Search PubMed⌕ Search

Biomedical subjects

L J Findley

Publications and source records attributed to L J Findley.

At least 73 records · Page 4Linked to original sources

Pneumothorax following transbronchial biopsy. Low diagnostic yield with routine chest roentgenograms.

A chest roentgenogram is commonly obtained after a transbronchial biopsy to exclude a pneumothorax. We hypothesized that these routine chest roentgenograms rarely demonstrate a pneumothorax in patients who have neither symptoms nor fluoroscopic findings of lung collapse. To test this hypothesis, we studied 305 consecutive patients undergoing bronchoscopy with fluoroscopically guided TBB. No patient without symptoms and fluoroscopic findings suggesting lung collapse had a pneumothorax demonstrated on the post-biopsy chest roentgenogram. At the University of Virginia, routine chest roentgenograms failed to demonstrate a single unsuspected pneumothorax among all patients undergoing TBB during a period of nearly six years. Given this low incidence of unsuspected pneumothorax, we conclude that routine chest roentgenograms have a low diagnostic yield and may not be necessary in all patients after fluoroscopically guided TBB.

Adolescent↗

Tremors.

In this article, normal tremor and common types of pathologic tremors seen in the elderly are defined and described along with a review of current treatments. Problems of differential diagnosis are emphasized.

Adrenergic beta-Antagonists↗

Early clinical experience with subcutaneous GR43175 in acute migraine: an overview.

In six European clinics 111 migraine patients were treated in a series of open dose-ranging studies with subcutaneous injections of 1 to 4 mg GR43175, a novel 5-HT 1-like receptor agonist. Response rates after 20-30 min were dose related and rose from 33% with 1 mg to 96% with 4 mg GR43175. Side effects were minor and transient. These promising results warrant confirmation in placebo-controlled double-blind trials. Migraine, treatment, 5-HT agonist, open studies.

Adolescent↗

Driving simulator performance in patients with sleep apnea.

Although previous studies have shown that patients with obstructive sleep apnea have a higher automobile crash rate than normal subjects, objective measurements of driving performance in patients with sleep apnea have not been reported. Therefore, we compared the driving performance of subjects with untreated, severe sleep apnea to that of control subjects on two driving simulators. Using a simulator with road films, six subjects with untreated, severe apnea performed worse than did a control group of seven normal subjects on both highway and city/rural driving (p less than 0.05). Using a personal computer program simulating a monotonous highway drive, 12 subjects with untreated sleep apnea performed worse than 12 control subjects. The patients with apnea hit a greater number of road obstacles during their 30-minute simulated drive than did the control subjects (44 +/- 52 in patients with apnea versus 9 +/- 7 in control subjects, p less than 0.05). Six patients with apnea hit fewer road obstacles after treatment with nasal continuous positive airway pressure (CPAP) than before treatment (29 +/- 19 before CPAP versus 13 +/- 8 after CPAP, p less than 0.05). We conclude that: (1) driving simulator performance of untreated subjects with severe obstructive sleep apnea is worse than that of control subjects; (2) driving simulator performance of subjects treated with nasal CPAP improves.

Adult↗

Prolonged relaxation rate of inspiratory muscles in patients with sleep apnea.

To evaluate whether inspiratory muscle function is impaired in patients with sleep apnea, we measured inspiratory muscle strength and relaxation rate before and after sleep in 13 patients. The sleep apnea group was composed of eight patients with severe obstructive sleep apnea, and the non-apnea group was composed of five patients without significant sleep apnea. We chose the time constant of relaxation (TauR) as an index of impaired inspiratory muscle contractility, and in subsets of each group, we measured the inspiratory pressure-time index as an indicator of a fatiguing breathing pattern. In patients with sleep apnea, presleep TauR was 79 +/- 22 ms (SD), longer than that of normal subjects (normal, 59 +/- 7 ms) (p less than 0.05). TauR increased by 21 +/- 16 ms during sleep (p less than 0.01). In patients without apnea, presleep TauR was 67 +/- 7 ms and it did not change after sleep. Maximal inspiratory and expiratory pressures were unchanged after sleep. We conclude that patients with sleep apnea do not develop overt inspiratory muscle failure but do have impaired contractility. We speculate that hypoxemia as well as increased work load was responsible.

