Background: There have been numerous reports of snake venoms being employed as analgesics in attempts to relieve severe pain associated with cancer, immune dysfunction and viral infections. This study investigates the antinociceptive effects of iranian cobra snake venom (Naja naja oxiana) in comparison with morphine and lidocain on laboratorial femal mice.

Materials and Methods: This study has been done on 48 NMRI female mice of 18-20 g in weight. Antinociceptive activeity of snake venom was evaluated by formalin test. In this test, the animals were divided into 6 groups (each group consisting of 8 mice): Sham, positive Control (receiving morphine at dose of 5 mg/kg, and receiving lidocain at dose of 20 mg/kg), and experimental groups receiving venom at doses of 1, 3 and 4.5 µg/mice. In all groups, the formalin test was recorded for 60 min after administration of venom and drugs in mice. Data were analyzed using one-way ANOVA and Tukey test.

Results: The results showed that the venom of Naja naja oxiana decreased nociception meaningfully in both acute and chronic phases. We also showed that this venom revealed even a better analgesic activity in comparison with morphine and lidocain.

Conclusion: This study showed that the antinociceptive effect of the venom was mediated through central nervous system and peripheral mechanisms. Although details of the mechanism remain unclear, and further studies should be considered to demonstrate its therapeutic effects.

Background: Subacromial impingement is one of the most common complaints of shoulder. Treatments include avoiding of painful activities, oral anti-pain drugs, physical therapy modalities, corticosteroid injection and exercise therapy. Some studies have shown that platelet- rich plasma(PRP) is effective on tendinitis and tearing of tendons, ligaments and muscles, but evidence that has proved PRP as a conservative treatment in shoulder pathologies is very limited. This study aims to investigate the effect of PRP injection on relieving pain and improving daily function of patients with shoulder impingement syndrome.

Materials and Methods: In this clinical trial study, patients older than 40 with pain more than three months were included. If they had three of four positive diagnostic clinical tests of shoulder impingement that were confirmed by shoulder MRI, could be injected PRP twice. The time between injections was 1 month. Pain was measured by visual analog scale (VAS) and function was measured by two questionnaires named disabilities of the arm, shoulder and hand (DASH) and western Ontario rotator cuff  (WORC) index. Range of motion (ROM) of shoulder was measured in five directions by goniometry . All of these parameters were evaluated before intervention and in 1, 3, 6 months later.

Results: with due attention to a six-month folloe-up, PRR injection was effective in pain reduction and improvement of patient's function (p<0.05). Shoulder Rom increased in all directions except external rotation and the power of shoulder muscles was evidently improved statistically in flexion, abduction and internal toration.

Conclusion: PRP injection could effectively reduce pain and improve daily activities in patients with shoulder impingement syndrome.

Background: MgSo4 (magnesium sulfate) is the first therapeutic line for preeclampsia. Recently, there have been many debates on pain relief property on MgSo4. The purpose of this study is to evaluate the effect of MgSo4 on pain relief after cesarean in preeclampsia parturient

Materials and Methods: In this analytic and cross-sectional clinical trial study, 88 pregnant wowen with mild preeclampsia who received MgSo4 (14g loading dose and 5 g/4h maintenance dose) (n=88, P group), were compared with 88 normal pregnant women(n=88, N group), according to the duration of paim relief and the amount of diclofenac suppository consumption after cesarean section from March 2013 to October 2014. After cesarean section, the assessment of pain relief performed with NRS (numerical rating scale), and diclofenac consumption.

Results: P group had a longer analgesic duration than N group. NRS in P group was significantly longer than N group(6.89 ±3.34 vs. 3.55± 2.13 hr, p=0.0001). The dose of diclofenac suppository in P group was significantly lower than N group (225mg±147 vs. 365.9±92mg, p<0.0001).

Conclusion: Post cesarean pain in preeclamptic group was significantly lower than non-preeclamptic group. This finding is probabley because of MgSo4 administration in preeclamptic group.

Background: Hysterectomy is one of the most common surgical procedures. Only after cesarian section, hysterectomys considered as second major surgical procedure. Problems such as severe pelvic pain, irregular or heavy bleeding and uterine cancer are cases that hysterectomy is used to care them. Abdominal pain after abdominal hysterectomy is one of the most common complaints of patients undergoing this type of surgery. This study aimed to compare the effects of bupivacaine into the subcutaneous tissue and skin ketamine to control pain after surgery in patients undergoing abdominal hysterectomy under general anesthesia.

Materials and Methods: This study is a randomized, double-blind clinical trial involving 99 women candidating for TAH referred to Taleghani center in Arak who were divided into three groups. The average duration of analgesia and pain and pain score were recorded.

Results: The average duration of analgesia in ketamine group, in the bupivacaine group and in the placebo group was 65.1±8.8, 65.4±8.7, and 57.6±5.5, respectively. According to p≤0.01, there was a significant difference between the three groups. The duration of analgesia in the placebo group was significantly lower than ketamine and bupivacaine groups, while that between ketamine and bupivacaine in terms of the average duration of analgesia, no significant difference was observed.

