Lung Ultrasound for Critically Ill Patients

Role of prognostic scores in predicting in-hospital mortality and failure of non-invasive ventilation in adults with COVID-19

We tested the prognostic performance of different scores for the identification of subjects with acute respiratory failure by COVID-19, at risk of in-hospital mortality and NIV failure. We conducted a retrospective study, in the Medical High-Dependency Unit of the University-Hospital Careggi. We included all subjects with COVID-19 and ARF requiring non-invasive ventilation (NIV) between March 2020 and January 2021. Clinical parameters, the HACOR score (Heart rate, Acidosis, Consciousness, Oxygenation, Respiratory Rate) and ROX index ((SpO2/FiO2)/respiratory rate) were collected 3 (-3) and 1 day (-1) before the NIV initiation, the first day of treatment (Day0) and after 1 (+1), 2 (+2), 5 (+5), 8 (+8) and 11 (+11) of treatment. The primary outcomes were in-hospital mortality and NIV failure. We included 135 subjects, mean age 69±13 years, 69% male. Patients, who needed mechanical ventilation, showed a higher HACOR score (Day0: 6 [5-7] vs 6 [6-7], p=.057; Day+2: 6 [6-6] vs 6 [4-6], p=.013) and a lower ROX index (Day0: 4.2±2.3 vs 5.1±2.3, p=.055; Day+2: 4.4±1.2.vs 5.5±1.3, p=.001) than those with successful NIV. An HACOR score >5 was more frequent among nonsurvivors (Day0: 82% vs 58%; Day2: 82% vs 48%, all p<0.01) and it was associated with in-hospital mortality (Day0: RR 5.88, 95%CI 2.01-17.22; Day2: RR 4.33, 95%CI 1.64-11.41) independent to age and Charlson index. In conclusion, in subjects treated with NIV for ARF caused by COVID19, respiratory parameters collected after the beginning of NIV allowed to identify those at risk of an adverse outcome. An HACOR score >5 was independently associated with increased mortality rate.

Lung Ultrasound Signs to Diagnose and Discriminate Interstitial Syndromes in ICU Patients: A Diagnostic Accuracy Study in Two Cohorts

OBJECTIVES

To determine the diagnostic accuracy of lung ultrasound signs for both the diagnosis of interstitial syndrome and for the discrimination of noncardiogenic interstitial syndrome (NCIS) from cardiogenic pulmonary edema (CPE) in a mixed ICU population.

DESIGN

A prospective diagnostic accuracy study with derivation and validation cohorts.

SETTING

Three academic mixed ICUs in the Netherlands.

PATIENTS

Consecutive adult ICU patients that received a lung ultrasound examination.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULT

The reference standard was the diagnosis of interstitial syndrome (NCIS or CPE) or noninterstitial syndromes (other pulmonary diagnoses and no pulmonary diagnoses) based on full post-hoc clinical chart review except lung ultrasound. The index test was a lung ultrasound examination performed and scored by a researcher blinded to clinical information. A total of 101 patients were included in the derivation and 122 in validation cohort. In the derivation cohort, patients with interstitial syndrome ( n = 56) were reliably discriminated from other patients based on the presence of a B-pattern (defined as greater than or equal to 3 B-lines in one frame) with an accuracy of 94.7% (sensitivity, 90.9%; specificity, 91.1%). For discrimination of NCIS ( n = 29) from CPE ( n = 27), the presence of bilateral pleural line abnormalities (at least two: fragmented, thickened or irregular) had the highest diagnostic accuracy (94.6%; sensitivity, 89.3%; specificity, 100%). A diagnostic algorithm (Bedside Lung Ultrasound for Interstitial Syndrome Hierarchy protocol) using B-pattern and bilateral pleural abnormalities had an accuracy of 0.86 (95% CI, 0.77-0.95) for diagnosis and discrimination of interstitial syndromes. In the validation cohort, which included 122 patients with interstitial syndrome, bilateral pleural line abnormalities discriminated NCIS ( n = 98) from CPE ( n = 24) with a sensitivity of 31% (95% CI, 21-40%) and a specificity of 100% (95% CI, 86-100%).

CONCLUSIONS

Lung ultrasound can diagnose and discriminate interstitial syndromes in ICU patients with moderate-to-good accuracy. Pleural line abnormalities are highly specific for NCIS, but sensitivity is limited.

How to Determine Fluid Management Goals during Continuous Kidney Replacement Therapy in Patients with AKI: Focus on POCUS

The utilization of kidney replacement therapies (KRT) for fluid management of patients who are critically ill has significantly increased over the last years. Clinical studies have suggested that both fluid accumulation and high fluid removal rates are associated with adverse outcomes in the critically ill population receiving KRT. Importantly, the ideal indications and/or fluid management strategies that could favorably affect these patients are unknown; however, differentiating clinical scenarios in which effective fluid removal may provide benefit to the patient by avoiding congestive organ injury, compared with other settings in which this intervention may result in harm, is direly needed in the critical care nephrology field. In this review, we describe observational data related to fluid management with KRT, and examine the role of point-of-care ultrasonography as a potential tool that could provide physiologic insights to better individualize decisions related to fluid management through KRT.

Head to toe ultrasound: a narrative review of experts' recommendations of methodological approaches

Critical care ultrasonography (US) is widely used by intensivists managing critically ill patients to accurately and rapidly assess different clinical scenarios, which include pneumothorax, pleural effusion, pulmonary edema, hydronephrosis, hemoperitoneum, and deep vein thrombosis. Basic and advanced critical care ultrasonographic skills are routinely used to supplement physical examination of critically ill patients, to determine the etiology of critical illness and to guide subsequent therapy. European guidelines now recommend the use of US for a number of practical procedures commonly performed in critical care. Full training and competence acquisition are essential before significant therapeutic decisions are made based on the US assessment. However, there are no universally accepted learning pathways and methodological standards for the acquisition of these skills.Therefore, in this review, we aim to provide a methodological approach of the head to toe ultrasonographic evaluation of critically ill patients considering different districts and clinical applications.

Non-invasive assessment of HFpEF in mouse models: current gaps and future directions

BACKGROUND

Heart failure (HF) with preserved ejection fraction (HFpEF) prevalence is increasing, and large clinical trials have failed to reduce mortality. A major reason for this outcome is the failure to translate results from basic research to the clinics. Evaluation of HFpEF in mouse models requires assessing three major key features defining this complex syndrome: the presence of a preserved left ventricular ejection fraction (LVEF), diastolic dysfunction, and the development of HF. In addition, HFpEF is associated with multiple comorbidities such as systemic arterial hypertension, chronic obstructive pulmonary disease, sleep apnea, diabetes, and obesity; thus, non-cardiac disorders assessment is crucial for a complete phenotype characterization. Non-invasive procedures present unquestionable advantages to maintain animal welfare and enable longitudinal analyses. However, unequivocally determining the presence of HFpEF using these methods remains challenging.

MAIN TEXT

Transthoracic echocardiography (TTE) represents an invaluable tool in HFpEF diagnosis, allowing evaluation of LVEF, diastolic dysfunction, and lung congestion in mice. Since conventional parameters used to evaluate an abnormal diastole like E/A ratio, isovolumic relaxation time, and E/e' may pose limitations in mice, including advanced TTE techniques to characterize cardiac motion, including an assessment under stress, will improve diagnosis. Patients with HFpEF also show electrical cardiac remodelling and therefore electrocardiography may add valuable information in mouse models to assess chronotropic incompetence and sinoatrial node dysfunction, which are major contributors to exercise intolerance. To complete the non-invasive diagnosis of HF, low aerobic exercise capacity and fatigue using exercise tests, impaired oxygen exchange using metabolic cages, and determination of blood biomarkers can be determined. Finally, since HFpEF patients commonly present non-cardiac pathological conditions, acquisition of systemic and pulmonary arterial pressures, blood glucose levels, and performing glucose tolerance and insulin resistance tests are required for a complete phenotyping.

CONCLUSION

Identification of reliable models of HFpEF in mice by using proper diagnosis tools is necessary to translate basic research results to the clinics. Determining the presence of several HFpEF indicators and a higher number of abnormal parameters will lead to more reliable evidence of HFpEF.

