Lung ultrasound training: how short is too short? observational study on the effects of a focused theoretical training for novice learners.

BACKGROUND: Lung ultrasound has been increasingly used in the last years for the assessment of patients with respiratory diseases; it is considered a simple technique, now spreading from physicians to other healthcare professionals as nurses and physiotherapists, as well as to medical students. These providers may require a different training to acquire lung ultrasound skills, since they are expected to have no previous experience with ultrasound. The aim of the study was to assess the impact of a short theoretical training focused on lung ultrasound pattern recognition in a population of novice nurse learners with no previous experience with ultrasound. METHODS: We included the nurses attending a critical care advanced course for nurses performed at the University of Pavia. Images' interpretation skills were tested on two slide sets (a 25-clip set focused on B-pattern recognition and a 25-clip set focused on identification of pleural movement as lung sliding, lung pulse, lung point, no movement) before and after three 30-minute teaching modules dedicated to general ultrasound principles, B-lines assessment and lung sliding assessment. A cut off of 80% was considered acceptable for correctly interpreted images after this basic course. RESULTS: 22 nurses were enrolled (age 26.0 [24.0-28.0] years; men 4 (18%)); one nurse had previous experience with other ultrasound techniques, none of them had previous experience with lung ultrasound. After the training, the number of correctly interpreted clips improved from 3.5 [0.0-13.0] to 22.0 [19.0-23.0] (p < 0.0001) for B-pattern and from 0.5 [0.0-2.0] to 8.5 [6.0-12.0] (p < 0.0001) for lung sliding assessment. The number of correct answers for B-pattern recognition was significantly higher than for lung sliding assessment, both before (3.5 [0.0-13.0] vs. 0.5 [0.0-2.0]; p = 0.0036) and after (22.0 [19.0-23.0] vs. 8.5 [6.0-12.0]; p < 0.0001) the training. After the training, nurses were able to correctly recognize the presence or the absence of a B-pattern in 84.2 ± 10.3% of cases; lung sliding was correctly assessed in 37.1 ± 15.3% of cases. CONCLUSIONS: Lung ultrasound is considered a simple technique; while a short, focused training significantly improves B-pattern recognition, lung sliding assessment may require a longer training for novice learners. TRIAL REGISTRATION: Not applicable.

Tidal lung hysteresis to interpret PEEP-induced changes in compliance in ARDS patients.

BACKGROUND: In ARDS, the PEEP level associated with the best respiratory system compliance is often selected; however, intra-tidal recruitment can increase compliance, falsely suggesting improvement in baseline mechanics. Tidal lung hysteresis increases with intra-tidal recruitment and can help interpreting changes in compliance. This study aims to assess tidal recruitment in ARDS patients and to test a combined approach, based on tidal hysteresis and compliance, to interpret decremental PEEP trials. METHODS: A decremental PEEP trial was performed in 38 COVID-19 moderate to severe ARDS patients. At each step, we performed a low-flow inflation-deflation manoeuvre between PEEP and a constant plateau pressure, to measure tidal hysteresis and compliance. RESULTS: According to changes of tidal hysteresis, three typical patterns were observed: 10 (26%) patients showed consistently high tidal-recruitment, 12 (32%) consistently low tidal-recruitment and 16 (42%) displayed a biphasic pattern moving from low to high tidal-recruitment below a certain PEEP. Compliance increased after 82% of PEEP step decreases and this was associated to a large increase of tidal hysteresis in 44% of cases. Agreement between best compliance and combined approaches was accordingly poor (K = 0.024). The combined approach suggested to increase PEEP in high tidal-recruiters, mainly to keep PEEP constant in biphasic pattern and to decrease PEEP in low tidal-recruiters. PEEP based on the combined approach was associated with lower tidal hysteresis (92.7 ± 20.9 vs. 204.7 ± 110.0 mL; p < 0.001) and lower dissipated energy per breath (0.1 ± 0.1 vs. 0.4 ± 0.2 J; p < 0.001) compared to the best compliance approach. Tidal hysteresis ≥ 100 mL was highly predictive of tidal recruitment at next PEEP step reduction (AUC 0.97; p < 0.001). CONCLUSIONS: Assessment of tidal hysteresis improves the interpretation of decremental PEEP trials and may help limiting tidal recruitment and energy dissipated into the respiratory system during mechanical ventilation of ARDS patients.

