Lung Recruitment Assessed by Electrical Impedance Tomography (RECRUIT): A Multicenter Study of COVID-19 Acute Respiratory Distress Syndrome.

Rationale: Defining lung recruitability is needed for safe positive end-expiratory pressure (PEEP) selection in mechanically ventilated patients. However, there is no simple bedside method including both assessment of recruitability and risks of overdistension as well as personalized PEEP titration. Objectives: To describe the range of recruitability using electrical impedance tomography (EIT), effects of PEEP on recruitability, respiratory mechanics and gas exchange, and a method to select optimal EIT-based PEEP. Methods: This is the analysis of patients with coronavirus disease (COVID-19) from an ongoing multicenter prospective physiological study including patients with moderate-severe acute respiratory distress syndrome of different causes. EIT, ventilator data, hemodynamics, and arterial blood gases were obtained during PEEP titration maneuvers. EIT-based optimal PEEP was defined as the crossing point of the overdistension and collapse curves during a decremental PEEP trial. Recruitability was defined as the amount of modifiable collapse when increasing PEEP from 6 to 24 cm H2O (ΔCollapse24-6). Patients were classified as low, medium, or high recruiters on the basis of tertiles of ΔCollapse24-6. Measurements and Main Results: In 108 patients with COVID-19, recruitability varied from 0.3% to 66.9% and was unrelated to acute respiratory distress syndrome severity. Median EIT-based PEEP differed between groups: 10 versus 13.5 versus 15.5 cm H2O for low versus medium versus high recruitability (P < 0.05). This approach assigned a different PEEP level from the highest compliance approach in 81% of patients. The protocol was well tolerated; in four patients, the PEEP level did not reach 24 cm H2O because of hemodynamic instability. Conclusions: Recruitability varies widely among patients with COVID-19. EIT allows personalizing PEEP setting as a compromise between recruitability and overdistension. Clinical trial registered with www.clinicaltrials.gov (NCT04460859).

The value of lung ultrasound in COVID-19 pneumonia, verified by high resolution computed tomography assessed by artificial intelligence.

BACKGROUND: Lung ultrasound (LUS) is an increasingly popular imaging method in clinical practice. It became particularly important during the COVID-19 pandemic due to its mobility and ease of use compared to high-resolution computed tomography (HRCT). The objective of this study was to assess the value of LUS in quantifying the degree of lung involvement and in discrimination of lesion types in the course of COVID-19 pneumonia as compared to HRCT analyzed by the artificial intelligence (AI). METHODS: This was a prospective observational study including adult patients hospitalized due to COVID-19 in whom initial HRCT and LUS were performed with an interval < 72 h. HRCT assessment was performed automatically by AI. We evaluated the correlations between the inflammation volume assessed both in LUS and HRCT, between LUS results and the HRCT structure of inflammation, and between LUS and the laboratory markers of inflammation. Additionally we compared the LUS results in subgroups depending on the respiratory failure throughout the hospitalization. RESULTS: Study group comprised 65 patients, median 63 years old. For both lungs, the median LUS score was 19 (IQR-interquartile range 11-24) and the median CT score was 22 (IQR 16-26). Strong correlations were found between LUS and CT scores (for both lungs r = 0.75), and between LUS score and percentage inflammation volume (PIV) (r = 0.69). The correlations remained significant, if weakened, for individual lung lobes. The correlations between LUS score and the value of the percentage consolidation volume (PCV) divided by percentage ground glass volume (PGV), were weak or not significant. We found significant correlation between LUS score and C-reactive protein (r = 0.55), and between LUS score and interleukin 6 (r = 0.39). LUS score was significantly higher in subgroups with more severe respiratory failure. CONCLUSIONS: LUS can be regarded as an accurate method to evaluate the extent of COVID-19 pneumonia and as a promising tool to estimate its clinical severity. Evaluation of LUS in the assessment of the structure of inflammation, requires further studies in the course of the disease. TRIAL REGISTRATION: The study has been preregistered 13 Aug 2020 on clinicaltrials.gov with the number NCT04513210.

Abdominal Imaging Findings on Computed Tomography as a Tool for COVID-19 Mortality Risk Assessment: Comparison With Chest Radiograph Severity Scores.