Reliability and clinical correlations of semi-quantitative lung ultrasound on BLUE points in COVID-19 mechanically ventilated patients: The 'BLUE-LUSS'-A feasibility clinical study

INTRODUCTION

Bedside lung ultrasound has gained a key role in each segment of the treatment chain during the COVID-19 pandemic. During the diagnostic assessment of the critically ill patients in ICUs, it is highly important to maximize the amount and quality of gathered information while minimizing unnecessary interventions (e.g. moving/rotating the patient). Another major factor is to reduce the risk of infection and the workload of the staff.

OBJECTIVES

To serve these significant issues we constructed a feasibility study, in which we used a single-operator technique without moving the patient, only assessing the easily achievable lung regions at conventional BLUE points. We hypothesized that calculating this 'BLUE lung ultrasound score' (BLUE-LUSS) is a reasonable clinical tool. Furthermore, we used both longitudinal and transverse scans to measure their reliability and assessed the interobserver variability as well.

METHODS

University Intensive Care Unit based, single-center, prospective, observational study was performed on 24 consecutive SARS-CoV2 RT-PCR positive, mechanically ventilated critically ill patients. Altogether 400 loops were recorded, rated and assessed off-line by 4 independent intensive care specialists (each 7+ years of LUS experience).

RESULTS

Intraclass correlation values indicated good reliability for transversal and longitudinal qLUSS scores, while we detected excellent interrater agreement of both cLUSS calculation methods. All of our LUS scores correlated inversely and significantly to the P/F values. Best correlation was achieved in the case of longitudinal qLUSS (r = -0.55, p = 0.0119).

CONCLUSION

Summarized score of BLUE-LUSS can be an important, easy-to-perform adjunct tool for assessing and quantifying lung pathology in critically ill ventilated patients at bedside, especially for the P/F ratio. The best agreement for the P/F ratio can be achieved with the longitudinal scans. Regarding these findings, assessing BLUE-points can be extended with the BLUE-LUSS for daily routine using both transverse and longitudinal views.

Correlation between hypoxaemia and lung ultrasound score in patients presenting to an emergency department with interstitial syndrome: a prospective physiological study

Objective: To assess for the presence of a correlation between lung ultrasound score (LUSS) and ratio between arterial partial pressure of oxygen (PaO2) and the fraction of inspired oxygen (FiO2) in patients presenting to an emergency department (ED) with interstitial syndrome (IS). Design: Prospective, multicentre, physiological study. Setting: Four Belgian hospitals: one tertiary academic centre and three secondary centres. Participants: A convenience sample of adult patients who presented to an ED with acute dyspnoea and needed an arterial blood gas (ABG) analysis (those with a LUSS < 2 were secondarily excluded). Main outcome measure: Correlation between PaO2/FIO2 and LUSS determined using Pearson correlation. Results: In total, 162 adult patients were included. A statistically significant negative linear correlation between PaO2/FIO2 and LUSS was found (correlation coefficient, -0.4860 [95% CI, -0.5956 to -0.3587]; P < 0.0001). Conclusions: Our data provide evidence of a statistically significant negative linear correlation between PaO2/FIO2 and LUSS for ED patients with lung IS. Given the representativeness of PaO2/FIO2 for hypoxaemia and the fact that hypoxaemia indicates IS severity, our findings suggest that LUSS could contribute to the evaluation of IS severity. If confirmed by future studies that include patient follow-up, a noninvasive approach using LUSS could decrease the need for ABG analysis in patients who do not require repeated measurement of ABG values other than PaO2, and thereby improve patient comfort.

Association Between Lung Ultrasound Patterns and Pneumonia

ABSTRACT

Pneumonia is a common respiratory infection that affects the lungs. Lung ultrasound (LUS) is a portable, cost-effective imaging method, which is free of ionizing radiation and has been shown to be useful for evaluating pneumonia. The aim of this retrospective analytical study was to determine the association between lung ultrasound patterns and pneumonia. For the purpose of performing the required analysis, LUS patterns including consolidations, pleural line irregularities, A lines and B lines from 90 subjects (44 patients with confirmed pneumonia and 46 controls) were retrieved from a published open-access data set, which was reviewed and approved by medical experts. A χ 2 test was used for the comparison of categorical variables to determine the association between each LUS pattern and the presence of pneumonia. There is a significant association between LUS consolidation and the presence of pneumonia ( P < 0.0001). Lung ultrasound A lines are significantly associated with the absence of pneumonia ( P < 0.0001), whereas there are no associations between B lines or pleural line irregularities with pneumonia. Lung ultrasound consolidation is found to be associated with the presence of pneumonia. A lines are associated with healthy lungs, and there is no association of B lines and pleural irregularities with the presence of pneumonia. Further studies investigating LUS patterns with clinical information and symptoms of patients with pneumonia are required.

Accurate assessment of the lung sliding artefact on lung ultrasonography using a deep learning approach

Pneumothorax is a potentially life-threatening condition that can be rapidly and accurately assessed via the lung sliding artefact generated using lung ultrasound (LUS). Access to LUS is challenged by user dependence and shortage of training. Image classification using deep learning methods can automate interpretation in LUS and has not been thoroughly studied for lung sliding. Using a labelled LUS dataset from 2 academic hospitals, clinical B-mode (also known as brightness or two-dimensional mode) videos featuring both presence and absence of lung sliding were transformed into motion (M) mode images. These images were subsequently used to train a deep neural network binary classifier that was evaluated using a holdout set comprising 15% of the total data. Grad-CAM explanations were examined. Our binary classifier using the EfficientNetB0 architecture was trained using 2535 LUS clips from 614 patients. When evaluated on a test set of data uninvolved in training (540 clips from 124 patients), the model performed with a sensitivity of 93.5%, specificity of 87.3% and an area under the receiver operating characteristic curve (AUC) of 0.973. Grad-CAM explanations confirmed the model's focus on relevant regions on M-mode images. Our solution accurately distinguishes between the presence and absence of lung sliding artefacts on LUS.

Point-of-care ultrasound training for residents in anaesthesia and critical care: results of a national survey comparing residents and training program directors' perspectives

BACKGROUND

Point-of-care ultrasound (POCUS) has become an essential tool for anaesthesia and critical care physicians and dedicated training is mandatory. This survey describes the current state of Italian residency training programs through the comparison of residents' and directors' perspective.

METHODS

Observational prospective cross-sectional study: 12-question national e-survey sent to Italian directors of anaesthesia and critical care residency programs (N = 40) and residents (N = 3000). Questions focused on POCUS teaching (vascular access, transthoracic echocardiography, focused assessment for trauma, transcranial Doppler, regional anaesthesia, lung and diaphragm ultrasound), organization (dedicated hours, teaching tools, mentors), perceived adequacy/importance of the training and limiting factors.

RESULTS

Five hundred seventy-one residents and 22 directors completed the survey. Bedside teaching (59.4-93.2%) and classroom lessons (29.7-54.4%) were the most frequent teaching tools. Directors reported higher participation in research projects (p < 0.05 for all techniques but focused assessment for trauma) and simulation (p < 0.05 for all techniques but transthoracic echocardiography). Use of online teaching was limited (< 10%); however, 87.4% of residents used additional web-based tools. Consultants were the most frequent mentors, with different perspectives between residents (72.0%) and directors (95.5%; p = 0.013). Residents reported self-training more frequently (48.5 vs. 9.1%; p < 0.001). Evaluation was mainly performed at the bedside; a certification was not available in most cases (< 10%). Most residents perceived POCUS techniques as extremely important. Residents underestimated the relevance given by directors to ultrasound skills in their evaluation and the minimal number of exams required to achieve basic competency. Overall, the training was considered adequate for vascular access only (62.2%). Directors mainly agreed on the need of ultrasound teaching improvement in all fields. Main limitations were the absence of a standardized curriculum for residents and limited mentors' time/expertise for directors.

CONCLUSION

POCUS education is present in Italian anaesthesia and critical care residency programs, although with potential for improvement. Significant discrepancies between residents' and directors' perspectives were identified.

