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Biomedical subjects

G N Olsen

Publications and source records attributed to G N Olsen.

At least 19 recordsLinked to original sources
PubMed1991

Stair climbing as an exercise test to predict the postoperative complications of lung resection. Two years' experience.

The results of a clinically performed preoperative stair climb was compared to the presence of postthoracotomy complications in the retrospective hospital record review of 54 adult men. The stair climb was a maximum of five flights (125 steps) performed at the patient's rate and terminated at his request. Pulmonary function measurements and facets of the stair climb physiology were also examined in reference to the presence, type, and severity of complications experienced. Most minor complications such as transient arrhythmias, atelectasis, and pneumonia were clearly not predicted by the stair climb performance. The ability to climb three flights preoperatively most clearly separated those patients having the longer postoperative intubation and hospital stay, greater frequency of complications, and cumulative complication score (p less than 0.005). This retrospective study did not have sufficient numbers of fatal cardiopulmonary complications to exclude the possibility that these may be predicted by the results of this simple test.

Adult↗
PubMed1991

Can concomitant restriction be detected in adult men with airflow obstruction?

A reduction in lung volume is used to diagnose physiologic restriction in the pulmonary function tests of patients with lung disease. Airflow obstruction is commonly associated with hyperinflation of static lung volume. Because restriction and obstruction exert opposite effects on lung volumes, we questioned whether the lack of hyperinflation of static lung volumes could indicate the presence of concomitant restriction in patients with airflow obstructive ventilatory defects. To assess this, we evaluated by pulmonary function tests and chest roentgenograms of 58 patients with airflow obstruction (group 1), 18 of whom then sustained various types of resection for lung cancer (group 2) as a type of superimposed restriction. We selected 80 percent of predicted as the lower limit of "normal" frequently used by clinical pulmonary function laboratories. Despite a statistically significant decrease in total lung capacity (p less than 0.05) for the postpneumonectomy patients, when the static lung volume measurements of the patients with resection were evaluated, no one lung volume showed a consistent reduction sufficient to detect the superimposed restriction in all these patients. Using 80 percent of predicted as "normal," 61 percent of our patients with airflow obstruction and superimposed restriction would have been missed. We conclude that it is clinically difficult, based on only static lung volume measurements alone, to detect restriction superimposed on the hyperinflation of airflow obstruction unless these lung volumes are reduced to below accepted "normal" limits.

Aged↗
PubMed1989

Failure of preoperative staging to assess unresectability in M0 bronchogenic carcinoma.

Despite extensive preoperative staging, unresectability of a bronchogenic carcinoma may not be known until an exploratory thoracotomy is done. Failures in anatomic staging occur because of inability to detect local extent of hilar lesions and inability to detect small deposits of metastatic disease. At the University of South Carolina, nine of 75 patients who underwent thoracotomies were found to be unresectable. Using an extensive staging protocol, the "back out" thoracotomy rate can be reduced to a minimum whereas no patient is denied a chance for surgical cure.

Carcinoma, Bronchogenic↗
PubMed1989

The evolving role of exercise testing prior to lung resection.

Exercise testing prior to lung resection has long and honored tradition. It began as a test of tolerance using simple techniques such as stair climbing. This was followed by aggressive and invasive protocols using right cardiac catheterization in the search for pulmonary hypertension. More recently, measurement of VO2 with exercise has been reported to predict both postoperative mortality and survivable morbidity. Exercise testing holds promise as a noninvasive test to predict the physiologic outcome from lung resection. Significant questions remain concerning the pathophysiologic mechanisms responsible for an abnormal result and who should be denied thoracotomy based on these results.

Exercise Test↗
PubMed1989

Submaximal invasive exercise testing and quantitative lung scanning in the evaluation for tolerance of lung resection.

