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Biomedical subjects

J Popovich

Publications and source records attributed to J Popovich.

At least 19 recordsLinked to original sources
PubMed1992

The clinical course of pulmonary embolism.

BACKGROUND: Pulmonary embolism is a potentially fatal disorder. Information about the outcome of clinically recognized pulmonary embolism is sparse, particularly given that new treatments for more seriously ill patients are now available. METHODS: We prospectively followed 399 patients with pulmonary embolism diagnosed by lung scanning and pulmonary angiography, who were enrolled in a multicenter diagnostic trial. We reviewed all hospitalizations, all new investigations of pulmonary embolism, and all deaths among the patients within one year of diagnosis. RESULTS: Of the 399 patients, 375 (94 percent) received treatment for pulmonary embolism, usually conventional anticoagulation. Only 10 patients (2.5 percent) died of pulmonary embolism; 9 of them had clinically suspected recurrent pulmonary embolism. Clinically apparent pulmonary embolism recurred in 33 patients (8.3 percent), of whom 45 percent died during follow-up. Ninety-five patients with pulmonary embolism (23.8 percent) died within one year. The conditions associated with these deaths were cancer (relative risk, 3.8; 95 percent confidence interval, 2.3 to 6.4), left-sided congestive heart failure (relative risk, 2.7; 95 percent confidence interval, 1.5 to 4.6), and chronic lung disease (relative risk, 2.2; 95 percent confidence interval, 1.2 to 4.0). The most frequent causes of death in patients with pulmonary embolism were cancer (in 34.7 percent), infection (22.1 percent), and cardiac disease (16.8 percent). CONCLUSIONS: When properly diagnosed and treated, clinically apparent pulmonary embolism was an uncommon cause of death, and it recurred in only a small minority of patients. Most deaths were due to underlying diseases. Patients with pulmonary embolism who had cancer, congestive heart failure, or chronic lung disease had a higher risk of dying within one year than did other patients with pulmonary embolism.

Adult↗
PubMed1992

The diagnosis of acute pulmonary embolism in patients with chronic obstructive pulmonary disease.

The clinical features and noninvasive tests, including ventilation perfusion (V/Q) lung scans, were assessed in 108 patients with chronic obstructive pulmonary disease (COPD) suspected of having pulmonary embolism (PE). Twenty-one (19 percent) of 108 patients had PE. In the majority of patients, it was impossible to distinguish between patients with and without PE by clinical assessment alone. However, when a high clinical index of suspicion was present, PE was confirmed by angiography in three of three patients, but the V/Q scan was of intermediate probability. No roentgenographic abnormalities distinguished between PE and no PE. There was no difference between the alveolar-arterial oxygen gradients in either group, nor was there evidence of a reduction in the PaCO2 in patients with PE who had prior hypercapnia. Among the 108 patients with COPD, high, intermediate, low, and normal/near normal probability scans were present in 5 percent, 60 percent, 30 percent, and 5 percent, respectively. The frequency of PE in these V/Q scan categories was five (100 percent) of five, 14 (22 percent) of 65, two (6 percent) of 33, and zero (0 percent) of five, respectively. In conclusion, in the majority of patients, the V/Q scan diagnosis is usually intermediate and such patients require further investigational studies, including angiography. However, among the few patients who demonstrated a high probability lung scan, there was a high positive predictive value for PE effectively avoiding the need for further studies. In those patients with low probability or near normal/normal V/Q scans, the negative predictive value was not lower than the general hospital population.

Acute Disease↗
PubMed1992

Respiratory physiology in pregnancy.

In conclusion, it is important to appreciate the anatomic and physiologic adaptations in pregnancy in order to accurately diagnose and treat cardiopulmonary disease states in the gravid woman. Without knowing what constitutes normalcy in pregnancy, inappropriate diagnosis and interventions may occur. Furthermore, this knowledge is fundamental for understanding how disease states affect pregnancy and how pregnancy affects disease.

