Fluctuating PEEP (F–PEEP) versus conventional PEEP in dogs with asymmetrical lung injury

Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with unilateral lung injury induced by the introduction of hydrochloric acid, F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at periods of 6 min, and conventional PEEP (C-PEEP) with an optimized EEP of 1.0 kPa, were each applied for 30 min. F-PEEP produced a significantly greater improvement of PaO2 and intrapulmonary shunt (QS/QT) than C-PEEP, and at the low EEP phase, the greatest improvement accompanied by an increased dynamic compliance and a large cardiac output was obtained. These results suggest that F-PEEP provides a useful mode of artificial ventilation for the treatment of unilateral lung injury.     

Results of surgical treatment in patients with arachnoid cysts

Summary A retrospective study of 35 patients operated upon for arachnoid cysts during the last 10 years was carried out. In 19 patients treated by craniotomy, membrane resection and drainage into the basal cisterns, clinical improvement could be noted in 13 cases. Correspondingly on the CT-controls the cysts were found to have disappeared in two cases and were reduced in size in seven patients.In 11 patients, however, who were initially treated by a shunting procedure, seven patients became free of symptoms. Postoperative CT-controls showed in three cases a significant reduction of the size of the cyst, which remained unchanged in two other cases.In five patients with the combination of a nonspace-occupying arachnoid cyst and subdural effusions, drainage of the latter only was sufficient to relieve the clinical symptoms.The prominent Endings were the high complication rate of the primary or secondary shunting procedures (48%), as well as the close correlation between the clinical outcome and the postoperative CT-controls.     

Intrapulmonary Schwannoma

A 58-year-old woman was admitted due to an abnormal shadow on chest X-ray, without any symptoms. Chest computed tomography showed a round mass in the anterior segment of the right upper lobe. Segmentectomy was performed and histopathological examination revealed a primary neurogenic tumor of Schwann cell origin. Immunohistochemical staining demonstrated the presence of S-100 protein in the tumor cells. We present a case of intrapulmonary schwannoma and review 62 cases of primary schwannoma of the lung.     

Experience of thoracoscopic extirpation of intrapulmonary lymphangioma

We report a 59-year-old woman who underwent thoracoscopic extirpation of the intrapulmonary cystic lymphangioma which was located in the subpleural space of the left upper lobe. A chest X-ray showed a solitary round nodule in the left pulmonary hilum. A computed tomography scan revealed a mass shadow at the interlobar region surrounding the interlobar pulmonary artery. A round nodule was recognized as low signal intensity on T1-weighted images by magnetic resonance imaging. There was biphasic signal intensity on T2-weighted images as well. Radiologically, we diagnosed this lesion as a benign cystic tumor in the lung. Thoracoscopic observation revealed a cystic lesion just beneath the visceral pleura of the upper lobe adjacent to the interlobular pulmonary artery. As this suggested a benign bronchogenic cyst, we performed extirpation of the cyst under thoracoscopy. After this operation, the cyst was diagnosed as an intrapulmonary cystic lymphangioma pathologically.     

A clinical comparison of indices of pulmonary gas exchange with changes in the inspired oxygen concentration

Several indices have been introduced as convenient alternatives to calculation of the physiological shunt fraction (Qs/QT) for the assessment of pulmonary gas exchange. These include: the arterial-alveolar oxygen tension ratio (a/APO2), the arterial oxygen tension-inspired oxygen concentration ratio (PaO2/FIO2), the respiratory index (RI), [A-a)DO2/PaO2) and the alveolar-arterial oxygen tension difference [A-a)Do2). These indices are in use clinically despite the fact that they may not accurately predict gas exchange in situations where FIO2, Qs/QT or arterial-venous oxygen content is changing. The clinical stability of each of these indices, relative to the behaviour of the physiological shunt, was therefore investigated prospectively in ten mechanically ventilated postoperative adults as FIO2 was varied from 0.30 to 1.00. None of the indices studied reliably reflected the behaviour of the physiological shunt. As FIO2 was increased incrementally from 0.30 to 1.00, 42 to 55 per cent of the measured changes in these indices were opposite in direction to the corresponding changes in the physiological shunt. The maximum magnitudes of the opposite changes were substantial; 24 and 22 per cent for the a/APO2 and PaO2/FIO2 ratio respectively, 67 per cent for the RI and 101 per cent for the (A-a)DO2. We conclude that the use of any of these indices for clinical assessment of a patient's gas exchange defect when FIO2 is varying can be substantially misleading.     

