[Blood loss and quality of controlled hypotension induced by magnesium sulfate versus remifentanil in PSF surgery]

Blood loss is one of the most critical problems in major surgery. Spinal surgery usually associated with considerable blood loss and allogenic transfusions. Controlled hypotension is one of efficient methods for decreasing operative blood loss. The objective of this study was evaluation of the efficacy of magnesium sulfate in comparison with remifentanil for induction of relative hypotension in posterior fusion of spine surgery. In this double blind randomized clinical trial, 40 patients with ASA I and II physical status candidate for lumbar posterior spinal fusion surgery were enrolled and assigned in two groups [remifentanil and magnesium sulfate] randomly. After the induction of anesthesia and giving the prone position, relative controlled hypotension was induced for one group with 0.15 micro g/kg remifentanil infusions and in second group with 50 mg/kg loading dose and then 15 mg/kg/hr magnesium sulfate infusion. All other aspects of anesthesia and surgery were similar in two groups. The target MAP range used in this study was 60-70 mmhg. In the course of surgery the hemodynamic variables, volume of blood loss, urine output, fluid intake and surgeon's satisfaction were recorded. Data was analyzed with SPSS version 13 software and P- value less than 0.05 was considered meaningful. Twenty patients in Mg group and 19 patients in remifentanil group were studied. There was no statistical difference between two groups according to the hemodynamic variables, volume of blood loss, urine output, fluid intake and surgeon's satisfaction [p > 0.05]. The target mean arterial pressure was achieved in 75% of Mg and 58% of remifentanil groups. Although, the frequency of TNG consumption was higher [42.1%] in remifentanil group than magnesium sulfate [25%], but this difference wasn't statistically significant [p= 0.320]. Our finding showed that in patients undergoing lumbar posterior spinal fusion surgery, remifentanil and magnesium sulfate has the same hypotensive effect and the volume of blood loss without any significant side effects

[Comparison of blood loss in femoral shaft surgeries between tranexamic acid and controlled hypotension]

Blood loss reducing approaches improve surgery outcomes through producing an appropriate operation field and reducing transfusion need. In this study two blood loss reducing techniques were compared. In a randomized clinical trial study 60 patients candidate for elective femoral shaft operation were devided in two groups. The first group went under induced hypotensionand the second group received tranexamic acid. Anesthesia technique and surgeon were the same in both groups. Bleeding amountwas measured based on site operation site and reservoir observing, pads counting. Traputic interventions such as crystalloids or colloids and blood transfusion were done as needed. Results were evaluated by Mann-witney U test. Dry field and surgeons satisfaction was good in 23 patinets of the hypotention group [76%] and was moderate in the rest of the group. In the tranexamic group the results were good in 21 patients [70%]. There was no significant difference in reducing blood loss between the groups. Both of the studied techniques can reduce bleeding and improve operation field and surgeon satisfaction, meanwhile there was no significant difference in two approaches