Acid-Base Equilibrium↗
PubMed1991

The diagnostic utility of the antibody-coated bacteria test in intubated patients.

PURPOSE: Pilot study to determine if the presence of antibody-coated bacteria (ACB) in sputum specimens obtained from endotracheal tube suctioning would aid in the diagnosis of lower respiratory tract infection (LRTI). PATIENTS AND METHODS: All endotracheally intubated and mechanically ventilated patients for a two-month period were recruited for study. The diagnosis of LRTI was based on a clinical suspicion sufficient enough to start or change antibiotic therapy. Specimens were obtained by blind endotracheal tube suctioning. After processing, sputum smears were stained with fluorescein-labelled antibody to the Fc portion of IgG, IgM, and IgA. More than five fluorescein-labelled bacteria per oil immersion field were considered positive smears. RESULTS: Seventy-one specimens were obtained from 36 patients. Eighteen specimens were positive in 12 patients, all of whom had LRTI. No specimen was positive in patients not diagnosed as having LRTI. The ACB test was positive in 12 of 25 patients with LRTI. Patients with LRTI but negative ACB were more likely to have received prior antibiotic therapy (p less than 0.001). ACB was positive prior to the clinical diagnosis of LRTI in seven of nine patients (av 4.1 days, range 2-6 days) and converted to negative in three specimens obtained seven or more days after starting appropriate antibiotics, while in three specimens it remained positive three-six days post treatment initiation. CONCLUSIONS: The ACB test appears to be highly specific for the presence of LRTI in intubated patients. Sensitivity of the test may be adversely affected by prior antibiotic therapy. A positive ACB test may predict the subsequent development of LRTI. Further study is warranted.

Cross Infection↗
PubMed1990

Silastic prosthesis plombage for right postpneumonectomy syndrome.

In rare instances, right pneumonectomy can produce progressive exertional dyspnea and reduce ventilatory reserve because of extreme mediastinal shift (right postpneumonectomy syndrome). The diagnosis can be made by bronchoscopy and computed tomography. We report a case of a 43-year-old patient in whom plombage with two Silastic breast implants produced mediastinal derotation and symptomatic relief of this syndrome.

Adenocarcinoma↗
PubMed1990

Elective surgery without transfusion: influence of preoperative hemoglobin level and blood loss on mortality.

To clarify the widespread practice of preoperative transfusion to attain a 10 g/dL level of hemoglobin, the relationship between preoperative hemoglobin level, operative blood loss, and mortality was studied by analyzing the results of 113 operations in 107 consecutive Jehovah's Witness patients who underwent major elective surgery. Ninety-three patients had preoperative hemoglobin values greater than 10 g/dL; 20 had preoperative hemoglobin levels between 6 to 10 g/dL. Mortality for preoperative hemoglobin levels greater than 10 g/dL was 3 of 93 (3.2%); for preoperative hemoglobin levels between 6 to 10 g/dL, mortality was 1 of 20 (5%). Mortality was significantly increased with an estimated blood loss of greater than 500 mL, regardless of the preoperative hemoglobin level (p less than 0.025). More importantly, there was no mortality if estimated blood loss was less than 500 mL, regardless of the preoperative hemoglobin level. From these data, we conclude that: (1) Mortality in elective surgery appears to depend more on estimated blood loss than on preoperative hemoglobin levels; and (2) Elective surgery can be done safely in patients with a preoperative hemoglobin level as low as 6 g/dL if estimated blood loss is kept below 500 mL.

Adolescent↗
PubMed1990

Bioimpedance assessment of antipyrine pharmacokinetics before and after enzyme induction.

