Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study

BACKGROUND: During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space. METHODS: We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans. RESULTS: The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye. CONCLUSIONS: We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural spaces.

Narrow band imaging (NBI) during medical thoracoscopy: first impressions

Background This is the first ever evaluation of narrow band imaging (NBI), an innovative endoscopic imaging procedure, for the visualisation of pleural processes. Methods The pleural cavity was examined in 26 patients with pleural effusions using both white light and narrow band imaging during thoracoscopy under local anaesthesia. Results In the great majority of the patients narrow band imaging depicted the blood vessels more clearly than white light, but failed to reveal any differences in number, shape or size. Only in a single case with pleura thickened by chronic inflammation and metastatic spread of lung cancer did narrow band imaging show vessels that were not detectable under white light. Conclusion It is not yet possible to assess to what extent the evidence provided by NBI is superior to that achieved with white light. Further studies are required, particularly in the early stages of pleural processes.

Malignant solitary fibrous tumor involving the liver

Solitary fibrous tumors are predominantly benign and are most commonly found in the thoracic cavity and pleura; while reports exist in the literature of malignant solitary fibrous tumors and those located in extrathoracic organs, these cases are considered extremely rare. Herein, a case is reported of a malignant solitary fibrous tumor involving the liver that was diagnosed and treated in a 62-year-old woman. The patient presented with complaints of upper abdominal pain and unintentional weight loss. Computed tomography scan of the abdomen revealed a remarkably large mass, measuring 15 cm × 10 cm × 20 cm, which appeared to be unrelated to any particular organ. The intraoperative finding of a wide communication with the left liver suggested hepatic origin, and served as an indicator for tumor resection via left hemihepatectomy. The diagnosis of solitary fibrous tumor and its malignant nature was confirmed by histological and immunohistochemical examination of the resected tissues. Hepatic solitary fibrous tumor is very rare, and surgery remains the mainstay of treatment. Due to limited reports of such tumors in the literature, little can be said about the benefit of adjuvant therapy and prognosis for the rare cases with malignant histological findings.

Scanning electron microscope study of the developing microvasculature in the postnatal rat lung.

During postnatal growth the parenchymal septa of rat lung undergo an impressive restructuring. While immature septa are thick and contain two capillary layers, mature septa are slender and contain a single microvascular network. Using the Mercox casting technique and scanning electron microscopy, we investigated the mode and the timing of the transformation of the pulmonary capillary bed. During the third postnatal week the parenchymal septa rapidly mature to match adult morphology. Even in adult lungs, however, remnants of the immature status are present: A capillary bilayer is regularly found at the base and the tip of the septa. Our observations support the concept that reduction of intervening tissue, partial fusion of the two capillary networks, and preferential growth lead to the mature vascular arrangement. The fact that true mature interalveolar septa show a denser capillary network than alveolar walls abutting onto pleura, bronchi, or larger vessels is consonant with the fusion theory. Towards the nonparenchyma, the capillary network surrounding every airspace had no counterpart to fuse with. From quantitative data it can be calculated that owing to lung growth, mesh size should increase more than four times between birth and adult age. The adult lung network, however, is denser than the one in young animals. This means that new meshes must be added during growth. We propose that small holes observed in sheet-like regions of the microvasculature enlarge to form new capillary meshes. With this mechanism of in-itself or intussusceptional growth, sprouting of individual capillary segments to increase network size is no longer needed.

Comparison of the diagnostic significance of clinical, radiographic and ultrasonographic results after an experimental aerosol infection of pigs with Actinobacillus pleuropneumoniae

Scoring schemes for clinical, ultrasonographic and radiographic findings in pigs were developed based upon a standardized animal model for Actinobacillus pleuropneumoniae infection.The results of these methods were compared to each other as well as with the corresponding pathomorphological findings during necropsy. Altogether 69 pigs of different breeding lines (Hampshire, Pietrain and German Landrace were examined. Positive correlations were found between the results of all three methods as well as with the necropsy scores (p <0.0001). Different pathomorphological findings were detected either by radiographic or by ultrasonographic examination dependent upon the type of lung tissue alterations: Alterations of the pleura as well as sequestration of lung tissue on the lung surface could be clearly identified during the ultrasonographic examination while deep tissue alterations with no contact to the lung surface could be detected reliably by radiographic examination. Both methods complement each other, and the application of a combined ultrasonographic and radiographic examination of the thorax allows a comprehensive inspection of the lung condition. Particularly during the acute phase of the disease the extent of lung tissue damage can be estimated more precisely than by clinical examination alone.

[Lung and pleural lesions before and after implementation of a national eradication program against enzootic pneumonia and actinobacillosis as well as changes of slaughter carcass organs in slaughter pigs in Switzerland].