The weaning from mechanical ventilation: a comprehensive ultrasound approach.

PURPOSE OF REVIEW: Due to heart, lung and diaphragm interactions during weaning from mechanical ventilation, an ultrasound integrated approach may be useful in the detection of dysfunctions potentially leading to weaning failure. In this review, we will summarize the most recent advances concerning the ultrasound applications relevant to the weaning from mechanical ventilation. RECENT FINDINGS: The role of ultrasonographic examination of heart, lung and diaphragm has been deeply investigated over the years. Most recent findings concern the ability of lung ultrasound in detecting weaning induced pulmonary edema during spontaneous breathing trial. Furthermore, in patients at high risk of cardiac impairments, global and anterolateral lung ultrasound scores have been correlated with weaning and extubation failure, whereas echocardiographic indexes were not. For diaphragmatic ultrasound evaluation, new indexes have been proposed for the evaluation of diaphragm performance during weaning, but further studies are needed to validate these results. SUMMARY: The present review summarizes the potential role of ultrasonography in the weaning process. A multimodal integrated approach allows the clinician to comprehend the pathophysiological processes of weaning failure.

Respiratory failure due to concomitant interstitial lung disease and diaphragmatic involvement in a patient with anti-MDA5 dermatomyositis: a case report.

Diaphragm myositis is a rare manifestation of idiopathic inflammatory myopathies, barely portrayed in literature despite its potential severity. We describe a 57-year-old Caucasian male with anti-MDA5 positive dermatomyositis, that had a 4-month history of progressive dyspnoea requiring oxygen-therapy, scarcely responsive to prednisolone. Chest high resolution computed tomography (HRCT) showed mild interstitial lung disease (ILD), whereas pulmonary function tests evidenced severe restrictive syndrome with high lung ultrasound score. Diaphragm ultrasound revealed a marked diaphragm dysmotility, confirmed by electromyography (EMG). The patient was treated with intravenous immunoglobulins and mofetil mycophenolate with progressive improvement of dyspnoea, lung volumes and ILD at CT scan. Ultrasound examination also revealed marked improvement of the diaphragmatic disfunction and a reduction of lung ultrasound score. The use of ultrasound may provide a valuable tool in the diagnosis of diaphragm myositis, which may play a major role in the respiratory impairment of these patients. A combined lung and diaphragm examination allowed bedside monitoring of the improvements in both lung aeration and diaphragm contractility.

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.

Ultrasound localization of central vein catheter tip by contrast-enhanced transthoracic ultrasonography: a comparison study with trans-esophageal echocardiography.

BACKGROUND: To assess the usefulness of pre-operative contrast-enhanced transthoracic echocardiography (CE-TTE) and post-operative chest-x-ray (CXR) for evaluating central venous catheter (CVC) tip placements, with trans-esophageal echocardiography (TEE) as gold standard. METHODS: A prospective single-center, observational study was performed in 111 patients requiring CVC positioning into the internal jugular vein for elective cardiac surgery. At the end of CVC insertion by landmark technique, a contrast-enhanced TTE was performed by both the apical four-chambers and epigastric bicaval acoustic view to assess catheter tip position; then, a TEE was performed and considered as a reference technique. A postoperative CXR was obtained for all patients. RESULTS: As per TEE, 74 (67%) catheter tips were correctly placed and 37 (33%) misplaced. Considering intravascular and intracardiac misplacements together, they were detected in 8 patients by CE-TTE via apical four-chamber view, 36 patients by CE-TTE via epigastric bicaval acoustic view, and 12 patients by CXR. For the detection of catheter tip misplacement, CE-TTE via epigastric bicaval acoustic view was the most accurate method providing 97% sensitivity, 90% specificity, and 92% diagnostic accuracy if compared with either CE-TTE via apical four-chamber view or CXR. Concordance with TEE was 79% (p < 0.001) for CE-TTE via epigastric bicaval acoustic view. CONCLUSIONS: The concordance between CE-TTE via epigastric bicaval acoustic view and TEE suggests the use of the former as a standard technique to ensure the correct positioning of catheter tip after central venous cannulation to optimize the use of hospital resources and minimize radiation exposure.

