential) respiratory interventions, administered as part of neonatal care, may negatively impact heart function and/or pulmonary or systemic hemodynamics. The available evidence regarding the hemodynamic impact of these respiratory practices is not well elucidated. Enhanced diagnostic precision and therapeutic judiciousness are warranted. In this narrative, we outline (1) the vulnerability of preterm infants to hemodynamic disturbances (2) the hemodynamic effects of common respiratory practices; including positive pressure ventilation and surfactant therapy, and (3) identify tools to assess cardiopulmonary interactions and guide management.

Utility of Lung Ultrasound in the Estimation of Extravascular Lung Water in a Pediatric Population-A Prospective Observational Study

OBJECTIVE

Lung ultrasound (LUS) is a promising bedside modality for the estimation of extravascular lung water index (EVLWI), but has not been validated against objective measures in children. This study aimed to investigate the correlation of LUS B-line scoring with EVLWI, thresholds indicating elevated EVLWI, and its outcome following pediatric cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Cardiothoracic surgical intensive care unit in a tertiary care teaching hospital.

PARTICIPANTS

Children younger than 12 years undergoing elective complete surgical correction of cyanotic or acyanotic congenital heart disease (Aristotle score ≤9), excluding neonates, those weighing <3.5 kg, and those with thoracic deformities, pulmonary pathology, and hemodynamic instability.

INTERVENTIONS

Extravascular lung water index measurement by transpulmonary thermodilution, along with concurrent LUS B-line and Chest-X ray (CXR) scoring.

MEASUREMENTS AND MAIN RESULTS

LUS B-line score had a moderate correlation with EVLWI (Pearson's correlation coefficient 0.57; 95% CI 0.44-0.69). LUS B-line scores showed acceptable discrimination only for higher thresholds of EVLWI (sensitivity 82% and 79%, respectively, for EVLWI >20 mL/kg v sensitivity and specificity 57% and 80% for EVLWI >10 mL/kg). Age, body surface area, vasoactive-inotropic score (VIS), chest X-ray score, and EVLWI but not LUS B-line score were significant predictors for duration of mechanical ventilation in this cohort.

CONCLUSIONS

LUS B-line scoring has limited utility in semiquantitative estimation of EVLWI at lower thresholds of EVLWI in pediatric cardiac surgical patients. It may have better discrimination and acceptable sensitivity and specificity at higher thresholds of EVLWI. Contrasting with multiple reports of clinical utility, these results call for wider evaluation of LUS and its clinical modifiers like age, pathology, and pretest probability in estimation of EVLWI.

Measuring lung water adds prognostic value in heart failure patients undergoing cardiac magnetic resonance

To assess whether a simplified cardiac magnetic resonance (CMR)-derived lung water density (LWD) quantification predicted major events in Heart Failure (HF). Single-centre retrospective study of consecutive HF patients with left ventricular ejection fraction (LVEF) < 50% who underwent CMR. All measurements were performed on HASTE sequences in a parasagittal plane at the right midclavicular line. LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 controls was used to derive the LWD upper limit of normal (21.2%). The primary endpoint was a composite of time to all-cause death or HF hospitalization. Overall, 290 patients (mean age 64 ± 12 years) were included. LWD measurements took on average 35 ± 4 s, with good inter-observer reproducibility. LWD was increased in 65 (22.4%) patients, who were more symptomatic (NYHA ≥ III 29.2 vs. 1.8%; p = 0.017) and had higher NT-proBNP levels [1973 (IQR: 809-3766) vs. 802 (IQR: 355-2157 pg/mL); p < 0.001]. During a median follow-up of 21 months, 20 patients died and 40 had ≥ 1 HF hospitalization. In multivariate analysis, NYHA (III-IV vs. I-II; HR: 2.40; 95%-CI: 1.30-4.43; p = 0.005), LVEF (HR per 1%: 0.97; 95%-CI: 0.94-0.99; p = 0.031), serum creatinine (HR per 1 mg/dL: 2.51; 95%-CI: 1.36-4.61; p = 0.003) and LWD (HR per 1%: 1.07; 95%-CI: 1.02-1.12; p = 0.007) were independent predictors of the primary endpoint. These findings were mainly driven by an association between LWD and HF hospitalization (p = 0.026). A CMR-derived LWD quantification was independently associated with an increased HF hospitalization risk in HF patients with LVEF < 50%. LWD is a simple, reproducible and straightforward measurement, with prognostic value in HF.

