Effects of lung collapse on pulmonary blood volume, flow and resistance

Pulmonary blood flow, pressures, volume and vascular resistance were measured when the lungs occupied an expiratory position in the closed chest and when they were collapsed by introducing air into the thorax. Circulation and innervation were intact. Variations due to respiratory movements or asphyxia were ruled out. Mongrel dogs were used, anesthetized with morphine and sodium pentobarbital. Pressures were measured from pulmonary artery, left atrium, aortic arch and intrapleural space. Pulmonary flow was evaluated utilizing the dye dilution method and the pulse contour method. Vascular volume was estimated by the product of mean circulation time and flow. When the lungs were collapsed there was an immediate elevation of intraluminal left atrial pressure but not a comparable rise in pulmonary arterial pressure. However, the direct records of arteriovenous pressure drop suggest that there was a delayed rise in pulmonary artery pressure. Flow, aortic pressure, heart rate and pulmonary vascular resistance showed no consistent changes. In 8 of 11 cases the pulmonary blood volume decreased when the lungs were collapsed.

The pulmonary circulation following pneumothorax and vagotomy in dogs

Induction of pneumothorax in anesthetized dogs with a volume of air equal to the functional residual capacity does not lead to any immediate change in pulmonary artery or vein pressures or the pressure gradient. Cardiac output drops and pulmonary vascular resistance is elevated. This change in pulmonary resistance is essentially unaffected by vagotomy and is likely a mechanical effect of decreasing lung volume. Vagotomy alone leads to a decrease in cardiac output and an increase in pulmonary vascular resistance, possibly also because of mechanical effects.

Hemodynamic effects of carbon dioxide insufflation under single-lung ventilation during thoracoscopy

BACKGROUND

The hemodynamic effects of carbon dioxide insufflation under single-lung ventilation were studied in 22 consecutive thoracoscopic harvests of the left internal mammary artery, which was used for minimally invasive coronary artery bypass grafting.

METHODS

An electrocardiograph, arterial catheter, Swan-Ganz catheter, and transesophageal echocardiograph were used to monitor seven hemodynamic variables. Baseline data were obtained during ventilation of both lungs and the measurements were repeated after the left lung was collapsed and at 5 and 30 minutes after hemithorax insufflation with low-flow (2 to 3 L/minute) carbon dioxide gas was begun. The intrapleural pressure was maintained at 8 to 10 mm Hg.

RESULTS

Thoracoscopic harvest of the internal mammary artery was completed in all cases with a mean insufflation time of 44+/-12 minutes. There were no significant changes in the mean arterial pressure, heart rate, cardiac index, and left ventricular ejection fraction throughout the procedure, whereas the central venous pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure (p < 0.05 for each variable) during insufflation.

CONCLUSIONS

Low-flow carbon dioxide insufflation into the left hemithorax with an intrapleural pressure of 8 to 10 mm Hg under selective right-lung ventilation does not compromise the human heart with normal to moderately depressed function and can be an efficacious adjunct in specific thoracoscopic procedures.

[Lung collapse during one lung ventilation does not change low frequency respiratory mechanics]

The present study was carried out to clarify the effects of lung collapse for one lung ventilation on respiratory system impedance during thoracic surgery. We measured the impedances of respiratory system (RS) in eight paralyzed subjects under anesthesia employing a pseudorandom noise forced volume oscillation technique. These measurements were performed before and after the one lung ventilation. The impedance values were fitted to a mathematical model consisting of a single conduit connected with a viscoelastic parenchyma. Lung collapse did not affect resistance and reactance in RS after the re-expansion. The mathematical modeling showed no significant effect of one lung ventilation on all the parameters of airway and parenchyma. There was no difference in model fit of the parameters, indicated by the presence of the goodness-of-fit parameter (chi 2), before and after lung collapse. In conclusion, lung collapse during one lung ventilation does not change low frequency respiratory mechanics.

Effect of pneumothorax on pleurodesis induced with talc in rabbits

OBJECTIVE

The purpose of this study was to determine if a small pneumothorax would influence the pleurodesis resulting from talc instillation.

