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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↗
PubMed1979

Segmental pulmonary angiography in the critically-ill patient using a flow-directed catheter.

Selective pulmonary angiography was performed using a flow-directed, balloon-tipped catheter in 20 consecutive intensive care unit patients requiring heart catheterizations on the right side for hemodynamic monitoring. No morbidity was encountered from this procedure. Adequate quality balloon-occlusion angiographs were obtained with a portable chest roentgenogram in 17 (85 percent) but appeared normal in only 12 (60 percent), seriously limiting the usefulness of this technique in the diagnosis of occult pulmonary embolisms. With this technique, the catheter tip was found to be in a segmental pulmonary artery anterior to the left atrium (zone I) in 30 percent of the patients. From these findings, we conclude that not infrequently the catheter tip was situated in zone I anterior to the left atriums. Slective pulmonary angiography using a flow-directed, balloon-tipped catheter proved useful in demonstrating the precise location of the catheter tip. When this is the case, the catheter tip should be relocated to a segment below the left atrium (zone III) in patients requiring positive end-expiratory pressure because the "wedge" pressure measured in zone I may not accurately reflect left atrial pressure.

Blood Pressure↗
PubMed1978

Severe hypoxemia secondary to pulmonary embolization treated successfully with the use of a CPAP (continuous positive airway pressure) mask.

We describe a patient who was admitted with acute onset of dyspnea and pleuritic chest pain. The patient was in acute hypoxic respiratory failure documented by arterial blood gas levels. The severe hypoxemia was refractory to 100 percent O2 administration. The cause of the patient's sudden deterioration was a pulmonary embolus documented by angiography. The patient was managed successfully with heparin therapy. A continuous positive airway pressure (CPAP) mask corrected the severe hypoxemia, which otherwise would have required a more invasive method of respiratory support.

Female↗
PubMed1977

Prospective evaluation for pneumonectomy using the 99mtechnetium quantitative perfusion lung scan.

We evaluated 33 high-risk patients before pneumonectomy, all of whom had a forced expiratory volume in one second (FEV1) of less than 2.0 L before surgery. A quantitative perfusion lung scan was used to assess the right-left distribution of blood flow. A predicted postoperative FEV1 was calculated from the information on the lung scan and the preoperative FEV1. If this calculated value exceeded 800 ml, the patient was physiologically cleared for surgery up to and including a pneumonectomy. Surgery was otherwise believed to be contraindicated in the absence of studies using balloon occlusion. Perioperative mortality (less than or equal to 30 days after surgery) was found to be 15 percent (5/33). In surgery of this magnitude, we find this to be an acceptable percentage of mortality and have continued to use these simple physiologic criteria to determine whether a patient can tolerate pneumonectomy.

Aged↗