Point-of-Care Ultrasound (POCUS) for the assessment of volume status and fluid management in patients with severe pre-eclampsia: A systematic review and meta-analysis

BACKGROUND AND AIMS

Appropriate volume assessment and fluid management can prevent maternal deaths in the severely pre-eclamptic (SPE) parturients. We planned a systematic review and meta-analysis (MA) to evaluate the role and ability of point-of-care ultrasound (POCUS) in the assessment of volume status and early detection of lung oedema in an SPE parturient.

METHODS

An e-literature search was done from several databases. Data were extracted under five domains including POCUS-derived parameters like echo comet score (ECS), lung ultrasound (LUS) scores, B-patterns, optic nerve sheath diameter (ONSD), E/e' ratio, presence of pleural effusion, pulmonary interstitial syndrome and pulmonary congestion. The risk of bias was assessed. Extracted data were analysed using MetaXL and Revman 5.3. Heterogeneity in the studies was evaluated using the Cochrane Q test and I2 statistics. Funnel plots were used for the assessment of publication bias.

RESULTS

Seven prospective studies including 574 parturients (including 396 pre-eclamptics) were selected. POCUS included lung, optic nerve, cardiac and thoracic US. In two studies, the ECS and LUS scores pre-delivery were higher in pre-eclamptics. Two studies found a mean ONSD of 5-5.84 mm before delivery. MA revealed a significantly lower mean ECS score at post-delivery than pre-delivery, and the summary prevalence of B-pattern and pleural effusion among SPE parturients was found to be 0.28 (0.03-0.84) and 0.1 (0-0.2), respectively. A good correlation was observed between B-line patterns and diastolic dysfunction (increased E/e' ratio), LUS score and thoracic fluid content, ONSD and ECS in individual studies.

CONCLUSION

POCUS parameters can be useful as early markers of fluid status and serve as useful tools in the precise clinical management of pre-eclampsia.

Sonographic Evaluation of Pulmonary Interstitial Edema in Patient With Preeclampsia

ABSTRACT

The aim of this study was to sonographically detect pulmonary edema, which is a major problem in pregnant women with preeclampsia, in the interstitial phase. We evaluated 41 preeclampsia patients and 21 control subjects prospectively. In the preeclampsia group, 26 patients had severe features, whereas the other 15 patients had none. To detect early fluid loading in lungs, sonographic B lines were counted from the intercostal space by using ultrasonography, and left ventricular loading findings were examined for corporation by using transthoracic echocardiography both before and after birth. In severe preeclampsia, the number of B lines before and after birth is statistically significant compared with the other groups. In addition, the total number of B lines calculated at 24 hours after delivery was significantly lower than that calculated before delivery (P < 0.018). In terms of prenatal E values, a statistically significant difference was found between all groups (P < 0.001). A strong positive and statistically significant relationship was found between B lines and prenatal E/e' (r = 0.768; P < 0.001). The overall accuracy rate of the prenatal E/e' and E value for estimation of the B line number classification is 0.791 (95% confidence interval, 0.674-0.908; P < 0.001) and 0.829 (95% confidence interval, 0.722-0.936; P < 0.001), respectively. Pulmonary edema is a serious complication in patients with severe preeclampsia and may be detected interstitially in some patients, even if it does not occur clinically.

Quantitative Lung Ultrasound: Technical Aspects and Clinical Applications

Lung ultrasound is increasingly used in emergency departments, medical wards, and critical care units-adult, pediatric, and neonatal. In vitro and in vivo studies show that the number and type of artifacts visualized change with lung density. This has led to the idea of a quantitative lung ultrasound approach, opening up new prospects for use not only as a diagnostic but also as a monitoring tool. Consequently, the multiple scoring systems proposed in the last few years have different technical approaches and specific clinical indications, adaptable for more or less time-dependent patients. However, multiple scoring systems may generate confusion among physicians aiming at introducing lung ultrasound in their clinical practice. This review describes the various lung ultrasound scoring systems and aims to clarify their use in different settings, focusing on technical aspects, validation with reference techniques, and clinical applications.

Effect of focused cardiopulmonary ultrasonography on clinical outcome of septic shock: a randomized study

Objective

To investigate the effect of focused ultrasonography on clinical outcomes of septic shock.