Extracorporeal membrane oxygenation for COVID-19 and influenza H1N1 associated acute respiratory distress syndrome: a multicenter retrospective cohort study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has become an established rescue therapy for severe acute respiratory distress syndrome (ARDS) in several etiologies including influenza A H1N1 pneumonia. The benefit of receiving ECMO in coronavirus disease 2019 (COVID-19) is still uncertain. The aim of this analysis was to compare the outcome of patients who received veno-venous ECMO for COVID-19 and Influenza A H1N1 associated ARDS. METHODS: This was a multicenter retrospective cohort study including adults with ARDS, receiving ECMO for COVID-19 and influenza A H1N1 pneumonia between 2009 and 2021 in seven Italian ICU. The primary outcome was any-cause mortality at 60 days after ECMO initiation. We used a multivariable Cox model to estimate the difference in mortality accounting for patients' characteristics and treatment factors before ECMO was started. Secondary outcomes were mortality at 90 days, ICU and hospital length of stay and ECMO associated complications. RESULTS: Data from 308 patients with COVID-19 (N = 146) and H1N1 (N = 162) associated ARDS who had received ECMO support were included. The estimated cumulative mortality at 60 days after initiating ECMO was higher in COVID-19 (46%) than H1N1 (27%) patients (hazard ratio 1.76, 95% CI 1.17-2.46). When adjusting for confounders, specifically age and hospital length of stay before ECMO support, the hazard ratio decreased to 1.39, 95% CI 0.78-2.47. ICU and hospital length of stay, duration of ECMO and invasive mechanical ventilation and ECMO-associated hemorrhagic complications were higher in COVID-19 than H1N1 patients. CONCLUSION: In patients with ARDS who received ECMO, the observed unadjusted 60-day mortality was higher in cases of COVID-19 than H1N1 pneumonia. This difference in mortality was not significant after multivariable adjustment; older age and longer hospital length of stay before ECMO emerged as important covariates that could explain the observed difference. TRIAL REGISTRATION NUMBER: NCT05080933 , retrospectively registered.

Level of Diffusion and Training of Lung Ultrasound during the COVID-19 Pandemic - A National Online Italian Survey (ITALUS) from the Lung Ultrasound Working Group of the Italian Society of Anesthesia, Analgesia, Resuscitation, and Intensive Care (SIAARTI).

PURPOSE: The goal of this survey was to describe the use and diffusion of lung ultrasound (LUS), the level of training received before and during the COVID-19 pandemic, and the clinical impact LUS has had on COVID-19 cases in intensive care units (ICU) from February 2020 to May 2020. MATERIALS AND METHODS: The Italian Lung Ultrasound Survey (ITALUS) was a nationwide online survey proposed to Italian anesthesiologists and intensive care physicians carried out after the first wave of the COVID-19 pandemic. It consisted of 27 questions, both quantitative and qualitative. RESULTS: 807 responded to the survey. The median previous LUS experience was 3 years (IQR 1.0-6.0). 473 (60.9 %) reported having attended at least one training course on LUS before the COVID-19 pandemic. 519 (73.9 %) reported knowing how to use the LUS score. 404 (52 %) reported being able to use LUS without any supervision. 479 (68.2 %) said that LUS influenced their clinical decision-making, mostly with respect to patient monitoring. During the pandemic, the median of patients daily evaluated with LUS increased 3-fold (p < 0.001), daily use of general LUS increased from 10.4 % to 28.9 % (p < 0.001), and the daily use of LUS score in particular increased from 1.6 % to 9.0 % (p < 0.001). CONCLUSION: This survey showed that LUS was already extensively used during the first wave of the COVID-19 pandemic by anesthesiologists and intensive care physicians in Italy, and then its adoption increased further. Residency programs are already progressively implementing LUS teaching. However, 76.7 % of the sample did not undertake any LUS certification.

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.

Second-order grey-scale texture analysis of pleural ultrasound images to differentiate acute respiratory distress syndrome and cardiogenic pulmonary edema.