Current Advances in Lung Ultrasound in COVID-19 Critically Ill Patients: A Narrative Review

Lung ultrasound (LUS) has a relatively recent democratization due to the better availability and training of physicians, especially in intensive care units. LUS is a relatively cheap and easy-to-learn and -use bedside technique that evaluates pulmonary morphology when using simple algorithms. During the global COVID-19 pandemic, LUS was found to be an accurate tool to quickly diagnose, triage and monitor patients with COVID-19 pneumonia. This paper aims to provide a comprehensive review of LUS use during the COVID-19 pandemic. The first section of our work defines the technique, the practical approach and the semeiotic signs of LUS examination. The second section exposed the COVID-19 pattern in LUS examination and the difference between the differential diagnosis patterns and the well-correlation found with computer tomography scan findings. In the third section, we described the utility of LUS in the management of COVID-19 patients, allowing an early diagnosis and triage in the emergency department, as the monitoring of pneumonia course (pneumonia progression, alveolar recruitment, mechanical ventilation weaning) and detection of secondary complications (pneumothorax, superinfection). Moreover, we describe the usefulness of LUS as a marker of the prognosis of COVID-19 pneumonia in the fourth section. Finally, the 5th part is focused on describing the interest of the LUS, as a non-ionized technique, in the management of pregnant COVID-19 women.

Nurse-Provided Lung and Inferior Vena Cava Assessment in Patients With Heart Failure

BACKGROUND

Residual congestion detected using handheld ultrasound may be associated with increased risk of readmission and death after hospitalization for acute decompensated heart failure (ADHF). However, effective application necessitates routine use by nonexperts delivering clinical care.

OBJECTIVES

The objective of this study was to determine the ability of heart failure (HF) nurses to deliver a predischarge lung and inferior vena cava (IVC) assessment (LUICA) to predict 90-day outcomes.

METHODS

In this multisite, prospective, observational study, HF nurses scanned 240 patients with ADHF (median age: 77 years; 56% men) using a 9-zone LUICA protocol. Obtained images were reviewed by independent nurses who were blinded to clinical characteristics and outcomes. Based on a B-line cut-off of 10, patients were dichotomized as congested (n = 115) or not congested (n = 125).

RESULTS

Congested patients were more likely to have previous cardiac operations, long-standing HF (>6 months), and renal impairment. At 90 days, HF readmission or mortality occurred in 42 congested patients (37%) compared with 18 noncongested patients (14%). Pulmonary congestion increased at 30-day (OR: 3.86; 95% CI: 1.65-8.99; P < 0.01) and 90-day (OR: 3.42; 95% CI: 1.82-6.4; P < 0.01) HF readmission or mortality risk and 90-day mortality (OR: 5.18; 95% CI: 1.44-18.69; P < 0.01). Pulmonary congestion increased the 90-day odds of HF readmission and/or death by 3.3- to 4.2-fold (P < 0.01), independent of demographics, HF characteristics, comorbidities, and event risk score. Over 90 days, days alive out of hospital were fewer (78.3 ± 21.4 days vs 85.5 ± 12.4 days; P < 0.01) in congested patients.

CONCLUSIONS

LUICA can be a powerful tool for detection of predischarge residual congestion. HF nurses can obtain images and provide diagnostic reports that are predictive of ADHF outcomes.

Effectiveness of the 10-valent pneumococcal conjugate vaccine on pediatric pneumonia confirmed by ultrasound: a matched case-control study

Background

Bangladesh introduced the 10-valent pneumococcal conjugate vaccine (PCV10) for children aged < 1 year in March 2015. Previous vaccine effectiveness (VE) studies for pneumonia have used invasive pneumococcal disease or chest X-rays. None have used ultrasound. We sought to determine the VE of PCV10 against sonographically-confirmed pneumonia in three subdistrict health complexes in Bangladesh.

Methods

We conducted a matched case–control study between July 2015 and September 2017 in three subdistricts of Sylhet, Bangladesh. Cases were vaccine-eligible children aged 3–35 months with sonographically-confirmed pneumonia, who were matched with two types of controls by age, sex, week of diagnosis, subdistrict health complex (clinic controls) or distance from subdistrict health complex (community controls) and had an illness unlikely due to Streptococcus pneumoniae (clinic controls) or were healthy (community controls). VE was measured using multivariable conditional logistic regression.

Results

We evaluated 8926 children (average age 13.3 months, 58% boys) with clinical pneumonia by ultrasound; 2470 had pneumonia with consolidations ≥ 1 cm; 1893 pneumonia cases were matched with 4238 clinic controls; and 1832 were matched with 3636 community controls. VE increased with the threshold used for consolidation size on ultrasound: the adjusted VE of ≥ 2 doses vs. non-recipients of PCV10 against pneumonia increased from 15.8% (95% CI 1.6–28.0%) for consolidations ≥ 1 cm to 29.6% (12.8–43.2%) for consolidations ≥ 1.5 cm using clinic controls and from 2.7% (− 14.2–17.2%) to 23.5% (4.4–38.8%) using community controls, respectively.

Conclusions

PCV10 was effective at reducing sonographically-confirmed pneumonia in children aged 3–35 months of age when compared to unvaccinated children. VE increased with the threshold used for consolidation size on ultrasound in clinic and community controls alike. This study provides evidence that lung ultrasound is a useful alternative to chest X-ray for case–control studies evaluating the effectiveness of vaccines against pneumonia.

Follow-up lung ultrasound to monitor lung failure in COVID-19 ICU patients

Objectives

Point-of-care lung ultrasound (LU) is an established tool in the first assessment of patients with coronavirus disease (COVID-19). To assess the progression or regression of respiratory failure in critically ill patients with COVID-19 on Intensive Care Unit (ICU) by using LU.

Materials and methods

We analyzed all patients admitted to Internal Intensive Care Unit, Ludwig-Maximilians-University (LMU) of Munich, from March 2020 to December 2020 suffering lung failure caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). LU was performed according to a standardized protocol at baseline and at follow up every other day for the first 15 days using a lung ultrasound score (LUSS). Ventilation data were collected simultaneously.

Results

Our study included 42 patients. At admission to ICU, 19 of them (45%) were mechanically ventilated. Of the non-invasive ventilated ones (n = 23, 55%), eleven patients required invasive ventilation over the course. While LUS did not differ at admission to ICU between the invasive ventilated ones (at baseline or during ICU stay) compared to the non-invasive ventilated ones (12±4 vs 11±2 points, p = 0.2497), LUS was significantly lower at d7 for those, who had no need for invasive ventilation over the course (13±5 vs 7±4 points, p = 0.0046). Median time of invasive ventilation counted 18 days; the 90-day mortality was 24% (n = 10) in our cohort. In case of increasing LUS between day 1 (d1) and day 7 (d7), 92% (n = 12/13) required invasive ventilation, while it was 57% (n = 10/17) in case of decreasing LUS. At d7 we found significant correlation between LU and FiO2 (Pearson 0.591; p = 0.033), p/F ratio (Pearson -0.723; p = 0.005), PEEP (Pearson 0.495; p = 0.043), pplat (Pearson 0.617; p = 0.008) and compliance (Pearson -0.572; p = 0.016).

Conclusion

LUS can be a useful tool in monitoring of progression and regression of respiratory failure and in indicating intubation in patients with COVID-19 in the ICU.

Prolonged mechanical ventilation in patients with severe COVID-19 is associated with serial modified-lung ultrasound scores: A single-centre cohort study

Lung ultrasound (LUS), a rapid, bedside, goal-oriented diagnostic test, can be quantitatively assessed, and the scores can be used to evaluate disease progression. However, little data exists on predicting prolonged mechanical ventilation (PMV) and successful extubation using serial LUS scores. We examined the relationship of PMV with successful extubation in patients with severe coronavirus disease (COVID-19) by using two types of serial LUS scores. One LUS score evaluated both the pleura and lung fields, while the other assessed each separately (modified-LUS score). Both LUS scores were determined for 20 consecutive patients with severe COVID-19 at three timepoints: admission (day-1), after 48 h (day-3), and on the seventh follow-up day (day-7). We compared LUS scores with the radiographic assessment of the lung oedema (RALE) scores and laboratory test results, at the three timepoints. The PMV and successful extubation groups showed no significant differences in mortality, but significant differences occurred on day-3 and day-7 both LUS scores, day-7 RALE score, and day-7 PaO2/FiO2 ratio, in the PMV group (p<0.05); and day-3 and day-7 modified-LUS scores, day-7 C-reactive protein levels, and day-7 PaO2/FiO2 ratio, in the successful extubation group (p<0.05). The area under the curves (AUC) of LUS scores on day-3 and day-7, modified-LUS scores on day-3 and day-7,RALE score on day-7, and PaO2/FiO2 ratio on day-7 in the PMV group were 0.98, 0.85, 0.88, 0.98, 0.77, and 0.80, respectively. The AUC of modified-LUS scores on day-3 and day-7, C-reactive protein levels on day-7, and PaO2/FiO2 ratio on day-7 in the successful extubation group were 0.79, 0.90, 0.82, and 0.79, respectively. The modified-LUS score on day 7 was significantly higher than that on day 1 in PMV group (p<0.05). While the LUS score did not exhibit significant differences. The serial modified-LUS score of patients with severe COVID-19 could predict PMV.