Methods

Patients with septic shock were randomized into an integrated cardiopulmonary ultrasonography (ICUS) group and conventional (CON) group. Within 1 hour of admission, the ICUS group underwent ICUS examination for hemodynamic decision-making, while the CON group received standard treatment. The primary endpoint was 28-day mortality after admission. The secondary endpoints were cumulative fluid administration in the first 6, 24, and 72 hours; use of vasoactive drugs; lactate clearance; duration of ventilation; and ICU stay.

Results

Ninety-four qualified patients were enrolled (ICUS group, 49; CON group, 45). ICUS showed no significant effect on 28-day mortality. Within the initial 6 hours, the ICUS group tended to have a higher fluid balance and fluid intake than the CON group. The duration of vasopressor support was shorter in the ICUS group. There were no differences in the cumulative fluid infusion within 24 or 72 hours, lactate clearance, ICU stay, or duration of ventilation.

Conclusions

The initially focused ICUS did not affect the clinical outcomes of septic shock, but it tended to be associated with a higher fluid balance within the initial 6 hours and shorter duration of vasopressor support.

B-Line Artifact as a Diagnostic Tool in Various Conditions at the Emergency Department

BACKGROUND: B-line artifacts (BLAs) play an important role in identifying lung pathology. They may indicate different diseases. However, the diagnostic study of BLA as applied to emergency patients has not been well studied. AIM: The aim of this study was to determine the diagnostic accuracy of BLA in various conditions. METHODS: This was a retrospective observational study of emergency patients who had received lung ultrasound at Srinagarind Hospital’s Emergency Department throughout January 2020–December 2020. Ultrasound artifacts were recorded. Ultrasonography findings were correlated with final diagnosis. Sensitivity and specificity were also calculated. RESULTS: A total of 105 patients were evaluated. The most prevalent condition which BLA found in this study was pulmonary edema (44.12%) with 88.24% sensitivity and 46.48% specificity. BLA also indicated pneumonia with 66.67% sensitivity and 35.71% specificity. Diffuse BLA indicated pulmonary edema with 70% sensitivity and 70.42% specificity. Focal BLA indicated pneumonia with 28.57% sensitivity and 76.19% specificity. CONCLUSIONS: The sensitivity of BLA for pulmonary edema and pneumonia diagnosis in this study was of moderate to good sensitivity, but low specificity. BLA may become crucial in the diagnosis of lung pathology in the emergency department.

The effect of vitamin C on pulmonary oedema in patients with severe preeclampsia: A single-centre, randomised, placebo-controlled, double-blind trial

OBJECTIVE

To determine whether vitamin C in the first three days postpartum reduces pulmonary oedema (PE) assessed by lung ultrasound in patients with severe preeclampsia.

DESIGN

Randomised, placebo-controlled, double-blind trial.

SETTING

Tertiary perinatal centre.

POPULATION

Consecutively admitted patients with singleton pregnancies complicated by severe preeclampsia.

METHODS

Thirty-four patients received vitamin C (1.5 g/6 h) (n = 17) or placebo (n = 17) at days 1, 2, and 3 postdelivery. Mann-Whitney-U test was used to compare vitamin C vs placebo groups. A p ≤ 0.05 was considered statistically significant.

MAIN OUTCOME MEASURES

Lung ultrasound was performed once daily in the first three days following delivery. Echo Comet Score (ECS) on day 1 postdelivery was the primary outcome studied and was obtained using the 28-rib interspaces technique. ECS on days 2 and 3 postdelivery were secondary outcomes.

RESULTS

There was no significant difference in ECS on day 1 (median 23 (inter-quartile range (IQR) 21-61) vs 18 (IQR 8-35); p = 0.31). All ultrasound examinations on day 1 were performed within six hours from delivery. On days 2 and 3, ECS was significantly lower in vitamin C group compared to placebo (8 (IQR 3-14) vs 35 (IQR 15-78); p = 0.03 and 5 (IQR 3-10) vs 18 (IQR 18-44); p = 0.04, respectively).

