Review of the use of gabapentin in the control of postoperative pain.

BACKGROUND AND OBJECTIVES: Gabapentin has been used as adjuvant in the treatment of postoperative pain with a neuropathic component. It is responsible for the inhibition of central sensitization, decreasing postoperative pain. CONTENTS: All clinical, randomized studies that evaluated the effects of gabapentin on postoperative pain in humans between 2002 and 2007 for a total of 26 studies were selected. In 17 studies, patients received a single preoperative dose, which ranged from 300 to 1,200 mg, 30 minutes to two hours before surgery in the remaining studies, the administration of the drug was initiated one to 24 hours before the procedure and continued for 10 days, in doses that ranged from 1,200 to 1,800 mg.day(-1). To measure pain severity, the Visual Analog or Numeric Rating Scale was used. In 75% of patients who received a single dose of gabapentin, scores were lower, and the same was seen in 55.6% of patients who received the drugs pre- and postoperatively. Opioid consumption was reduced in 82.4% of patients who received a single dose, and in 77.8% of patients who received pre- and postoperative gabapentin. Among the studies using a single dose of gabapentin, four did not describe adverse effects; 52.9% showed no differences, 11.8% detected more nausea or vomiting, 5.9% experienced more dizziness, 5.9% more sedation, less nausea or vomiting in one, and less urinary retention in one. Among the studies with pre- and postoperative administration of gabapentin, four did not describe adverse effects; 22.2% showed no differences, 11.1% had more nausea or vomiting, 22.2% more dizziness, and 11.1% more sedation. CONCLUSIONS: Gabapentin, used before as well as before and after surgery, decreased pain severity and the need of analgesic supplementation.

[Effect of intraoperative intravenous lidocaine on pain and plasma interleukin-6 in patients undergoing hysterectomy]. / Efeito da lidocaína venosa intraoperatória sobre dor e interleucina-6 plasmática em pacientes submetidas a histerectomia.

BACKGROUND AND OBJECTIVES: Interleukin-6 (IL-6) is a predictor of trauma severity. The purpose of this study was to evaluate the effect of intravenous lidocaine on pain severity and plasma IL-6 after hysterectomy. METHOD: A prospective, randomized, comparative, double-blind study with 40 patients, aged 18-60 years. G1 received lidocaine (2mg.kg(-1).h(-1)) or G2 received 0.9% saline solution during the operation. Anesthesia was induced with O2/isoflurane. Pain severity (T0: awake and 6, 12, 18 and 24hours), first analgesic request, and dose of morphine in 24hours were evaluated. IL-6 was measured before starting surgery (T0), five hours after the start (T5), and 24hours after the end of surgery (T24). RESULTS: There was no difference in pain severity between groups. There was a decrease in pain severity between T0 and other measurement times in G1. Time to first supplementation was greater in G2 (76.0±104.4min) than in G1 (26.7±23.3min). There was no difference in supplemental dose of morphine between G1 (23.5±12.6mg) and G2 (18.7±11.3mg). There were increased concentrations of IL-6 in both groups from T0 to T5 and T24. There was no difference in IL-6 dosage between groups. Lidocaine concentration was 856.5±364.1 ng.mL(-1) in T5 and 30.1±14.2 ng.mL(-1) in T24. CONCLUSION: Intravenous lidocaine (2mg.kg(-1).h(-1)) did not reduce pain severity and plasma levels of IL-6 in patients undergoing abdominal hysterectomy.

Effects of preoperative intravenous clonidine in patients undergoing cataract surgery: a double-blind, randomized trial.