METHODS

Sixty rabbits received an intrapleural injection of 400 mg/kg talc slurry. One half also received 10 mL of air intrapleurally after the talc. Ten rabbits in each group were killed 2, 14, and 28 days after instillation.

RESULTS

Two days after the injection, the mean volume of air in the animals that had received the air was 7.5+/-0.4 mL. There was no air present in any other rabbits. The volume of pleural fluid and the pleural fluid glucose, protein, cell count, and differential were similar in both groups on day 2, while the LDH level was significantly higher in the air group (p<0.05). The degree of gross adhesions and microscopic fibrosis was similar in both groups and increased with time.

CONCLUSIONS

A small pneumothorax does not decrease the efficacy of talc pleurodesis in our experimental model. These results suggest that the presence of a small amount of intrapleural air is not a contraindication to talc pleurodesis in humans.

Pyothorax-associated lymphoma: description of the first two cases detected in Italy

BACKGROUND

Pyothorax-associated lymphoma (PAL) is a rare, but distinct, clinico-pathologic entity which occurs most often in Japanese people; to the best of our knowledge, only six cases of it have been reported in Western countries. The tumour develops several decades following artificial pneumothorax or chronic pleuritis due to tuberculous infection, produces pleural effusion associated with extensive local lymphomatous infiltrates, and is sustained by a polymorphic large B-cell clonal proliferation showing EBV integration in the genoma of the neoplastic cells.

PATIENTS AND METHODS

Herein we describe two cases of PAL observed in Italian patients, both extensively studied on the clinical, pathological, phenotypic, virological, and molecular levels.

RESULTS

The two cases occurred, respectively, 45 and 50 years after therapeutic pneumothorax because of tuberculous pleuritis and were characterized by a pleural mass extending to the thoracic wall, which on histological examination were seen to consist of large elements with immunoblastic morphology. Immunohistochemistry show monotypic restriction of Ig light chains, as well as the expression of CD45, B-cell markers (CD20, CD79a, CD45RA), bcl-2 oncogene product, EBNA-2 and, partially, LMP-1. The ratio of cycling cells was extremely high as was the number of mitotic figures. In situ hybridization displayed the presence in the neoplastic cells of the EBV-related small RNAs EBER 1 and 2, which in turn, along with the positivity for EBNA-2 and LMP-1, further strengthened the close relationships between PAL and latent viral infection. Molecular studies revealed, on one hand, clonal rearrangement of the Ig heavy chain J region genes, and on the other, negativity for HHV8 in one case and positivity in the other.

CONCLUSIONS

These cases of PAL are the first to be documented in Italy; they serve to direct attention to the fact that this condition is not confined to Japanese people, and that its occurrence in Western countries might be underestimated.

Effects of oxygenation during selective lobar versus total lung collapse with or without continuous positive airway pressure

Hypoxemia is common during anesthesia with one-lung ventilation (OLV). This study tested the hypothesis that selective lobar blockade would result in higher PaO2 values compared with those found with total lung collapse independent of continuous positive airway pressure (CPAP) application. Thirty patients undergoing lobectomy were randomly assigned to one of four groups with the following maneuvers during OLV: Group 1 (n = 8) total lung collapse (TLC) plus 5 cm H2O of CPAP to the nonventilated operative lung for 15 mins, followed by selective lobe collapse plus 5 cm H2O of CPAP (during selective collapse only the surgical lobe was collapsed and the rest of that lung was ventilated); Group 2 (n = 6) selective lobar collapse plus 5 cm H2O of CPAP to the operative lung, followed by TLC plus 5 cm H2O of CPAP; Group 3 (n = 8) total lung collapse without CPAP, followed by selective lobe collapse and no CPAP; Group 4 (n = 8) selective lobe collapse without CPAP, followed by TLC and no CPAP. To obtain selective lobe collapse, the bronchial blocker of the Univent (Vitaid, Lewiston, NY) endotracheal tube was guided into the operative bronchus with the aid of a fiberoptic bronchoscope. Blood pressure, heart rate, and arterial blood gas measurements were obtained during the following times: Time 1--while the patient was awake; Time 2--two-lung ventilation (2LV) in the supine position; Time 3--after 30 min of OLV in the lateral decubitus position (no CPAP or selective blockade); Time 4 and Time 5--during maneuvers described above (see group description); Time 6--2LV resumed; Time 7--30 min after extubation. Twenty-eight patients completed the study. There were no differences among groups with regard to arterial blood pressure, heart rate, or arterial oxygen saturation during the experimental maneuvers. All four groups showed a decrease in PaO2 from 2LV to OLV (P < 0.05). Both with and without CPAP application, oxygenation was improved with selective lobe collapse compared with TLC. When selective lobe collapse with 5 cm H2O of CPAP followed TLC (group 1), PaO2 values increased to values similar to those found for 2LV (PaO2 449 +/- 122 vs 394 +/- 105 mm Hg). This study indicates that by using a bronchial blocker, changing from total lung collapse to selective lobar blockade improves PaO2 during lung surgery.