CONCLUSION

A single dose of intravenous vitamin C did not reduce PE in postpartum patients with severe preeclampsia on day 1 after delivery. Repeated doses, however, seem to have a delayed effect with a reduction in PE detected on ultrasound on days 2 and 3 following delivery.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov: ID NCT03451266 (https://clinicaltrials.gov/ct2/show/NCT03451266?term=NCT03451266&draw=2&rank=1).

Point-of-care lung ultrasound in neonatology: classification into descriptive and functional applications

Lung ultrasound (LUS) is the latest amongst imaging techniques: it is a radiation-free, inexpensive, point-of-care tool that the clinician can use at the bedside. This review summarises the rapidly growing scientific evidence on LUS in neonatology, dividing it into descriptive and functional applications. We report the description of the main ultrasound features of neonatal respiratory disorders and functional applications of LUS aiming to help a clinical decision (such as surfactant administration, chest drainage etc). Amongst the functional applications, we propose SAFE (Sonographic Algorithm for liFe threatening Emergencies) as a standardised protocol for emergency functional LUS in critical neonates. SAFE has been funded by a specific grant issued by the European Society for Paediatric Research. Future potential development of LUS in neonatology might be linked to its quantitative evaluation: we also discuss available data and research directions using computer-aided diagnostic techniques. Finally, tools and opportunities to teach LUS and expand the research network are briefly presented.

Prognostic value of pulmonary oedema assessed by lung ultrasound in patient with acute heart failure

It is very important to assess pulmonary oedema in patients with acute heart failure. The aim of the study was to investigate the accuracy of lung ultrasound in evaluating pulmonary oedema and to explore lung ultrasound in predicting the prognosis. One hundred twenty-four acute heart failure patients were divided into 3 groups, according to the total number of lung ultrasound B-lines groups: B-lines < 15 was the mild pulmonary oedema group (33 cases), 15 ≤ B-lines < 30 was the moderate pulmonary oedema group (33 cases), and B-lines ≥ 30 was the severe pulmonary oedema group (58 cases). The PiCCO monitoring system was used in 11 patients and measured 26 times in different clinical situations. EVLWI have a higher positive correlation with B-lines (r = 0.95), compared with NT-proBNP and E/e' (r = 0.72, r = 0.62). During 1 year of follow-up, a multivariate cox regression analysis showed that age, E/e' and B-lines ≥ 30 at admission (C-index of 75%) were risk factors for prognosis. 12-month event-free survival showed a significantly worse outcome was observed in patients with ≥ 30 B-lines at admission. B-lines have a good correlation with EVLWI; age, E/e' and B-lines ≥ 30 at admission were risk factors for prognosis.

B-Lines Scores Derived From Lung Ultrasound Provide Accurate Prediction of Extravascular Lung Water Index: An Observational Study in Critically Ill Patients

Introduction:

Visualization of B-lines via lung ultrasound provides a non-invasive estimation of pulmonary hydration. Extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) assessed by transpulmonary thermodilution (TPTD) represent the most validated parameters of lung water and alveolocapillary permeability, but measurement is invasive and expensive. This study aimed to compare the correlations of B-lines scores from extensive 28-sector and simplified 4-sector chest scan with EVLWI and PVPI derived from TPTD in the setting of intensive care unit (primary endpoint).

Methods:

We performed scoring of 28-sector and 4-sector B-Lines in 50 critically ill patients. TPTD was carried out with the PiCCO-2-device (Pulsion Medical Systems SE, Maquet Getinge Group). Median time exposure for ultrasound procedure was 12 minutes for 28-sector and 4 minutes for 4-sector scan.

Results:

Primarily, we found close correlations of 28-sector as well as 4-sector B-Lines scores with EVLWI (R² = 0.895 vs. R² = 0.880) and PVPI (R² = 0.760 vs. R² = 0.742). Both B-lines scores showed high accuracy to identify patients with specific levels of EVLWI and PVPI. The extensive 28-sector B-lines score revealed a moderate advantage compared to simplified 4-sector scan in detecting a normal EVLWI ≤ 7 (28-sector scan: sensitivity = 81.8%, specificity = 94.9%, AUC = 0.939 versus 4-sector scan: sensitivity = 81.8%, specificity = 82.1%, AUC = 0.902). Both protocols were approximately equivalent in prediction of lung edema with EVLWI ≥ 10 (28-sector scan: sensitivity = 88.9%, specificity = 95.7%, AUC = 0.977 versus 4-sector scan: sensitivity = 81.5%, specificity = 91.3%, AUC = 0.958) or severe pulmonary edema with EVLWI ≥ 15 (28-sector scan: sensitivity = 91.7%, specificity = 97.4%, AUC = 0.995 versus 4-sector scan: sensitivity = 91.7%, specificity = 92.1%, AUC = 0.978). As secondary endpoints, our evaluations resulted in significant associations of 28-sector as well as simplified 4-sector B-Lines score with parameters of respiratory function.