Objectives. The aim of this study was to assess the effects of clonidine on intraoperative analgesia, sedation, intraocular and blood pressure, arrhythmia, and ischemia. Methods. Forty patients undergoing cataract surgery were allocated into two groups. They were monitored with Holter machine, the pupil was dilated, and 30 minutes later, 20 patients received clonidine (4 µg/kg), while the other 20 patients were given a 0.9% saline intravenously. Twenty minutes later, 2% lidocaine gel was applied. There were assessed intraoperative analgesia, intraocular pressure, blood pressure, heart rate, and the occurrence of arrhythmias and myocardial ischemia. Results. Pain intensity was lower in G1 during the phacoemulsification, irrigation, aspiration, and intraocular lens implantation. The HR and BP were lower with clonidine. The IOP was lower with clonidine after 15 minutes and at the end of the surgery. Sedation was higher with clonidine. The incidence of arrhythmia was lower at the end of surgery with clonidine. The incidence of myocardial ischemia did not differ between the groups. Conclusions. Clonidine (4 µg/kg) before a phacoemulsification reduced the intensity of pain during cataract surgery. It also induced sedation, reduction of BP, HR, and incidence of arrhythmia at the end of the surgery, and did not alter myocardial ischemia. This trial is registered with Clinicaltrials.gov NCT01677351.

Assessment of the effect of ketamine in combination with remifentanil on postoperative pain.

BACKGROUND AND OBJECTIVES: The combination of ketamine and remifentanil seems to be associated with better analgesia and duration. The aim of this study was to evaluate whether a ketamine- remifentanil combination promotes improved postoperative analgesia. METHODS: Prospective, randomized, double blind study of 40 patients undergoing video laparoscopic cholecystectomy. Anesthesia was performed with remifentanil, propofol, atracurium, and 50% oxygen. Group 1 (GI) patients received remifentanil (0.4 mcg.kg(-1).min(-1)) and ketamine (5 mcg.kg(-1).min(-1)) and Group 2 (G2) received remifentanil (0.4 mcg.kg(-1).min(-1)) and saline solution. Morphine 0.1 mg.kg(-1) was administered at the end of the procedure, and postoperative pain was treated with morphine via PCA. We evaluated the severity of postoperative pain by a numerical scale from zero to 10 during 24 hours. We registered the time to the first analgesic supplementation, amount of morphine used in the first 24 hours, and adverse effects. RESULTS: There was a decrease in pain severity between extubation and other times evaluated in G1 and G2. There was no significant difference in pain intensity between the groups. There was no difference between G1 (22 ± 24.9 min) and G2 (21.5 ± 28.1 min) regarding time to first dose of morphine and dose supplement of morphine consumed in G1 (29 ± 18.4 mg) and G2 (25.1 ± 13.3 mg). CONCLUSION: The combination of ketamine (5 mcg.kg(-1).min(-1)) and remifentanil (0.4 mcg.kg(-1).min(-1)) for cholecystectomy did not alter the severity of postoperative pain, time to first analgesic supplementation or dose of morphine in 24 hours.

Assessment of the effect of ketamine in combination with remifentanil on postoperative pain.

BACKGROUND AND OBJECTIVES: The combination of ketamine and remifentanil seems to be associated with better analgesia and duration. The aim of this study was to evaluate whether a ketamine-remifentanil combination promotes improved postoperative analgesia. METHODS: Prospective, randomized, double blind study of 40 patients undergoing video laparoscopic cholecystectomy. Anesthesia was performed with remifentanil, propofol, atracurium, and 50% oxygen. Group 1 (GI) patients received remifentanil (0.4 mcg.kg(-1).min(-1)) and ketamine (5 mcg.kg(-1).min(-1)) and Group 2 (G2) received remifentanil (0.4 mcg.kg(-1).min(-1)) and saline solution. Morphine 0.1mg.kg(-1) was administered at the end of the procedure, and postoperative pain was treated with morphine via PCA. We evaluated the severity of postoperative pain by a numerical scale from zero to 10 during 24 hours. We registered the time to the first analgesic supplementation, amount of morphine used in the first 24 hours, and adverse effects. RESULTS: There was a decrease in pain severity between extubation and other times evaluated in G1 and G2. There was no significant difference in pain intensity between the groups. There was no difference between G1 (22±24.9 min) and G2 (21.5±28.1min) regarding time to first dose of morphine and dose supplement of morphine consumed in G1 (29±18.4mg) and G2 (25.1±13.3mg). CONCLUSION: The combination of ketamine (5 mcg.kg(-1).min(-1)) and remifentanil (0.4mcg.kg(-1).min(-1)) for cholecystectomy did not alter the severity of postoperative pain, time to first analgesic supplementation or dose of morphine in 24hours.