Time course of lung ultrasound findings in patients with COVID-19 pneumonia and cardiac dysfunction

Background

Lung ultrasound (LUS) is a valuable tool to predict and monitor the COVID-19 pneumonia course. However, the influence of cardiac dysfunction (CD) on LUS findings remains to be studied. Our objective was to determine the effect of CD on LUS in hospitalized patients with COVID-19 pneumonia.

Material and methods

Fifty-one patients with COVID-19 pneumonia participated in the study. Focused echocardiography (FoCUS) was carried out on day 1 to separate patients into two groups depending on whether they had FoCUS signs of CD (CD+ vs CD−). LUS scores, based on the thickness of the pleural line, the B-line characteristics, and the presence or not of consolidations, were obtained three times along the patient’s admission (D1, D5, D10) and compared between CD+ and CD− patients. A correlation analysis was carried out between LUS scores and the ratio of the arterial partial pressure of oxygen to the fraction of the inspired oxygen (P/F ratio).

Results

Twenty-two patients were CD+ and 29 patients were CD−. Among the CD+ patients, 19 were admitted to the intensive care unit (ICU), seven received invasive mechanical ventilation (IMV), and one did not survive. Among the CD− patients, 11 were admitted to the ICU, one received IMV and seven did not survive. CD+ patients showed a significantly lower P/F ratio than CD− patients. However, LUS scores showed no between-group differences, except for fewer subpleural consolidations in the upper quadrants of CD+ than on CD− patients.

Conclusion

In patients with COVID-19, CD contributed to a worse clinical course, but it did not induce significant changes in LUS. Our findings suggest that pathophysiological factors other than those reflected by LUS may be responsible for the differences in clinical condition between CD+ and CD− patients.

A Call for Development of Point-of-Care Ultrasound Training Recommendations in Obstetrics and Gynecology Residency

Point-of-care ultrasound (POCUS) skillsets are now taught throughout training levels from medical school through fellowship given the broad utility in assisting with bedside procedures and triaging clinical presentations for expedited workup. This is reflected in training curricula for emergency medicine, internal medicine, and general surgery residencies. However, these skillsets are not formally taught or required in obstetrics and gynecology residency. We present the opinion that these skillsets and curricula should be developed for obstetrics and gynecology trainees given their exposure to patients with similar clinical presentations in which the clinical management would be aided by POCUS.

Quantitative Assessment of Lung Ultrasound Grayscale Images Based on Shannon Entropy for the Detection of Pulmonary Aeration: An Animal Study

OBJECTIVE

Lung ultrasound (LUS) is a radiation-free, affordable, and bedside monitoring method that can detect changes in pulmonary aeration before hypoxic damage. However, visual scoring methods of LUS only enable subjective diagnosis. Therefore, quantitative analysis of LUS is necessary for obtaining objective information on pulmonary aeration. Because raw data are not always available in conventional ultrasound systems, Shannon entropy (ShanEn) of information theory without the requirement of raw data is valuable. In this study, we explored the feasibility of ShanEn estimated through grayscale histogram (GSH) analysis of LUS images for the quantification of pulmonary aeration.

METHODS

Different degrees of pulmonary aeration caused by edema was induced in 32 male New Zealand rabbits intravenously injected with 0.1 mL/kg saline (the control group) and 0.025, 0.05, and 0.1 mL/kg oleic acid (mild, moderate, and severe groups, respectively). In vivo grayscale LUS images were acquired using a commercial point-of-care ultrasound system for estimation of GSH and corresponding ShanEn. Both lungs of each rabbit were dissected, weighed, and dried to determine the wet weight-to-dry weight ratio (W/D) through gravimetry.

RESULTS

The determination coefficients of linear correlations between ShanEn and W/D increased from 0.0487 to 0.7477 with gain and dynamic range (DR). In contrast to visual scoring methods of pulmonary aeration that use median gain and low DR, ShanEn for quantifying pulmonary aeration requires high gain and DR.

CONCLUSION

The current findings indicate that ShanEn estimated through GSH analysis of LUS images acquired using conventional ultrasonic imaging systems has great potential to provide objective information on pulmonary aeration.

Insights Regarding the Berlin Definition of ARDS from Prospective Observational Studies

The definition of acute respiratory distress syndrome (ARDS), has evolved since it was first described in 1967 by Ashbaugh and Petty to the current "Berlin" definition of ARDS developed in 2012 by an expert panel, that provided clarification on the definition of "acute," and on the cardiac failure criteria. It expanded the definition to include patients receiving non-invasive ventilation, and removed the term "acute lung injury" and added a requirement of patients to be receiving a minimum 5 cmH₂O expiratory pressure.Since 2012, a series of observational cohort studies have generated insights into the utility and robustness of this definition. This review will examine novel insights into the epidemiology of ARDS, failures in ARDS diagnosis, the role of lung imaging in ARDS, the novel ARDS cohort that is not invasively ventilated, lung compliance profiles in patients with ARDS, sex differences that exist in ARDS management and outcomes, the progression of ARDS following initial diagnosis, and the clinical profile and outcomes of confirmed versus resolved ARDS. Furthermore, we will discuss studies that challenge the utility of distinguishing ARDS from other causes of acute hypoxemic respiratory failure (AHRF) and identify issues that may need to be addressed in a revised definition.

Multi-organ point-of-care ultrasound for detection of pulmonary embolism in critically ill COVID-19 patients - A diagnostic accuracy study

PURPOSE

Critically ill COVID-19 patients have an increased risk of developing pulmonary embolism (PE). Diagnosis of PE by point-of-care ultrasound (POCUS) might reduce the need for computed tomography pulmonary angiography (CTPA), while decreasing time-to-diagnosis.

MATERIALS & METHODS

This prospective, observational study included adult ICU patients with COVID-19. Multi-organ (lungs, deep vein, cardiac) POCUS was performed within 24 h of CTPA, looking for subpleural consolidations, deep venous thrombosis (DVT), and right ventricular strain (RVS). We reported the scan time, and calculated diagnostic accuracy measures for these signs separately and in combination.

RESULTS

70 consecutive patients were included. 23 patients (32.8%) had a PE. Median scan time was 14 min (IQR 11-17). Subpleural consolidations' diagnostic accuracy was: 42.9% (95%CI [34.1-52.0]). DVT's and RVS' diagnostic accuracy was: 75.6% (95%CI [67.1-82.9]) and 74.4% (95%CI [65.8-81.8]). Their sensitivity was: 24.0% (95%CI [9.4-45.1]), and 40.0% (95%CI [21.3-61.3]), while their specificity was: 88.8% (95%CI [80.8-94.3]), and: 83.0% (95%CI [74.2-89.8]), respectively. Multi-organ POCUS sensitivity was: 87.5% (95%CI [67.6-97.3]), and specificity was: 25% (95%CI [16.9-34.7]).

CONCLUSIONS

Multi-organ rather than single-organ POCUS can be of aid in ruling out PE in critically ill COVID-19 and help select patients for CTPA. In addition, finding RVS can make PE more likely, while a DVT would preclude the need for a CTPA.

REGISTRATION

www.trialregister.nl: NL8540.

