Biomedical subjects

C L Bryan

Publications and source records attributed to C L Bryan.

25 records · Page 2Linked to original sources

PubMed1991

Single lung transplantation. Alternative indications and technique.

Twenty-two patients have undergone 23 single lung transplants between March 1980 and April 1990 at the University of Texas Health Science Center at San Antonio. The actuarial survival rate is 77.27% at 12 months and 72.73% at 24 months. There have been no instances of bronchial dehiscence or stenosis, even though 13 of the patients were on a program of preoperative prednisone, every patient had high-dose perioperative methylprednisolone, and omental wraps were not used on any bronchial anastomosis. Of particular interest is the fact that three patients had primary pulmonary hypertension, three had secondary pulmonary hypertension, and 10 patients had chronic obstructive pulmonary disease, due in five cases to an alpha 1-antitrypsin deficiency. Each of these entities was previously thought to contraindicate single lung transplantation. Donor selection was based on an oxygen tension/inspired oxygen concentration ratio greater than 300, donor/recipient chest circumference within 3 inches, clear chest x-ray film, negative sputum Gram stain, and less than 6-hour estimated ischemic time. Harvest technique included donor prostaglandin E1 500 micrograms, topical slush, and pulmonoplegia with cold Euro-Collins solution. The heart and lung were separated in situ rather than the heart lung block being removed. A telescoping bronchial anastomosis was performed with 4-0 Prolene (not absorbable) sutures. We conclude that single lung transplantation has evolved into a simple operation, necessitating meticulous preoperative and postoperative care, which can be performed on a wide spectrum of critically ill patients with an acceptable mortality rate.

Adult↗

PubMed1990

Single lung transplantation for primary pulmonary hypertension.

Single lung transplantation has become a therapeutic option for end-stage interstitial lung disease and obstructive lung disease. Our group recently extended this treatment to three patients with primary pulmonary hypertension. All patients had marked decreases in pulmonary artery pressures and pulmonary vascular resistance and increases in cardiac output following single lung transplantation. Spirometry, lung volumes, and diffusion capacity were not different in comparison to preoperative studies. Quantitative ventilation-perfusion scans revealed the majority of perfusion distributed to the transplanted lung, with ventilation approximately equally divided between the native and the transplanted lung. Despite ventilation-perfusion imbalance, there was no resting hypoxemia and there was no arterial oxygen desaturation with exercise. One patient expired on the 30th postoperative day due to cytomegalovirus infection of the lungs. In the remaining two patients, maximum exercise capacity following transplantation was near normal in one recipient and reduced in the second recipient. Of note, there was no evidence of ventilatory limitation or impaired oxygenation during exercise in these two recipients. Although an exaggerated exercise ventilatory response was present, this did not limit exercise performance. This report supports the use of single lung transplantation for the treatment of primary pulmonary hypertension.

Adult↗

PubMed1988

Oxygen toxicity.

Ventilating patients with elevated oxygen tensions alters normal respiratory physiology and may damage lung tissue, depending on coexisting host and iatrogenic factors. Pulmonary oxygen toxicity begins at a cellular level when the generation of reduced oxygen intermediates exceeds local defenses. The mainstay of therapy is prevention. Supplemental oxygen should be prescribed at the lowest concentration possible that will still allow adequate tissue oxygenation. Presently, no specific therapeutic interventions are approved for use in humans to treat pulmonary oxygen toxicity. New agents that act as free radical scavengers or reduce free radical formation may prove useful in future clinical trials based on many of the scientific studies summarized in this review.

Animals↗

PubMed1987

Species variation in lung antioxidant enzyme activities.

Exposure of several different animal models to O2-induced lung injury has revealed marked differences in sensitivity of various species to O2 damage. These differences may be due in part to variation of cellular antioxidant defenses. To characterize lung antioxidant enzyme activities in different species, we measured lung activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GSH S-trans) in rat, hamster, baboon, and human lung. Soluble lung fractions were also fractionated on Sephadex G-150-S columns and GSH-Px activity was measured using both cumene hydroperoxide and H2O2. This was done to evaluate non-Se-dependent GSH-Px activity in these lung samples. Human lung was obtained at surgery from patients undergoing lobectomy or pneumonectomy for localized lung tumors. SOD activity was similar for all four groups. GSH-Px activity was higher in rat lung than baboon or hamster lung. Lung CAT activity was variable with the highest activity present in the baboon which revealed a lung CAT activity 10 times higher than activity present in the rat. Lung GSH S-trans activities were higher in hamster, baboon, and human lung than in rat lung. Non-Se-dependent GSH-Px was present in rat lung but absent in hamster, baboon, and human lung. We conclude that the hamster was the best model of the animals studied for mimicking human lung antioxidant enzyme activities. Rat lung antioxidant enzyme activities were markedly different from any of the other species examined.

