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Biomedical subjects

J C McDougall

Publications and source records attributed to J C McDougall.

At least 19 recordsLinked to original sources
PubMed1997

Native lung complications after single lung transplantation for emphysema.

We reviewed the impact of the presence of the native diseased contralateral lung on the outcome after single lung transplantation for emphysema. Twenty consecutive recipients of single lung transplants for emphysema were reviewed for complications related to the native lung. Five patients (25%) suffered major complications arising in the native lung and resulting in serious morbidity and mortality. The timing of onset varied from 1 day to 43 months after transplantation. We conclude that the susceptibility of the native lung to complications such as those described in this report is an additional fact to be considered in choosing the ideal transplant procedure for patients with obstructive lung disease.

Adult↗
PubMed1997

Lung transplantation: selection of patients and analysis of outcome.

Lung transplantation is an important option for patients with respiratory failure and limited life expectancy. Herein we review the current indications for and outcome after lung transplantation. These results are compared with the natural history of various respiratory diseases, estimated from available databases. Candidates for lung transplantation are generally younger than 60 years of age, have a limited life expectancy because of end-stage lung disease, and have no other major organ dysfunction. Single lung transplantation is performed most commonly for emphysema, pulmonary fibrosis, and pulmonary hypertension. Survival after single lung transplantation is approximately 70% at 1 year, 60% at 2 years, and 40% at 3 years. The median duration of survival for patients with end-stage lung diseases ranges from approximately 2 to 6 years, with wide variation based on the diagnosis and severity of illness. Currently, prolongation of the average survival has not been clearly substantiated after lung transplantation. Further evaluation of outcomes, functional status, and quality of life after lung transplantation is necessary.

Humans↗
PubMed1997

Posttransplantation physiologic features of the lung and obliterative bronchiolitis.

Obliterative bronchiolitis remains the major obstacle to long-term survival after lung transplantation. Herein we provide a brief review of the key literature as well as our own experience with this condition. Obliterative bronchiolitis has occurred in up to two-thirds of all lung transplant recipients. The characteristic physiologic changes include declines in (1) forced expiratory volume in 1 second, (2) forced vital capacity, and (3) diffusing capacity of the lungs for carbon monoxide. Lung biopsy in patients with obliterative bronchiolitis reveals occlusion of bronchioles in a patchy but extensive distribution. Mucous plugging and bronchiectasis may also be seen. Furthermore, intimal thickening of pulmonary vessels together with mild arteriosclerotic changes of the muscular and elastic pulmonary arterioles may be observed. To date, the main risk factor for the development of obliterative bronchiolitis is recurrent, severe, and persistent acute lung rejection. The recommended management is prevention because the established fibrotic condition may necessitate retransplantation.

Bronchiolitis Obliterans↗
PubMed1997

Medical management and complications in the lung transplant recipient.

Lung transplantation has evolved as a viable therapy for patients with end-stage lung disease. Improvements in surgical techniques, avoidance of rejection by effective strategies of immunosuppression, and other aspects of medical management allow successful lung transplantation, with 1-year survivorship of 70 to 93%. In this review, we address the medical management of patients who have undergone lung transplantation. The immunosuppressive protocol used at Mayo Clinic Rochester is presented, along with a discussion of the mechanisms of action and potential complications associated with the various drugs used. The recognition and treatment of early graft dysfunction, infection, rejection, stenosis of the airway anastomosis, and posttransplantation lymphoproliferative disorder are also reviewed. Careful surveillance of patients after lung transplantation helps maintain graft function and facilitates identification, treatment, and potential avoidance of complications.

Clinical Protocols↗
PubMed1997

Right and left ventricular remodeling after orthotopic single lung transplantation for end-stage emphysema.

BACKGROUND: Orthotopic single lung transplantation (LTX) is now an established treatment modality for patients with end-stage emphysema. LTX has been shown to cause unloading of the right ventricle with improvement in right ventricular (RV) structure and function both immediately and up to weeks after surgery, mostly in patients with severe pulmonary hypertension and decreased RV function. Long-term effects of lung transplantation on both RV and left ventricular (LV) anatomy and function, however, are not well known. METHODS: Seventeen patients undergoing LTX for end-stage emphysema and preserved RV function underwent serial electron beam computed tomography RV and LV function studies before, 3 months after, 1 year after, and 2 years after transplantation. Right-sided heart catheterization was performed before transplantation and at 1 and 2 years follow-up. RESULTS: RV end systolic volume decreased significantly (-15.5%), and RV ejection fraction increased significantly (+16%) in the first 3 months after LTX. This change was paralleled by a decrease in pulmonary pressure and vascular resistance, indicating a permanent RV unloading. This improvement was maintained up to 2 years after LTX. LV end-diastolic volume (+25%), LV stroke volume (+29%), and LV muscle mass (+28%) increased significantly in the first 3 months after LTX. This remodeling was maintained during the 2-year follow-up. CONCLUSIONS: Significant changes in cardiac anatomy and function occur shortly after LTX, most likely as a consequence of adaptation to a new hemodynamic state in patients with well preserved RV function before LTX. Furthermore, these acute changes persist for at least 2 years after LTX.