Lung Ultrasound Improves Outcome Prediction over Clinical Judgment in COVID-19 Patients Evaluated in the Emergency Department

In the Emergency Department (ED), the decision to hospitalize or discharge COVID-19 patients is challenging. We assessed the utility of lung ultrasound (LUS), alone or in association with a clinical rule/score. This was a multicenter observational prospective study involving six EDs (NCT046291831). From October 2020 to January 2021, COVID-19 outpatients discharged from the ED based on clinical judgment were subjected to LUS and followed-up at 30 days. The primary clinical outcome was a composite of hospitalization or death. Within 393 COVID-19 patients, 35 (8.9%) reached the primary outcome. For outcome prognostication, LUS had a C-index of 0.76 (95%CI 0.68−0.84) and showed good performance and calibration. LUS-based classification provided significant differences in Kaplan−Meier curves, with a positive LUS leading to a hazard ratio of 4.33 (95%CI 1.95−9.61) for the primary outcome. The sensitivity and specificity of LUS for primary outcome occurrence were 74.3% (95%CI 59.8−88.8) and 74% (95%CI 69.5−78.6), respectively. The integration of LUS with a clinical score further increased sensitivity. In patients with a negative LUS, the primary outcome occurred in nine (3.3%) patients (p < 0.001 vs. unselected). The efficiency for rule-out was 69.7%. In unvaccinated ED patients with COVID-19, LUS improves prognostic stratification over clinical judgment alone and may support standardized disposition decisions.

The Role of Lung Ultrasound Monitoring in Early Detection of Ventilator-Associated Pneumonia in COVID-19 Patients: A Retrospective Observational Study

Specific lung ultrasound signs combined with clinical parameters allow for early diagnosis of ventilator-associated pneumonia in the general ICU population. This retrospective cohort study aimed to determine the accuracy of lung ultrasound monitoring for ventilator-associated pneumonia diagnosis in COVID-19 patients. Clinical (i.e., clinical pulmonary infection score) and ultrasound (i.e., presence of consolidation and a dynamic linear−arborescent air bronchogram, lung ultrasound score, ventilator-associated lung ultrasound score) data were collected on the day of the microbiological sample (pneumonia-day) and 48 h before (baseline) on 55 bronchoalveolar lavages of 33 mechanically-ventilated COVID-19 patients who were monitored daily with lung ultrasounds. A total of 26 samples in 23 patients were positive for ventilator-associated pneumonia (pneumonia cases). The onset of a dynamic linear−arborescent air bronchogram was 100% specific for ventilator-associated pneumonia. The ventilator-associated lung ultrasound score was higher in pneumonia-cases (2.5 (IQR 1.0 to 4.0) vs. 1.0 (IQR 1.0 to 1.0); p < 0.001); the lung ultrasound score increased from baseline in pneumonia-cases only (3.5 (IQR 2.0 to 6.0) vs. −1.0 (IQR −2.0 to 1.0); p = 0.0001). The area under the curve for clinical parameters, ventilator-associated pneumonia lung ultrasound score, and lung ultrasound score variations were 0.472, 0.716, and 0.800, respectively. A newly appeared dynamic linear−arborescent air bronchogram is highly specific for ventilator-associated pneumonia in COVID-19 patients. A high ventilator-associated pneumonia lung ultrasound score (or an increase in the lung ultrasound score) orients to ventilator-associated pneumonia.

A new approach in the diagnosis of lung lesions in patients with COVID-19: lung ultrasound protocol versus CT scan

Aim. To develop a protocol for ultrasound diagnostics of COVID-19 pneumonia and to assess the diagnostic capabilities of the method in comparison with computer tomography (CT). Materials and methods. The study included 59 patients with a new coronavirus infection. In order to identify changes in the lung tissue characteristic of a new coronavirus infection, we used a special protocol for ultrasound of the lungs, which was developed by us in such a way that the data obtained were compared by segment with the results of CT of the lungs. Results. When comparing the results of lung ultrasound with the data of CT diagnostics, according to the new protocol, the percentage of lung tissue damage during ultrasound of the lungs averaged 70.8% in the group [62.5; 87.5], and according to the results of CT 70.0% [60.0; 72.5] (p=0.427). Thus, the ultrasound of the lung lesions was almost completely consistent with the changes revealed by CT. In order to assess the diagnostic value of lung ultrasound in identifying severe lung tissue lesions corresponding to CT 34, ROC analysis was performed, which showed the high diagnostic value of lung ultrasound in identifying severe lung tissue lesions. Conclusion. A new protocol was developed for assessing the severity of lung tissue damage according to ultrasound data, which showed a high diagnostic value in detecting COVID-19 pneumonia in comparison with CT. The results obtained give reason to recommend this protocol of ultrasound of the lungs as a highly sensitive method in diagnosing the severity of COVID-19 pneumonia. Its application is very important for dynamic examination of patients, especially in conditions of low availability of CT.

The impact of ultrasound-guided recruitment maneuvers on the risk of postoperative pulmonary complications in patients undergoing general anesthesia

Introduction

Postoperative pulmonary complications are among the most frequent problems in perioperative care. The risk of their development depends not only on the parameters associated with the patient’s initial clinical condition, but also on the employed anesthesia technique, the method of mechanical ventilation, and the type and technique of the surgical procedure. Atelectasis is the most common complication, affecting nearly 90% of the patients undergoing general anesthesia.

Aim

The aim of this study was to determine whether it was possible to positively impact the postoperative period and reduce the frequency of postoperative pulmonary complications via patient-based intraoperative ultrasound-guided recruitment maneuvers.

Methodology

The course of the postoperative period was analyzed in two groups of patients. One of them comprised 100 patients in whom no recruitment maneuvers were performed during general anesthesia. The other group (100 patients) consisted of patients in whom patient-based ultrasound-guided pulmonary recruitment maneuvers were performed.

Results

In the recruitment group, the postoperative hospitalization was statistically significantly shorter (p = 0.003) and the risk of intensive care treatment significantly lower. Additionally, the need for prolonged postoperative mechanical ventilation was reduced, as was the risk of respiratory tract infections.

Conclusions

Intraoperative ultrasound-guided recruitment maneuvers reduce the frequency of postoperative pulmonary complications.

Lung Ultrasound Artifact Findings in Pediatric Patients Admitted to the Intensive Care Unit for Acute Respiratory Failure

PURPOSE

To describe point-of-care lung ultrasound (POC-LUS) artifact findings in children admitted to the pediatric intensive care unit (PICU) for acute respiratory failure (ARF).

METHODS

This is a secondary analysis of a prospective observational study completed in a 21-bed PICU. Children > 37 weeks gestational age and ≤ 18 years were enrolled from December 2018 to February 2020. POC-LUS was completed and interpreted by separate physicians blinded to all clinical information. POC-LUS was evaluated for the presence of lung sliding, pleural line characteristics, ultrasound artifacts, and the ultrasound diagnosis.

RESULTS

Eighty-seven subjects were included. A-lines were the most frequent artifact, occurring in 58% of lung zones (163/281) in those with bronchiolitis, 39% of lung zones (64/164) in those with pneumonia, and 81% of lung zones (48/59) in those with status asthmaticus. Sub-pleural consolidation was second most common, occurring in 28% (80/281), 30% (50/164), and 12% (7/59) of those with bronchiolitis, pneumonia, and status asthmaticus, respectively. The pattern a priori defined as bronchiolitis, pneumonia, and status asthmaticus was demonstrated in 31% (15/48), 10% (3/29), and 40% (4/10) of subjects with bronchiolitis, pneumonia, and status asthmaticus, respectively.

CONCLUSION

We found significant heterogeneity and overlap of POC-LUS artifacts across the most common etiologies of ARF in children admitted to the PICU. We have described the POC-LUS artifact findings in pediatric ARF to support clinicians using POC-LUS and to guide future pediatric POC-LUS studies. Determining the optimal role of POC-LUS as an adjunct in the care of pediatric patients requires further study.

A systematic review and meta-analysis of pulmonary surfactant combined with budesonide in the treatment of neonatal respiratory distress syndrome

BACKGROUND

Neonatal respiratory distress syndrome (NRDS), if caused by a lack of pulmonary surfactant (PS), leads to progressive alveolar collapse. Glucocorticoids have anti-inflammatory and anti-allergic effects and can reduce bronchial and pulmonary edema. This research hopes to systematically evaluate the efficacy and safety of animal-derived PS combined with the glucocorticoid drug budesonide in the treatment of NRDS.

METHODS

Electronic databases (i.e., Wanfang, Weipu, CNKI, PubMed, Embase, Cochrane Library) were searched from inception until May 30th, 2021. Studies relevant to the treatment of pulmonary surfactant combined with budesonide in the treatment of neonatal respiratory distress syndrome were identified. Consequently, all the studies that met the inclusion criteria were considered qualified for screening. For the meta-analysis, all data were analyzed using RevMan 5.3 software. Furthermore, subgroup analysis was performed to evaluate the administration method of budesonide (nebulized inhalation, intratracheal instillation) combined with intratracheal instillation of pulmonary surfactant.