Conclusion:

Both B-line protocols provide accurate non-invasive evaluation of lung water in critically ill patients. The 28-sector scan offers a marginal advantage in prediction of pulmonary edema, but needs substantially more time than 4-sector scan.

Extravascular Lung Water and Effect on Oxygenation Assessed by Lung Ultrasound in Adult Cardiac Surgery

Introduction

The extravascular lung water content is determined by the use of lung ultrasound (LUS) which is represented as B-lines. The aim of this study was to investigate whether the LUS measurement of extravascular lung water was correlated to changes in oxygenation.

Methods

This prospective cohort study was comprised of 73 patients with an average age of 56 (range: 18 to 87 years) who underwent elective cardiac surgery using cardiopulmonary bypass. The LUS score was performed preoperatively, time zero (T0), at one hour (T1), and at 24 hours (T2) post-surgery. Additionally, arterial oxygen partial pressure and fraction of inspired oxygen (PaO₂/FiO₂) ratio were measured at each time and the time-to-extubation.

Results

A negative correlation was found between the LUS score and PaO₂/FiO₂ at T1 (p < 0.004). Extubation time and changes in the lung ultrasound score at T0 - T2 were positively correlated (p < 0.03). Plus, there was a positive correlation between fluid balance and lung ultrasound score at T2 (p < 0.03).

Conclusion

We found three significant correlations that support the use of LUS in cardiac surgery: 1) the more B-lines, the lower the oxygenation; 2) the more B-lines, the longer the period of ventilation; 3) the more B-lines, the more positive the fluid balance. LUS is a non-invasive bedside investigation that can be used to judge extravascular lung water, providing useful information in the management of patient oxygenation, fluid balance, and extubation.

Lung Ultrasound Scanning for Respiratory Failure in Acutely Ill Patients: A Review

Lung ultrasonography (LUS), an imaging modality quickly performed, interpreted, and integrated by the treating physician at the bedside, is a particularly useful tool for acutely ill patients. In the evaluation of a patient with respiratory failure in the ICU or ED, LUS is superior to chest radiograph and generally comparable with CT imaging and reduces the need for patient transport and radiation exposure. This article will provide a concise review of LUS as it pertains to respiratory failure in general and will include examples of relevant ultrasound images and video clips from critically ill patients.

Furosemide: Would it help to improve the lungs as evaluated by sonography and compliance during aortic coarctation surgery

Background

We evaluated furosemide on attenuating lung injury and/or edema during coarctation repair surgery. We evaluated dynamic lung compliance. We measured the degree of lung edema by means of lung ultrasound (LUS). We recorded the (PaO₂/FiO₂ratio) as an indicator for oxygenation.

Materials and Methods

A study was conducted on 56 patients. Patients were divided into two groups: control group (Group C) which did not receive furosemide and furosemide group (Group F) at a dose of 1 mg/kg at induction of anesthesia. Dynamic lung compliance was calculated at induction (Cdyn 1) and at the end of the surgery (Cdyn 2). The (PaO₂/FiO₂ratio) was calculated at start and end of surgery as (PF 1) and (PF 2), respectively. LUS was performed after induction (LUS 1) and at the end of the surgery. LUS 2 using the 12 regions method plotting the results on scale from 0 to 36. Mechanical ventilation days were recorded.

Results

Administering furosemide attenuated the lung injury/edema and other pulmonary complications. Furosemide administration improved the dynamic lung compliance in the F Group compared to the C Group. Furthermore, it increased the (PaO₂/FiO₂ratio) in the F Group compared to the C Group. LUS scale values were lower in the F Group compared to the C Group. There was also less postoperative mechanical ventilation days.

Conclusions

The use of furosemide was accompanied by improved lung injury/edema profile as indicated by a much less drop in dynamic lung compliance, better oxygenation, a more favorable LUS scale with less parenchymal lung affection.