IMPLICATIONS

This study examines how oxygen tension in arterial blood can be higher during one-lung ventilation. The use of a bronchial blocker, which changes a total lung collapse to selective lobar blockade, improves oxygenation during lung surgery.

[Malignant hemangioendothelioma associated with chronic pyothorax]

A 67-year-old man was admitted to the hospital because of a fever. A chest CT scan showed multilobular heterogeneous shadows on the right side in the chest wall and the lung, but clinical examinations and examination of a biopsy specimen did not lead to a diagnosis. At autopsy, a hemorrhagic tumor was found on the right side in the chest wall. Microscopical examination showed that large atypical cells had proliferated and formed vascular structures, which were stained positively with anti-factor VIII antibody. The histological findings led to the diagnosis of malignant hemangioendothelioma. Chronic empyema-associated malignant hemangioendothelioma is rare.

[Home oxygen therapy (HOT) in patients with pulmonary tuberculosis sequelae--comparison between patients medically treated and those surgically treated]

In Japan there are about 40,000 patients under home oxygen therapy (HOT), of whom about 30 to 40% are pulmonary tuberculosis sequelae (TBS). These patients can be divided into three groups depending on the treatments they had, Group 1: those who had medical treatments only, Group 2: those who had artificial pneumothorax, and Group 3: those who had thoracoplasties or other surgical treatments. The purpose of this study was to observe the distributions and possible differences in the survival rates among these groups. The study included 1537 patients with TBS under HOT followed at National Hospitals and Sanatoriums nationwide in Japan. In 819 patients the treatments were specified and of those 354 were in Group 1, 29 in Group 2, and 436 in Group 3, so that the proportion of surgically treated patients in PTS was estimated between 28.4% (436/ 1537) to 53.2% (436/819). The ages at the onset of tuberculosis, at the start of HOT and the intervals in between were 36.6, 66.2 and 29.8 in Group 1, and 26.8, 65.5, and 38.1 in Group 3 respectively. Though the ages at the start of HOT were the same, those at the onset of tuberculosis were about ten years younger in Group 3 than in Group 1. Comparing Group 1 and 3, the survival rates after the initiation of HOT (Kaplan-Meier method) was better in Group 2 (surgically treated) than in Group 1 (medically treated). It is speculated that the reason could be a better preservation of the function of the remaining lung in the surgically treated and a higher incidence of obstructive impairments in the medically treated patients.

[Malignant lymphoma of the chest wall in a patient with chronic empyema]

A 76-year-old man presented with the chief complaints of appetite loss and general fatigue. He was admitted with the initial diagnosis of empyema necessitatis, and right thoracic drainage was performed. Nevertheless, the subcutaneous mass in the right side of the chest wall did not shrink, and examination of a specimen obtained by percutaneous needle biopsy resulted in the diagnosis of non-Hodgkin's lymphoma, intermediate lymphocytic type. The patient was treated with Adriamycin, vincristine, prednisolone, and cyclophosphamide, but died of pneumonia and cachexia five months after symptoms first appeared. The diagnosis of intermediate lymphocytic lymphoma, B cell type was made at autopsy. Only 53 cases of malignant lymphoma associated with chronic empyema have been reported in Japan. Surgery was often not done because of the patient's advanced age or poor pulmonary function; diagnosis was often difficult. However, review of the 53 reported cases suggested that resection of the tumor, if possible, would improve the prognosis. Malignant lymphoma should be considered when there is chronic empyema, because such cases are now being reported more frequently.