Evaluation of preemptive effect of epidural S(+)-ketamine for hysterectomy: plasmatic concentrations of interleukins.

BACKGROUND AND OBJECTIVES: Some studies showed that ketamine inhibits the production of cytokines. The objective of this study was to evaluate the preemptive analgesic effect of epidural S(+)-ketamine in hysterectomy and plasmatic cytokines (IL-6, TNF-α and IL-10). METHOD: A double-blinded study with 29 patients was conducted. Patients in Group 1 received 13 mL of 0.25% bupivacaine with 25mg of S(+)- ketamine 30 minutes before surgical incision and 15 mL of saline solution via the epidural route 30 minutes after. Patients in Group 2 received 15 mL of saline solution 30 minutes before the surgical incision, followed by 13 mL of 0.25% bupivacaine with 25mg of S(+)-ketamine 30 minutes after. Postoperative analgesia was made with epidural bupivacaine and fentanyl. Dipyrone 1 g was used whenever required. The following paramenters were evaluated: concentration of cytokines, intensity of pain, time of first request of analgesic and total quantity of analgesic used. RESULTS: Time for the first request for analgesics was 61.5 minutes in Group 1 and 69.0 in Group 2, without difference between these groups. There was no difference for total dose of fentanyl used in Group 1 (221.4 µg) and Group 2 (223.3 µg). A similar analgesic effect was obtained in both groups, except in T12 (Group 1 = 2.4±3.2; Group 2 = 5.5±3.4). No differences in concentration of cytokines were observed. CONCLUSIONS: The epidural injection of 25mg S(+)-ketamine before incision reduced the pain intensity only 12 hours after surgical incision and did not alter concentration of cytokines.

Assessing the effects of transcutaneous electrical nerve stimulation (TENS) in post-thoracotomy analgesia.

BACKGROUND AND OBJECTIVES: Transcutaneous electrical nerve stimulation (TENS) is commonly used to treat musculoskeletal pain, but it may also be indicated for postoperative analgesia. The objective of this study was to evaluate the analgesic effects of TENS on post-thoracotomy. METHODS: Thirty patients between 18 and 60 years of age undergoing thoracotomy for lung cancer resection on the second postoperative day were included in this study. Patients were divided into two groups (G1 and G2). G1 patients were treated with TENS; and in G2 (without TENS) electrodes were placed but the equipment was not turned on. TENS was maintained for one hour. The visual analogue scale was used to evaluate the analgesic effects on three moments: before TENS (M0), immediately after TENS (M1), and one hour later (M2), with the patient at rest, elevation of the upper limbs, change in decubitus, and coughing. RESULTS: The intensity of pain at rest was higher in G2 immediately after TENS, but not one hour after the procedure. There was no difference between both groups with elevation of the upper limbs, decubitus change, and coughing. CONCLUSIONS: With the use of TENS for one hour on the second post-thoracotomy day in patients who received fentanyl (50 µg) associated with bupivacaine (5 mL), a reduction in pain intensity was observed at rest immediately after TENS; with elevation of the upper limbs, change in decubitus, and coughing, a reduction in pain severity was not observed.

Effect of intravenous lidocaine associated with amitriptyline on pain relief and plasma serotonin, norepinephrine, and dopamine concentrations in fibromyalgia.