Conclusion: The results of our study indicate that the use of bupivacaine and cutaneous ketamine is effective in reducing postoperative pain in patients undergoing abdominal hysterectomy and further doses of ketamine and bupivacaine single dose resulted in a significant reduction of postoperative pain in patients compared to the placebo group.

Background: The definite treatment of indicated Hypertrophy of the tonsils is Tonsillectomy. The aim of this study was to compare the efficacy and necessity of diclofenac suppository and simultaneous prescription of acetaminophen alone in controlling and reducing pain and improving swallowing and satisfaction after surgery for tonsillectomy in children.

Materials and Methods: In this clinical trial, 180 children 7 to 14 years Tvnsykltvmy surgery were enrolled. Patients in an improbable way, easy and were divided into three groups of 60. Immediately after the surgery acetaminophen, diclofenac, or a combination of both was used. The cases of pain in the early hours, seventh, thirteenth and nineteenth after surgery were compared.

Results: There was a significant difference between the average pains of all groups in all hours (p<0.05). There was a significant difference between the groups from the point of view of side effects such as Nausea, Vomiting and Pyrexia (p<0.05), But there was no significant difference between the groups from the point of view of After Surgery Bleeding (p>0.05).

Conclusion: We can say that Rectal Diclofenac is a more effective medication for reducing pain after the Tonsillectomy surgery in contrast with Rectal Acetaminophen or a mixture of the two, which may cause the patients to use less Narcotics after the surgery.

Background: Neuropathic pain is a chronic pain that affects on the patient’s quality of life. Use of herbal instead of synthetic drugs recently has been increased due to side effects of synthetic drugs and herbal effective components. Flavonoids are herbal compounds that have analgesic and anti-inflammatory effects. Because Allium cepa L. has a great amount of flavonoids, this study has been designed to evaluate analgesic effects of alcoholic extract of Allium cepa L. on neuropathic pain behavior in chronic constriction injury model in rats.

Materials and Methods: In this experimental study, neuropathic pain induced by chronic constriction injury (CCI model) in Rats. Animals were randomly divided into 4 groups (n=10 for each): Sham, CCI model, receiving red onion hydroalcoholic extract at a dose of 100 mg/kg and a group receiving gabapentin (100 mg/kg). Red onion extract and gabapentin were administered by gavage for 21 days. Using thermal hyperalgesia, mechanical and thermal allodynia tests, the analgesic effects of extract have been measured.

Results: Findings of this study revealed that CCI surgery on rats induced hyperalgesia, mechanical and thermal allodynia. Daily intakes of alcoholic extract of red onion and gabapentin significantly increase the paw withdrawal latency; increase the threshold to mechanical allodynia and decrease in response to acetone.

Conclusion: Oral use of alcoholic extract of Allium cepa L. reduces neuropathic pain behavior in CCI model in rats.

Abstract

Background: The aim of this study is to evaluate the impact of preemptive adding topical Ketorolac to Tetracaine drop on pain intensity and hemodynamic parameters during and after cataract surgery.

Materials and Methods: Eighty patients scheduled for elective cataract surgery under sedation and topical anesthesia, were randomly allocated to two equal groups: group T received Tetracaine 0.5%, and group TK received Tetracaine with ketorolac eye drops. One drop of each ophthalmic drug was applied every 10 minutes from 30 minutes before surgery. Pain intensity and hemodynamic parameters were assessed just before starting the operation and 5, 10, 15and 20 minutes during the operation, and then 0, 5, 10, 15 and 20 minutes after arrival of the patient to the recovery room.

Results: Mean pain intensity was significantly lower in TK group (1 ± 0.128) compared with T group (2 ± 1.54) during the surgery (p = 0.003), but there was no significant difference between the two groups in this regard during the recovery time (p =0.157). The number of patients requiring additional analgesic was not significantly different between the groups. There was no significant difference between the two groups regarding hemodynamic parameters except at 20th minutes and 15^th and 20^th minutes (heart rate and respiratory rate) after arrival to the recovery room.

Conclusion: Preemptive adding topical Ketorolac to Tetracaine drop is more effective than Tetracaine alone to reduce pain during cataract surgery.

Abstract

Background: Pain is a protective process in the body. There are different pathways for pain control in the central nervous system. Descending pain control system is one of pathways. The periaqueductal gray (PAG) is a structure known for its role in pain transmission and modulation. The aim of this study is to investigate the percent of interaction between the left and right PAG in unilateral left foot induced pain.

Materials and Methods: In this study, 60 rats (280+30g) in six groups were used (3test groups and 3 controls groups). In test groups, 0.5 microliter lidocaine was injected in the left PAG, right PAG or both to make local anesthesia. In control groups, 0.5 microliter of normal saline were injected. After 15 minutes, 50 microliter of 2.5% of formalin were injected subcutaneously to right hind paw of rats and nociception was detected in every 15 seconds for one hour.

Results: The induction of unilateral pain (left hind paw) in rats, can affect not only the ipsilateral but also the contralateral PAG nucleus.

Conclusion: This study showed that the left and right PAG nuclei have significant role on unidirectional nociception in formalin test in rats. The contralateral PAG, however, has a minor effect on nociception.