Adult↗
PubMed1994

Evolving strategies in lung transplantation for emphysema.

Evolving strategies of pulmonary preservation, bronchial revascularization, immunosuppression, and infectious disease management were used in 15 initial consecutive patients undergoing lung transplantation for emphysema. There were 10 women and 5 men with a mean age of 49 years (range, 36 to 60 years). All patients required supplemental oxygen therapy. One bilateral, 9 left, and 5 right transplantations were performed. Mean preoperative forced expiratory volume in 1 second and total lung capacity were 16% and 146%, respectively, of predicted. Quadruple drug immunosuppression was used. Actuarial 1-year survival in this initial series is 93.3% +/- 6.4% (Kaplan-Meier) with one early cardiac death at day 71. Mean forced expiratory volume in 1 second and diffusing capacity for carbon monoxide at discharge were 43% and 62%, respectively, of predicted. Rehabilitation has been excellent, and all survivors are active and free of supplemental oxygen. During the study, the following treatment strategies have evolved: (1) University of Wisconsin solution has replaced Euro-Collins' solution for pulmonary preservation; (2) direct bronchial revascularization with the internal thoracic artery now is used; (3) an algorithm-based variable dose OKT3 induction regimen has resulted in a major reduction in dosage; and (4) infectious disease management focuses on the prophylaxis of cytomegalovirus and fungal infection using prolonged ganciclovir and early itraconazole therapy as well as the avoidance of Epstein-Barr virus mismatches. Single-lung transplantation for emphysema has excellent early results with continuing evolving management strategies.

Adenosine↗
PubMed1993

Diagnostic tests for lung cancer.

The goals of diagnostic testing in patients with suspected lung cancer are to establish the diagnosis and to determine the stage of the disease so that appropriate therapy can be initiated. Unless a patient has hemoptysis, fever, or a change in cough as an initial manifestation, resectable lung cancer will seldom be diagnosed on the basis of the history. Screening tests--particularly chest roentgenography--have usually identified the abnormality. The managing physician should then select diagnostic procedures that are associated with low risk and that will provide further diagnostic and staging information. A biopsy will almost always be necessary before definitive therapy can be planned. In many cases, a single procedure--for example, a needle biopsy of a hepatic lesion or biopsy of a supraclavicular lymph node--will provide a definitive diagnosis and establish the stage of the disease. The roles of cytology, histopathologic examination, radiologic studies, and various types of biopsy in the diagnosis of lung cancer are reviewed in this report.

Biopsy, Needle↗
PubMed1993

Role of radiation therapy in the management of lung cancer.

Most patients who have lung cancer will receive radiation therapy at some point during the course of their disease. For patients with non-small-cell lung cancer, radiation therapy is sometimes used after complete resection, particularly in patients with lymph node involvement. In addition, irradiation is commonly used after incomplete resection. In patients with unresectable non-small-cell lung cancer, radiation therapy alone is typically used, although recent studies of a combination of chemotherapy and radiation therapy, or radiation therapy given in twice-daily fractions, have yielded promising results. For patients with small-cell lung cancer who have limited (that is, nonmetastatic) disease, the addition of thoracic radiation therapy to chemotherapy has improved survival over that with chemotherapy only. The role of prophylactic cranial irradiation in small-cell lung cancer remains controversial. Radiation therapy has a major role in the management of locally recurrent and metastatic lung cancer. Both the bones and the brain are common metastatic sites in patients with lung cancer. Radiation therapy provides effective palliation of symptoms from these and other metastatic lesions.

Carcinoma, Non-Small-Cell Lung↗
PubMed1993

Ancillary therapies in the management of lung cancer: photodynamic therapy, laser therapy, and endobronchial prosthetic devices.

Endoscopic therapy for cancer that involves the tracheobronchial tree is currently available for two distinct types of lesions: radiographically occult superficial squamous cell carcinoma and advanced malignant tumors that cause severe airway obstruction. Photodynamic therapy, which uses a photosensitizing agent, is effective for managing early superficial squamous cell carcinoma. Neodymium:yttrium-aluminum-garnet laser therapy has been effective in the palliative management of patients with advanced or recurrent malignant obstructive airway lesions, either alone or in combination with intraluminal radiation therapy. Most recently, endobronchial prosthetic devices (stents) have been used in patients with advanced airway obstruction. The use of each of these modalities in the management of lung cancer is reviewed.

Airway Obstruction↗
PubMed1993

Right ventricular assessment in patients presenting for lung transplantation.