OBJECTIVE: The objective of this study was to evaluate the effect of intravenous lidocaine combined with amitriptyline on pain relief and plasma serotonin, norepinephrine, and dopamine levels. METHODS: A prospective, randomized, double-blind comparative study was conducted in 30 patients. All patients received 25 mg amitriptyline; monotherapy group (n=15) received 125 mL saline, and combined therapy group (n=15) received 240 mg lidocaine in 125 mL saline once a week for 4 weeks. Serotonin, norepinephrine, and dopamine were measured in plasma at time zero (T0) and after 4 weeks (T4). Pain intensity was rated on a numerical scale at the beginning of the study and weekly for 4 weeks. RESULTS: All patients were females and the mean age was 44.7±10.5 years for monotherapy group and 40.9±11.6 years for combined therapy group. No difference in pain intensity at baseline was observed between groups, with a decrease after treatment in monotherapy group (T0: 7.0±1.2 and T4: 4.0±2.1) and in combined therapy group (T0: 7.6±0.8 and T4: 4.1±2.3). Plasma serotonin and norepinephrine levels were similar in the 2 groups at T0 and T4. An increase in dopamine levels was observed in monotherapy group from the beginning to the end of treatment. CONCLUSIONS: Combined administration of 240 mg intravenous lidocaine (once a week) and 25 mg amitriptyline for 4 weeks did not modify pain intensity or plasma serotonin, norepinephrine, or dopamine concentrations in fibromyalgia patients.

Cytokines and pain.

BACKGROUND AND OBJECTIVES: Cytokines are necessary for the inflammatory response, favoring proper wound healing. However, exaggerated proinflammatory cytokine production can manifest systemically as hemodynamic instability or metabolic derangements. The objective of this review was to describe the effects of cytokines in pain. CONTENTS: This article reviews the effects of cytokines in pain. In diseases with acute or chronic inflammation, cytokines can be recognized by neurons and used to trigger several cell reactions that influence the activity, proliferation, and survival of immune cells, as well as the production and activity of other cytokines. Cytokines can be proinflammatory and anti-inflammatory. Proinflammatory cytokines are related with the pathophysiology of pain syndromes. Cells that secrete proinflammatory (IL-1, IL-2, IL-6, IL-7, and TNF) and anti-inflammatory (IL-4, IL-10, IL-13, and TGFß) cytokines, the functions of each cytokine, and the action of those compounds on pain processing, have been described. CONCLUSIONS: Cytokines have an important role in pain through different mechanisms in several sites of pain transmission pathways.

Evaluating the cost of drugs used in the outpatient treatment of chronic pain.

BACKGROUND AND OBJECTIVES: Chronic pain is very prevalent and the cost of its treatment can cause a relevant impact on people and society. The objective of this study was to evaluate the monthly cost of drugs used in the outpatient treatment of chronic pain. METHODS: In the present study the cost of the drugs used by 233 patients with chronic pain (117 with nociceptive pain, 59 with neuropathic pain, and 57 with mixed pain) followed at the Alpha Center of UNIFESP between January 2004 and January 2008 was evaluated. RESULTS: The mean general cost was R$ 127.74 (from R$ 5.00 to R$ 780.00). CONCLUSIONS: This study showed that the cost of the drugs does not differ significantly taking into consideration the type of pain.

Intraoperative intravenous lidocaine.

BACKGROUND AND OBJECTIVES: Most patients undergoing surgery experience moderate to severe pain, indicating the need to improve the anesthetic technique. Intravenous lidocaine has been widely used in the treatment of chronic pain. The objective of this report was to review the use of intravenous lidocaine for postoperative analgesia. CONTENTS: The pharmacologic aspects and mechanism of action of lidocaine as well as clinical studies in which the authors used intraoperative lidocaine were reviewed. CONCLUSIONS: Intravenous lidocaine can promote analgesia in surgical procedures, representing another alternative for the treatment of acute pain. Controlled studies with different surgical interventions could bring more information on this modality of analgesia.

Serum cytokine levels in patients with chronic low back pain due to herniated disc: analytical cross-sectional study.