RESULTS

A total of 10 articles were included in this study, involving 527 children. This meta-analysis suggests that the treatment of intratracheal infusion of pulmonary surfactant combined with budesonide therapy can effectively (I) reduce the time of mechanical ventilation (OR =-1.72,95% CI: -2.44 to -1.01, P<0.00001); (II) reduce the length of stay (OR =-5.17, 95% CI: -9.35 to -0.99, P=0.02); (III) reduce the incidence of bronchopulmonary dysplasia (BPD) (OR =0.52, 95% CI: 0.39-0.68, P<0.00001); and (IV) reduce the incidence of BPD (RR =0.73, 95% CI: 0.40-1.35, P=0.32). There was no significant difference in the incidence of retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), patent ductus arteriosus (PDA), or sepsis between the experimental group and the control group.

DISCUSSION

The treatment of animal-derived pulmonary surfactant combined with budesonide can effectively shorten the hospital stay and reduce the time of invasive mechanical ventilation and the incidence of BPD. Meanwhile, it does not increase the risk of related complications or death. This approach can be applied clinically.

Factors for success of awake prone positioning in patients with COVID-19-induced acute hypoxemic respiratory failure: analysis of a randomized controlled trial

Background

Awake prone positioning (APP) improves oxygenation in coronavirus disease (COVID-19) patients and, when successful, may decrease the risk of intubation. However, factors associated with APP success remain unknown. In this secondary analysis, we aimed to assess whether APP can reduce intubation rate in patients with COVID-19 and to focus on the factors associated with success.

Methods

In this multicenter randomized controlled trial, conducted in three high-acuity units, we randomly assigned patients with COVID-19-induced acute hypoxemic respiratory failure (AHRF) requiring high-flow nasal cannula (HFNC) oxygen to APP or standard care. Primary outcome was intubation rate at 28 days. Multivariate analyses were performed to identify the predictors associated to treatment success (survival without intubation).

Results

Among 430 patients randomized, 216 were assigned to APP and 214 to standard care. The APP group had a lower intubation rate (30% vs 43%, relative risk [RR] 0.70; CI₉₅ 0.54–0.90, P = 0.006) and shorter hospital length of stay (11 interquartile range [IQR, 9–14] vs 13 [IQR, 10–17] days, P = 0.001). A respiratory rate ≤ 25 bpm at enrollment, an increase in ROX index > 1.25 after first APP session, APP duration > 8 h/day, and a decrease in lung ultrasound score ≥ 2 within the first 3 days were significantly associated with treatment success for APP.

Conclusion

In patients with COVID-19-induced AHRF treated by HFNC, APP reduced intubation rate and improved treatment success. A longer APP duration is associated with APP success, while the increase in ROX index and decrease in lung ultrasound score after APP can also help identify patients most likely to benefit.

Trial registration: This study was retrospectively registered in ClinicalTrials.gov at July 20, 2021. Identification number NCT04477655. https://clinicaltrials.gov/ct2/show/NCT04477655?term=PRO-CARF&draw=2&rank=1

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03950-0.

Specification and guideline for technical aspects and scanning parameter settings of neonatal lung ultrasound examination

Lung ultrasound (LUS) is now widely used in the diagnosis and monitor of neonatal lung diseases. Nevertheless, in the published literatures, the LUS images may display a significant variation in technical execution, while scanning parameters may influence diagnostic accuracy. The inter- and intra-observer reliabilities of ultrasound exam have been extensively studied in general and in LUS. As expected, the reliability declines in the hands of novices when they perform the point-of-care ultrasound (POC US). Consequently, having appropriate guidelines regarding to technical aspects of neonatal LUS exam is very important especially because diagnosis is mainly based on interpretation of artifacts produced by the pleural line and the lungs. The present work aimed to create an instrument operation specification and parameter setting guidelines for neonatal LUS. Technical aspects and scanning parameter settings that allow for standardization in obtaining LUS images include (1) select a high-end equipment with high-frequency linear array transducer (12-14 MHz). (2) Choose preset suitable for lung examination or small organs. (3) Keep the probe perpendicular to the ribs or parallel to the intercostal space. (4) Set the scanning depth at 4-5 cm. (5) Set 1-2 focal zones and adjust them close to the pleural line. (6) Use fundamental frequency with speckle reduction 2-3 or similar techniques. (7) Turn off spatial compounding imaging. (8) Adjust the time-gain compensation to get uniform image from the near-to far-field.

The Diagnostic Contribution of Systematic Lung Ultrasonography in Patients Admitted to a Conventional Pulmonology Hospitalization Unit

OBJECTIVE

Although the evidence to date remains limited, we hypothesized that performing protocolized lung ultrasound (LUS) in patients, admitted to a conventional pulmonology hospitalization unit, could improve diagnostic precision. The main objectives of this study were to evaluate the diagnostic contribution and changes in the treatments administered after performing a protocolized LUS in patients hospitalized in a Pulmonology Department ward.

METHODOLOGY

This was a prospective, observational study, which included patients admitted from the Emergency Department to a conventional Pulmonology Department hospitalization unit, after first being evaluated by a pulmonologist. LUS was performed within the first 48 hours of admission. The diagnosis at the time of discharge was used as the reference diagnosis.

RESULTS

A total of 180 patients were included in this study. The admitting diagnoses were the decompensation of an underlying obstructive disease in 60 patients (33.3%), respiratory infection in 93 (51.7%), pulmonary thromboembolism (PE) in 9 (5%), exacerbation of an interstitial lung disease in 14 (7.8%), and other causes in 4 cases (2.2%). Ultrasonography provided new information, unsuspected at the patient's admission, in 117 (65%) of the patients by capturing images suggestive of infection in 63 patients (35%), 1 new case of ILD, 23 (12.7%) cases of cardiogenic edema, and pleural pathology in 19 (10.5%), as well as two tumors and indirect data related to a PE. The use of LUS resulted in the decision to change the already established treatment in 17.2% of the cases.

CONCLUSIONS

LUS provided additive information in more than half of patients that ended up reclassifying or potentially changing diagnosis or treatment. Thus, including LUS in management algorithms could reduce the need for other complementary tests or unnecessary treatments.

The Role of Lung Ultrasound in Low-Resource Settings During the Coronavirus (SARS-CoV-2) Pandemic

Lung ultrasound (LUS) has proven to be a helpful diagnostic tool for evaluating lung involvement in respiratory pathologies. The usage of this imaging technique became even more widespread during the SARS-CoV-2 pandemic. The latest generation ultrasound scanners are conveniently portable and this permits ultrasound examinations to be performed even in extreme environments where no other diagnostic tool is available. Our team has developed the first guide that assists the clinician while operating in low-resource settings, in managing a SARS-CoV-2 patient based on the clinical examination and the LUS findings.

Effects of positive end-expiratory pressure on lung ultrasound patterns and their correlation with intracranial pressure in mechanically ventilated brain injured patients

Background

The effects of positive end-expiratory pressure (PEEP) on lung ultrasound (LUS) patterns, and their relationship with intracranial pressure (ICP) in brain injured patients have not been completely clarified. The primary aim of this study was to assess the effect of two levels of PEEP (5 and 15 cmH₂O) on global (LUStot) and regional (anterior, lateral, and posterior areas) LUS scores and their correlation with changes of invasive ICP. Secondary aims included: the evaluation of the effect of PEEP on respiratory mechanics, arterial partial pressure of carbon dioxide (PaCO₂) and hemodynamics; the correlation between changes in ICP and LUS as well as respiratory parameters; the identification of factors at baseline as potential predictors of ICP response to higher PEEP.

Methods

Prospective, observational study including adult mechanically ventilated patients with acute brain injury requiring invasive ICP. Total and regional LUS scores, ICP, respiratory mechanics, and arterial blood gases values were analyzed at PEEP 5 and 15 cmH₂O.