Adult↗

Lack of association between essential tremor and Parkinson's disease.

Four aspects of a possible association between essential tremor (ET) and Parkinson's disease (PD) were investigated: (1) the frequency of extrapyramidal signs in ET; (2) the frequency of concurrent ET and PD (i.e., monosymptomatic postural tremor for 5 or more years prior to onset of PD); (3) the frequency of ET in the families of PD patients; and (4) the frequency of PD in families of ET patients. Two hundred and thirty-seven ET patients (137 in London and 100 in Chicago) were evaluated. One hundred patients with PD and 100 normal control subjects were also investigated. Mild extrapyramidal signs occurred in only 4.5% of ET patients and were consistent with those found in normal aging. Only 3% of PD patients gave a history of uncomplicated ET. There was no difference in the frequency of a family history of PD between ET patients, a group of PD patients, and control subjects. Frequency of a family history of ET was higher among PD patients than control subjects, although the difference was not statistically significant. These data indicate that there is no association or genetic link between ET and PD.

Adolescent↗

Propranolol and propranolol-LA in essential tremor: a double blind comparative study.

In a double blind, comparative study with 15 patients, a long-acting formulation of propranolol taken once daily (at doses of 160, 240 and 320 mg), was shown to be as effective as conventional propranolol (80 mg three times daily) in reducing the amplitude of essential tremor. The specific protocol employed demonstrated problems inherent in chronic pharmacological trials in essential tremor which have implications for future studies.

Adolescent↗

Plasma adenosine and hypoxemia in patients with sleep apnea.

Severe hypoxemia causes ATP depletion and increased adenosine production in many body tissues. Therefore we hypothesized that patients with sleep apnea and severe hypoxemia during sleep have higher adenosine production and higher plasma adenosine levels than patients without hypoxemia. Twelve patients with sleep apnea and six normal volunteers had plasma adenosine levels measured by high-performance liquid chromatography. Each patient with sleep apnea had a polysomnograph sleep study with oxyhemoglobin saturation continuously recorded. Five of 12 patients with sleep apnea had both sleep apnea and severe hypoxemia during sleep. These patients with severe nocturnal hypoxemia had significantly higher plasma adenosine levels (means +/- SD 9.7 +/- 5.5 X 10(-8) M) than either a group of six normal volunteers (3.5 +/- 0.7 X 10(-8) M) or a group of seven patients with sleep apnea without hypoxemia at night (3.1 +/- 1.5 X 10(-8) M) (P less than 0.01). In addition plasma adenosine levels were significantly correlated with two indexes of nocturnal hypoxemia (desaturation index rs = 0.79, and median oxyhemoglobin saturation during sleep rs = -0.75, P less than 0.01). Plasma adenosine markedly fell to a normal level in the only two patients with sleep apnea who had successful treatment of their multiple apneas and accompanying severe hypoxemia during sleep.

Adenosine↗

Automobile accidents involving patients with obstructive sleep apnea.

Although patients with obstructive sleep apnea often report falling asleep while driving, the frequency of auto accidents involving these patients has not been rigorously studied. Therefore, we compared the driving records of 29 patients with obstructive sleep apnea with those of 35 subjects without sleep apnea. The patients with sleep apnea had a sevenfold greater rate of automobile accidents than did the subjects without apnea (p less than 0.01). The percentage of persons with one or more accidents was also greater in the patients with apnea than in the control subjects without apnea (31% versus 6%, p less than 0.01). The percentage of persons having one or more accidents in which they were at fault was also greater in the patients with apnea than in the control subjects (24% versus 3%, p less than 0.02). The automobile accident rate of the patients with sleep apnea was 2.6 times the accident rate of all licensed drivers in the state of Virginia (p less than 0.02). In addition, 24% of patients with sleep apnea reported falling asleep at least once per week while driving. We conclude that patients with obstructive sleep apnea have a significantly higher frequency of auto accidents than do subjects without apnea. Impaired drivers with sleep apnea may cause many preventable auto accidents.

Accidents, Traffic↗