Bioimpedance (BI) technology, a noninvasive method of measuring body composition, has been previously used to develop a predictive model for metabolic clearance under basal conditions. The present investigation was conducted to assess the ability of BI-derived models to predict drug disposition in a perturbed system. An antipyrine pharmacokinetic and impedance analysis of 15 healthy male subjects was performed before and on the 14th day of phenobarbital administration (i.e., after enzyme induction). The all subsets multiple regression technique was used to develop preinduction models for clearance (CI), (p = 0.021, R2 = 0.654) and volume of distribution at steady-state (Vdss) (p = 0.001, R2 = 0.867), using demographic and mean BI parameters. The preinduction Cl model significantly underestimated postinduction measurements and was not predictive of changes in Cl. The preinduction Vdss model was predictive of postinduction Vdss. It appears that the BI-derived model is unable to predict perturbations in metabolic clearance caused by enzyme induction.

Adult↗
PubMed1990

Mechanical disruption of pulmonary emboli in dogs with a flexible rotating-tip catheter (Kensey catheter).

Pulmonary embolism was induced in 11 dogs by the injection of three- to four-day-old allogeneic blood clots. The clots were made radiopaque by soaking them in contrast material. The resulting clots were firm, 3 to 4 cm long, and 1 cm in diameter. Injection of the clots into the external jugular vein consistently produced occlusion of at least one of the lobar pulmonary arteries. In every instance in which the tip of the catheter could be positioned at the clot embolus (six dogs), the clots were readily fragmented with a number 8 French (2.67 mm OD) flexible rotating tip catheter (Kensey catheter) activated at 80,000 rpm. Overall perfusion was shown by posttreatment angiograms to be markedly improved. These studies show that catheter-tip fragmentation of pulmonary emboli with a Kensey catheter has excellent potential for therapeutic application in patients with pulmonary embolism.

Animals↗
PubMed1990

Expanded gentamicin volume of distribution in patients with indicators of malnutrition.

Visceral protein, body weight, and body composition were assessed in patients receiving gentamicin to determine whether a meaningful analysis of nutritional status can be used to identify patients with an expanded gentamicin volume of distribution (V). Adults with gram-negative infections were selected sequentially from among hospitalized patients being treated with gentamicin. Serum gentamicin concentrations before and after an intravenous dose of gentamicin were determined by an enzyme-mediated immunoassay. Noncompartmental analysis was used to determine pharmacokinetic variables. Body composition was assessed by bioelectric impedance techniques. Of 26 patients, 10 were considered to be at high risk of malnutrition by meeting at least two of the following criteria: serum albumin concentration, less than or equal to 3.5 g/dL; actual weight, less than 80% of ideal weight; and ratio of exchangeable sodium to exchangeable potassium (Nae/Ke), greater than 1.22. The non-high-risk group (n = 16) had a gentamicin V at steady state of 0.294 +/- 0.105 L/kg (mean +/- S.D.), which was significantly lower than that observed in the high-risk group (0.415 +/- 0.294 L/kg). The accuracy of the high risk classification in identifying patients with an expanded gentamicin V was improved by revising the definition of the high-risk group. In the revised definition, patients were considered to be at high risk for malnutrition if they met at least two of the following criteria: serum albumin concentration, less than or equal to 3.1 g/dL; actual weight, less than 90% of ideal weight; and Nae/Ke' greater than 1.22.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Relationship of bioelectrical impedance to pharmacokinetic parameters of theophylline in healthy males.

Bioelectrical impedance is a reliable, safe, non-invasive and valid method of determining body composition, using measures of resistance and reactance by passing a low voltage alternating current through the body. This study investigates relationships between the pharmacokinetics of theophylline and parameters of bioelectrical impedance in 15 non-smoking, healthy, adult male volunteers. After an overnight fast, subjects received 5 mg/kg of aminophylline intravenously over 30 minutes. Blood samples were obtained serially over a period of 12 hours. Bioelectrical impedance measurements were made in triplicate, using a 4-electrode plethysmograph. Sera were assayed in duplicate by enzyme-mediated immunoassay (coefficient of variation less than 5%), and data were fitted to a non-compartmental regression program. An all-subsets multiple-regression technique was employed to arrive at predictive equations for theophylline clearance (CL) and volume of distribution at steady-state (Vss) using age, height, weight and mean bioelectrical impedance parameters. Equations for Vss and CL revealed p-values of less than 0.001 and coefficients of variation of 8.5 and 13.33% respectively. Although the equations display some degree of colinearity they account for 95 and 86.5% of the variability in Vss and CL respectively, and represent an innovative approach to the estimation of pharmacokinetic parameters.