In a representative cross-sectional study during 12 months of the years 2008/2009 in four abattoirs in Switzerland, lung and pleura lesions as well as lesions of slaughter carcasses and organs of 34 706 pigs were studied for frequency and type of macroscopic lesions. Of the 24276 examined pigs, 91.2% of the lungs, 94.4% of the heart and 95.5% of the livers showed no macroscopically visible lesions. Pigs that were produced for a label program had significantly less bronchopneumonia and pneumonia residuals, pleuritis and liver lesions due to echinococcosis. Pigs supervised by the Swiss Pig Health Service (SGD), showed significantly less bronchopneumonia and pneumonia residuals, diffuse pleuritis, pleuritis/pericarditis and milkspots compared to the non-SGD supervised farms. Thanks to the national eradication program for enzootic pneumonia (EP) and actinobacillosis, the health-status of lungs has been considerably improved and the prevalence of pleurisy decreased considerably. The results of this study indicate a good herd health in Swiss pig production.

Entwicklung und Implementierung von Modellen für ein Skills-Training-Parcours für internistische Assistenzärzte

„Entwicklung und Implementierung von Modellen für ein Skills-Training-Parcours für internistische Assistenzärzte “ V. Maier1 - K. Schnabel2 1 Universitätslinik für Allgemeine Innere Medizin, Inselspital, Bern 2 Berner interdisziplinäres Skills- und Schauspielpatientenzentrum (BiSS), Institut für Medizinische Lehre (IML), Abteilung für Unterricht und Medien (AUM) Einleitung: Im klinischen Alltag sind praktische Fertigkeiten gefordert, um Patienten sicher zu behandeln. Auch in der Schweizer Fachgesellschaft FMH kam es zu einer stärkeren Gewichtung der praktischen Fertigkeiten und müssen jetzt ein Logbuch über Art und Zeitpunkt der Intervention führen [1]. Am Inselspital Bern wurde dafür ein Skillsparcours etabliert, da in vielen Bereichen simulationsbasierte Ausbildungen traditionellen Methoden überlegen ist [2]. Der Skillsparcours besteht aus einem Nachmittag mit 4 nicht-invasiven Prozeduren und einem Nachmittag mit 5 invasiven Prozeduren. Eigens dafür wurden drei Modelle entwickelt und deren Tauglichkeit evaluiert. Fragestellung: Bilden die selbst gefertigten Modelle die Realität ausreichend ab? Material und Methoden: Innerhalb der 9 Posten (5 invasiv und 4 nichtinvasiv) wurden für die 5 invasiven Posten zwei Modelle aus dem Skillslab (BiSS) genutzt (Lumbalpunktion (LP) und Blasenkatheter (BK)) und drei Modelle neu entwickelt (Pleura-(PP), Aszites-(AP) und Knochenmarks-Punktion (KMP)). Die Modelle wurden mit Materialien aus dem Baumarkt entwickelt (Material ca. CHF 50/Stück). Der Aufbau der Modelle soll auf der Tagung demonstriert werden. Die Teilnehmer (N=12) und Dozenten (N=5) wurden zu der Qualität mittels Fragebogen befragt. Dabei wurde die individuelle Vorerfahrung und die Einschätzung der Teilnehmer erfragt. Die Frage zur Eignung des Modells war: „Das Modell war zum Üben geeignet“. Als Skala wurde eine Likert-Skala von 0 bis 5 (1=sehr ungeeignet, 5=sehr geeignet) benutzt. Ergebnisse: Die Assistenzärzte beurteilten die Modelleignung wie folgt (Median (Min;Max)): LP: 5 (4;5) KMP: 4.5 (3;5), PP: 4 (3;5), AP: 4.5 (2;5), BK-Einlage: 4.5 (4;6). Die Oberärzte, die jeweils nur das Modell bewerteten, an welchem sie den Kurs durchführten, beurteilten die Modelleignung wie folgt: LP 5.0, KMP: 5.0, PP 5.0, AP: 4.0, BK-Einlage: 3.0. Diskussion: Alle Modelle wurden sowohl von den Oberärzten als auch von den Assistenzärzten als zum Üben tauglich eingeschätzt. Zwischen den selbst hergestellten Low-Fidelity Modellen und den High-Fidelity Modellen gab es hierein keinen signifikanten Unterschied. Als am wenigsten tauglich wurde von den Oberärzten mit der Simulation der Blasenkatheter-Einlage ein High-Fidelity-Modell bewertet. Schlussfolgerungen: Alle Modelle für die Simulation der Punktionstechniken haben gut bis sehr gut funktioniert. Die selbst hergestellten Modelle bilden die Wirklich zum Üben der Techniken hinreichend gut und nicht schlechter als die High-Fidelity-Modelle ab. Selbst gebaute Modelle mit Materialien aus dem Baumarkt können das sonst sehr materialaufwändige Training mit Simulatoren genauso effektiv aber wesentlich effizienter durchführbar machen. Literatur bei den Autoren (1) Weiterbildungsordnung FMH 2014 (letzte Revision 4. September 2014). www.fmh.ch/files/pdf15/wbo_d.pdf (2) McGaghie WC, Issenberg SB, Cohen ER, Barsuk JH, Wayne DB (2011) Does simulation-based medical education with deliberate practice yield better results than traditional clinical education? A meta-analytic comparative review of the evidence. Acad Med. 2011 Jun;86(6):706-11