CONTEXT AND OBJECTIVE: the role of immune response and proinflammatory cytokines in the pathogenesis of chronic pain has been of growing interest. In order to evaluate whether there is any association between disc herniation and elevated cytokine levels, we measured cytokine levels in patients with chronic low back pain and in healthy subjects. DESIGN AND SETTING: analytical cross-sectional study at the Pain Clinic of Universidade Federal da Bahia (UFBA). METHODS: cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique on 23 patients with low back pain (G1) and on 10 healthy subjects (G2). RESULTS: the levels of tumor necrosis factor-alpha [TNF-alpha] (G1 = 5.6 ± 2.3 pg/ml; G2 = 1.6 ± 0.5 pg/ml; P = 0.01) and interleukin-6 [IL-6] (G1 = 4.1 ± 3.0 pg/ml; G2 = 0.9 ± 0.4 pg/ml; P = 0.01) were higher in G1. There were no statistically significant differences in relation to interleukin-1 [IL-1] (G1 = 0.5 ± 0.3 pg/ml; G2 = 0.5 ± 0.1 pg/ml; P = 1) or soluble tumor necrosis factor receptor [sTNF-R] (G1 = 572 pg/ml ± 36; G2 = 581 ± 50 pg/ml; P = 0.87). CONCLUSION: The patients with chronic low back pain due to disc herniation presented higher levels of TNF-alpha and IL-6, but not of IL-1 or sTNF-R.

Epidural versus intravenous fentanyl for postoperative analgesia following orthopedic surgery: randomized controlled trial.

CONTEXT AND OBJECTIVE: Controversy exists regarding the site of action of fentanyl after epidural injection. The objective of this investigation was to compare the efficacy of epidural and intravenous fentanyl for orthopedic surgery. DESIGN AND SETTING: A randomized double-blind study was performed in Hospital São Paulo. METHODS: During the postoperative period, in the presence of pain, 29 patients were divided into two groups: group 1 (n = 14) received 100 microg of fentanyl epidurally and 2 ml of saline intravenously; group 2 (n = 15) received 5 ml of saline epidurally and 100 microg of fentanyl intravenously. The analgesic supplementation consisted of 40 mg of tenoxicam intravenously and, if necessary, 5 ml of 0.25% bupivacaine epidurally. Pain intensity was evaluated on a numerical scale and plasma concentrations of fentanyl were measured simultaneously. RESULTS: The percentage of patients who required supplementary analgesia with tenoxicam was lower in group 1 (71.4%) than in group 2 (100%): 95% confidence interval (CI) = 0.001-0.4360 (P = 0.001, Fisher's exact test; relative risk, RR = 0.07). Epidural bupivacaine supplementation was also lower in group 1 (14.3%) than in group 2 (53.3%): 95% CI = 0.06-1.05 (P = 0.03, Fisher's exact test; RR = 0.26). There was no difference in pain intensity on the numerical scale. Mean fentanyl plasma concentrations were similar in the two groups. CONCLUSION: Intravenous and epidural fentanyl appear to have similar efficacy for reducing pain according to the numerical scale, but supplementary analgesia was needed less frequently when epidural fentanyl was used. CLINICAL TRIAL REGISTRATION NUMBER: NCT00635986.

Effect of intraoperative intravenous lidocaine on pain and plasma interleukin-6 in patients undergoing hysterectomy / Efeito da lidocaína venosa intraoperatória sobre dor e interleucina-6 plasmática em pacientes submetidas a histerectomia / Efecto de la lidocaína venosa intraoperatoria sobre el dolor e interleucina-6 plasmática en pacientes sometidas a histerectomía