Adult↗
PubMed1988

Treatment of massive acute pulmonary embolism. The use of low doses of intrapulmonary arterial streptokinase combined with full doses of systemic heparin.

The efficacy of low-dose, locally administered streptokinase (SK) combined with full therapeutic systemic doses of heparin was investigated. Seven patients with angiographically proven massive acute pulmonary embolism were treated. Streptokinase, 10,000-20,000 units/hour, was administered directly into the left or right pulmonary artery for 9 to 24 hours. Heparin was administered concurrently. The number of unperfused segments of the infused lung shown on the lung scan decreased from 5 +/- 2 to 2 +/- 1 after 12-24 hours (p less than .01). No change was shown in the contralateral lung. The angiographic index of severity score in the infused lung decreased from 16 +/- 1 to 9 +/- 4 (p less than .01). The partial pressure of oxygen in arterial blood improved within four hours. In spite of the low doses of streptokinase, however, two major bleeding episodes occurred that required blood transfusion. In conclusion, low dose intrapulmonary streptokinase, combined with intravenous heparin, may provide a therapeutic option in patients with life-threatening massive acute pulmonary embolism in whom full dose lytic therapy may be hazardous, although even low dose lytic therapy was associated with risk.

Aged↗
PubMed1988

Variability in theophylline volume of distribution and clearance in patients with acute respiratory failure requiring mechanical ventilation.

This study examines the intrasubject variability in theophylline volume of distribution (V) and clearance (CL) in critically ill, mechanically ventilated adults. Fifteen patients received two intravenous doses of theophylline approximately ten hours apart. Although there was no statistical difference between the mean VI (first dose, 0.51 L/kg) and V2 (second dose, 0.47 L/kg), the absolute difference between measurements of 0.15 L/kg was statistically significant (p less than .05). Range of differences follows: between VI and V2, 3.8 to 72.4 percent (mean, 33.5 percent); between CL1 and CL2, 6.1 to 100 percent (mean, 32.2 percent). Absolute difference between clearances was 0.019 L/kg/hr. A comparative error analysis revealed an absolute difference for V of 27.9 percent and for CL of 37 percent. Considerable intra-subject variability was shown for theophylline V and CL in these critically ill adults. Variability in V was not significantly different than variability in CL, and may result in severe underdosing or overdosing.

Acute Disease↗
PubMed1987

Active tuberculosis in the medical intensive care unit: a 15-year retrospective analysis.

Of approximately 6000 admissions to the Henry Ford Hospital medical ICU between October 1969 and September 1984, 61 (1%) had active tuberculosis (TB). Forty-three (70%) of these 61 had acute respiratory failure (ARF). TB was considered to be the sole cause of ARF in 12 and contributory in 31. Eighteen patients with TB but without ARF were admitted for treatment of other critical illnesses. Alcoholism was present in 31 (51%) of the TB patients. Only one of 12 whose ARF was caused primarily by TB had a history of known TB at the time of admission. Important factors contributing to ARF in TB patients included Gram-negative pneumonia and/or sepsis, chronic obstructive pulmonary disease, prior TB with anti-TB medication noncompliance, and malignancy. Six patients were not suspected of having TB when admitted to the medical ICU; three patients who had not been treated for TB were found to have TB on autopsy. The inhospital mortality rate for all patients with TB requiring intensive care was 67%, but was 81% in those with ARF.

Female↗