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Biomedical subjects

H Levison

Publications and source records attributed to H Levison.

At least 127 records · Page 7Linked to original sources
PubMed1985

Long-term follow up of children with the Wilson-Mikity syndrome.

Nine children who survived the development of Wilson-Mikity (W-M) syndrome were studied at a mean age of 7.6 +/- 0.3 years. Persistent respiratory symptoms during the year preceding the study were present in one child. Pulmonary function studies demonstrated a significant degree of airway obstruction in 3 children. Positive methacholine challenge was observed in 6 children indicating bronchial hyperreactivity. Abnormal chest radiographs were present in 3 children. One showed the characteristic appearances of asthma with air trapping, bronchial wall thickening and redistribution of pulmonary vessels. The other child showed minimal residual peribronchial thickening and the third child had normal lungs, but a rather prominent pulmonary artery segment. Echocardiographic studies revealed enlarged right ventricular cavity in 2 children. However, the pre-ejection period and the systolic time intervals were all within normal limits. It appears that unlike patients with bronchopulmonary dysplasia survivors of W-M syndrome have a good prognosis.

Adult↗
PubMed1984

Association of respiratory viral infections with pulmonary deterioration in patients with cystic fibrosis.

In a two-year prospective study, we examined the effect of respiratory viral infections on pulmonary function in 49 patients with cystic fibrosis (mean age, 13.7 years). Nineteen normal siblings (mean age, 14) served as controls. Subjects were assessed quarterly and at the time of any respiratory illness. Each assessment included nasal washes for viral isolation and blood drawing for respiratory viral serologic studies. Pulmonary-function tests were performed at least twice yearly. Respiratory illnesses were reported significantly more often in the patients (3.7 per year) than in the normal siblings (1.7 per year), although the frequency of proved viral infections (1.67 per year) was identical. In the patients with cystic fibrosis significant correlations (P less than 0.0001) were found between the annual incidence of viral infections and every measure of disease progression in the two-year period, including the rate of decline of the Shwachman score (r = 0.71), the percentage of ideal weight for height (r = 0.80), the forced vital capacity (r = 0.85), the forced expiratory volume in the first second (r = 0.84), the forced midexpiratory flow rate (r = 0.68), and the frequency (r = 0.53) and duration (r = 0.84) of hospitalizations for respiratory exacerbations. We conclude that frequency of viral respiratory infections is closely associated with pulmonary deterioration in patients with cystic fibrosis.

Adolescent↗
PubMed1984

Pseudomonas cepacia infection in cystic fibrosis: an emerging problem.

The prevalence of Pseudomonas cepacia infection increased from 10% in 1971 to 18% by 1981 in a population of approximately 500 patients with cystic fibrosis. Carriage of P. aeruginosa has remained unchanged at 70% to 80% over the same period. Patients infected with P. cepacia have greater impairment of pulmonary function than those with P. aeruginosa. A syndrome characterized by high fever, severe progressive respiratory failure, leukocytosis, and elevated erythrocyte sedimentation rate has occurred in eight patients over the past 3 years, with a 62% fatality rate. Because P. cepacia strains are uniformly resistant to ticarcillin, piperacillin, and aminoglycosides, and because ceftazidime is ineffective despite in vitro activity, treatment of these infections is very difficult. Prevention of acquisition and effective treatment of P. cepacia in patients with cystic fibrosis are now major clinical problems in our clinic.

Adolescent↗
PubMed1984

Improved prognosis in CF patients with normal fat absorption.

