Tehran University Medical Journal

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Background: Magnesium Sulfate (MgSO4) has been used as a pharmacologic agent in different situations for many years in the treatment of tachyarrhythmias, myocardial ischemia, preeclampsia, and tocolysis among others. The analgesic effect of MgSO4 for postoperative pain has been used since the 1990s. Postoperative pain is one of the most common complications in the perioperative period and can result in serious consequences in different organs if left untreated. Inguinal herniorrhaphy is among the most common surgeries and is almost always accompanied by severe pain. The object of this study is to determine the effect of a pre-induction infusion of MgSO4 on the reduction of postsurgical pain after herniorrhaphy.
Methods: This double-blind, randomized clinical trial included 105 ASA class I and class II herniorrhaphy patients at Shariati Hospital in years 2004 and 2005. For statistical analysis, the 2 and T tests were used. The patients were divided into three groups based on block randomization. Patients in the following groups received: Group A, 200 ml of normal saline infusion (placebo) Group B, 25 mg/kg MgSO4 in 200 ml of normal saline Group C, 50 mg/kg MgSO4 in 200 ml of normal saline. All groups were infused twenty minutes before induction of anesthesia using identical methods and dosage in all three groups. Heart rate and mean arterial pressure (MAP) at pre- and postintubation and so at skin incision time were charted. Visual analog scale (VAS) pain score, nausea, vomiting and the amount of morphine used before recovery room discharge and in six, twelve and twenty-four hours after recovery discharge was recorded.
Results: The average age for the different groups was as follows: Group A: 33.6, Group B: 37.37, Group C: 32.74. Nausea and vomiting between the case and control groups were not statistically different (60% vs. 71.4%, p=0.0499), nor was the amount of Morphine used. On recovery room discharge, the VAS scores were 8.1, 7.2, and 5.5 for the first, second and third groups, respectively (P<0.001). However, no statistical significance was found for the VAS scores six hours after recovery room discharge.
Conclusion: The results in this study show that pre-induction with MgSO4 has no remarkable effect on decreasing postoperative pain or morphine use for inguinal herniorrhaphy.

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Background: About one-forth of the patients admitted to the emergency department complain of acute abdominal pain. According to surgical records, most surgeons believe that pain relief for these patients may interfere with the clinical examinations and the final diagnoses. As a result, analgesics are withheld in patients with acute abdominal pain until the determination of a definite diagnosis and suitable management plan. The purpose of this study was to evaluate the effect of analgesics on the evaluation course and treatment in acute abdomen.

Methods: Two hundred patients at a surgical emergency department with acute abdominal pain were enrolled in this prospective study and randomly divided into two groups at the time of admission. The case group consisted of 98 patients who received intravenous analgesia immediately after admission. The other 102 patients in the control group did not receive analgesia until a definite diagnosis was made. Diagnostic and therapeutic procedures were similar between the two groups. The primary and final diagnoses, and the time intervals between the admission and definite diagnosis, and that between admission and surgery were gathered and analyzed.

Results: The mean time to definitive diagnosis was 1.7 and 2.04 hours in the case and control groups, respectively. There was no statistically significant relationship between analgesic use and gender, age, time to definite diagnosis, or accuracy of the diagnosis. In fact, the time required to achieve a definite diagnosis and the time between admission and surgery were less in the group that had received analgesics.

Conclusions: In spite of the fact that analgesics remove the very symptoms that brings patients to the emergency room, appropriate use of analgesics does not reduce diagnostic efficiency for patients with acute abdominal pain.

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Background: Post-tonsillectomy pain is often severe and usually prevents patients from routine eating and drinking. A new option for reducing postoperative pain is "preemptive analgesia", the pre-, intra- or post-operative administration of analgesic agents. Ketamine, an N-methyl D-aspartate receptor antagonist, has recently received attention for this aim. Herein, we study the effect of submucosal injection of ketamine in the tonsillar bed for the reduction of post-tonsillectomy pain.

Methods: In this double-blind clinical trial, three groups of patients underwent infiltration of 0.5mg/kg ketamine, 1mg/kg ketamine or normal saline in their tonsillar bed. Age, sex and weight of patients, duration of surgery, systolic and diastolic blood pressure (before and after surgery), volume of blood loss, reoccurrence of bleeding, time to initiation of oral intake, nausea, vomiting, pain score and dysphasia were recorded in information sheet. Data analysis was performed by one-way ANOVA and chi squared tests, with significance at a P value of <0.5.

Results: There is no significant difference between the three groups with regard to age, sex, weight, duration of surgery, blood pressure (before surgery), volume of blood loss, nausea and vomiting. However, for the ketamine groups, pain score, dysphasia, need for opioid administration and time to initiation of oral intake is significantly lower (P<0.00). Reoccurrence of bleeding was observed in one patient in the lower-dose ketamine group, which is not statistically significant. The effectiveness of the two doses of ketamine is similar, with no statistical difference between the two groups (P=0.84).

Conclusions: This study demonstrated that a submucosal injection of ketamine into the tonsillar bed preoperatively is a safe option for reducing post-tonsillectomy pain, dysphasia, need for opioid and time to initiation of oral intake, without increasing the risk of excessive bleeding, reoccurrence of bleeding, nausea and vomiting.