Discriminating acute respiratory distress syndrome (ARDS) from acute cardiogenic pulmonary edema (CPE) may be challenging in critically ill patients. Aim of this study was to investigate if gray-level co-occurrence matrix (GLCM) analysis of lung ultrasound (LUS) images can differentiate ARDS from CPE. The study population consisted of critically ill patients admitted to intensive care unit (ICU) with acute respiratory failure and submitted to LUS and extravascular lung water monitoring, and of a healthy control group (HCG). A digital analysis of pleural line and subpleural space, based on the GLCM with second order statistical texture analysis, was tested. We prospectively evaluated 47 subjects: 16 with a clinical diagnosis of CPE, 8 of ARDS, and 23 healthy subjects. By comparing ARDS and CPE patients' subgroups with HCG, the one-way ANOVA models found a statistical significance in 9 out of 11 GLCM textural features. Post-hoc pairwise comparisons found statistical significance within each matrix feature for ARDS vs. CPE and CPE vs. HCG (P ≤ 0.001 for all). For ARDS vs. HCG a statistical significance occurred only in two matrix features (correlation: P = 0.005; homogeneity: P = 0.048). The quantitative method proposed has shown high diagnostic accuracy in differentiating normal lung from ARDS or CPE, and good diagnostic accuracy in differentiating CPE and ARDS. Gray-level co-occurrence matrix analysis of LUS images has the potential to aid pulmonary edemas differential diagnosis.

Quantitative Lung Ultrasound: Technical Aspects and Clinical Applications.

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

Mechanical Ventilation Guided by Uncalibrated Esophageal Pressure May Be Potentially Harmful.

BACKGROUND: Esophageal balloon calibration was proposed in acute respiratory failure patients to improve esophageal pressure assessment. In a clinical setting characterized by a high variability of abdominal load and intrathoracic pressure (i.e., pelvic robotic surgery), the authors hypothesized that esophageal balloon calibration could improve esophageal pressure measurements. Accordingly, the authors assessed the impact of esophageal balloon calibration compared to conventional uncalibrated approach during pelvic robotic surgery. METHODS: In 30 adult patients, scheduled for elective pelvic robotic surgery, calibrated end-expiratory and end-inspiratory esophageal pressure, and the associated respiratory variations were obtained at baseline, after pneumoperitoneum-Trendelenburg application, and with positive end-expiratory pressure (PEEP) administration and compared to uncalibrated values measured at 4-ml filling volume, as per manufacturer recommendation. Data are expressed as median and [25th, 75th percentile]. RESULTS: Ninety calibrations were successfully performed. Chest wall elastance worsened with pneumoperitoneum-Trendelenburg and PEEP (19.0 [15.5, 24.6] and 16.7 [11.4, 21.7] cm H2O/l) compared to baseline (8.8 [6.3, 9.8] cm H2O/l; P < 0.0001 for both comparisons). End-expiratory and end-inspiratory calibrated esophageal pressure progressively increased from baseline (3.7 [2.2, 6.0] and 7.7 [5.9, 10.2] cm H2O) to pneumoperitoneum-Trendelenburg (6.2 [3.8, 10.2] and 16.1 [13.1, 20.6] cm H2O; P = 0.014 and P < 0.001) and PEEP (8.8 [7.7, 15.6] and 18.9 [16.3, 22.0] cm H2O; P < 0.0001 vs. baseline for both comparison; P < 0.001 and P = 0.002 vs. pneumoperitoneum-Trendelenburg) and, at each study step, they were persistently lower than uncalibrated esophageal pressure (P < 0.0001 for all comparisons). Overall, difference among uncalibrated and calibrated esophageal pressure was 5.1 [3.8, 8.4] cm H2O at end-expiration and 3.8 [3.0, 6.3] cm H2O at end-inspiration. Uncalibrated esophageal pressure swing was always lower than calibrated one (P < 0.0001 for all comparisons) with a difference of -1.0 [-1.8, -0.4] cm H2O. CONCLUSIONS: In a clinical setting with variable chest wall mechanics, uncalibrated measurements substantially overestimated absolute values and underestimated respiratory variations of esophageal pressure. Calibration could substantially improve mechanical ventilation guided by esophageal pressure.

Correction to: Inhaled nitric oxide in patients admitted to intensive care unit with COVID-19 pneumonia.

An amendment to this paper has been published and can be accessed via the original article.