Assessing Extravascular Lung Water in Critically Ill Patients Using Lung Ultrasound: A Systematic Review on Methodological Aspects in Diagnostic Accuracy Studies

Lung ultrasound (LUS) is a non-invasive bedside method used to quantify extravascular lung water (EVLW). To evaluate the methodology and diagnostic accuracy of LUS in studies assessing EVLW in intensive care unit patients, PubMed and Embase were searched for studies comparing LUS with imaging modalities. In 14 relevant studies a wide variety of equipment used and training of examiners were noted. Four scoring systems were reported: (i) a binary score (the presence of three or more B-lines); (ii) a categorical score; (iii) a numerical score; (iv) a quantitative LUS score using software. The diagnostic accuracy of LUS varied: sensitivity ranged from 50%-98%, specificity from 76%-100% and r² from 0.20-0.91. Methodology and diagnostic accuracy varies substantially in published reports. Further research is needed to correlate methodological factors with diagnostic accuracy. Hospitals should standardize LUS methodology. Consensus is needed to harmonize LUS methodology for lung water assessment.

Chinese Association of Anesthesiologists Expert Consensus on the Use of Perioperative Ultrasound in Coronavirus Disease 2019 Patients

The COVID-19 pandemic is spreading globally. COVID-19 has an effect on the systemic state, cardiopulmonary function and primary disease of patients undergoing surgery. COVID-19's high contagiousness makes anesthesia and intraoperative management more difficult. This expert consensus aims to comprehensively introduce the application of perioperative ultrasound in COVID-19 patients, including pulmonary ultrasound and anesthesia management, ultrasound and airway management, ultrasound-guided regional anesthesia and echocardiography for COVID-19 patients.

Thoracic ultrasound evaluation and B-type natriuretic peptide value in elective cesarean section under spinal anesthesia

Background

Pregnancy-induced changes in cardiovascular status make women more susceptible to pulmonary edema. During cesarean section, to counterbalance the effect of hypotension caused by spinal anesthesia, anesthesiologists must choose between two fundamental approaches to maintain the hemodynamic state—intravenous fluids or vasopressors—and this choice will depend upon their particular opinions and experience. We aim to assess for any correlations between thoracic ultrasound A- and B-line artifacts, brain natriuretic peptide (BNP) levels, and the amount of intraoperative fluids administered.

Results

From December 2016 to August 2018, at the University-Hospital of Udine, we enrolled 80 consecutive pregnant women undergoing cesarean section. We observed a statistically significant difference in the volume of fluids administered in the first 24 h (p = 0.035) between the patients presenting B-lines in at least one basal area of their thoracic ultrasound and patients with no evident B-lines (AUC 66.4%; IC 0.49–0.83). Dividing the population on whether their BNP levels were higher or less than 20 pg/mL, no statistically significant difference was revealed with regard to fluids administered in the first 24 h (p = 0.537).

Conclusions

Thoracic ultrasound is a non-invasive and easy-to-use tool for detecting fluid intolerance in pregnant women undergoing cesarean section. BNP levels were slow to rise following the cesarean section and did not show any clear correlation with fluid volumes administered.

International evidence-based guidelines on Point of Care Ultrasound (POCUS) for critically ill neonates and children issued by the POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

BACKGROUND

Point-of-care ultrasound (POCUS) is nowadays an essential tool in critical care. Its role seems more important in neonates and children where other monitoring techniques may be unavailable. POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) aimed to provide evidence-based clinical guidelines for the use of POCUS in critically ill neonates and children.

METHODS

Creation of an international Euro-American panel of paediatric and neonatal intensivists expert in POCUS and systematic review of relevant literature. A literature search was performed, and the level of evidence was assessed according to a GRADE method. Recommendations were developed through discussions managed following a Quaker-based consensus technique and evaluating appropriateness using a modified blind RAND/UCLA voting method. AGREE statement was followed to prepare this document.

RESULTS

Panellists agreed on 39 out of 41 recommendations for the use of cardiac, lung, vascular, cerebral and abdominal POCUS in critically ill neonates and children. Recommendations were mostly (28 out of 39) based on moderate quality of evidence (B and C).

CONCLUSIONS

Evidence-based guidelines for the use of POCUS in critically ill neonates and children are now available. They will be useful to optimise the use of POCUS, training programs and further research, which are urgently needed given the weak quality of evidence available.

