Comparison of the effects of intravenous midazolam alone and in combination with meperidine on hemodynamic and respiratory responses and on patient compliance during upper gastrointestinal endoscopy: a randomized, double-blind trial - ÖZEL, A. Melih; ÖNCÜ, Kemal; YAZGAN, Yusuf; GÜRBÜZ, Ahmet Kemal; DEMİRTÜRK, Levent (Turkish Journal of Gastroenterology, 2008)