Biomedical subjects

M S Gorby

Publications and source records attributed to M S Gorby.

8 recordsLinked to original sources

PubMed1992

A multivariate model for the prediction of relapse after outpatient treatment of decompensated chronic obstructive pulmonary disease.

PURPOSE: To develop and validate a multivariate model for predicting relapses after treatment of decompensated chronic obstructive pulmonary disease in an emergency department. METHODS: A 5-year survey was conducted, including training and validation periods. Stepwise logistic regression was used to develop a multivariate predictive model using clinical data obtained at the time of each visit. A relapse was defined as an unscheduled return to the emergency department within 48 hours. SITE: The study was conducted in the emergency department of the Albuquerque (New Mexico) Veterans Affairs Medical Center. SUBJECTS: The subjects were 289 patients with documented chronic obstructive pulmonary disease. MEASUREMENTS AND MAIN RESULTS: During the first 3 years, there were 705 visits in which the patient was treated and released from the emergency department. Relapse occurred 82 times (11.6%). Logistic regression showed that the following variables had an effect on the risk of relapse: the relapse rate for previous visits, a previous visit within 7 days, long-term home oxygen therapy, the number of doses of nebulized bronchodilators, the administration of aminophylline, and the use of antibiotics and prednisone at the time of discharge from the emergency department. During the next 2 years, the 48-hour relapse rate was 9.9% (47 of 476 discharges). When the model was fitted to these data, all of the original variables contributed to the prediction of relapse except antibiotic use and long-term home oxygen therapy. The logistic model was used to categorize each visit during the validation phase. The relapse rate for "high-risk" visits was significantly higher than that for "low-risk" visits (18.4% vs 6.1%). The method identified 57.4% of visits that ended in relapse at 48 hours. CONCLUSIONS: A multivariate model can be used to identify patients with a poor prognosis after the outpatient treatment of decompensated chronic obstructive pulmonary disease.

Ambulatory Care↗

PubMed1992

A multivariate model for predicting hospital admissions for patients with decompensated chronic obstructive pulmonary disease.

PURPOSE: To develop a method for predicting hospital admissions for patients with decompensated chronic obstructive pulmonary disease treated in an emergency department. METHODS: A 4-year survey including training and validation periods was conducted. Stepwise logistic regression was used to develop a multivariate model using information from the patient's previous visits and results of baseline pulmonary function tests. MEASUREMENTS AND MAIN RESULTS: During the first 2 years, there were 693 visits to the emergency department for decompensated chronic obstructive pulmonary disease. The patient was admitted to the hospital on 210 occasions (30.3%). Logistic regression showed that the probability of admission was related to the following: the admission and relapse rates for previous visits, the proportion of previous discharges from the emergency department in which "conservative therapy" was given, the highest baseline post-bronchodilator forced expiratory volume in 1 second within 3 years of entry, and the highest baseline pre-bronchodilator forced expiratory volume in 1 second-vital capacity ratio. A relapse was defined as an unscheduled return to the emergency department within 48 hours. "Conservative therapy" was any treatment regimen that did not include parenteral medications. During the next 2 years, the model was validated with patients not previously treated at this medical center. Seventy-six (28.3%) of 269 episodes resulted in hospital admission. The logistic model was used to categorize each visit during the validation phase. "High-risk" visits had calculated probabilities of admission greater than .208, while "low-risk" visits had values that were less. The admission rate for 98 low-risk visits (8.2%) was much lower than the rate for 171 high-risk visits (39.8%). CONCLUSIONS: A multivariate model can be used to identify patients with decompensated chronic obstructive pulmonary disease who are unlikely to need hospitalization. This model could be used to select episodes of decompensated chronic obstructive pulmonary disease for treatment at home.

Aged↗

PubMed1991

Treatment of decompensated chronic obstructive pulmonary disease in the emergency department--correlation between clinical features and prognosis.