松果体区肿瘤的放射治疗27例临床分析

 自1978年2月～1992年2月共收治松果体肿瘤患者27例。年龄分布9～36岁，其中25岁以下23例（85．2％），男女之比为2：1。有3例经组织学证实，18例采用脑室分流术加术后放疗，9例行单纯放疗。3年、5年生存率分别为66．7％（18／27）和55．6％（15/27），主要死因是局部复发。因为手术治疗本病有较高的并发症和死亡率，虽然大多数肿瘤不能全切，但对放射线敏感。因此，在无法取得组织寻诊断时，可采用脑室分流术和术后放疗。     

Trichoptysis caused by intrapulmonary teratoma: Computed tomography and magnetic resonance imaging findings

We describe a 9-year-old child with a history of trichoptysis caused by intrapulmonary teratoma and we present the CT and MRI findings of the teratoma. A heterogeneous mass containing cystic and solid elements was detected on both CT and MRI scans. Histopathological examination confirmed the diagnosis of teratoma. Teratomas arising from lung parenchyma, as in this case, are extremely rare in childhood. In the thoracic region, the most common localization of teratomas is the anterior mediastinal compartment. We also discuss the CT and MRI findings and the differential diagnosis of teratomas.     

Renosplenic Shunting in the Nutcracker Phenomenon: A Discussion and Paradigm Shift in Options? A Novel Approach to Treating Nutcracker Syndrome

The nutcracker syndrome is a rare clinical manifestation of symptoms caused by the compression of the left renal vein by an overriding superior mesenteric artery, an anatomical variant otherwise known as the nutcracker phenomenon. Usually present in women and children, when symptomatic, it commonly presents with hematuria, proteinuria, and chronic pelvic pain. Effective modalities of treatment apart from conservative management, include both invasive surgical procedures such as renal vein transposition and autotransplantation of the kidney and more popular recently, the less invasive endovascular stenting. Both options, however, are not without complications, such as, retroperitoneal hematomas or stent migration, thrombosis and restenosis. We now present a case of spontaneous renosplenic shunting in a 68-year-old lady of Chinese descent with the nutcracker syndrome—the first of such cases to be ever reported in a patient with no preexisting predilection for chronic liver disease and portosystemic shunting. Despite having significant pelvic venous congestion as evident on computed tomography scans, she remained asymptomatic. This may present a novel paradigm shift for the treatment of the nutcracker syndrome —surgical creation of a renosplenic bypass instead of current modalities, an alternative solution which can be performed laparoscopically and is without problems related to stent use. The creation of laparoscopic splenorenal bypass has been reported once thus far in Cleveland Ohio by Chung and Gill with good symptomatic improvement but no further studies since to validate its long-term effectiveness.     

Perfluorocarbon compounds as vehicles for pulmonary drug delivery

Drug delivery to the diseased lung is hindered by the buildup of fluid and shunting of blood flow away from the site of injury. The use of perfluorocarbon compounds (PFCs) as drug delivery vehicles has been proposed to overcome these obstacles. This drug delivery approach is based on the unique properties of PFCs. For example, PFCs can homogeneously fill the lung and recruit airways by replacing edematous fluid. Analogously, drugs administered with a PFC vehicle are expected to be homogeneously distributed throughout the lung. At the same time, intrapulmonary administration of the drug will achieve higher drug concentrations in the lung than conventional approaches, while reducing systemic exposure. Unfortunately, PFCs are poor solvents for typical drug molecules. To overcome this obstacle, several approaches, such as dispersions, prodrugs, solubilizing agents and (micro)emulsions, are under investigation to develop homogeneous PFC–drug mixtures suitable for intrapulmonary administration.     

Combined splenocaval or mesocaval C shunt and portoazygous devascularization in the treatment of portal hypertension: analysis of 150 cases

BACKGROUND: Portal hypertension is a common disease and its major surgical therapeutic approaches include devascularization and shunting. This study was undertaken to investigate the effects of combined splenocaval or mesocaval C shunt and portoazygous devascularization (combined procedures) on portal hypertension. METHODS: The clinical data of 150 patients with portal hypertension who had undergone combined procedures at the First Affiliated Hospital of Zhengzhou University from May1990 to May 2003 were analyzed retrospectively. RESULTS: The mean free portal pressure (FPP) was 25.6±1.83 mmHg, 18.0±2.07 mmHg and 18.4±2.19 mmHg before operation, after splenectomy plus splenocaval or mesocaval C shunt, and combined procedures, respectively. There was no operative death in all patients. The 1-7 year follow-up of 100 patients showed rebleeding in 3 patients, encephalopathy in 4, thrombosis of artificial vascular graft in 3, and dying from liver failure in 2. CONCLUSIONS: The combined procedures can not only decrease portal pressure but also preserve hepatic blood flow to some extent. It may be one of the best choices for treating portal hypertension in China.