Effect of dexmedetomidine on hemodynamic changes in children undergoing laparoscopic surgery

Stress response to surgery is modulated by numerous factors, including magnitude of the injury, type of procedure and anesthetic technique. Dexmedetomidine, a highly selective alpha[2]-adrenergic agonist, increases perioperative hemodynamic stability in healthy patients but decreases arterial blood pressure and heart rate. Purpose: This study was designed to assess the hemodynamic effects to nociceptive stimuli in children submitted to laparoscopic surgery under balanced anesthesia with sevoflurane and dexmedetomidine. Randomized, double-blind and placebo-controlled study including thirty children submitted to laparoscopic surgery. Patients were allocated to three equal groups [n=10]: [1] Low-dose DEX group: infusion of 0.5 micro g.kg[-1] over 10 minutes and maintenance dose of 0.5 beta g.kg.h[-1] [2] High-dose DEX group: infusion of 1 micro g.kg[-1] over 10 minutes and maintenance dose of 0.5 micro g.kg.h[-1] as an adjuvant to inhaled sevoflurane anesthesia; [3] Placebo group: normal saline infusion at a similar rate and volume of the dexmedetomidine infusion. Arterial blood pressure, heart rate, arterial oxygen saturation, end-tidal carbon dioxide tension as well as supplemental fentanyl requirement were observed. ANOVA, Chi-Square and kruskal-Wallis tests, with Bonferroni correction for inter-group comparison were used for statistical analysis. During the strongest nociceptive stimuli [airway access and abdominal catheter placement], children receiving high dose dexmedetomidine showed a remarkable reduction in all hemodynamic variables, and supplemental fentanyl doses [P<0.01]. Combined use of dexmedetomidine with inhaled sevoflurane in pediatric patients submitted to laparoscopic surgery, efficiently blocks the hemodynamic responses to nociceptive stimuli and surgical trauma due to suppression of sympathetic overactivity

Preemptive prophylactic intravenous granisetron reduces the incidence and severity of intrathecal fentanyl-induced pruritus

Pruritus is a common adverse event of intrathecal fentanyl for postoperative analgesia. Activation of central 5-hydroxytryptamine subtype[3] [5-HT [3]] receptors is one of its possible mechanisms. This randomized, double-blind, placebo-controlled study aimed at evaluating the effectiveness of granisetron for the prevention of intrathecal fentanyl-induced pruritus in patients undergoing gynecologic, urologic, orthopedic and general surgery. 120 parturients [American Society of Anesthesiologists [ASA] I-II status] undergoing surgery under spinal anesthesia using 15 mg hyperbaric bupivacaine [0.5%] and 25 micro g fentanyl were randomly divided to three equal groups [n=40]. Thirty minutes before spinal anesthesia, patients received granisetron 1 mg IV [GRN], granisetron 1 mg plus 8 mg dexamethasone IV [GRN/DEX], or normal saline IV [Placebo]. Pruritus, pain, sedation, nausea and vomiting scores were evaluated during the initial 24 hours postoperatively. The incidence of pruritus was significantly more frequent in Placebo group compared with GRN and GRN/DEX groups [75% versus 50% and 45%] [P

Sub-tenon's block; effect of addition of fentanyl to local anesthetic for quality of block and postoperative analgesia

The "perfect" regional anesthetic technique involves "painless application, hundred percent anesthesia, hundred percent akinesia, and risk free". The quality of perioperative analgesia and intraoperative akinesia are the main aims of ophthalmic regional anesthesia. Sub-Tenon's local anesthesia becomes an accepted technique for posterior segment eye surgery. It is a safe, quick, and effective method of local anesthesia. However, it requires a certain amount of skill for dissection into the sub-Tenon's space. Fentanyl is powerful opioid analgesic drug used in neuraxial and peripheral nerve blocks, this study aimed at evaluating whether fentanyl has contributed to blockade quality and postoperative analgesia in sub-Tenon's local anesthesia. This study included fifty eyes of patients in a randomized, prospective clinical study undergoing vitreoretinal surgery under sub-Tenon's local anesthesia. After departmental approval and informed consent was obtained from all patients, fifty patients of both gender, 20-75 years old, ASA physical status I-III, participated in this study, the patients were distributed into two groups [1] Control group: 6 ml a mixture of lidocaine 2%, bupivacaine 0.5% in equal proportion, and hyaluronidase 25 IU.ml[-1]; [2] Fentanyl group: 6 ml of the same mixture associated with 25 micro g fentanyl. Blockade quality was evaluated according to the following parameters: intraoperative pain, eyelid and/or eyeball movement, quality of akinesia, postoperative analgesia and patient satisfaction of blockade, Results showed that fentanyl has significantly improved blockade quality of analgesia intraoperatively [with fentanyl 100%; without fentanyl 74% p value 0.008] and has highly significant efficient postoperative analgesics at 1, 2, 4, 6, and 24 hrs postoperatively [with fentanyl 72%; without fentanyl 16% P value 0.001]. Concomitant use of fentanyl with local anesthetics in Sub-Tenon's block is a safe and effective method to improve quality, reduce intraoperative local anesthetics and analgesics, and finally enhance postoperative analgesia in patients undergoing vitreoretinal surgery