Chronic pulmonary disease is associated with varying degrees of cardiac dysfunction. Because of the potentially predominant effect of severe lung disease on right ventricular (RV) size and function, a reliable method to assess RV mechanics before and after lung transplantation may provide information of long-term significance and/or prognosis. Conventional invasive and non-invasive imaging methods have a number of limitations in evaluating RV function. Ultrafast computed tomographic (ultrafast CT) scanning has been shown to provide quantitative assessment of RV and left ventricular (LV) function in individuals with and without cardiac disease. Twenty-two patients presenting during evaluation for possible lung transplantation with end-stage pulmonary disease formed the basis of this study. There were 14 patients with chronic obstructive pulmonary disease and 8 with pulmonary fibrosis. Conventional transthoracic echocardiography and ultrafast CT were used for the assessment of RV and LV function. All patients had invasive assessment of right-sided hemodynamics and pulmonary function studies performed within 7-10 days of cardiac imaging. A qualitative assessment of RV size or function was possible in all but two patients by echocardiogram, but in 45%, the echocardiographic examination was described as suboptimal. In contrast, a quantitative assessment of ventricular volumes and systolic function was obtained in all patients by ultrafast CT. Pulmonary function parameters or hemodynamic measurements obtained during cardiac catheterization did not correlate with any assessment of RV function. We concluded that (1) ultrafast CT provides measurement of the RV and LV cavity dimension and systolic function; (2) invasive right-sided hemodynamics or pulmonary function studies do not predict RV function; and (3) echocardiography does not uniformly provide assessment of RV function in patients with chronic pulmonary disease.

Adult↗
PubMed1993

Colchicine in the treatment of pulmonary fibrosis.

There is no standard or known optimal treatment for idiopathic pulmonary fibrosis. Corticosteroids have been used with widely variable benefit. Colchicine has been reported to suppress fibroblast growth factors and to inhibit collagen deposition. A potential role has been proposed for colchicine in the treatment of fibrotic pulmonary diseases. We retrospectively assessed the outcome of 23 patients with idiopathic pulmonary fibrosis in whom colchicine was used as empiric treatment. Eighteen patients had received prior corticosteroid therapy. By clinical and pulmonary function criteria, five patients (22 percent) improved following colchicine, nine (39 percent) remained stable, and nine (39 percent) worsened. The average duration of follow-up was 22 months. Despite limitations of this retrospective analysis, colchicine may be of benefit in pulmonary fibrosis and should be considered for further clinical trials.

Adult↗
PubMed1993

Pediatric tracheobronchial foreign bodies. A case report.

Pediatric tracheobronchial foreign bodies (PTBFBs) remain a significant cause of childhood morbidity and mortality. Because physicians do not always obtain a history of aspiration, and because the signs and symptoms of a PTBFB are nonspecific, diagnosis may be delayed, which increases the risk of complications when the foreign body is removed. Flexible fiberoptic and rigid bronchoscopy are often used in tandem for the identification and removal of PTBFBs. Recent advances in bronchoscopic equipment and technique have made removal of PTBFBs safer and more successful. Education of parents, child care providers, and medical personnel can reduce morbidity and mortality due to PTBFBs.

Airway Obstruction↗
PubMed1993

The sensitivity of transbronchial biopsy for the diagnosis of acute lung rejection.

Transbronchial biopsy has become the procedure of choice for the diagnosis of acute lung rejection after transplantation, but the sensitivity of the technique in this setting remains unknown. In this study, 14 mongrel dogs underwent left lung transplantation, after which triple-drug immunosuppression was given for 5 days and then all immunosuppression was stopped. All animals had clear chest radiographs at this time. Transbronchial biopsy was performed in nine lung regions (two to six pieces of lung tissue were obtained per region, with a mean of 4.3 pieces per region) before the animals were killed 2 to 4 days later, at which time varying degrees of rejection had occurred. Rejection was graded histologically on a scale of 0 to 3 (0 = no rejection, 1 = mild rejection, 2 = moderate rejection, 3 = severe rejection) in each piece of lung tissue obtained at transbronchial biopsy. After the dogs were put to death, the true state of lung rejection was determined by histologic examination of the entire lung. We calculated the sensitivity of transbronchial biopsy with 95% confidence intervals. Five pieces of lung tissue were needed to yield a sensitivity of 92% (82%, 100%) to identify mild rejection in the entire lung with transbronchial biopsy. Three pieces of lung tissue were needed to yield a sensitivity of 92% (84%, 100%) to identify the presence of moderate to severe rejection in the entire lung (that is, rejection that requires pulse therapy) on transbronchial biopsy. These results indicate that three to five pieces of lung tissue that are suitable for diagnostic purposes obtained at transbronchial biopsy are adequate for the diagnosis of acute pulmonary rejection after lung transplantation.

Acute Disease↗