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Background: Axillary block is used for inducing anesthesia in outpatient hand and forearm surgeries. Few researches have studied hemodynamic and blockade effects of low doses of Epinephrine. The aim of the present study was to compare the duration of analgesia and hemodynamic changes following the injection of high/low epinephrine doses in such surgeries.

Methods: The present randomized clinical trial study was conducted on healthy individuals (ASA I-II) who were candidates for hand and forearm surgeries. The patients were randomly divided into three groups. The first two groups were allocated to receive lidocaine with low (0.6µg/cc) and high (5µg/cc) doses of epinephrine whereas lidocaine plus normal saline was injected in the third group. The hemodynamic changes (Mean arterial blood pressure and heart rate) and the occurance of any side-effects along with the duration of analgesia and motor block were recorded.

Results: From among the total of 75 patients, 15 cases were excluded due to incomplete blockade or failure needing general anesthesia. The duration of analgesia and the motor block were longer in the high dose epinephrine group, the difference, however, was not statistically significant. Heart rate changes within the groups was significant in the 4^th-7^th and 10^th minutes. Mean arterial blood pressure changes was only significant in the 4^th minute, within the groups.

Conclusions: Administering low doses of epinephrine plus lidocaine as a local anesthetic not only provides acceptable analgesia compared to higher doses of the medication, but also is associated with fewer side effects.

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Background: Pain is one of the greatest concerns of patients undergoing total knee arthroplasty (TKA) which is severe and intolerable within 72 hours post-surgery. Appropriate pain management is a key factor in patient's early mobilization, launching physiotherapy, less hospital length of stay and more importantly, patient's satisfaction. New studies with the infiltration of combined analgesic agents peri and intra-articularly has shown encouraging results in pain reduction, good clinical outcome and patient's satisfaction. The purpose of this study was to compare the analgesic effect of locally infiltrated analgesia (I) compared with single injection femoral nerve block (F) and its impact on pain relief, patient's satisfaction, morphine consumption and clinical outcome.

Methods: This research was a double-blind randomized clinical trial on 36 consecutive patients undergone TKA divided into group (F) in which the ipsilateral femoral nerve in the inguinal area was blocked by a single injection of 20 ml ropivacaine (10 mg/ml) and group (I) which a combination of ketorolac, ropivacaine and epinephrine was injected peri and intra-articularly on the knee during TKA. Pain intensity measured by visual analog scale (VAS), clinical outcome (based on range of motion), morphine consumption and patient's satisfaction of pain management after TKA were compared between the two groups.

Results: Pain intensity score (VAS) and Morphine consumption were statistically less in group I than group F during the first 6 hours and 24 hours post surgery respectively (P< 0.05) however, group F had 12-hour VAS score of 5 which was less than group (I) by 1 grade in pain scale (VAS) (P< 0.05). Other parameters were not statistically different in the two groups and patients' response to our pain management protocols proved to be satisfactory in both groups.

Conclusion: Lower level of pain and morphine consumption in group (I) during the first 24 hours post-surgery in contrast to group (F) and its ease of use by a surgeon intra-operatively, introduce local infiltration analgesia as an effective method to decrease the patient's pain and improve patient's satisfaction in early post-surgery period after total knee arthroplasty.

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Background: Pain control after orthognathic surgeries due to severity of pain and limitations of opioids use in these patients are particular importance. The aim of this study was to evaluate the effect of oral gabapentin and intramuscular ketorolac in combination with intravenous acetaminophen for pain control after this surgery.

Methods: This study was a randomized clinical trial (RCT) on 75 patients (18-60 years old American Society of Anesthesiologists (ASA) physical status classification system, I, II) that undergo orthognathic surgery in Sina University Hospital, Tehran University of Medical Sciences, Tehran, Iran from June 2013 to August 2014. The patients were randomly divided in 3 groups. All of groups received 1 gr (intravenous acetaminophen) 30 minutes before the end of surgery. The control group (n= 25) received placebo. The second group (n= 25) received 30 mg ketorolac intramuscular after induction of anesthesia and the third group (n= 25) received 600 mg Gabapentin orally 30 minute before the induction of anesthesia. The pain severity score assessed by visual analogue scale (VAS), the level of sedation assessed by Ramsey scale, opioid requirement, nausea and vomiting was recorded in the post-anesthesia care unit (PACU) at 1, 3, 6, 12 and 24 hours after surgery. For rescue pain management intravenous morphine was administered.

Results: Seventy-five patients were enrolled in this study. Use of Ketorolac and gabapentin declines the pain intensity, level of agitation and morphine requirement in the recovery room and early hours in the ward (P= 0.011). The 24-hour opioid consumption, nausea and vomiting was significantly higher in control group compared with the both intervention groups (15±1.4 vs. 5±0.5 mg) (P< 0.05) retrospectively. Mean arterial pressure and heart rate changes was significantly lower in ketorolac and gabapentin groups compare to control group in recovery room (P< 0.05).

Conclusion: The result of this study suggest that ketorolac as well as gabapentin can decline the pain intensity and opioid requirement with less nausea and vomiting and good hemodynamic control after orthognathic surgery.