OBJECTIVE: To quantify the association between computed tomography abdomen and pelvis with contrast (CTAP) findings and chest radiograph (CXR) severity score, and the incremental effect of incorporating CTAP findings into predictive models of COVID-19 mortality. METHODS: This retrospective study was performed at a large quaternary care medical center. All adult patients who presented to our institution between March and June 2020 with the diagnosis of COVID-19 and had a CXR up to 48 hours before a CTAP were included. Primary outcomes were the severity of lung disease before CTAP and mortality within 14 and 30 days. Logistic regression models were constructed to quantify the association between CXR score and CTAP findings. Penalized logistic regression models and random forests were constructed to identify key predictors (demographics, CTAP findings, and CXR score) of mortality. The discriminatory performance of these models, with and without CTAP findings, was summarized using area under the characteristic (AUC) curves. RESULTS: One hundred ninety-five patients (median age, 63 years; 119 men) were included. The odds of having CTAP findings was 3.89 times greater when a CXR score was classified as severe compared with mild (P = 0.002). When CTAP findings were included in the feature set, the AUCs for 14-day mortality were 0.67 (penalized logistic regression) and 0.71 (random forests). Similar values for 30-day mortality were 0.76 and 0.75. When CTAP findings were omitted, all AUC values were attenuated. CONCLUSIONS: The CTAP findings were associated with more severe CXR score and may serve as predictors of COVID-19 mortality.

Cardiac Computed Tomography to exclude left atrial appendage thrombus in atrial arrhythmias prior to electrical cardioversion during the COVID-19 pandemic.

Nil.

Dynamic Classification of Imageless Bioelectrical Impedance Tomography Features with Attention-Driven Spatial Transformer Neural Network.

Point-of-Care monitoring devices have proven to be pivotal in the timely screening and intervention of critical care patients. The urgent demands for their deployment in the COVID-19 pandemic era has translated into the escalation of rapid, reliable, and low-cost monitoring systems research and development. Electrical Impedance Tomography (EIT) is a highly promising modality in providing deep tissue imaging that aids in patient bedside diagnosis and treatment. Motivated to bring forth an accurate and intelligent EIT screening system, we bypassed the complexity and challenges typically associated with its image reconstruction and feature identification processes by solely focusing on the raw data output to extract the embedded knowledge. We developed a novel machine learning architecture based on an attention-driven spatial transformer neural network to specifically accommodate for the patterns and dependencies within EIT raw data. Through elaborate precision-mapped phantom experiments, we validated the reproduction and recognition of features with systemically controlled changes. We demonstrated over 95% accuracy via state-of-the-art machine learning models, and an enhanced performance using our adapted transformer pipeline with shorter training time and greater computational efficiency. Our approach of using imageless EIT driven by a novel attention-focused feature learning algorithm is highly promising in revolutionizing conventional EIT operations and augmenting its practical usage in medicine and beyond.

Pulmonary pathophysiology development of COVID-19 assessed by serial Electrical Impedance Tomography in the MaastrICCht cohort.

Patients with SARS-CoV-2 infection present with different lung compliance and progression of disease differs. Measures of lung mechanics in SARS-CoV-2 patients may unravel different pathophysiologic mechanisms during mechanical ventilation. The objective of this prospective observational study is to describe whether Electrical Impedance Tomography (EIT) guided positive end-expiratory pressure (PEEP) levels unravel changes in EIT-derived parameters over time and whether the changes differ between survivors and non-survivors. Serial EIT-measurements of alveolar overdistension, collapse, and compliance change in ventilated SARS-CoV-2 patients were analysed. In 80 out of 94 patients, we took 283 EIT measurements (93 from day 1-3 after intubation, 66 from day 4-6, and 124 from day 7 and beyond). Fifty-one patients (64%) survived the ICU. At admission mean PaO2/FiO2-ratio was 184.3 (SD 61.4) vs. 151.3 (SD 54.4) mmHg, (p = 0.017) and PEEP was 11.8 (SD 2.8) cmH2O vs. 11.3 (SD 3.4) cmH2O, (p = 0.475), for ICU survivors and non-survivors. At day 1-3, compliance was ~ 55 mL/cmH2O vs. ~ 45 mL/cmH2O in survivors vs. non-survivors. The intersection of overdistension and collapse curves appeared similar at a PEEP of ~ 12-13 cmH2O. At day 4-6 compliance changed to ~ 50 mL/cmH2O vs. ~ 38 mL/cmH2O. At day 7 and beyond, compliance was ~ 38 mL/cmH2O with the intersection at a PEEP of ~ 9 cmH2O vs. ~ 25 mL/cmH2O with overdistension intersecting at collapse curves at a PEEP of ~ 7 cmH2O. Surviving SARS-CoV-2 patients show more favourable EIT-derived parameters and a higher compliance compared to non-survivors over time. This knowledge is valuable for discovering the different groups.

Serum gasdermin D levels are associated with the chest computed tomography findings and severity of COVID-19.

