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Biomedical subjects

D Kohn

Publications and source records attributed to D Kohn.

At least 91 records · Page 5Linked to original sources

The use of conventional ventilators for high frequency positive pressure ventilation.

Ten randomly selected patients were ventilated for defined periods with 2 ventilatory modes: (a) high frequency positive pressure ventilation (HFPPV) (frequency 66-70 min; tidal volume 1-3 ml/kg body weight), (b) conventional IPPV (frequency 16/min; tidal volume (VT) 10-15 ml/kg). This was done successfully using conventional ventilators, and keeping other variables (FIO2, PEEP) constant. Various ventilatory and hemodynamic variables were measured and compared during both modes of ventilation. The most prominent finding was a considerable reduction of cardiac output (CO) and stroke volume (SV) during intermittent positive pressure ventilation (IPPV) compared with HFPPV. Peak tracheal pressure was significantly lower during HFPPV. An increase in mean systemic arterial pressure and in oxygen transport was observed during HFPPV, whereas transpulmonary shunt and pulmonary vascular resistance (PVR) decreased during HFPPV. These findings are in accordance with previously reported advantages of HFPPV, and might be of importance in the treatment of patients with bronchopleural fistula, adult respiratory distress syndrome (ARDS), left ventricular failure and other conditions in which conventional positive pressure ventilation (PPV) fails.

Adult

Schönlein-Henoch syndrome in patients with familial Mediterranean fever.

Ten episodes of Schönlein-Henoch purpura (SHP) in 8 patients with familial Mediterranean fever (FMF) were observed. Five episodes developed 3-14 days after penicillin injections, suggesting an etiologic association. FMF and SHP have clear clinical similarities, and if the frequency of association of the 2 diseases is indeed high, perhaps a common etiologic factor should be sought. An immune complex mechanism might be the link between these 2 disease entities.

Adolescent

West Nile fever encephalitis.

Three cases of meningoencephalitis caused by the West Nile virus in young people are described. All patients had high fever, severe headaches, and meningeal irritation. One patient had papillitis and a maculopapular rash. Lymphadenopathy, which is a common finding in West Nile fever, was not found in any of our patients. Duration of the disease was one to two weeks, and recovery was complete. Cerebrospinal fluid examination revealed an increase in protein and pleocytosis (predominantly polymorphonuclears). We believe that West Nile encephalitis is not rare in Israel.

Adolescent

Adult respiratory distress syndrome treated with high-frequency positive pressure ventilation.

Adult respiratory distress syndrome (ARDS) is a severe disease that carries a poor prognosis (50 to 60% mortality). Although modern ventilatory techniques, especially positive end-expiratory pressure ventilation, have reduced the mortality rate somewhat, they are still far from serving as the ideal solution to this grave condition. High-frequency positive pressure ventilation (HFPPV) is a relatively new technique that enables effective alveolar ventilation without creating high intrapulmonary pressures. HFPPV using a conventional ventilator, Bennett MA-1B (Suffex, England), was tried in a 22-yr-old man with ARDS due to pyocyanea sepsis, who had failed to respond to conventional ventilation. A dramatic improvement was achieved within 60 min of increasing the ventilatory rate from 12 to 80/min, with a concomitant decrease of tidal volume from 12 to between 2 and 23 ml/kg. HFPPV may be a useful alternative method in the treatment of patients with ARDS.

Adult

Thrombotic thrombocytopenic purpura with a subacute course: remission after steroids and high-dose plasma exchange.

A case of thrombotic thrombocytopenic purpura with an unusual subacute course is described. Treatment was initiated after the patient had been ill for four weeks. Low-dose plasma exchange (10 ml/kg body weight per day) was associated with a sharp drop in the reticulocyte count and a transient reduction of lactate dehydrogenase activity to within the normal range. The administration of corticosteroids was followed immediately by the disappearance of neurological symptoms, and after high-dose plasma exchange (25 ml/kg body weight per day) all the symptoms of disease remitted. The remission has lasted for 10 months; we suggest that each of the therapeutic measures employed played a role.

Adrenal Cortex Hormones

Iron loading and endocrine functions in nontransfused patients with beta-thalassemia intermedia or sickle-cell thalassemia.

Body iron stores and endocrine functions were determined in eight patients with chronic hemolytic anemia who had received only small amounts of blood and no iron preparations. Four patients had beta-thalassemia intermedia (BTI) and four had sickle-cell thalassemia (SCT). Hemoglobin levels and degrees of hemolysis were similar in both groups of patients. The patients with BTI showed clear evidence of iron overload, whereas there was no evidence of iron accumulation in the patients with SCT. The three patients with BTI who had endocrinologic evaluations showed endocrine dysfunctions. Two patients with SCT had no endocrine abnormalities and the other two probably had some degree of primary hypogonadism. Iron overload in patients with thalassemia probably results from excessive intestinal iron absorption and can damage various parenchymal and endocrine organs, even in the absence of an external source of iron.

Adult