[A case of T-cell malignant lymphoma developing in the chest wall of chronic pyothorax after artificial pneumothorax]

A 66-year-old man, with a past history of artificial pneumothorax for pulmonary tuberculosis at the age of 17, was admitted to our hospital because of progressive left precordial pain and left anterior chest wall tumor. Because of chronic pyothorax complicated by a tumor suggested by imaging diagnosis, surgery was performed for the purpose of fenestration. A diagnosis of diffuse large cell T-cell malignant lymphoma was made by the biopsy taken at surgery. Postoperatively the patient received 6 courses of combination chemotherapy with CHOP, the course turned favorable. The left precordial pain and tumor disappeared. The patient is doing well at 11 months postoperatively. Recently, cases of malignant lymphoma developing in the chest wall of chronic pyothorax have been increased and the majority of cases of the malignant lymphoma is B-cell type. T-cell type is rare. Follow-up of chronic pyothorax's patients necessarily are attentioned on the developing of the malignant lymphoma.

Treatment of tuberculous pleurisy with effusion by artificial pneumothorax

57 patients were divided into two groups at random. The patients of two groups were all given standard treatments with anti-tuberculous drugs. Treatment group received artificial pneumothorax to help the cure. Results showed that the frequency and quantity of drawing liquid in the treatment group were obviously less than those in the control group and the duration of the complete liquid absorption was shortened markedly in the treatment group and that total effective rate in treatment group (92.5%) was obviously higher than that of the control group (83.33%). We found that the artificial pneumothorax could raise the intra-pleural pressure by 0.20-0.39 kPa, reduce leakage in parietal pleurae and increase the absorption in visceral layer evidently. As it can isolate the two layers of pleurae from one another by the air in thorax, the incidence of pleurae adhesion can be decreased.

Left, but not right, one-lung ventilation causes hypoxemia during endoscopic transthoracic sympathectomy

OBJECTIVE

To describe the respiratory and cardiovascular effects of one-lung ventilation, using a double-lumen tube, during endoscopic transthoracic sympathectomy.

DESIGN

A prospective clinical study.

SETTING

A university-affiliated medical center.

PARTICIPANTS

Nineteen adult patients (10 men, 1 woman) between 16 and 35 years of age, ASA (American Society of Anesthesiologists) physical status I and II, participated in the study.

INTERVENTIONS

Endoscopic transthoracic sympathectomy was performed under general anesthesia, using a double-lumen endobronchial tube, after induction of artificial pneumothorax plus insufflation of CO2 into the operated chest. Via radial artery cannulae, one to three arterial blood gas samples were taken during two-lung ventilation before surgery, at each one-lung ventilation, in most cases during the period of two-lung ventilation when switching between the operated sides, and after surgery.

MEASUREMENTS AND MAIN RESULTS

Comparisons were performed using the Wilcoxon matched-pairs single-ranks test. Left-lung ventilation and right-chest operation caused profound decrease of arterial oxygen partial pressure (PaO2), compared with two-lung ventilation before surgery (70.7%, P > 0.0003) and compared with PaO2 at two-lung ventilation during and after surgery (decrease of 80.1% and 75.3%, respectively; P > 0.001 and < 0.005, respectively). Right-lung ventilation and left-chest operation did not cause hypoxemia. Arterial CO2 partial pressure, pH, and bicarbonate, as well as hemodynamic parameters, did not change from baseline values throughout surgery.

CONCLUSIONS

Pulse oximetry and repeated blood gas measurements are needed during endoscopic transthoracic sympathectomy in order to detect and treat hypoxemic events, which may jeopardize the patient's life.