BACKGROUND: The role of programmed cell death, especially pyroptosis and apoptosis, in unfavorable immune responses in COVID-19 remains to be elucidated. METHODS: We conducted a cross-sectional analysis to investigate the association between the serum gasdermin D (GSDMD) levels, a pyroptotic marker, and caspase-cleaved cytokeratin 18 fragment (M30), an apoptotic marker, and the clinical status and abnormal chest computed tomography (CT) findings in patients with COVID-19. RESULTS: In this study, 46 patients diagnosed with COVID-19 were divided into the following three groups according to the disease severity: mild to moderate group (n = 10), severe group (n = 14), and critical group (n = 22). The serum GSDMD levels were higher in the critical group than in the mild to moderate group (P = 0.016). In contrast, serum M30 levels were lower in the critical group than in the severe group (P = 0.048). Patients who required mechanical ventilation or died had higher serum GSDMD levels than those who did not (P = 0.007). Area of consolidation only and of ground glass opacity plus consolidation positively correlated with serum GSDMD levels (r = 0.56, P < 0.001 and r = 0.53, P < 0.001, respectively). CONCLUSION: Higher serum GSDMD levels are associated with critical respiratory status and the consolidation area on chest CT in patients with COVID-19, suggesting that excessive activation of pyroptosis may affect the clinical manifestations in patients with COVID-19.

Should Thorax Thin-Section Computed Tomography Be a Standard Diagnostic Procedure in the Evaluation of Potential Kidney Transplant Recipients? Lessons Learned From the COVID-19 Pandemic.

BACKGROUND: Kidney transplant is the preferred treatment for most patients with end-stage renal disease. Because dialyzed patients often have significant comorbidities or multimorbidities, they should be carefully evaluated before being waitlisted for transplant. The COVID-19 pandemic presents a major challenge for surgery, including transplant surgery. Owing to a fear of COVID-19 symptoms occurring in lungs, thin-section computed tomography (TSCT) became a standard evaluation technique in potential kidney transplant recipients before surgery. METHODS: The aim of the study was to evaluate the rationale and usefulness of TSCT in deceased donor kidney transplant during the COVID-19 pandemic. All adult patients who underwent deceased donor kidney transplant between May 1, 2020, and December 15, 2021, were included in the study. Potential kidney transplant recipients who were admitted to the Department of General, Vascular, and Transplant Surgery at the Medical University of Warsaw in Warsaw, Poland, were tested for COVID-19 (CovGenX rapid test); blood chemistries were performed; dialysis was performed (if needed); and, on a negative reverse transcriptase polymerase chain reaction test, HRCT was performed. RESULTS: From May 2020 until the end of December 2021, 54 patients were transplanted; however, 7 patients were disqualified after TSCT and consulted with a pulmonary specialist. Disqualification from kidney transplant accounted for 13% of the potential kidney allograft recipients. CONCLUSIONS: Despite the possibility of overdiagnosis by TSCT, TSCT should be considered a standard evaluation technique in potential kidney transplant recipients. Potential kidney transplant recipients must be periodically reassessed given the prolonged wait time for a donor kidney and the significant number of comorbid conditions in this patient population. However, more data with longer follow-ups are needed to prove or disprove the rationale to use TSCT in transplant surgery.

Semiquantitative Chest CT Severity Score Predicts Failure of Noninvasive Positive-Pressure Ventilation in Patients Hospitalized for COVID-19 Pneumonia.

OBJECTIVE: Noninvasive positive-pressure ventilation (NPPV) emerged as an efficient tool for treatment of COVID-19 pneumonia. The factors influencing NPPV failure still are elusive. The aim of the study was to investigate the relationships between semiquantitative chest computed tomography (CT) scoring and NPPV failure and mortality in patients with COVID-19. DESIGN: Observational study. SETTING: Nonintensive care setting. PARTICIPANTS: A total of 112 patients consecutively admitted for COVID-19 pneumonia. INTERVENTIONS: Usual care including various degrees of respiratory support. MEASUREMENTS AND MAIN RESULTS: The semiquantitative CT score was calculated at hospital admission. Subgroups were identified according to the ventilation strategy used (oxygen delivered by Venturi mask n = 53; NPPV-responder n = 38; NPPV-failure n = 21). The study's primary endpoint was the use of NPPV. The secondary endpoints were NPPV failure and in-hospital death, respectively. CT score progressively increased among groups (six v nine v 14, p < 0.05 among all). CT score was an independent predictor of all study endpoints (primary endpoint: 1.25 [95% confidence interval {CI} 1.1-1.4], p = 0.001; NPPV failure: 1.41 [95% CI 1.18-1.69], p < 0.001; in-hospital mortality: 1.21 [95% CI 1.07-1.38], p = 0.003). According to receiver operator characteristics curve analysis, CT score was the most accurate variable for prediction of NPPV failure (area under the curve 0.862 with p < 0.001; p < 0.05 v other variables). CONCLUSIONS: The authors reported the common and effective use of NPPV in patients with COVID-19 pneumonia. In the authors' population, a semiquantitative chest CT analysis at hospital admission accurately identified those patients responding poorly to NPPV.