CF patients with normal fat absorption, as a group, have lower mean sweat chloride levels, maintain better pulmonary function and weight for their age, and appear to survive longer than CF patients with steatorrhea. The prognostic advantage for CF males in general is not seen in the pulmonary function data for patients with normal fat absorption, but may be reflected in the smaller number of females in this group. Males in both groups are clearly better at maintaining good weight than are females. Whether this means that nutritional intervention can improve pulmonary course or that other factors (genetic, endocrinological, environmental) dictate nutritional and pulmonary state, as well as sex differences, remains to be shown. Non-steatorrheic patients are far less likely than steatorrheic patients to have Pseudomonas infecting their lungs. This is a significant prognostic advantage since the progressive lung disease and eventual mortality of most CF patients can be charted by their acquisition of P. aeruginosa and the increasing frequency of exacerbation and attempts to eradicate this organism. CF has been called a lethal genetic disease because affected homozygotes did not generally survive to procreate. However, increasing numbers of young women with CF are surviving to an age where pregnancy and child-rearing are options for them. The majority of patients who reach this stage with sufficiently good health to embark on a pregnancy are patients with normal fat absorption. They also appear to be more likely to remain well throughout pregnancy and as young mothers. There is no doubt that CF patients with normal fat absorption have a better prognosis than those with typical CF malabsorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

The effect of oxygen on sleep, blood gases, and ventilation in cystic fibrosis.

We determined the effect of nocturnal low-flow oxygen (NLFO) on arterial oxygen saturation (SaO2), transcutaneous PCO2 (TcPCO2), and sleep quality in 10 patients with cystic fibrosis (CF) and severe stable chronic obstructive pulmonary disease (COPD). The patients were studied on 2 nights, 1 with oxygen and 1 with air at 2 L/min. The NLFO had no effect upon sleep quality in our patients. The minimal SaO2 occurred during REM sleep and averaged 79.4%. With NLFO, this improved to 92.7%. The average maximal rise in TcPCO2 was 5.6 mmHg on falling asleep while breathing air; this increased a further 5.1 mmHg with NLFO. Two patients also had obstructive sleep apnea. Their SaO2 improved dramatically with NLFO, with no deterioration of ventilation. In 4 patients, ventilation was measured quantitatively. The only consistent changes during air were an increase in abdominal contribution to tidal volume and a drop in minute ventilation from Stage 3-4 to REM sleep of 26%, almost entirely caused by a drop in breathing frequency. The same changes occurred with NLFO. We conclude that NLFO is effective in alleviating the nocturnal hypoxemia of patients with CF with stable COPD and does not cause clinically important hypercapnia.

Adolescent↗
PubMed1983

Gastroesophageal reflux during sleep in asthmatic patients.

To determine what relationship might exist between gastroesophageal reflux and nocturnal asthma, we studied nine patients with asthma and seven control subjects overnight in the sleep laboratory, monitoring sleep state, esophageal pH, tidal volume (including the relative contribution of rib cage and abdomen), and oxygen saturation. There were 15 episodes of gastroesophageal reflux, in three patients with asthma and four control subjects. There were no significant differences between the two groups in the number of reflux episodes, duration of the longest episode, and the percentage of reflux time. Thirteen of the 15 episodes occurred during the awake state or after movement arousal. None of the episodes caused coughing, wheezing, or changes in oxygen saturation in any of the subjects. These patients with chronic asthma did not have an increased incidence of gastroesophageal reflux at night, and reflux did not play any role in the production of their nighttime symptoms.

Adolescent↗
PubMed1983

Dose-response characteristics of nebulized fenoterol in asthmatic children.

Fenoterol hydrobromide, a beta 2-selective bronchodilator, was administered by aqueous nebulization to 31 children with stable asthma. An initial comparison of 0, 100, 300, and 1000 micrograms drug in 20 of these patients showed a significant change in forced expiratory volume in 1 second for all three doses compared with change after placebo (P less than 0.0001). However, the differences in peak pulmonary response from 100 to 1000 micrograms were not large (P greater than 0.2). Assessment of spirometric responses of 11 children to 3, 10, 30, or 100 micrograms nebulized fenoterol clearly revealed the dose-response effect (P less than 0.01). When all the FEV1 data were plotted over the entire range of 3 to 1000 micrograms, the resultant log dose vs response curve could be characterized by the ED50, the amount of drug producing half-maximal response. At 15, 30, or 60 minutes, the ED50 was in the range 8 to 10 micrograms. With increasing time there was a parallel shift of the entire dose response curve to the right, manifested by ED50 of 47 and 150 micrograms at two and three hours, respectively, after administration. This decreasing potency of a sympathomimetic drug with time shows that duration of effect and dosage are interdependent variables and must be evaluated simultaneously. Such considerations cannot be derived from cumulative dose-response studies. In our patients, 100 to 300 micrograms fenoterol delivered by aqueous nebulization achieved optimal bronchodilation with no detectable cardiovascular side effects.