BACKGROUND AND OBJECTIVES: Interleukin-6 is a predictor of trauma severity. The purpose of this study was to evaluate the effect of intravenous lidocaine on pain severity and plasma interleukin-6 after hysterectomy. METHOD: A prospective, randomized, comparative, double-blind study with 40 patients, aged 18-60 years. G1 received lidocaine (2 mg kg-1 h-1) or G2 received 0.9% saline solution during the operation. Anesthesia was induced with O2/isoflurane. Pain severity (T0: awake and 6, 12, 18 and 24 h), first analgesic request, and dose of morphine in 24 h were evaluated. Interleukin-6 was measured before starting surgery (T0), 5 h after the start (T5), and 24 h after the end of surgery (T24). RESULTS: There was no difference in pain severity between groups. There was a decrease in pain severity between T0 and other measurement times in G1. Time to first supplementation was greater in G2 (76.0 ± 104.4 min) than in G1 (26.7 ± 23.3 min). There was no difference in supplemental dose of morphine between G1 (23.5 ± 12.6 mg) and G2 (18.7 ± 11.3 mg). There were increased concentrations of IL-6 in both groups from T0 to T5 and T24. There was no difference in IL-6 dosage between groups. Lidocaine concentration was 856.5 ± 364.1 ng mL-1 in T5 and 30.1 ± 14.2 ng mL-1 in T24. CONCLUSION: Intravenous lidocaine (2 mg kg-1 h-1) did not reduce pain severity and plasma levels of IL-6 in patients undergoing abdominal hysterectomy. .

JUSTIFICATIVA E OBJETIVOS: A interleucina-6 (IL-6) é preditora de intensidade no trauma. O objetivo deste estudo foi avaliar o efeito da lidocaína por via venosa sobre a intensidade da dor e IL-6 após histerectomia. MÉTODO: O estudo foi prospectivo, randomizado, comparativo e duplo-encoberto em 40 pacientes, entre 18 e 60 anos. Foi administrada lidocaína (2 mg.kg-1.h-1) no G1 ou solução salina a 0,9% no G2 durante a operação. A anestesia foi com O2/isoflurano. Foi avaliada a intensidade da dor (T0: despertar e seis, 12, 18 e 24 horas), a primeira solicitação de analgésico, a dose de morfina nas 24 horas. A IL-6 foi medida antes do início da operação (T0), após cinco horas do início (T5) e 24 horas após o término (T24). RESULTADOS: Não houve diferença na intensidade da dor entre os grupos. Ocorreu diminuição da intensidade da dor entre T0 e os outros momentos avaliados no G1. O tempo para primeira complementação foi maior no G2 (76,0 ± 104,4 min) do que no G1 (26,7 ± 23,3 min). Não houve diferença na dose de morfina complementar entre G1 (23,5 ± 12,6 mg) e G2 (18,7 ± 11,3 mg). Houve aumento das concentrações de IL-6 em ambos os grupos de T0 para T5 e T24. Não houve diferença na dosagem de IL-6 entre os grupos. A concentração de lidocaína foi 856,5 ± 364,1 ng.mL-1 em T5 e 30,1 ± 14,2 ng.mL-1 em T24. CONCLUSÃO: A lidocaína (2 mg.kg-1.h-1) por via venosa não promoveu redução da intensidade da dor e dos níveis plasmáticos de IL-6 em pacientes submetidas a histerectomia abdominal. .