Lung resection in patients with cardiopulmonary dysfunction is associated with increased risk. We studied 52 elderly male patients with airflow obstruction and a lung mass. Studies were performed at rest with routine ventilatory tests and lung scan quantitation of right-left lung function. Cycle ergometry exercise was then performed at 2 submaximal work loads (25 and 40 watts). Data were obtained using systemic and pulmonary artery catheterization for blood pressures, thermal dilution cardiac output, and blood gases. Twenty-nine patients underwent lung resection and seven failed to tolerate the procedure (death within 60 days or prolonged ventilator dependence). Those parameters most clearly separating the group tolerating surgery (n = 22) from the intolerant group (n = 7) were obtained during exercise and included: cardiac index (tolerant 5.5 +/- 1.3 vs intolerant 3.9 +/- 0.3 L/min/m2, p less than .01), O2 delivery (p less than .01) and calculated VO2 ml/kg/min (tolerant 11.3 +/- 2.1 vs intolerant 7.8 +/- 1.5 ml/kg/min, p less than .001). Pulmonary vascular pressures and calculated resistance did not predict intolerance. Calculated VO2 at 40 watts did not separate those patients who had survivable complications from those who did not (p much greater than .05). Multivariate analysis suggests that exercise VO2 is an important predictor of tolerance of lung resection because it reflects the effects of cardiac function and O2 transport. In our patients with COPD, submaximal exercise testing predicted intolerance of lung resection better than calculation using quantitative lung scanning. Exercise testing may accomplish this goal by uncovering deficits in O2 transport.

Aged↗
PubMed1987

Stair climbing as an indicator of pulmonary function.

Seventy male patients with a mean age of 56.8 years scheduled for pulmonary function testing were subjected to a stair climb in order to determine the relationship, if any, between the number of steps climbed and the results of pulmonary function testing. The number of steps completed was plotted against the different parameters which may be used as predictors of post-thoracotomy outcome. The stair climb acts as a stress test and, although there is a strong relationship to pulmonary function tests, it also is an indicator of many other parameters including cardiovascular status, cooperation, and determination. Based on results of this study, the stair climb can be used as a reliable screening test of pulmonary function. Also, preoperative patients who are unable to perform pulmonary function tests can be evaluated accurately for lung resection by use of the stair climb test.

Adult↗
PubMed1985

Phagocytic activity of alveolar macrophages in patients with bronchogenic carcinoma.

Human bronchoalveolar cells were obtained by lavage during diagnostic fiberoptic bronchoscopy of 21 patients suspected of having lung malignancies. Of these patients 11 were diagnosed as having primary lung cancer (Group I) and included individuals with squamous cell carcinoma, adenocarcinoma, undifferentiated large and oat cell carcinoma at varying locations and TNM stages, 4 patients demonstrated nonprimary metastatic carcinoma (Group II), and 6 patients did not reveal detectable tumors by bronchoscopy or follow-up (Group III) and were included as study controls. We examined the ability of pulmonary alveolar macrophages (PAMs) lavaged from patients in each of the three study groups to phagocytose opsonized sheep red blood cells. Phagocytic activity varied among patients in the same and different study groups; however, no significant differences were observed in the phagocytic or tumoristatic activities of PAMs recovered from tumor-bearing and nontumor-bearing lung regions of the same patient. Moreover, lavage fluids collected from tumor-bearing regions did not suppress the phagocytic activity of PAMs collected from control lungs nor lung regions contralateral to the tumor-bearing lung. The data do not support the view that bronchial neoplasms or their secreted products suppress phagocytic functions of alveolar macrophages.

Adult↗
PubMed1985

Bronchoalveolar lavage and the immunology of primary lung cancer.

Bronchoalveolar lavage (BAL) is a powerful tool with which the immunology of the lung in health and disease can be studied. This technique has been successfully used to characterize localized humoral and cell-mediated responses in sarcoidosis and a number of other interstitial pneumonitides. In contrast, BAL in patients with lung cancer has resulted in some confusion regarding the extent and type of local and systemic immunity in these patients. This review summarizes some of the data obtained from these patients via BAL, but does not attempt to explain the reported discrepancies. The objective of this review is rather to identify gaps which exist in our knowledge of the environmental factors influencing pulmonary immunity in primary lung cancer.

Antibodies, Neoplasm↗