Background: Fentanyl which is frequently used during cataract surgery has been found to induce cough. The aim of this study was to evaluate the effect of IV lidocaine and dexamethasone and different speeds of injection of fentanyl on cough induced by this drug.
Methods: In this randomized double blind clinical trial study, patients were allocated randomly to four groups to receive 1 mg.kg^-1 lidocaine (group i), 0.1 mg.kg^-1 dexamethasone (group II) and 5 cc normal saline as placebo (group III & IV) intravenously. Four minutes later, all patients were given 1.5 µg.kg^-1 fentanyl intravenously. Fentanyl was administered within 15 seconds in group I-III and within 2 seconds in group IV. Incidence, number and intensity of cough were recorded. Heart rate and blood pressure were also recorded before administration of drug, 1 minute after administration of drug and 2 minutes after administration of fentanyl.
Results: 139 patients were evaluated. There was no significant difference in demographic features of groups including age, weight, gender and also heart rates and blood pressures. Incidence and intensity of cough was significantly higher in group IV while there was no statistically considerable difference between other groups.
Conclusion: This study demonstrated that slowing injection of fentanyl can effectively reduce the incidence of cough induced by drug; hereby administration of lidocaine or dexamethasone becomes unnecessary in this speed of injection. Additionally cough incidence after fentanyl injection is affected by patients' ethnicity.

Background: Post Anesthesia Shivering (PAS) is one of the common complications throughout recovery from general and regional anesthesia. The incidence of this complication is reported to be 40-70% among patients. PAS occurrence depends on various factors such as age, gender and drugs used in anesthesia and surgery time. Granisetron is a serotonin 5HT3 receptor antagonist. Beneficial effects of such drugs have been shown in a limited number of studies. In this study, preventive effects of granisetron in prevention of shivering, nausea and vomiting following spinal anesthesia were evaluated in patients undergoing lower abdominal surgery.
Methods: One hundred and five patients aged 18-60 years and with ASA class I or II who were scheduled to undergo elective lower abdominal surgery under spinal anesthesia were studied in 3 groups of 35 patients. After spinal anesthesia, group L received low dose granisetron with a dose of 10μg/kg, group H received high dose granisetron with a dose of 40 μg/kg and group C received normal saline as placebo. After leaving the operating room, patients were monitored in terms of shivering occurrence, time and severity of it and incidence of nausea and vomiting.
Results: Incidence of shivering, nausea and vomiting was significantly lower in group H than C. (P=0.009 and 0.008, respectively). However, there was no significant difference between L and C or L and H groups in terms of shivering, or nausea and vomiting occurrence. No side effects of granisetron were observed in the study.
Conclusion: High dose granisetron with dose of 40μg/kg significantly reduced the prevalence and severity of PAS and PONV in comparison to placebo.

Background: Strabismus surgery under general anesthesia is one of the most common ophthalmic procedures in children with emergence delirium as an important post-operative complication. Additionally, postoperative pain is another important issue which is considered as a contributing factor to emergence delirium. We conducted a study to compare meperidine with paracetamol on postoperative pain and emergence delirium.
Methods: This double blind randomized clinical trial was carried out on 60 children underwent elective strabismus surgery under general anesthesia. Patients were randomly allocated in two groups of 30 that received intravenous meperidine (1mg/kg) or paracetamol (15 mg/kg). Severity of pain were assessed one minute after extubation and every 5 minutes up to 1 hour by using CHEOPS and PAED was used for assessment of emergence delirium by time interval of every 10 minutes up to 30 minutes. Other complications such as bronchospasm, laryngospasm, nausea and vomiting were also recorded.
Results: Pain severity was significantly higher is in paracetamol group while in meperidine group no patients received additional fentanyl in recovery room and emergence delirium was lower 30 minutes after surgery.
Conclusion: Although meperidine and paracetamol are both effective in reducing incidence of emergence delirium and controlling postoperative pain after strabismus surgery, meperidine is significantly more efficient.