Results

Thirty patients were included; 19 of them (63.3%) were male, with median age of 65 years [interquartile range (IQR) = 66.7–76.0]. PEEP from 5 to 15 cmH₂O reduced LUS score in the posterior regions (LUSp, median value from 7 [5–8] to 4.5 [3.7–6], p = 0.002). Changes in ICP were significantly correlated with changes in LUStot (rho = 0.631, p = 0.0002), LUSp (rho = 0.663, p < 0.0001), respiratory system compliance (rho = − 0.599, p < 0.0001), mean arterial pressure (rho = − 0.833, p < 0.0001) and PaCO₂ (rho = 0.819, p < 0.0001). Baseline LUStot score predicted the increase of ICP with PEEP.

Conclusions

LUS-together with the evaluation of respiratory and clinical variables-can assist the clinicians in the bedside assessment and prediction of the effect of PEEP on ICP in patients with acute brain injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03903-7.

Machine learning empowered COVID-19 patient monitoring using non-contact sensing: An extensive review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused the coronavirus disease 2019 (COVID-19) pandemic, has affected more than 400 million people worldwide. With the recent rise of new Delta and Omicron variants, the efficacy of the vaccines has become an important question. The goal of various studies has been to limit the spread of the virus by utilizing wireless sensing technologies to prevent human-to-human interactions, particularly for healthcare workers. In this paper, we discuss the current literature on invasive/contact and non-invasive/non-contact technologies (including Wi-Fi, radar, and software-defined radio) that have been effectively used to detect, diagnose, and monitor human activities and COVID-19 related symptoms, such as irregular respiration. In addition, we focused on cutting-edge machine learning algorithms (such as generative adversarial networks, random forest, multilayer perceptron, support vector machine, extremely randomized trees, and k-nearest neighbors) and their essential role in intelligent healthcare systems. Furthermore, this study highlights the limitations related to non-invasive techniques and prospective research directions.

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This article describes cutting-edge technology (invasive/non-invasive) and its role in the recognition of COVID-19 symptoms.

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This article summarizes state-of-art machine-learning algorithms and their roles in modern healthcare systems.

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This article presents the challenges associated with wireless sensing techniques and potential future research directions.

The Value of Lung Ultrasound Score in Neonatology

Point-of-care lung ultrasound (LUS) is increasingly applied in the neonatal intensive care unit (NICU). Diagnostic applications for LUS in the NICU contain the diagnosis of many common neonatal pulmonary diseases (such as Respiratory distress syndrome, Transient tachypnea of the newborn, Meconium aspiration syndrome, Pneumonia, Pneumothorax, and Pleural effusion) which have been validated. In addition to being employed as a diagnostic tool in the classical sense of the term, recent studies have shown that the number and type of artifacts are associated with lung aeration. Based on this theory, over the last few years, LUS has also been used as a semi-quantitative method or as a "functional" tool. Scores have been proposed to monitor the progress of neonatal lung diseases and to decide whether or not to perform a specific treatment. The semi-quantitative LUS scores (LUSs) have been developed to predict the demand for surfactant therapy, the need of respiratory support and the progress of bronchopulmonary dysplasia. Given their ease of use, accuracy and lack of invasiveness, the use of LUSs is increasing in clinical practice. Therefore, this manuscript will review the application of LUSs in neonatal lung diseases.

Gravity-induced loss of aeration and atelectasis development in the preterm lung: a serial sonographic assessment

OBJECTIVE

To assess the impact of gravity and time on the changes in the distribution patterns of loss of aeration and atelectasis development in very preterm infants.

STUDY DESIGN

Preterm infants less than 32 weeks gestation were included in this prospective, observational study. Infants were assessed via serial lung ultrasound (LUS) score in four lung zones, performed on days 7, 14, 21, and 28 after birth.

RESULT

Eighty-eight patients were enrolled. There was a significant main effect of gravity (P < 0.001) and time (P = 0.01) on the LUS score between gravity-dependent lungs and non-dependent lungs. Moreover, there was a significant main effect of gravity (P = 0.003) on atelectasis development between the lungs.

CONCLUSION

Gravity and time have an impact on the changes in the distribution patterns of gravity-induced lung injuries in preterm infants.

Recent ultrasound advancements for the manipulation of nanobiomaterials and nanoformulations for drug delivery

Recent advances in ultrasound (US) have shown its great potential in biomedical applications as diagnostic and therapeutic tools. The coupling of US-assisted drug delivery systems with nanobiomaterials possessing tailor-made functions has been shown to remove the limitations of conventional drug delivery systems. The low-frequency US has significantly enhanced the targeted drug delivery effect and efficacy, reducing limitations posed by conventional treatments such as a limited therapeutic window. The acoustic cavitation effect induced by the US-mediated microbubbles (MBs) has been reported to replace drugs in certain acute diseases such as ischemic stroke. This review briefly discusses the US principles, with particular attention to the recent advancements in drug delivery applications. Furthermore, US-assisted drug delivery coupled with nanobiomaterials to treat different diseases (cancer, neurodegenerative disease, diabetes, thrombosis, and COVID-19) are discussed in detail. Finally, this review covers the future perspectives and challenges on the applications of US-mediated nanobiomaterials.

Diagnostic Modalities in Critical Care: Point-of-Care Approach

The concept of intensive care units (ICU) has existed for almost 70 years, with outstanding development progress in the last decades. Multidisciplinary care of critically ill patients has become an integral part of every modern health care system, ensuing improved care and reduced mortality. Early recognition of severe medical and surgical illnesses, advanced prehospital care and organized immediate care in trauma centres led to a rise of ICU patients. Due to the underlying disease and its need for complex mechanical support for monitoring and treatment, it is often necessary to facilitate bed-side diagnostics. Immediate diagnostics are essential for a successful treatment of life threatening conditions, early recognition of complications and good quality of care. Management of ICU patients is incomprehensible without continuous and sophisticated monitoring, bedside ultrasonography, diverse radiologic diagnostics, blood gas analysis, coagulation and blood management, laboratory and other point-of-care (POC) diagnostic modalities. Moreover, in the time of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, particular attention is given to the POC diagnostic techniques due to additional concerns related to the risk of infection transmission, patient and healthcare workers safety and potential adverse events due to patient relocation. This review summarizes the most actual information on possible diagnostic modalities in critical care, with a special focus on the importance of point-of-care approach in the laboratory monitoring and imaging procedures.

Italian Society of Anesthesia, Analgesia, Resuscitation, and Intensive Care expert consensus statement on the use of lung ultrasound in critically ill patients with coronavirus disease 2019 (ITACO)

BACKGROUND

To produce statements based on the available evidence and an expert consensus (as members of the Lung Ultrasound Working Group of the Italian Society of Analgesia, Anesthesia, Resuscitation, and Intensive Care, SIAARTI) on the use of lung ultrasound for the management of patients with COVID-19 admitted to the intensive care unit.

METHODS

A modified Delphi method was applied by a panel of anesthesiologists and intensive care physicians expert in the use of lung ultrasound in COVID-19 intensive critically ill patients to reach a consensus on ten clinical questions concerning the role of lung ultrasound in the following: COVID-19 diagnosis and monitoring (with and without invasive mechanical ventilation), positive end expiratory pressure titration, the use of prone position, the early diagnosis of pneumothorax- or ventilator-associated pneumonia, the process of weaning from invasive mechanical ventilation, and the need for radiologic chest imaging.

RESULTS

A total of 20 statements were produced by the panel. Agreement was reached on 18 out of 20 statements (scoring 7-9; "appropriate") in the first round of voting, while 2 statements required a second round for agreement to be reached. At the end of the two Delphi rounds, the median score for the 20 statements was 8.5 [IQR 8.9], and the agreement percentage was 100%.

CONCLUSION

The Lung Ultrasound Working Group of the Italian Society of Analgesia, Anesthesia, Resuscitation, and Intensive Care produced 20 consensus statements on the use of lung ultrasound in COVID-19 patients admitted to the ICU. This expert consensus strongly suggests integrating lung ultrasound findings in the clinical management of critically ill COVID-19 patients.

Ultrasound and Other Advanced Hemodynamic Monitoring Techniques in the Intensive Care Unit

The ideal device for hemodynamic monitoring of critically ill patients in the intensive care unit (ICU) or the operating room has not yet been developed. This would need to be affordable, consistent, have a very low margin of error (<30%), be minimally or noninvasive, and allow the clinician to make a reasonable therapeutic decision that consistently led to better outcomes. Such a device does not yet exist. This article will describe the distinct options we, as critical care physicians, currently possess for this Herculean endeavor.

