Background:In patients undergoing septorhinoplasty, control of bleeding and hemodynamic variables is of great importance and laryngoscopy and tracheal intubation could be followed by a specific and transient increase in systemic blood pressure and heart rate.Objectives:This study aimed to examine the effects of oral gabapentin on hemodynamic changes, during direct laryngoscopy, and the amount of bleeding in the patients undergoing septorhinoplasty.Patients and Methods:In a double-blind clinical trial, 103 patients (American society of anesthesiologists class I, II) aged 18 - 45 years old, who were septorhinoplasty candidates, were randomly assigned into two groups, a 900 mg gabapentin group and placebo, in Amir-Al-Momenin academic hospital. The drug was prescribed to the patients orally, 2 hours before the operation. Anesthetic technique was similar for all the patients. Heart rate (HR), systolic (SBP) and diastolic blood pressures (DBP), mean arterial blood pressure (MAP), oxygen saturation percentage of arterial blood (SaO2), before induction of anesthesia, 3, 5, 10, and 15 minutes after the intubation and tracheal extubation, and the amount of bleeding during operation were measured. Statistical analysis was performed with the SPSS (v. 16) software.Results:Variations in the HR, DBP and SaO2, in the specified time intervals, did not show any statistically significant difference, although variations in SBP were statistically significant (higher in gabapentin group). Regarding the average amount of bleeding volume, although there was a lower amount of bleeding in the gabapentin group, the difference was not statistically significant. Also, regarding the pain, there was no significant difference between the two groups in terms of visual analog scale (VAS) average and the received analgesic.Conclusions:The present study showed that premedication with 900 mg gabapentin did not affect the hemodynamic changes induced by laryngoscopy and the amount of bleeding. However, the decreased amount of bleeding was observed in the gabapentin group.

The relation between climatic parameters (relative air humidity) and the water activity of the Urmia Sea water determines the possible maximum evaporation of the lake. Using the Pitzer thermodynamic approach, the activity of the Urmia Lake water during evaporation was calculated and compared to the present relative air humidity above the water. Present climatic conditions allow the Urmia Sea water to evaporate down to water with activity of 0.55, corresponding to the lowest air humidity measured over the lake. This water activity falls in the range of halite precipitation, while carnalite precipitation starts at somewhat lower (a H2O = 0.499) point. Our dynamic model predicts that for air humidity as low as 55% (reflecting present climate conditions), the Urmia Sea level may drop to as low as 1270 m (i. e., 1270 m above mean sea level). At that point, the lake water volume will have a volume of 11 km3. For the sake of comparison, at the beginning of 1990, the level of the lake was 1275 m, its volume was 25 km3, and its surface area was 5145 km2.

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Background & Aim: Although most patients experience severe pain after major spinal fixation surgery, little attention has been paid to control it with a multi-modal approach. The aim of this study is to select appropriate method of pain management after spinal surgery. Methods & Materials/Patients:This study was a randomized clinically controlled trial in candidates of spondylolisthesis and spinal fixation surgery under general anesthesia. 90 patients were divided into three groups, as follows: 1) Intervention group of epidural fentanyl (F): patient-controlled analgesia (PCA) pump infused 100 µg of fentanyl and 98cc of normal saline at the rate of 3-5 ml/h in the epidural space via an epidural catheter placed by surgeon 2) Intervention group of epidural fentanyl-bupivacaine (FB): PCA pump infused 100 µg of fentanyl and bupivacaine 0.125% at the rate of 3-5 ml/h in the epidural space. 3) IV morphine group (M): No medication was received epidurally. In case of visual analog scale (VAS) score more than four, one mg of IV morphine bolus was administered to patient. The blood pressure, heart rate, respiratory rate and pain severity were recorded at the moment of patient's transfer from recovery room to the ward and compared in three groups every six hours for 24 hours. The results of this study were analyzed by statistical tests including repeated measures ANOVA, Kruskal-Wallis, Fisher's exact test and SPSS software 16. P values less than 0.05 were considered statistically significant. Results:The results of the study showed that VAS score in fentanyl-bupivacaine group was significantly lower than that in the two other groups during the first 18 hours. However, VAS score in all groups decreased at 24th hour postoperatively (less than three) suggesting that there was no statistically significant difference between the three groups. In this study, no serious and severe complications were observed except for a few cases of nausea in the control group. Conclusion:Epidural analgesia with fentanyl-bupivacaine is a safe and effective way to postoperative pain management in listhesis and spinal surgeries.