Brief Report: A Case of Tramadol Overdose: Extracorporeal Life Support and Hemoperfusion as Life-Saving Treatment.

We describe the case of a 49-year-old woman with a Tramadol intoxication associated with multiorgan failure. Veno-arterial femoro-femoral extracorporeal life support (VA-ECLS) and hemoperfusion (HP) were used as rescue treatments. The emergency medical service found a woman at home unconscious. Once in the hospital, she was intubated and catecholamines support was immediately started for a severe shock. Brain CT was normal, whereas EEG revealed a metabolic encephalopathy pattern. Toxic levels of Tramadol and Quetiapine were detected. VA-ECLS was implanted due to persistent multiorgan failure, and HP with a charcoal cartridge was set to increase the Tramadol clearance. To quantify the charcoal cartridge's removal efficiency of Tramadol, Tramadol concentration was measured before and after the cartridge and before and after the treatment in the patient's blood. The charcoal cartridge showed good extraction ratio during the treatment and no significant rebound effect. VA-ECLS and HP allowed the patient to be weaned from vasoconstrictors and the resolution of the organ failures. These treatments might be lifesaving in the Tramadol intoxication.

Lung Ultrasound for Critically Ill Patients.

Point-of-care ultrasound is increasingly used at the bedside to integrate the clinical assessment of the critically ill; in particular, lung ultrasound has greatly developed in the last decade. This review describes basic lung ultrasound signs and focuses on their applications in critical care. Lung semiotics are composed of artifacts (derived by air/tissue interface) and real images (i.e., effusions and consolidations), both providing significant information to identify the main acute respiratory disorders. Lung ultrasound signs, either alone or combined with other point-of-care ultrasound techniques, are helpful in the diagnostic approach to patients with acute respiratory failure, circulatory shock, or cardiac arrest. Moreover, a semiquantification of lung aeration can be performed at the bedside and used in mechanically ventilated patients to guide positive end-expiratory pressure setting, assess the efficacy of treatments, monitor the evolution of the respiratory disorder, and help the weaning process. Finally, lung ultrasound can be used for early detection and management of respiratory complications under mechanical ventilation, such as pneumothorax, ventilator-associated pneumonia, atelectasis, and pleural effusions. Lung ultrasound is a useful diagnostic and monitoring tool that might in the near future become part of the basic knowledge of physicians caring for the critically ill patient.

Ten-year experience with standardized non-operating room anesthesia with Sevoflurane for MRI in children affected by neuropsychiatric disorders.

BACKGROUND: Children require anesthesia for MRI to maintain immobility and reduce discomfort; clear indications about the best anesthesiologic management are lacking and each center developed its own protocol. Moreover, children with neuropsychiatric disorders more likely require sedation and are described in literature as more prone to general and respiratory complications. Aim of this study was to analyze the applicability of a sevoflurane-based approach, to describe general and respiratory complications and to identify risk factors in a pediatric neuropsychiatric population. METHODS: Retrospective cohort study, university Hospital (January 2007-December 2016). All the 1469 anesthesiologic records of children addressed from Neuropsychiatric Unit to undergo MRI under general anesthesia were analyzed; 12 patients equal or older than 18-year-old were excluded. We identified post-hoc nine macro-categories: static encephalopathies, metabolic/evolutive encephalopathies, epileptic encephalopathies, neuromuscular diseases, autistic spectrum disorders, migraine, psychiatric disorders, intellectual disabilities, others. A logistic regression model for events with low frequency (Firth's penalized likelihood approach) was carried out to identify the mutually adjusted effect among endpoints (complications) and the independent variables chosen on the basis of statistical significance (univariate analysis, p ≤ 0.05) and clinical judgment. RESULTS: Of 1457 anesthesiologic records (age 4.0 (IQR 2.0 to 7.0) year-old, males 891 (61.2%), weight 17.0 (IQR 12.0 to 24.9) kg), 18 were cancelled for high anesthesiologic risk, 50 were cooperative, 1389 were anesthetized. A sevoflurane-based anesthesia was feasible in 92.3%; these patients required significantly less mechanical ventilation (8.6 vs. 16.2%; p = 0.012). Complications' rate was low (6.2%; 3.1% respiratory). The risk for general complications increases with ASA score > 1 (OR 2.22, 95 CI% 1.30 to 3.77, p = 0.003), male sex (OR 1.73, 95% CI 1.07 to 2.81, p = 0.025), multi-drug anesthesia (OR 2.98, 95 CI% 1.26 to 7.06, p = 0.013). For respiratory complications, it increases with ASA score > 1 (OR 2.34, 95 CI% 1.19 to 4.73, p = 0.017), autumn-winter (OR 2.01, 95 CI% 1.06 to 3.78, p = 0.030), neuromuscular disorders (OR 3.18, 95 CI% 1.20 to 8.41, p = 0.020). We had no major complications compromising patients' outcome or requiring admission to ICU. CONCLUSIONS: Sevoflurane anesthesia is feasible and safe for children affected by neuropsychiatric disorders undergoing MRI. Specific risk factors for general and respiratory complications should be considered.