Treating tuberculous pleurisy with effusion by artificial pneumothorax

The efficacy of artificial pneumothorax therapy was evaluated in subjects with tuberculous pleurisy with effusion. The patients (57 cases) were divided into two groups at random: 30 cases in the control group and 27 cases in the group under treatment. They were all given standard treatment with antituberculous drugs drawing liquid accumulated and injecting antituberculous drugs and corticosteroids into their intrapleural cavity. In addition, the treating group received artificial pneumothorax to enhance the treatment efficacy. The frequency and amount of liquid drawn in the treating group were obviously less than those in the control group. Time necessary to draw all the liquid was substantially shortened in the former case with a higher degree of efficiency (92.59%) than that of the latter (83.33%). We also found that the artificial pneumothorax could raise the intrapleural pressure of 2 to 4 cm H2O, reduce leakage in parietal pleura and evidently increase the absorption in visceral pleura. The results suggest that artificial pneumothorax can reduce the liquid leakage and accelerate absorption of the liquid in thorax. As the two layers of pleura can be isolated by the air in thorax, the occurrence rate of pleural adhesion can be cut down. Hence, it is an effective assistant therapy for tuberculous pleurisy with effusion.

Decortication is a valuable option for late empyema after collapse therapy

BACKGROUND

Infection of previous collapse therapy spaces may raise challenging problems. This study evaluated a conservative surgical approach based on decortication.

METHODS

Since 1979, 28 patients (mean age, 60 +/- 6 years) have presented at an average of 37 +/- 7 years after artificial pneumothorax for tuberculosis. Diagnosis of empyema was made on follow-up in 12 patients and on symptoms in 16 patients. Mean vital capacity was 66% +/- 16% of normal. Microorganisms were isolated in 13 patients (Aspergillus fumigatus in 5, Mycobacterium tuberculosis in 4, anaerobes in 4). Decortication was made in 24 patients, associated with thoracoplasty in 4, and with partial lung resection in 2 patients. Thoracoplasty alone was performed in 2 patients, and 2 patients underwent an extrapleural pneumonectomy.

RESULTS

Both extrapleural pneumonectomies were complicated with empyema requiring thoracoplasty, resulting in one postoperative death. Operative mortality after decortication was nil. Mean intraoperative blood loss during decortication was 1,830 +/- 1,310 mL. All patients were extubated within 24 hours, except 1 patient who was ventilator-dependent preoperatively. Prolonged air leaks were common (mean duration of drainage, 16 +/- 11 days), but ultimately sealed. Existence of symptoms was predictive of prolonged air leaks (p < 0.01).

CONCLUSIONS

We conclude that decortication may provide a one-stage cure avoiding the hazards of extrapleural pneumonectomy; the nonfunctioning remaining lung may resolve the space problem.

[A case of malignant lymphoma arising from chronic pyothorax; usefulness of magnetic resonance imaging (MRI) for diagnosis]

A 79-year-old man had a history of pneumothorax induced to treat pulmonary tuberculosis when he was 40 years old, and of chronic pyothorax when he was 60 years old. He was admitted to our hospital because of chest pain and swelling of the right lateral chest wall. Soft tissues of the chest wall and rib had been destroyed, and a fistula had formed at the skin. The diagnosis was confirmed by examination of a biopsy specimen from the chest wall tumor. The tumor was successfully treated by radiation therapy. 67Ga scintigraphy, CT, and MRI were useful for diagnosis and follow up. Pyothorax and the tumor could be distinguished only with MRI.

[Reactive eosinophilic pleuritis]

Reactive changes in human pleura were studied 6 hrs, 1, 3 and 7 days after artificial pneumothorax. Thoracoscopically, grey-white deposits were seen which consisted of disorderly accumulation of monocytes, neutrophils, eosinophils and fibrin during the first hours. Later (the 3rd and the 7th days), the layer was observed formed of histiocyte-like cells and few multinuclear cells. The membrane on the pleura surface most likely represents a culture of monocyte cells. Morphologically, reactive eosinophilic pleuritis by the 7th day has a similarity with histiocytosis X; this may be the source of error diagnosis at the biopsy examination. Wrong interpretation of changes as a proliferative process, neoplasia or pleura tuberculosis is also possible.