ERS statement on chest imaging in acute respiratory failure

Chest imaging in patients with acute respiratory failure plays an important role in diagnosing, monitoring and assessing the underlying disease. The available modalities range from plain chest X-ray to computed tomography, lung ultrasound, electrical impedance tomography and positron emission tomography. Surprisingly, there are presently no clear-cut recommendations for critical care physicians regarding indications for and limitations of these different techniques.The purpose of the present European Respiratory Society (ERS) statement is to provide physicians with a comprehensive clinical review of chest imaging techniques for the assessment of patients with acute respiratory failure, based on the scientific evidence as identified by systematic searches. For each of these imaging techniques, the panel evaluated the following items: possible indications, technical aspects, qualitative and quantitative analysis of lung morphology and the potential interplay with mechanical ventilation. A systematic search of the literature was performed from inception to September 2018. A first search provided 1833 references. After evaluating the full text and discussion among the committee, 135 references were used to prepare the current statement.These chest imaging techniques allow a better assessment and understanding of the pathogenesis and pathophysiology of patients with acute respiratory failure, but have different indications and can provide additional information to each other.

Imaging the Injured Lung: Mechanisms of Action and Clinical Use

Acute respiratory distress syndrome (ARDS) consists of acute hypoxemic respiratory failure characterized by massive and heterogeneously distributed loss of lung aeration caused by diffuse inflammation and edema present in interstitial and alveolar spaces. It is defined by consensus criteria, which include diffuse infiltrates on chest imaging-either plain radiography or computed tomography. This review will summarize how imaging sciences can inform modern respiratory management of ARDS and continue to increase the understanding of the acutely injured lung. This review also describes newer imaging methodologies that are likely to inform future clinical decision-making and potentially improve outcome. For each imaging modality, this review systematically describes the underlying principles, technology involved, measurements obtained, insights gained by the technique, emerging approaches, limitations, and future developments. Finally, integrated approaches are considered whereby multimodal imaging may impact management of ARDS.

Quantitative lung ultrasonography: a putative new algorithm for automatic detection and quantification of B-lines

BACKGROUND

This pilot study was designed to develop a fully automatic and quantitative scoring system of B-lines (QLUSS: quantitative lung ultrasound score) involving the pleural line and to compare it with previously described semi-quantitative scores in the measurement of extravascular lung water as determined by standard thermo-dilution.

METHODS

This was a prospective observational study of 12 patients admitted in the intensive care unit with acute respiratory distress and each provided with 12 lung ultrasound (LUS) frames. Data collected from each patient consisted in five different scores, four semi-quantitative (nLUSS, cLUSS, qLUSS, %LUSS) and quantitative scores (QLUSS). The association between LUS scores and extravascular lung water (EVLW) was determined by simple linear regression (SLR) and robust linear regression (RLR) methods. A correlation analysis between the LUS scores was performed by using the Spearman rank test. Inter-observer variability was tested by computing intraclass correlation coefficient (ICC) in two-way models for agreement, basing on scores obtained by different raters blinded to patients' conditions and clinical history.

RESULTS

In the SLR, QLUSS showed a stronger association with EVLW (R² = 0.57) than cLUSS (R² = 0.45) and nLUSS (R² = 0.000), while a lower association than qLUSS (R² = 0.85) and %LUSS (R² = 0.72) occurred. By applying RLR, QLUSS showed an association for EVLW (R² = 0.86) comparable to qLUSS (R² = 0.85) and stronger than %LUSS (R² = 0.72). QLUSS was significantly correlated with qLUSS (r = 0.772; p = 0.003) and %LUSS (r = 0.757; p = 0.005), but not with cLUSS (r = 0.561; p = 0.058) and nLUSS (r = 0.105; p = 0.744). Moreover, QLUSS showed the highest ICC (0.998; 95%CI from 0.996 to 0.999) among the LUS scores.

CONCLUSIONS

This study demonstrates that computer-aided scoring of the pleural line percentage affected by B-lines has the potential to assess EVLW. QLUSS may have a significant impact, once validated with a larger dataset composed by multiple real-time frames. This approach has the potentials to be advantageous in terms of faster data analysis and applicability to large sets of data without increased costs. On the contrary, it is not useful in pleural effusion or consolidations.