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Biomedical subjects

J M Kohan

Publications and source records attributed to J M Kohan.

3 recordsLinked to original sources
PubMed1988

Inhaled metaproterenol is superior to inhaled cromolyn in protecting against cold-air-induced bronchospasm.

Eucapneic hyperventilation of cold air (EHCA) provokes bronchospasm in asthmatics. Although inhaled cromolyn powder and sympathomimetic solutions have attenuated the bronchospasm induced by EHCA, comparison of both drugs in solution has not been performed. We performed a prospective double-blind study comparing cromolyn solution, metaproterenol solution, and placebo (normal saline) given prior to EHCA. Eight asthmatics defined by a 20% reduction in forced expiratory volume in 1s (FEV1) after EHCA consented to the study. Patients were tested on 3 separate occasions at a similar time of day. Each session began with a determination of FEV1 followed by a randomized double-blind treatment. A repeat FEV1 (pre-EHCA) was performed 20 min after drug inhalation. Twelve minutes of EHCA was performed consisting of 4 min of tidal breathing, 4 min of eucapneic hyperventilation (60-70% of the predicted MVV) and a final 4 min of tidal breathing. FEV1 was performed immediately, 5 min, and 10 min after EHCA. The lowest value was defined as the post-EHCA FEV1. The pre-EHCA FEV1 was significantly larger after metaproterenol pretreatment compared to the pre-EHCA FEV1 following cromolyn (p = 0.01) and saline (p = 0.04). Metaproterenol pretreatment had a significant protective effect in comparison to placebo pretreatment (p less than 0.01). No other paired comparisons (cromolyn vs. placebo, cromolyn vs. metaproterenol) achieved statistical significance at a 0.05 level. In conclusion, metaproterenol is superior to cromolyn in protecting against cold-air-induced bronchospasm.

Administration, Inhalation↗
PubMed1986

Value of chest ultrasonography versus decubitus roentgenography for thoracentesis.

Chest ultrasonography (CU) has been advocated as an effective tool for diagnosis and localization of pleural fluid. Studies to date supporting the technique have been anecdotal and nonrandomized. To determine if CU was beneficial when thoracentesis was performed by clinicians or house staff, we evaluated prospectively 205 patients presenting with pleural effusion at 2 community teaching hospitals. Decubitus roentgenograms were obtained on all patients, but CU with targeting by skin marker was performed on a randomized basis. Results were evaluated as to (1) whether the quantity of fluid obtained was sufficient for the intent of the procedure, (2) the number of needle insertions required to obtain the fluid, and (3) the incidence of complications such as pneumothorax. One hundred three effusions were evaluated by CU and 102 by roentgenography alone. The effusions in each group were stratified as small (obliteration of less than half of the hemidiaphragm on roentgenogram) or large. Small effusions were further stratified as free flowing or loculated (no layering of fluid on decubitus roentgenograms). By chi-square test, CU was significantly superior to decubitus roentgenograms alone for obtaining adequate fluid samples in small effusions (p less than 0.01). This was true regardless of whether the effusion was loculated (p less than 0.02) or free flowing (p less than 0.05). The technique had no such advantage in large effusions. We did not find that CU significantly reduced the need for multiple attempts nor incidence of complications in any group.

Drainage↗