Diagnostic ultrasound imaging of the lung: A simulation approach based on propagation and reverberation in the human body

Although ultrasound cannot penetrate a tissue/air interface, it images the lung with high diagnostic accuracy. Lung ultrasound imaging relies on the interpretation of "artifacts," which arise from the complex reverberation physics occurring at the lung surface but appear deep inside the lung. This physics is more complex and less understood than conventional B-mode imaging in which the signal directly reflected by the target is used to generate an image. Here, to establish a more direct relationship between the underlying acoustics and lung imaging, simulations are used. The simulations model ultrasound propagation and reverberation in the human abdomen and at the tissue/air interfaces of the lung in a way that allows for direct measurements of acoustic pressure inside the human body and various anatomical structures, something that is not feasible clinically or experimentally. It is shown that the B-mode images beamformed from these acoustical simulations reproduce primary clinical features that are used in diagnostic lung imaging, i.e., A-lines and B-lines, with a clear relationship to known underlying anatomical structures. Both the oblique and parasagittal views are successfully modeled with the latter producing the characteristic "bat sign," arising from the ribs and intercostal part of the pleura. These simulations also establish a quantitative link between the percentage of fluid in exudative regions and the appearance of B-lines, suggesting that the B-mode may be used as a quantitative imaging modality.

COVID-19 pneumonia: A review of typical radiological characteristics

Coronavirus disease 2019 (COVID-19) was first discovered after unusual cases of severe pneumonia emerged by the end of 2019 in Wuhan (China) and was declared a global public health emergency by the World Health Organization in January 2020. The new pathogen responsible for the infection, genetically similar to the beta-coronavirus family, is known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and the current gold standard diagnostic tool for its detection in respiratory samples is the reverse transcription-polymerase chain reaction test. Imaging findings on COVID-19 have been widely described in studies published throughout last year, 2020. In general, ground-glass opacities and consolidations, with a bilateral and peripheral distribution, are the most typical patterns found in COVID-19 pneumonia. Even though much of the literature focuses on chest computed tomography (CT) and X-ray imaging and their findings, other imaging modalities have also been useful in the assessment of COVID-19 patients. Lung ultrasonography is an emerging technique with a high sensitivity, and thus useful in the initial evaluation of SARS-CoV-2 infection. In addition, combined positron emission tomography-CT enables the identification of affected areas and follow-up treatment responses. This review intends to clarify the role of the imaging modalities available and identify the most common radiological manifestations of COVID-19.

Point-of-Care Lung Ultrasonography: A Clinical Update for the Emergency Nurse Practitioner

Since the introduction of ultrasonography, clinicians have discovered different uses for embedding this technology in the clinical setting. The use of point-of-care ultrasonography has gained a lot of interest in the emergency department. It is a procedure that a clinician can rapidly utilize to triage, risk stratify, evaluate, and monitor the patient's condition. The COVID-19 pandemic has highlighted the significance and application of ultrasonography in identifying and managing patients presenting with lung pathology in the emergency setting.

Diagnostic value of pleural ultrasound to refine endotracheal tube placement in pediatric intensive care unit

AIM

To assess the diagnostic performance of a simplified lung point-of-care ultrasound (POCUS) to confirm the correct positioning of an endotracheal tube (ETT) in a pediatric intensive care unit (PICU) used to chest radiography (CXR), and to compare the time to obtain the ETT position between POCUS and CXR.

METHODS

We conducted a single-center prospective study in critically ill children requiring urgent endotracheal intubation. Esophageal tube malposition was first avoided using auscultation and end-tidal CO2. The ETT position was assessed with CXR and lung POCUS using the lung sliding sign on a pleural window. All of the investigators had to read guidelines and received 1-h training on the technical aspects of lung sliding. The primary objective was the accuracy of POCUS in confirming correct nonselective endotracheal intubation as compared with CXR.

RESULTS

A total of 71 patients were included from December 2016 to November 2018. CXR identified proper nonselective ETT placement in 43 of 71 (61%) patients, while the rate for selective intubation was 39%. The sensitivity and specificity of POCUS as compared with CXR were 77% and 68%, respectively. Median time to POCUS was significantly shorter than CXR (2 min to perform POCUS, 10 min to obtain radiographs, p<10-4).

CONCLUSION

Pleural ultrasound, although faster than CXR, appears to be inadequate for identifying selective ETT after urgent intubation in a PICU less accustomed to this kind of ultrasound. In this heterogeneous and fragile population, timely POCUS may remain useful at the bedside as compared with auscultation, aiming at guiding optimal ETT placement and reducing respiratory complications, provided by trained physicians.

Lung Ultrasound Assessment of Focal and Non-focal Lung Morphology in Patients With Acute Respiratory Distress Syndrome

Background: The identification of phenotypes based on lung morphology can be helpful to better target mechanical ventilation of individual patients with acute respiratory distress syndrome (ARDS). We aimed to assess the accuracy of lung ultrasound (LUS) methods for classification of lung morphology in critically ill ARDS patients under mechanical ventilation.

Methods: This was a post hoc analysis on two prospective studies that performed LUS and chest computed tomography (CT) scanning at the same time. Expert panels from the two participating centers separately developed two LUS methods for classifying lung morphology based on LUS aeration scores from a 12-region exam (Amsterdam and Lombardy method). Moreover, a previously developed LUS method based on anterior LUS scores was tested (Piedmont method). Sensitivity and specificity of all three LUS methods was assessed in the cohort of the other center(s) by using CT as the gold standard for classification of lung morphology.

Results: The Amsterdam and Lombardy cohorts consisted of 32 and 19 ARDS patients, respectively. From these patients, 23 (45%) had focal lung morphology while others had non-focal lung morphology. The Amsterdam method could classify focal lung morphology with a sensitivity of 77% and a specificity of 100%, while the Lombardy method had a sensitivity and specificity of 100 and 61%. The Piedmont method had a sensitivity and specificity of 91 and 75% when tested on both cohorts. With both the Amsterdam and Lombardy method, most patients could be classified based on the anterior regions alone.

Conclusion: LUS-based methods can accurately classify lung morphology in invasively ventilated ARDS patients compared to gold standard chest CT. The anterior LUS regions showed to be the most discriminant between focal and non-focal lung morphology, although accuracy increased moderately when lateral and posterior LUS regions were integrated in the method.

Transoesophageal Ultrasound Assessment of Lung Aeration in Patients With Acute Respiratory Distress Syndrome

Introduction: The effect of positive end-expiratory pressure (PEEP) depends closely on the potential for lung recruitment. Bedside assessment of lung recruitability is crucial for personalized lung-protective mechanical ventilation in acute respiratory distress syndrome (ARDS) patients. Methods: We developed a transoesophageal lung ultrasound (TE-LUS) method in which a quantitative (computer-assisted) grayscale determination served as a guide to PEEP-induced lung recruitment. The method is based on the following hypothesis: when the PEEP increases, inflation of the recruited alveoli leads to significant changes in the air/water ratio. Normally ventilated areas are hypoechoic because the ultrasound waves are weakly reflected while poorly aerated areas or non-aerated areas are hyperechoic. We calculated the TE-LUS re-aeration score (RAS) as the ratio of the mean gray scale level at low PEEP to that value at high PEEP for the lower and upper lobes. A RAS > 1 indicated an increase in ventilated area. We used this new method to detect changes in ventilation in patients with a low (<0.5) vs. high (≥0.5) recruitment-to-inflation (R/I) ratio (i.e., the ratio between the recruited lung compliance and the respiratory system compliance at low PEEP). Results: We included 30 patients with moderate-to-severe ARDS. In patients with a high R/I ratio, the TE-LUS RAS was significantly higher in the lower lobes than in the upper lobes (1.20 [1.12-1.63] vs. 1.05 [0.89-1.38]; p = 0.05). Likewise, the TE-LUS RAS in the lower lobes was significantly higher in the high R/I group than in the low R/I group (1.20 [1.12-1.63] vs. 1.07 [1.00-1.20]; p = 0.04). Conclusion: The increase in PEEP induces a substantial gain in the ventilation detected by TE-LUS of poorly or non-aerated lower lobes (dependent lung regions), especially in patients with a high R/I ratio.