STUDY OBJECTIVE: Patients with decompensated chronic obstructive pulmonary disease (COPD) are at high risk of relapse after treatment in an emergency department. The purpose of this study was to determine if the risk of relapse correlates with the clinical features of the disease. PATIENTS: Three hundred fifty-two patients with documented COPD who were treated for dyspnea in the ED of the Albuquerque Veterans Administration Medical Center over a three-year period. METHODS: We reviewed the clinical features and pulmonary function tests of the patients, who were considered to have COPD if the baseline prebronchodilator one-second forced expiratory volume (FEV1) was less than 80% predicted, and less than 80% of the forced vital capacity and inhaled bronchodilators failed to increase the FEV1 to levels of more than 80% predicted. Visits for pneumonia, pneumothorax, pleural effusion, or pulmonary emboli were excluded. A relapse was defined as an unscheduled revisit to the ED within 14 days of initial treatment. Data were entered into a microcomputer data base and analyzed by a commercial statistical package. RESULTS: Of 877 visits in which the patient was treated and released from the ED, 281 (32.0%) resulted in relapse and were considered unsuccessful Compared with successful visits, unsuccessful visits were characterized by a shorter duration of dyspnea (P = .002), a lower entry FEV1 (P = .027), a lower discharge FEV1 (P = .040), a greater number of treatments with nebulized bronchodilators (P = .009), more frequent use of parenteral adrenergic drugs (P = .006), and less frequent use of oral prednisone on discharge (P = .016). Patients with one or more relapse visits during the study period (relapsers) differed from nonrelapsers in several respects. Relapsers had a greater bronchodilator response on baseline FEV1 than nonrelapsers (P = .047). Nevertheless, relapsers required more bronchodilator treatments in the ED (P less than .001); were treated more frequently with parenteral adrenergic drugs (P less than .001), IV glucocorticoids (P less than .001), and oral prednisone (P less than .001); and recovered less of their baseline FEV1 (P less than .014). CONCLUSION: Bronchodilator response on baseline pulmonary function testing appears to identify patients with COPD who have a poor prognosis after emergency treatment. Their poor response to intensive bronchodilator treatment suggests that loss of bronchodilator response may be involved in the pathogenesis of respiratory decompensation.

Aged↗

PubMed1990

Intravenous and oral corticosteroids for the prevention of relapse after treatment of decompensated COPD. Effect on patients with a history of multiple relapses.

To determine if a regimen of intravenous and oral corticosteroids reduces the relapse rate after treatment of decompensated COPD in the ED, 30 patients were studied. Forty-five visits in which intravenous and oral corticosteroids were given (T visits) were compared with an equal number of matched visits in which they were withheld (N visits). No differences were noted between T and N visits with respect to clinical findings, laboratory results and other forms of therapy. Treatment with corticosteroids reduced the relapse rate within 24 h of discharge. At 48 h, the cumulative relapse rate for T visits (8.9 percent) was significantly lower than for N visits (33.3 percent; p = 0.005). For patients with a history of multiple relapses, a regimen consisting of intravenous and oral corticosteroids reduces the risk of relapse after ED treatment of decompensated COPD.

Acute Disease↗

PubMed1990

Aminophylline in the outpatient management of decompensated chronic obstructive pulmonary disease.

The objective of this study was to determine if IV aminophylline reduces the risk of relapse after treatment of decompensated COPD in an ED. Forty-six visits in which IV aminophylline was given (T visits) were compared with an equal number of visits in which it was withheld (N visits) with respect to pretreatment serum theophylline level, number of treatments with nebulized bronchodilators and use of parenteral beta-adrenergic drugs, IV corticosteroids and prednisone. The difference in 48-h relapse rates for T and N visits was examined by McNemar's test. No differences were found between T and N visits with respect to vital signs, pretreatment FEV1, arterial blood gas values, hematocrit level or blood leukocyte count. The 48-h relapse rate for T visits (22.2 percent) was significantly higher than for N visits (6.7 percent; p = 0.035). Aminophylline does not appear to be beneficial for outpatients with decompensated COPD and may be harmful.

