the effects of adding meperidine to heavy intrathecal lidocaine on hemodynamic changes and blood loss in open prostatectomy: a randomized double-blind clinical trial

background: clinical investigations have reported several anesthetic properties of intrathecal injections of meperidine. the purpose of this study was to investigate the effect of adding meperidine to intrathecal heavy lidocaine on hemodynamic changes and blood loss in patients undergoing elective suprapubic open prostatectomy. methods: in a randomized double-blind clinical trial, 77 patients candidate for elective suprapubic open prostatectomy were allocated to two equal groups. all patients in the control and experimental groups received heavy lidocaine intrathecally. a low dose of meperidine was added to lidocaine in the experiment group. changes in blood pressure and heart rate were measured and documented in several intervals. blood loss, transfusion rate, shivering, nausea, vomiting, need to an analgesic drug, and transient neurologic symptoms were also recorded. results: no significant difference was observed between the two groups in regards to blood pressure changes in operating room. blood pressure increase was more prevalent among patients of the control group immediately in post-operating period. there were significantly (p<0.0001) less post-operative bleeding and need to transfusion in the experimental group. conclusion: adding low dose of meperidine to lidocaine induces minimal effect on blood pressure change in operating room, but prevent increasing of blood pressure in post-operative period with a reduction of bleeding. trial registration number: irct138903061936n2