Silvia Mongodi

Ultrasound for “Lung Monitoring” of Ventilated Patients

LUS is normally performed in supine patients. Operator should firstly locate the diaphragm and the lungs. Lung consolidation or pleural effusion is found predominantly in dependent and dorsal lung regions and can be easily distinguished from liver or spleen once the diaphragm has been identified. By using the anterior and posterior axillary lines as anatomical landmarks, three areas per hemithorax (anterior, lateral, and posterior) can be iden-tified. Each area is divided in two, superior and inferior. In a given region of interest, lung surface of all adjacent inter-costal spaces must be explored by moving the probe trans-versally.

Lung Ultrasound for Early Diagnosis of Ventilator-Associated Pneumonia

BACKGROUND Lung ultrasound (LUS) has been successfully applied for monitoring aeration in ventilator-associated pneumonia (VAP) and to diagnose and monitor community-acquired pneumonia. However, no scientific evidence is yet available on whether LUS reliably improves the diagnosis of VAP. METHODS In a multicenter prospective study of 99 patients with suspected VAP, we investigated the diagnostic performance of LUS findings of infection, subpleural consolidation, lobar consolidation, and dynamic arborescent/linear air bronchogram. We also evaluated the combination of LUS with direct microbiologic examination of endotracheal aspirates (EA). Scores for LUS findings and EA were analyzed in two ways. First, the clinical-LUS score (ventilator-associated pneumonia lung ultrasound score [VPLUS]) was calculated as follows: ≥ 2 areas with subpleural consolidations, 1 point; ≥ 1 area with dynamic arborescent/linear air bronchogram, 2 points; and purulent EA, 1 point. Second, the VPLUS-direct gram stain examination (EAgram) was scored as follows: ≥ 2 areas with subpleural consolidations, 1 point; ≥ 1 area with dynamic arborescent/linear air bronchogram, 2 points; purulent EA, 1 point; and positive direct gram stain EA examination, 2 points. RESULTS For the diagnosis of VAP, subpleural consolidation and dynamic arborescent/linear air bronchogram had a positive predictive value of 86% with a positive likelihood ratio of 2.8. Two dynamic linear/arborescent air bronchograms produced a positive predictive value of 94% with a positive likelihood ratio of 7.1. The area under the curve for VPLUS-EAgram and VPLUS were 0.832 and 0.743, respectively. VPLUS-EAgram ≥ 3 had 77% (58-90) specificity and 78% (65-88) sensitivity; VPLUS ≥ 2 had 69% (50-84) specificity and 71% (58-81) sensitivity. CONCLUSIONS By detecting ultrasound features of infection, LUS was a reliable tool for early VAP diagnosis at the bedside. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT02244723; URL: www.clinicaltrials.gov.

Usefulness of combined bedside lung ultrasound and echocardiography to assess weaning failure from mechanical ventilation: A suggestive case

Objective:Recognition of the cardiac origin of weaning failure is a crucial issue for successful discontinuation of mechanical ventilation. Bedside lung ultrasound and echocardiography have shown a potential in predicting weaning failure. Objective of this report was to describe the case of a patient repeatedly failing to wean from mechanical ventilation, where the combined use of lung ultrasound and echocardiography during a spontaneous breathing trial uncovered an unexpected cause of the failure. Design:Case report. Setting:General ICU of a university teaching hospital. Patients:Single case, abdominal surgery postoperative patient, not predicted to experience a difficult weaning. Interventions:Cardiovascular therapy adjustments consistent with lung ultrasound and echocardiography findings acquired during spontaneous breathing trials. Measurements and Main Results:All patient’s standard hemodynamic and respiratory parameters, datasets from comprehensive lung ultrasound and echocardiographic examinations, and pertinent data from biochemistry exams, were collected during two spontaneous breathing trials. Data from beginning and end of each of the two ultrasound monitored weaning trials, and from the end of the successful weaning trial following therapy and the previously failed one, were analyzed and qualitatively compared. Lung ultrasound performed at the end of the failed spontaneous breathing trial showed a pattern consistent with increased extravascular lung water (diffuse, bilateral, symmetrical, homogeneous sonographic interstitial syndrome). Concurrent echocardiography diagnosed left ventricular diastolic failure. Ultrasound findings at the end of the successful weaning trial showed normalization of the lung pattern and improvement of the echocardiographic one. The atient eventually returned to spontaneous respiration and was discharged from the ICU. Conclusions:The use of bedside lung ultrasound and echocardiography disclosed left ventricular diastolic dysfunction as unexpected cardiogenic cause of weaning failure and lead to subsequent correct patient management.