Animals↗

PubMed1987

Transbronchial needle aspiration in the diagnosis of bronchogenic carcinoma.

Transbronchial needle aspiration (TBNA) was performed as a diagnostic procedure in 91 consecutive patients ultimately proven to have bronchogenic carcinoma. Results of TBNA were compared, in the same patients, to the diagnostic yield of cytologic examination of sputum, endobronchial brushings and washings, and endobronchial/transbronchial biopsy. The diagnostic yield for sputum was 13 percent (10 of 75); brushings, 40 percent (34 of 84); washings, 29 percent (26 of 89); biopsy, 56 percent (42 of 75); and TBNA, 45 percent (41 of 91). Aspirates were positive in 35 percent of patients with adenocarcinoma, 41 percent with squamous cell carcinoma, 52 percent with large cell undifferentiated carcinoma, and 55 percent of patients with small cell carcinoma. Carinal aspirates were positive in 54 percent (6 of 11); paratracheal aspirates, 57 percent (13 of 23); parabronchial aspirates, 39 percent (11 of 28); endobronchial, 78 percent (7 of 9), and peripheral mass or solitary pulmonary nodule, 40 percent (17 of 42). The overall diagnostic yield for brushings, washings, and biopsy was 64 percent. The addition of TBNA increased the yield to 71 percent. Bronchogenic carcinoma was diagnosed solely by TBNA in six patients, all with extrabronchial or extratracheal lesions. We conclude that TBNA increases the diagnostic yield of bronchoscopy, particularly in patients with extratracheal and extrabronchial lesions. An equally important observation is that TBNA fails to contribute significantly to the diagnosis of cancer in patients with lesions readily accessible by conventional bronchoscopic techniques. Exceptions to this observation include occasional patients with necrotic endobronchial tumors, submucosal lesions, and rarely patients with peripheral lung nodules or masses.

Adenocarcinoma↗

PubMed1986

Transbronchial needle aspiration staging of bronchogenic carcinoma.

Transbronchial needle aspiration (TBNA) has been advocated as a reliable technique in the nonsurgical staging of patients with bronchogenic carcinoma. Some have questioned the reliability of TBNA, however. We used TBNA directed by computed tomography (CT) in 88 consecutive patients with bronchogenic carcinoma who had undergone chest CT. Chest CT was 94% sensitive, 79% specific, and 85% accurate in evaluating the mediastinum for malignant lymphadenopathy. There were 19 malignant aspirates in 44 patients with malignancy and apparent adenopathy evaluated by chest CT. No malignant carinal aspirates were obtained in any patient with a normal mediastinum evaluated by chest CT. There were 2 false positive needle aspirates. One patient with apparent right paratracheal adenopathy and malignant needle aspirate had no mediastinal neoplasm detected at surgery. The other false positive aspirate had been contaminated by tracheal debris. The overall sensitivity, specificity, and accuracy of TBNA mediastinal staging were 50, 96, and 78%, respectively. We conclude that CT scanning is a useful adjunct in the staging of patients with bronchogenic carcinoma, and that TBNA is a sensitive and highly specific staging technique that may negate the need for surgical staging in a large number of patients with bronchogenic carcinoma.

Adenocarcinoma↗

PubMedDate not supplied

Exercise performance after lung transplantation.

Heart-lung, double lung, and single lung transplantation have been shown to be effective in the treatment of patients with advanced cardiopulmonary disorders. An overlap in indications occurs for the different procedures, and in many situations the factors that are important in selecting the best operation for a given patient have not been clearly elucidated. To determine whether the anticipated exercise capacity should be an important consideration in the selection of the optimal procedure for a given patient, we compared exercise performance in patients who had undergone the different lung transplantation procedures in the preceding year and were otherwise well. Eleven heart-lung, six double lung, and 16 single lung recipients and 28 control subjects underwent maximal symptom-limited incremental exercise tests using a cycle ergometer. At peak exercise, transplant recipients reached maximum oxygen uptakes in the range of 40% to 60% of predicted values; no significant differences existed between the means of the different transplant groups. Ventilatory factors did not appear to limit exercise in any group. The exercise responses in the transplant subjects were characterized by reduced aerobic capacity and diminished oxygen pulse, factors indicating abnormal cardiovascular performance. Our data indicate that moderate levels of exercise can be anticipated early after heart-lung, double lung, and single lung transplantation. In the absence of substantial differences in exercise capacity, other considerations would appear to be more important in guiding the selection of the optimal lung replacement procedure for an individual patient.

Adult↗