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Biomedical subjects

D M Orenstein

Publications and source records attributed to D M Orenstein.

68 records · Page 4Linked to original sources
PubMed1983

Exercise and heat stress in cystic fibrosis patients.

Cystic fibrosis (CF) is characterized by high sweat sodium and chloride concentrations. CF patients have long been assumed to be at risk for heat illness, but there has been no quantitative documentation that CF patients actually have a greater loss of sodium and chloride than normals when under environmental stress. We compared thermoregulatory responses of eight CF patients with five normal controls during 90-min exposures to exercise and heat stress. Both groups reached similar peak rectal temperatures and peak heart rates; they had similar sweat volumes and rates. CF patients showed the normal rise in renin and aldosterone and the normal fall in urine sodium excretion; however, CF patients lost significantly more sodium (48.8 +/- 23.4 mEq/liter/m2 versus 20.2 +/- 11.2 mEq/liter/m2) and chloride (46.6 +/- 21.6 mEq/liter/m2 versus 18.5 +/- 11.3 mEq/liter/m2) per unit of surface area than the controls. Serum sodium and chloride concentrations fell in the CF patients but not in the normals. After exercise/heat stress, CF serum chloride was significantly less than normals' (99 +/- 3 mEq/liter versus 104 +/- 1 mEq/liter, P less than 0.01). CF patients have normal temperature, heart rate, hormonal, and renal responses to exercise and heat stress, yet still lose significantly more sodium and chloride than normal. These losses are reflected in part in lower serum concentrations of these ions. There may be important effects of these losses on respiratory tract secretions.

Adolescent↗
PubMed1983

Gastroesophageal reflux causing stridor.

We describe an infant with stridor associated with gastroesophageal reflux (GER). This is the first report in which there is clear documentation by pH probe of a temporal association between individual episodes of GER and stridor. We review the literature and speculate on the relationship between these two phenomena. GER should be considered in patients with stridor.

Bethanechol Compounds↗
PubMed1981

Exercise conditioning and cardiopulmonary fitness in cystic fibrosis. The effects of a three-month supervised running program.

Exercise intolerance is common in cystic fibrosis (CF). We examined the effects of a supervised three-month running program on exercise tolerance, pulmonary function, cardiorespiratory fitness (peak oxygen consumption), and respiratory muscle endurance in CF patients. We studied 31 patients, 21 exercise and ten control, aged 10 to 30 years, with pulmonary involvement ranging from mild to severe. The exercise and control groups were not significantly different with respect to age, sex, pulmonary function, exercise tolerance, or cardiorespiratory fitness. After three months of physical conditioning, the exercise group had significantly increased exercise tolerance and peak oxygen consumption and significantly lower heart rates for submaximal work loads, while the nonexercising (control) group was unchanged in all these variables. The FEV1 decreased significantly in the control group. There were no other significant changes in pulmonary function in either the control or exercise group. Respiratory muscle endurance increased significantly in the exercise patients, and did not change in the control patients. There were no adverse effects of the program. The data suggest that a supervised running program can increase CF patients' exercise tolerance and cardiorespiratory fitness, perhaps in part by increasing respiratory muscle tolerance. The effects of a much longer program deserve study.

Adolescent↗
PubMed1978

Treatment and prognosis of lobar and segmental atelectasis in cystic fibrosis.

Lobar atelectasis occurred in 30 (4.1 per cent) and segmental atelectasis occurred in 6 (0.8 per cent) of 728 patients with cystic fibrosis. The right lung was involved in all 11 patients less than 5 years of age and in 18 of 26 episodes in 19 older patients. Five of the younger patients died within 5 years of the initial episode. Bronchoscopy (with or without local lavage) performed in addition to intensified medical therapy did not appear to improve the outcome. Future studies of therapeutic measures (including bronchoscopy) for treatment of atelectasis complicating cystic fibrosis must include appropriate control patients who receive only medical therapy.

Adolescent↗
PubMed1977

Hemangioma thrombocytopenia syndrome. A case masquerading as an encephalocele.

The association of hemangioma and thrombocytopenia has been recognized since 1940. We cared for a newborn boy whose hemangioma resembled an occipital encephalocele. The true diagnosis was suspected only when his platelet count dropped to 3,000/cu mm with severe intestinal hemorrhage on the third day of life. The diagnosis was confirmed by arteriography. The hemangioma was excised surgically, and the platelet count returned quickly to normal. The baby has done well subsequently. When feasible, surgical excision of the platelet-trapping hemangioma is the treatment of choice in the hemangioma thrombocytopenia syndrome.

Diagnosis, Differential↗
PubMed1977

The effect of early diagnosis and treatment in cystic fibrosis: a seven-year study of 16 sibling pairs.

Data on 16 sibling pairs with cystic fibrosis were analyzed to test the hypothesis that early treatment of this condition improves prognosis. Younger siblings' conditions were diagnosed before 1 year of age, usually before the onset of pulmonary disease. Older siblings' conditions were diagnosed after 1 year of age and after the onset of pulmonary disease. Although the sibling pairs received similar treatment, comparison at 7 years of age showed that the younger siblings had significantly better chest roentgenogram scores, total clinical scores, residual lung volumes, and ratios of residual volume to total lung volume. Younger siblings also required fewer hospital admissions to control their lung disease. The results suggest that, in general, early initiation of therapy is beneficial for patients with cystic fibrosis.

Child↗
PubMedDate not supplied

Stridor and gastroesophageal reflux: diagnostic use of intraluminal esophageal acid perfusion (Bernstein test).

Five pediatric patients with stridor were evaluated to determine whether gastroesophageal reflux (GER) contributed to their stridor. Intraluminal esophageal acid perfusion (Bernstein test), pH probe, radiographic studies, laryngobronchoscopy, and esophageal histology were utilized. Thereafter, three of the five patients responded to therapy for GER; two did not. The Bernstein test proved to have greater diagnostic reliability than any other test employed, using response to antireflux therapy as the "gold standard" for diagnosing reflux-provoked stridor.

Child↗
PubMedDate not supplied

Bethanechol for pediatric gastroesophageal reflux: a prospective, blind, controlled study.

To investigate the effect of bethanechol on postprandial gastroesophageal reflux in children, and the relationship between its effect on the lower esophageal sphincter pressure and its effect on reflux, we studied 31 consecutive children with pathologic reflux, using manometry and pH probe, both before and after administration of bethanechol. The initial sphincter pressure was subnormal in only 35% of the patients. The bethanechol-treated sphincter pressure was increased in 97% of the patients (from 13.4 +/- 1.3 to 34.1 +/- 2.6 mm Hg) and was normal in 97% of the patients, yet bethanechol did not improve any measure of postprandial reflux in the patient group as a whole. Furthermore, the 20 patients with normal sphincter pressures had significant worsening of their percent of postprandial time with reflux (from 21.8 +/- 5.3 to 33.8 +/- 6.0%, p = 0.009). Thus, this study demonstrates a failure of the acute administration of bethanechol to improve postprandial gastroesophageal reflux and raises the issue of whether the widespread use of bethanechol to treat reflux in children is appropriate.

Bethanechol Compounds↗