Adolescent↗
PubMed1983

Ceftazidime alone and in combination in patients with cystic fibrosis: lack of efficacy in treatment of severe respiratory infections caused by Pseudomonas cepacia.

Fourteen patients with cystic fibrosis received 18 treatment courses with ceftazidime for acute respiratory illnesses associated with Pseudomonas cepacia. All patients had severe chronic lung disease. Clinical improvement occurred in only six treatment courses; eight treatment courses resulted in failure and four patients died. Severe illness was characterized by high fever, marked elevation of WBC and ESR. Treatment had no effect on sputum colony counts of Ps. cepacia in 17 of 18 courses, but significantly reduced counts of Ps. aeruginosa in 90% of those patients infected with both bacteria.

Adolescent↗
PubMed1983

Maturation of lung function in children with hypopituitarism.

To identify factors that bring about maturation of the respiratory system, we studied pulmonary function in 18 patients 9 to 19 yr of age with severe growth retardation caused by hypopituitarism. In 6 we measured pulmonary pressure-volume (P-V) curves before and after a 4 to 6 yr period of human growth-hormone-induced catch-up growth. Even when size-corrected according to total lung capacity (TLC), all measurements were more appropriate for height than for age. The ratio of functional residual capacity to TLC was low for age (less than 2 SD in 8 of 18 patients), and the ratio of closing capacity to TLC was slightly high for age (108% of predicted, p less than 0.05). The diffusion constant for carbon monoxide and the slope of the nitrogen washout alveolar plateau were both high for age. Lung elastic recoil was low for age; Pst(L) at 60% TLC was less than 2 SD in 3 of the 6 patients studied. During the period of catch-up growth, TLC increased appropriately for height, the slope of the alveolar plateau decreased (1.9 to 1.0% N2 L, p less than 0.01) and Pst(L) at 60% TLC increased (6.3 to 7.9 cm H2O, p less than 0.02). The P-V results indicate that growth of the lungs per se causes the increase in lung elastic recoil previously observed during childhood.

Adolescent↗
PubMed1983

Theophylline disposition in cystic fibrosis.

The disposition of intravenously and orally administered theophylline was compared in 10 patients with cystic fibrosis (CF) and 10 healthy volunteers. The mean total body clearance of the patients with CF was twice that of the control subjects (p less than 0.001). The volume of distribution of theophylline was also greater in the patients with CF (p less than 0.05). These observations indicate that if theophylline is used in patients with CF, doses larger than those commonly given to asthmatics may be required to maintain therapeutic serum concentrations.

Administration, Oral↗
PubMed1983

Partial and complete maximum expiratory flow-volume curves in asthmatic patients with spontaneous bronchospasm.

Bronchodilatation follows a deep inspiration in normal subjects with pharmacologically induced bronchoconstriction. To determine to what extent this occurs in asthmatic patients with spontaneous bronchospasm, we obtained partial (PEFV) and complete (MEFV) maximum expiratory flow volume curves in 20 adults (helium-oxygen responders and nonresponders) and 13 children with asthma. We measured maximum expiratory flow at 25 percent of forced vital capacity from the partial (Vmax - p) and complete (Vmax - c) flow-volume curves and expressed this relationship as the Vmax - p/Vmax - c ratio. Three of the adult subjects and one of the children had a V max-p/V max-c less than 1.0. Following inhalation of nebulized bronchodilators, none of the children or adults had a Vmax - p/Vmax - c ratio less than 1.0. Reasons for Vmax - p to be higher than Vmax - c include bronchoconstriction, decreased lung elastic recoil following a deep inspiration, and time dependence of maximum expiratory flow due to lung inhomogeneity. We conclude that asthmatic patients with spontaneous bronchospasm are only seldom able to obtain bronchodilation following a deep inspiration.

Adolescent↗