RESUMO
BACKGROUND: Blood loss in spine surgery is an important issue, even though it has been understudied compared with hip and knee arthroplasty. OBJECTIVES: In this study, we evaluated the effect of oral clonidine as premedication on blood loss in lumbar spine fusion surgery under anesthesia with propofol and remifentanil. PATIENTS AND METHODS: In this double-blind, randomized clinical trial, 30 patients who were undergoing lumbar spine posterior fusion surgery due to traumatic fracture were allocated randomly into 2 groups. The study group (clonidine group) received a 200-µg oral clonidine tablet 60-90 minutes before anesthesia, and the control group received placebo at the same time. Induction and maintenance of anesthesia and the mean target arterial pressure for controlled hypotension with remifentanil were the same in the 2 groups. We compared the amount of intraoperative blood loss, dose of remifentanil/hour administered, need for nitroglycerine to reach the mean target arterial pressure when remifentanil was insufficient, duration of operation, and surgeon's satisfaction of a bloodless field between groups. RESULTS: There was no statistically significant difference between groups in age (P = 0.115), sex (P = 0.439), weight (P = 0.899), operation time (P = 0.2), or American Society of Anesthesiologists physical status score (P = 0.390). Intraoperative blood loss and remifentanil dose administered per hour in the clonidine group were significantly less than in the control group (P = 0.002 and P = 0.001, respectively), but there was no significant difference in surgeon's satisfaction between groups (P = 0.169). CONCLUSIONS: As an oral premedication, clonidine can reduce surgical blood loss in lumbar spine posterior fusion surgery, even at the same levels of mean arterial pressure (MAP) with the control group. Its use can be studied in more complicated spine surgeries, such as scoliosis and spinal deformity surgeries.
RESUMO
BACKGROUND: Opioids, such as alfentanil, are used to facilitate endotracheal intubation without the use of neuromuscular blocking agents in patients undergoing elective surgery. OBJECTIVES: The goal of this study was to evaluate the endotracheal intubation conditions when remifentanil or alfentanil was used with propofol without the application of neuromuscular blocking agents. PATIENTS AND METHODS: One hundred American Society of Anesthesiologists (ASA) grade I patients scheduled for elective surgery were enrolled in this prospective, randomized, triple-blinded study. The patients were randomized to group A (alfentanil) or R (remifentanil). In group A, alfentanil (50 mcg/kg) was intravenously injected over 10 seconds, and after 45 seconds or at the occurrence of apnea, propofol (2 mg/kg) was intravenously injected over 5 seconds. Thirty seconds after the administration of propofol, laryngoscopy and endotracheal intubation were attempted. In group R, remifentanil (5 mcg/kg) was administered instead of alfentanil. Intubation conditions, including ease of laryngoscopy, patency of the vocal cords, jaw relaxation, limb movement (1-4 score), and also, demographic data were evaluated. RESULTS: There were no demographic data differences between groups (age, weight, and sex). Further, laryngoscopy, jaw relaxation, and limb movement scores were similar in the R and A groups and there were no significant differences, but vocal cords were significantly more patent in group R than those in group A (P = 0. 028). CONCLUSIONS: The results of this study showed that remifentanil, similar to alfentanil, provided excellent conditions for endotracheal intubation when used with propofol for the induction of anesthesia; however, remifentanil improved the patency of the vocal cords to a greater extent than alfentanil.
