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Biomedical subjects

David Nelson

Publications and source records attributed to David Nelson.

42 records · Page 3Linked to original sources

Tamsulosin for treating lower urinary tract symptoms compatible with benign prostatic obstruction: a systematic review of efficacy and adverse effects.

PURPOSE: We systematically reviewed the effectiveness and adverse effects of tamsulosin for lower urinary tract symptoms compatible with benign prostatic obstruction. MATERIALS AND METHODS: Studies were included in analysis when they involved a randomized trial of at least 1 month in duration, men with lower urinary tract symptoms and a comparison of tamsulosin with placebo or an active control. Study, patient and outcome data were extracted onto standard forms using a prospective protocol. RESULTS: Of the series 13 involving 3,418 men with a mean age of 64 years met our inclusion criteria. Study duration was 4 to 26 weeks. Baseline symptom scores and flow rates showed moderate lower urinary tract symptoms. Tamsulosin improved symptoms and peak urine flow compared with placebo. The weighted mean difference in the mean change from baseline for the Boyarsky symptom score for 0.4 and 0.8 mg. tamsulosin versus placebo was -1.1 (95% confidence interval [CI] -1.49 to -0.72 or 12% improvement) and -1.6 points (95% CI -2.3 to -1.0 or 16% improvement), respectively. The weighted mean difference in the mean change from baseline in peak urine flow was 1.1 (95% CI 0.59 to 1.51) and 1.1 ml. per second (95% CI 0.65 to 1.48) for 0.4 and 0.8 mg., respectively. The 0.2 to 0.4 mg. tamsulosin dose was as effective as other alpha-antagonists for improving symptoms and the flow rate, although the doses of all alpha-antagonists evaluated may not have been optimal. Treatment withdrawals and adverse effects increased markedly as the tamsulosin dose increased. CONCLUSIONS: Tamsulosin improves lower urinary tract symptoms and flow. Its effectiveness was similar to that of other alpha-antagonists, increasing slightly at higher doses. Adverse effects were generally mild but the incidence, including treatment withdrawals, increased substantially at higher doses.

Humans↗

Prevalence of patch testing and methodology of dermatologists in the US: results of a cross-sectional survey.

BACKGROUND: Patch testing is considered to be the standard for diagnosis of delayed-type hypersensitivity reactions of the skin (allergic contact dermatitis). OBJECTIVE: The objective of this study was to examine the prevalence of patch testing by US dermatologists and associated practice characteristics. METHODS: One-third of US Fellows of the American Academy of Dermatology were sampled systematically with a written survey. Responses from this survey were compared with responses from a 1990 survey of dermatologists. RESULTS: Eighty-three percent of responding dermatologists stated that they performed patch testing in their practice. Whereas the majority of patch testing dermatologists (52%) used a 48-hour, 96-hour patch test reading schedule, 26% performed a single reading at 48 or 72 hours. Among patch testing dermatologists, most (74%) used TRUE Test, and many (44%) did so because it was less time consuming for staff. Many dermatologists (46%) felt that they were patch testing more patients now than when TRUE Test was not available. Eleven percent of dermatologists who patch tested also photopatch tested. CONCLUSIONS: The proportion of US dermatologists who patch test has significantly increased from 1990 to 1997 (P <.0001). Whereas the majority of US dermatologists patch test, one quarter of those who do so perform only a single reading.

Cross-Sectional Studies↗

Heparin-induced thrombocytopenia complicating support by the Berlin Heart.

Since 1992, miniaturized pulsatile air-driven ventricular assist devices (VADs), "Berlin Heart," have been used at many institutions (36 cases in North America in 19 different institutions) for pediatric use. Heparin-induced thrombocytopenia (HIT II) is a significant complication rarely reported in the setting of adult VAD support; no similar report exists concerning pediatric VAD support. We report on a 13-month-old, 8.1 kg girl who required LVAD support for cardiogenic shock of unclear etiology. The patient had a history of multiple surgical repairs for correction of complex congenital heart disease consisting of a series of left heart obstructive lesions (Shone's complex). Despite aggressive ventilatory and inotropic support, the patient continued to deteriorate and subsequently required extracorporeal life support. After 7 days of conventional venoarterial extracorporeal membrane oxygenation, a 10 ml Berlin Heart VAD was implanted. After implantation, the patient developed persistent low-grade fever of unclear etiology, gradual thrombocytopenia, and deterioration of renal function. On postimplant day 10, the pump required replacement because of concerns about an inlet valve thrombus; the explanted device demonstrated a nearly occlusive clot not appreciable from external inspection. Simultaneously, HIT II was diagnosed as a result of hematology workup for persistent thrombocytopenia. We discuss the unique challenges posed by HIT II complicating pediatric VAD support and in relation to the heparin coating of the device.

Anticoagulants↗