JUSTIFICACIÓN Y OBJETIVOS: La interleucina-6 (IL-6) es predictora de intensidad en el trauma. El objetivo de este estudio fue evaluar el efecto de la lidocaína por vía venosa sobre la intensidad del dolor e IL-6 después de la histerectomía. MÉTODO: El estudio fue prospectivo, aleatorizado, comparativo y doble ciego en 40 pacientes, entre 18 y 60 años. Fue administrada lidocaína (2 mg/kg-1.h-1) en el G1 o solución salina al 0,9% en el G2 durante la operación. La anestesia fue con O2/isoflurano. Se calculó la intensidad del dolor (T0: despertar y 6, 12, 18 y 24 h), la primera solicitud de analgésico, y la dosis de morfina en las primeras 24 h. La IL-6 se midió antes del inicio de la operación (T0), después de 5 h del inicio (T5) y 24 h después de finalizada (T24). RESULTADOS: No hubo diferencia en la intensidad del dolor entre los grupos. Hubo disminución de la intensidad del dolor entre T0 y los otros momentos evaluados en el G1. El tiempo para la primera complementación fue mayor en el G2 (76 ± 104,4 min) que en el G1 (26,7 ± 23,3 min). No hubo diferencia en las dosis de morfina complementaria entre G1 (23,5 ± 12,6 mg) y G2 (18,7 ± 11,3 mg). Hubo aumento en las concentraciones de IL-6 en los 2 grupos de T0 para T5 y T24. No hubo diferencia en la dosificación de IL-6 entre los grupos. La concentración de lidocaína fue 856,5 ± 364,1 ng/ml-1 en T5 y 30,1 ± 14,2 ng/ml-1 en T24. CONCLUSIÓN: La lidocaína (2 mg/kg-1 /h-1) por vía venosa no generó reducción de la intensidad del dolor y de los niveles plasmáticos de IL-6 en pacientes sometidas a histerectomía abdominal. .

[A comparative study between bupivacaine and clonidine associated with bupivacaine in cervical plexus block for carotid endarterectomy]. / Estudo comparativo entre clonidina associada à bupivacaína e bupivacaína isolada em bloqueio de plexo cervical para endarterectomia de carótida.

BACKGROUND AND OBJECTIVES: Neurological evaluation can be done during cervical plexus block for endarterectomy, which also maintains postoperative analgesia. The objective of this study was to compare the analgesic effects of clonidine associated with bupivacaine to those of bupivacaine in cervical plexus block. METHODS: A randomized double-blind study was undertaken with 30 patients divided in two groups: G1 received 1.5 mg.kg-1 of 0.375% bupivacaine associated with 150 (1/4)g of clonidine (2 mL), and G2 received 1.5 mg.kg-1 of 0.375% bupivacaine associated with NS (2 mL). The following parameters were evaluated: heart rate and blood pressure at 0 (block), 30, 60, 90, and 120 minutes; the need for anesthetic supplementation; time until the first analgesic supplementation; amount of analgesic used; and pain severity at 0 (end of the surgery), 30, 60, 120, 240, and 360 minutes. RESULTS: Group 1 received 3.8 mL of lidocaine for anesthetic supplementation, while G2 received 3.6 mL of lidocaine, but this difference was not statistically significant. In G1, the time until the first supplementation was 302.6 +/- 152.6 minutes, and in G2 it was 236.6 +/- 132.9 minutes, which was not statistically significant. Differences between the doses of dypirone and tramadol were not observed. Differences in pain severity between both groups were not observed either. CONCLUSION: The association of 150 (1/4)g of clonidine and bupivacaine in cervical plexus block for carotid endarterectomy did not improve significantly the analgesic effects evaluated by pain severity, time until the first analgesic supplementations and amount of supplementary analgesics.

Proinflammatory cytokines in patients with neuropathic pain treated with Tramadol.