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.

An ultrasonographic sign of intrapulmonary shunt.

B. Bouhemad Anesthesia and Intensive Care, Centre Hospitalier Universitaire de Dijon, Dijon, France Lung ultrasound is a valuable bedside tool for the differential diagnosis of hypoxemia, a frequent issue in critically ill patients. In particular, a tissue-like pattern visualized above the diaphragm corresponds to complete loss of aeration, defined as lung consolidation (Fig. 1a). A consolidated lobe may have a variable impact on oxygenation, depending on hypoxic vasoconstriction and degree of intrapulmonary shunt. Color Doppler ultrasound may be used to identify vessels within consolidations: in some patients, intrapulmonary arteries can be visualized (Fig. 1b), identified by a pulsing pattern synchronous with heartbeats. In these patients, the non-aerated lobe appears to be well perfused, which corresponds to the definition of intrapulmonary shunt. Although no quantification is possible, the visualization of a main vessel within a

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.

Acute respiratory failure from esophageal dilatation

A 44-year-old woman with a history of asthma was intubated for severe acute respiratory failure with stridor, not responding to bronchodilators and steroids. In ICU, passive respiratory mechanics under volume-controlledventilation excluded both peripheral obstructive disease (airways resistance 13 cm H2O/l/s) and restrictive disease (respiratory system compliance 50 ml/cm H2O), with rapid normalization of gas exchange. An upper airways obstruction was suspected, consistent with no air leak at the endotracheal tube’s cuff deflation test. A chest x-ray (Fig. 1a) showed a mid-proximal esophageal kinking and important dilatation, with large amounts of air and ingested food and thickened esophageal walls. This orients to extrinsic tracheal compression as the cause of acute respiratory failure related to a sudden pressure increase in the esophagus due to food ingestion. Recognition of esophageal dilatation redirected therapeutic management. Esophageal emptying by esophagogastroduodenoscopy is the key treatment to allow restoration of tracheal patency and therefore weaning from mechanical ventilation; nasogastric tube placement is crucial to prevent subsequent postprandial relapses. If a partial tracheal compression is visualized by CT-scan (Fig. 1b), despite esophageal emptying, the patient should be oriented to surgical treatment (Heller myotomy).

A 70-Year-Old Develops Refractory Hypotension in the ICU

A 70-year-old woman is admitted to the ICU for status epilepticus requiring intubation and mechanical ventilation. Her medical history includes ischemic stroke with no sequelae and breast cancer, treated surgically 12 months earlier; she is still undergoing radiochemotherapy. At day 6, despite good control of electrical activity with adequate therapy, she remains unconscious (Glasgow Coma Scale, 4) and mechanically ventilated; a tracheostomy is performed.

A 44-Year-Old Woman Presents to the ED With Agitation, Dyspnea, and Hypotension

In the ED she becomes more hypotensive (BP, 90/ 60 mm Hg), so she is shifted to an acute-care bed and given intravenous fluids. Arterial blood gas analysis shows compensated lactic acidosis and hypoxemia (pH 7.38; lactates, 7 mM; PaCO2, 27 mm Hg; PaO2, 60 mm Hg). Further history reveals chronic anemia and hemorrhoids; digital rectal exploration shows purulent fluid. A surgical consultation is requested (it having been determined that there was no need for urgent surgery).

Temperature Monitoring During Ecmo: An in Vitro Study

The need of heat exchanger in the ECMO circuit is controversial. Moreover, how to monitor patient central temperature during extracorporeal support is still not clear, but potentially useful for the detection of “unexpressed” fever, eventually related to septic complications.