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

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. 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. 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 postoperative bleeding and need to transfusion in the experimental group. Adding low dose of meperidine to lidocaine induces minimal effect on blood pressure change in operating room, but prevent increasing of blood pressure in postoperative period with a reduction of bleeding

Effect of fentanyl versus buprenorphine on the pupil size in phacoemulsification cataract surgery

Despite several recent innovations in phacoemulsification surgery, importance of pupil diameter in this surgery is becoming more evident. To compare the effect of opioid agonist [fentanyl] versus opioid agonist-antagonist [buprenorphine] on pupil diameter in cataract surgery and to choose the best opioid in high-risk phacoemulsification surgery. In this randomized double-blinded clinical trial, 60 patients who were candidates for elective phacoemulsification surgery were randomly divided into two equal groups: experimental [buprenorphine, 0.3 microg/kg] and control [fentanyl, 1 microg/kg]. Pupil diameter was measured preinjection and at several times postinjection. Blood pressure was recorded at several intervals, as well as shivering, nausea and vomiting, and recovery time. Mean [SD] recovery time was significantly less in the control group [19.46 +/- 5.43] than in the experimental group [33.23 +/- 10.75] [P < 0.0001]. The constriction effect [ie, pupillary diameter in mm] was significantly lower in the experimental group [0.53 +/- 0.45] than in the control group [1.06 +/- 0.52] [P=0.0001]. The percentages of constriction effect in experimentaland control groups were 7.68% and 15.07%, respectively. The eye was two times more constricted in the control group in comparison with the experimental group after induction of anesthesia. Buprenorphine is a better solution to decrease pupil constriction in comparison with fentanylinhigh-risk phacoemulsification surgery

effect of different intrathecal doses of meperidine on shivering during delivery under spinal anesthesia

This study was performed to compare the effect of different doses of intrathecal meperidine on the incidence and intensity of shivering and other side-effects after spinal anesthesia for cesarean delivery. One hundred and fifty-six parturient women scheduled for elective cesarean delivery were enrolled in four groups. Spinal anesthesia consisted of heavy bupivacaine 0.5% [10 mg] in the standard group [Group I], heavy bupivacaine 0.5% [10 mg] plus meperidine [0.2 mg per kg] in Group II, heavy bupivacaine 0.5% [10 mg] plus meperidine [0.3 mg per kg] in Group III, heavy bupivacaine 0.5% [10 mg] plus meperidine [0.4 mg per kg] in Group IV. The signs and symptoms were recorded by an observer unaware of the study groups. The systolic blood pressure, amount of bleeding, Pulse Rate, O2 saturation, neonatal apgar scores, core temperatures and sensory level revealed no difference between groups [P > 0.05]. The incidence [47.5%, 37.5%, 27.5% and 15.0%, respectively] and intensity of shivering decreased as the dose of meperidine increased [P=0.002] but the incidence of nausea and vomiting [8.0%, 15.4%, 25.9% and 35.8%, respectively] [P=0.000] and pruritis [25.64, 28.21, 38.46, and 48.72 respectively] increased as the dose of meperidine increased [P=0.000]. The high dose of intrathecal meperidine is effective in reducing the incidence and intensity of shivering associated with spinal anesthesia for cesarean delivery but the high incidence of nausea and vomiting is unpleasant for the patient and can be a major problem with a high dose of meperdine