Background: This study was designed to investigate the effect of intravenous magnesium sulfate on hemodynamic changes induced by pneumoperitoneum in patients undergoing laparoscopic cholecystectomy.
Methods: A randomized, placebo controlled study was performed on 52 ASA class I or II aged 20-70 years patients undergoing laparoscopic cholecystectomy with pneumoperitoneum with carbon dioxide. Before induction, Magnesium group received 50 mcg.kg-1 magnesium sulfate, within 10 minutes, in 100 ml of normal saline and control group received 100 ml normal saline. Hemodynamic variables were recorded before induction, before the infusion of magnesium sulfate, during intubation, during pneumoperitoneum and finally during extubation, every 10 minutes. Postoperative pain and other complications were recorded in post anesthesia care unit (PACU) also.
Results: Variations in heart rate and mean arterial pressure between the two groups during pneumoperitoneum were not significantly different (P>0.05). Propofol consumption in the magnesium group compared with the control group was significantly decreased (P<0.05). The prescribed dose of TNG and total amount of administrated TNG (SUM), both were significantly higher in control group than in the magnesium group (respectively P=0.02 and P=0.042). In PACU, patients in the magnesium presented lower shivering, nausea vomiting and post operative pain than the control group (P <0.05).
Conclusion: Magnesium sulfate reduces the amount of anesthetic drug (propofol), TNG and intraoperative blood pressure, during pneumoperitoneum induced by laparoscopy. The postoperative pain of laparoscopy and anesthesia side effects such as nausea, vomiting and shivering were blunted, with bolus administration of magnesium sulfate before induction of anesthesia.

Background: Weaning from mechanical ventilation is one of the main stages of treatment as well as applying a tool that can predict the success in weaning is very important. This study aimed to evaluate the success rate of weaning from ventilator in patients admitted at the Intensive Care Unit (ICU) using Burn’s Wean Assessment Program (BWAP) checklist.
Methods: The present analytical cross-sectional study was carried out on 100 mechanical ventilation-dependent patients connected to the ventilator for more than 72 hours. All patients were selected by simple available sampling based on purposive sampling method and examined by BWAP checklist and were weaned from ventilator by obtaining scores over 18.
Results: The total number of patients participating in the study was 100, 71 males and 29 females. There was no significant relationship between gender and success or failure of weaning process based on chi-square test (p<0.784). There was no relationship between weight and the result of weaning according to t-test. T-test showed a relationship between the number of hospitalization days with the result of weaning (P<0.001). Mann-Whitney test showed a significant relationship between age and the result of weaning according to which higher age leads to less success (p<0.001). Logistic regression indicated that age and airway could predict the result of weaning up to 78%.
Conclusion: Investigating preparation for weaning using Burn’s Scale is more useful for patients who had no prolonged hospitalization at ICU and ventilated through an endotracheal tube.

General anesthetic drugs produce extensive neuronal changes in the central nervous system by enhancing inhibitory and reducing excitatory neurotransmission. The major neurotransmitters, which are thought to play a role in anesthesia, are glutamate, serotonin, norepinephrine, dopamine, acetylcholine, and GABA. The knowledge of neurotransmitters and their receptors’ function is very important in perception of anesthesia in routines practice.
The purpose of this review article is to give an overview of the different types of neurotransmitters in CNS, classification of neurotransmitters and mechanism of action of various types of neurotransmitters and their receptors.

Intubating a patient with panfacial fractures is always a challenge to the anesthesiologist as both the anesthesiologist and the surgeon are essentially competing for the same space. The anesthetic management of a 19-year-old boy who presented with multiple maxillofacial injuries, pneumocephalus, and cerebral edema sustained during a road traffic accident has been described. He was posted for open reduction and internal fixation of the fractures, frontal sinus fracture elevation and basal repair which required access to scalp, mouth and the nose. As all the conventional modalities to secure airway seemed unsuitable, orotracheal intubation was done via submental route. Following intravenous induction the patient was intubated with a cuffed oral flexometallic tracheal tube. This was then modified to the submental route through a submental incision. The surgery proceeded uneventfully and the patient was extubated a day later in the ICU. He made a satisfactory recovery and the submental scar healed without complication or scarring. We briefly review the technique of submental intubation in adults which serves as an excellent alternative to tracheostomy.

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