Use of tracheal ultrasound combined with clinical parameters to select left double-lumen tube size: A prospective observational study.

BACKGROUND: Left double-lumen tubes (LDLTs) are used in thoracic surgery to allow one-lung ventilation. Their size is usually chosen on the basis of clinical parameters (height, sex). Double-lumen endobronchial tubes are frequently undersized/oversized, risking tube displacement or tracheal trauma. A correlation between ultrasound tracheal diameter and left main bronchus dimension has been demonstrated. OBJECTIVES: We hypothesised that the insertion of undersized/oversized double-lumen tubes is frequent when the size is selected using standard criteria, and that the use of ultrasound to estimate tracheal diameter may help to reduce the frequency of insertion of oversized tubes. DESIGN: Two-step prospective observational study. SETTING: The operating room of a French University hospital from January 2016 to February 2017. PATIENTS: We enrolled 102 and 50 consecutive patients undergoing elective thoracic surgery in Steps 1 and 2 (males 63.7 and 60.0%, age 63 (13) and 63 (11) years, height 170 (13) and 169 (9) cm, respectively). INTERVENTION: In Step 1, the size of the LDLT inserted was selected on the basis of clinical parameters. Ultrasound data about tracheal diameter were collected to determine cut-off points associating height and tracheal diameter. Cut-off values for ultrasound tracheal diameter were applied retrospectively to test their capability to reduce the insertion rate of oversized tube. In Step 2, the LDLT size was chosen according to the determined combined cut-off values. MAIN OUTCOME MEASURE: LDLT size was considered adequate if the bronchial cuff volume required for isolation of the lung (i.e. no difference between inspiratory and expiratory lung volumes) was 0.5 to 2.5 ml of air; undersized and oversized tubes required more than 2.5 ml and less than 0.5 ml, respectively. RESULTS: In Step 1, LDLT size was appropriate/undersized/oversized in 40 (39.2%)/23 (22.6%)/39 (38.6%) of patients. Cut-off values derived from ultrasound measurements would have reduced the use of oversized tubes by 20.6% (P < 0.001). In Step 2, the frequency of use of adequately sized tubes increased (86.0 vs. 39.2%, P < 0.001), and the frequency of insertion of oversized and undersized tubes decreased (6.0 vs. 38.2% and 8.0 vs. 22.6%, both P < 0.001). CONCLUSION: Combining ultrasound measurement of tracheal diameter and clinical parameters improves the choice of LDLT size.

Assessment of Lung Aeration and Recruitment by CT Scan and Ultrasound in Acute Respiratory Distress Syndrome Patients.