Electrical impedance tomography in the adult intensive care unit: clinical applications and future directions.

PURPOSE OF REVIEW: Electrical impedance tomography (EIT) is a novel, noninvasive, radiation-free, bedside imaging and monitoring tool to assess and visualize regional distribution of lung ventilation and perfusion. Although primarily a research tool, rapidly emerging data are beginning to define its clinical role, and it is poised to become a ubiquitous addition to the arsenal of the intensive care unit (ICU). In this review, we summarize the data supporting clinical use of EIT in adult ICUs, with an emphasis on appropriate application while highlighting future directions. RECENT FINDINGS: Recent major studies have primarily focused on the role of EIT in setting correct positive end-expiratory pressure to balance regional overdistention and collapse. Over the last few years, our Lung Rescue Team has demonstrated that incorporating EIT into a multimodal approach to individualizing ventilator management can improve outcomes, particularly in the obese. We also review recent data surrounding EIT use during COVID, as well as other broad potential applications. SUMMARY: As EIT becomes more common and its clinical role more defined, intensivists will benefit from a clear understanding of its applications and limitations.

ACE2 and ANGII levels in patients with COVID-19 based on thoracic tomography findings and PCR test results.

INTRODUCTION: Reverse transcriptase polymerase chain reaction tests and thoracic tomography have been widely employed in the diagnosis of the disease, but doubts about their sensitivity still persist. Also there are controversial results about ACE2 and AngII levels according to the severity of disease. In this study, we aimed to analyze the ACE2 and AngII levels in patients with suspected COVID-19 based on polymerase chain reaction test results and thoracic tomography findings and to examine their relationship with disease severity. METHODOLOGY: Patients with suspected COVID-19 in the emergency department were divided into 4 groups according to thoracic tomography findings and PCR test results. The in-hospital mortality of patients was recorded. ACE2 and AngII levels in patients were analyzed according to groups and severity of the disease. RESULTS: ACE2 levels for the patients with suspected COVID-19 were significantly lower than in the control group, but AngII levels were higher (not statistically significant). The mean age and male sex ratio of patients who developed acute respiratory distress syndrome (ARDS) and died were significantly higher than those who survived. Whereas there was no difference in ACE2 levels in patients with severe diseases such as ARDS and mortality, their AngII levels were significantly lower. CONCLUSIONS: It can be suggested that decreased ACE2 levels combined with increased AngII levels are determinative at disease onset and in the development of lung damage. However, decreased AngII levels are more determinative in patients with severe diseases such as ARDS and mortality.

Assessment of pacemaker lead-related infective endocarditis with three-dimensional echocardiography and cardiac computed tomography.

Pacemaker endocarditis is rare and symptoms may be misleading. If missed, it carries significant morbidity and mortality, particularly in the elderly. Advances in multi-modality imaging in recent years have emphasised its role in clinical decision making. This case highlights the ability of multi-modality imaging techniques to individualise diagnosis, management and prognosis in patients with suspected cardiovascular implantable electronic device (CIED) endocarditis.

Potential links between COVID-19-associated pulmonary aspergillosis and bronchiectasis as detected by high resolution computed tomography.

PURPOSE: The aim of this observational study was to highlight high resolution CT scan characteristics of COVID-19-associated pulmonary aspergillosis (CAPA) with a focus on the detection of de-novo appeared or evolved bronchiectasis. METHODS: From March 2020 to May 2021, we enrolled 350 consecutive mechanically ventilated ICU patients with COVID-19. Patients with CAPA and at least one chest CT scan performed within 15 days from the diagnosis were included. Two radiologists were asked to identify typical and atypical signs of COVID-19 pneumonia. Bronchiectasis locations were described and a modified Reiff score was calculated, as severity score. A total of 19 CAPA patients (median age 71.0, Interquartile range (IQR) 62.5-75.0; male 16, 84.2%) were included. RESULTS: According to the 2020 ECMM/ISHAM criteria, 18 patients had probable CAPA and one had proven CAPA. The median time between hospital admission and CT scan was 21 days (IQR 14.5-25.0). The incidence of bronchiectasis in the study population was 57.9% (n = 11). Tubular bronchiectasis was detected in 10 patients and were scored as follows: three patients had a score of 1, three patients had a score of score 2, one patient had a score of 5 and four patients had a score of 6. Eight patients had a previous CT scan (performed at hospital admission), among them: 5 patients developed de-novo bronchiectasis, while 2 patients demonstrated a volumetric increase of bronchiectasis. At the 6-months follow-up, the mortality rate for patients with CAPA was >60%. CONCLUSION: the radiologic detection of de-novo appearance or volumetric increase of bronchiectasis in COVID-19 should lead clinicians to search for fungal superinfections.