Aged↗

PubMed1989

Use of emergency medical services by patients with decompensated obstructive lung disease.

Little information is available about the risk of relapse when patients with decompensated obstructive lung disease are treated in an emergency department for dyspnea. The purpose of our study was to determine if the risk of relapse was related to the severity and type of airway obstruction or to the time and duration of treatment. Over a period of 29 months, 496 patients with decompensated chronic obstructive pulmonary disease (COPD), asthma, or both were seen in the ED of the Albuquerque Veterans Administration Medical Center. Of 868 visits in which patients were treated and released, 244 (28.1%) were followed by a relapse within 14 days. Those who relapsed had a slightly higher one-second forced expiratory volume at baseline than those who did not (50.1 +/- 22.2% versus 45.5 +/- 20.6% predicted, P = .054). For 94 patients (group 1), asthma was the exclusive clinical diagnosis, and all available pulmonary function tests showed a bronchodilator response. For 268 patients (group 2), COPD was the exclusive diagnosis, and all tests showed no bronchodilator response. One hundred thirty-four patients (group 3) were either diagnosed as having both disorders or had varying bronchodilator response on sequential testing. The risk of relapse for group 3 patients (35.6%) was higher than for those in groups 2 (23.1%, P less than .001) or 1 (19.7%, P = .001). The frequency of relapse was higher for nighttime than daytime visits (36.1% versus 24.5%, P = .006) and for weekend than weekday visits (33.6% versus 26.6%, P = .049). Prognosis did not vary with the season or duration of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗

PubMed1988

Arsenic poisoning.

This discussion was selected from the weekly Grand Rounds in the Department of Medicine, University of New Mexico School of Medicine, Albuquerque. Taken from a transcription, it has been edited by Ralph C. Williams, Jr, MD, Professor and Chair of the Department of Medicine.

Arsenic Poisoning↗

PubMed1980

Catalytic mechanism of Escherichia coli alkaline phosphatase: resolution of three variants of the acyl-enzyme mechanism.

Three variants of the classical acyl-enzyme mechanism were compared theoretically with respect to the predicted transient kinetics of substrate hydrolysis by Escherichia coli alkaline phosphatase. In all three, acyl-enzyme hydrolysis was assumed to exist initially primarily as a noncovalent complex with the acid product, inorganic phosphate. In one mechanism, the pre-steady-state rate-controlling step was assumed to be the dissociation of acid product from its initial complex with enzyme. In the other two, pre-steady-state rate control was assigned to an enzyme isomerization occurring before or after substrate binding to free enzyme. Under concentration conditions of excess substrate and acid product, integrated rate laws were used to reject the possibility of pre-steady-state rate control by enzyme isomerization between phosphate dissociation and substrate binding. Whereas this mechanism predicts a pre-steady-state noncompetitive relationship between substrate and acid product, the stopped-flow kinetics of 4-methylumbelliferyl phosphate hydrolysis demonstrates a competitive relationship, consistent with either of the other two mechanisms. Under concentration conditions of stoichiometrically limiting substrate, computer simulations eliminated the possibility of rate control by enzyme isomerization after substrate binding. This mechanism predicts a substrate concentration dependence for the apparent first-order rate constant of substrate hydrolysis which disagrees with previously published data [Halford, S. E. (1971) Biochem. J. 125, 319--327]; the other two mechanisms are consistent with experiment. Comparison of transient kinetic theory and experiment under these two contrasting concentration conditions suggests strongly that the rate-controlling step in phosphate ester hydrolysis by E. coli alkaline phosphate is the dissociation of "sticky" acid product from its noncovalent complex with enzyme. This mechanism explains an anomaly in the stopped-flow kinetic trace, a substoichiometric pre-steady-state burst of alcohol product release.

Alkaline Phosphatase↗