OBJECTIVES: Lung ultrasound is commonly used to evaluate lung morphology in patients with acute respiratory distress syndrome. Aim of this study was to determine lung ultrasound reliability in assessing lung aeration and positive end-expiratory pressure-induced recruitment compared with CT. DESIGN: Randomized crossover study. SETTING: University hospital ICU. PATIENTS: Twenty sedated paralyzed acute respiratory distress syndrome patients: age 56 years (43-72 yr), body mass index 25 kg/m (22-27 kg/m), and PaO2/FIO2 160 (113-218). INTERVENTIONS: Lung CT and lung ultrasound examination were performed at positive end-expiratory pressure 5 and 15 cm H2O. MEASUREMENTS AND MAIN RESULTS: Global and regional Lung Ultrasound scores were compared with CT quantitative analysis. Lung recruitment (i.e., decrease in not aerated tissue as assessed with CT) was compared with global Lung Ultrasound score variations. Global Lung Ultrasound score was strongly associated with average lung tissue density at positive end-expiratory pressure 5 (R = 0.78; p < 0.0001) and positive end-expiratory pressure 15 (R = 0.62; p < 0.0001). Regional Lung Ultrasound score strongly correlated with tissue density at positive end-expiratory pressure 5 (rs = 0.79; p < 0.0001) and positive end-expiratory pressure 15 (rs = 0.79; p < 0.0001). Each step increase of regional Lung Ultrasound score was associated with significant increase of tissue density (p < 0.005). A substantial agreement was found between regional Lung Ultrasound score and CT classification at positive end-expiratory pressure 5 (k = 0.69 [0.63-0.75]) and at positive end-expiratory pressure 15 (k = 0.70 [0.64-0.75]). At positive end-expiratory pressure 15, both global Lung Ultrasound score (22 [16-27] vs 26 [21-29]; p < 0.0001) and not aerated tissue (42% [25-57%] vs 52% [39-67%]; p < 0.0001) decreased. However, Lung Ultrasound score variations were not associated with lung recruitment (R = 0.01; p = 0.67). CONCLUSIONS: Lung Ultrasound score is a valid tool to assess regional and global lung aeration. Global Lung Ultrasound score variations should not be used for bedside assessment of positive end-expiratory pressure-induced recruitment.

Modified Lung Ultrasound Score for Assessing and Monitoring Pulmonary Aeration.

Purpose Lung Ultrasound Score (LUSS) is a useful tool for lung aeration assessment but presents two theoretical limitations. First, standard LUSS is based on longitudinal scan and detection of number/coalescence of B lines. In the longitudinal scan pleura visualization is limited by intercostal space width. Moreover, coalescence of B lines to define severe loss of aeration is not suitable for non-homogeneous lung pathologies where focal coalescence is possible. We therefore compared longitudinal vs. transversal scan and also cLUSS (standard coalescence-based LUSS) vs. qLUSS (quantitative LUSS based on % of involved pleura). Materials and methods 38 ICU patients were examined in 12 thoracic areas in longitudinal and transversal scan. B lines (number, coalescence), subpleural consolidations (SP), pleural length and pleural involvement (> or ≤ 50 %) were assessed. cLUSS and qLUSS were computed in longitudinal and transversal scan. Results Transversal scan visualized wider (3.9 [IQR 3.8 - 3.9] vs 2.0 [1.6 - 2.5] cm, p < 0.0001) and more constant (variance 0.02 vs 0.34 cm, p < 0.0001) pleural length, more B lines (70 vs 59 % of scans, p < 0.0001), coalescence (39 vs 28 %, p < 0.0001) and SP (22 vs 14 %, p < 0.0001) compared to longitudinal scan. Pleural involvement > 50 % was observed in 17 % and coalescence in 33 % of cases. Focal coalescence accounted for 52 % of cases of coalescence. qLUSS-transv generated a different distribution of aeration scores compared to cLUSS-long (p < 0.0001). Conclusion In unselected ICU patients, variability of pleural length in longitudinal scans is high and focal coalescence is frequent. Transversal scan and quantification of pleural involvement are simple measures to overcome these limitations of LUSS.

Patent foramen ovale diagnosis: The importance of provocative maneuvers.

Patent foramen ovale (PFO) is a frequent congenital anomaly, but massive right-to-left shunt (RTLS) is normally prevented by higher pressures in left heart chambers. However, mechanical ventilation with positive end-expiratory pressure (PEEP) can significantly increase right atrial pressure, accentuating the RTLS, mainly after major cardiothoracic surgery. We report a patient admitted to the intensive care unit after cardiac surgery. Pre- and intraoperative transesophageal echocardiography only described an aneurysmal interatrial septum with no shunt. However, high-PEEP ventilation induced a paradoxical response with life-threatening hypoxemia, triggering further echocardiographic evaluation, revealing massive RTLS across a stretch PFO. Provocative maneuvers (Valsalva/PEEP) significantly increase echocardiographic sensitivity, unmasking silent PFO. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:58-61, 2017.