BACKGROUND AND METHODS: Proinflammatory cytokines play an important role in the pathophysiology of neuropathic pain syndromes. The objective of this study was to evaluate plasma levels of proinflammatory cytokines before and after treatment with tramadol in patients with herniated intervertebral disks and carpal tunnel syndrome, and to compare them with normal individuals. METHODS: Thirty-eight patients with neuropathic pain secondary to herniated intervertebral disks or carpal tunnel syndrome participated in this study. All patients were treated with controlled release tramadol (100 mg every 12 hours) for 10 days. Venous blood (5 mL) was collected in the morning, before treatment and on the 11th day, and stored (-70 degrees C) until analysis. ELISA was used to determine the plasma levels of cytokines (TNF-+/-, IL-1, IL-6) and receptors sTNF-R1 (R & D Systems). Plasma levels of cytokines of 10 healthy volunteers were also determined. RESULTS: The concentration of TNF-+/- before (5.8 +/- 2.8 pg.mL-(1)) was significantly higher than after treatment with tramadol (4.8 +/- 2.1 pg.mL-1; p = 0.04, Mann-Whitney test). The levels of IL-1(2), IL-6, and sTNF-R1 before and after treatment with tramadol showed no significant differences. Plasma levels of TNF-+/- (healthy individuals: 1.4 +/- 0.5; pain patients: 5.8 +/- 2.8 pg.mL-1; p = 0.01) and IL-6 (healthy individuals: 1.2 +/- 0.8; pain patients: 3.5 +/- 2.6 pg.mL-1; p = 0.01) were significantly higher in patients with neuropathic pain, Mann-Whitney Test. CONCLUSIONS: In patients with herniated intervertebral disks and carpal tunnel syndrome, plasma levels of TNF-+/- and IL-6 were higher than in healthy volunteers, while differences in the concentrations of sTNF-R and IL-1(2) were not observed. Plasma levels of TNF-+/-, but not of IL-6, sTNF-R, and IL-1(2), decreased after treatment with tramadol (100 mg every 12 hours).

[Bilateral trigeminal neuralgia: case report]. / Neuralgia do trigêmeo bilateral: relato de caso.

BACKGROUND AND OBJECTIVES: Trigeminal neuralgia is an extremely painful condition characterized by recurrent episodes of sudden, lancinating, shock-like pain lasting from a few seconds to two minutes usually unilateral. It has an annual incidence of approximately 4.3 in 100,000 in the general population and only 3% of those cases present bilateral manifestation. The objective of this report was to describe a rare case of bilateral trigeminal neuralgia. CASE REPORT: A 61 years old housewife from Maranhão, Brazil, married, with a history of hypertension, presented with a six-year history of severe pain in the left V2-V3 regions, lasting 5 to 10 seconds, in the lateral aspect of the nose and mandible, worsening by talking, chewing, and with a decrease in temperature. She had been treated with chlorpromazine (3 mg every eight hours) and carbamazepine (200 mg every eight hours) during six months without improvement. On physical exam, the patient presented thermal and mechanical allodynia in the V2-V3 regions. She was using gabapentin (1,200 mg/day) with partial relief of the pain. The dose of gabapentin was increased to 1,500 mg/day and amitriptyline 12.5 mg at night was added to the therapeutic regimen. The patient evolved with mild and sporadical pain and a reduction in pain severity during 10 months; the dose of gabapentin was progressively reduced to 600 mg/day, and amitriptyline was maintained at 12.5 mg/day. After one year, the patient developed similar pain in the region of the right mandible, which improved with an increase in the dose of gabapentin to 900 mg/day. Head CT and MRI did not show any abnormalities. CONCLUSIONS: Carbamazepine is the first choice for the treatment of trigeminal neuralgia; however, the use of gabapentin as the first pharmacological choice or in cases refractory to conventional therapy has been increasing.

Intra-articular morphine versus bupivacaine for knee motion among patients with osteoarthritis: randomized double-blind clinical trial.

CONTEXT AND OBJECTIVE: Osteoarthritis causes pain and disability in a high percentage of elderly people. The aim of the present study was to assess the efficacy of intra-articular morphine and bupivacaine on the joint flexion and extension angles of patients with knee osteoarthritis. DESIGN AND SETTING: A randomized double-blind study was performed at a pain clinic of Universidade Federal de São Paulo. METHODS: Thirty-nine patients with pain for more than three months, of intensity greater than three on a numerical scale (zero to 10), were included. G1 patients received 1 mg (1 ml) of morphine diluted in 9 ml of saline, intra-articularly, and G2 patients received 25 mg (10 ml) of 0.25% bupivacaine without epinephrine. Pain was assessed on a numerical scale and knee flexion and extension angles were measured after administration of the drugs at rest and during movement. The total amount of analgesic supplementation using 500 mg doses of paracetamol was also determined. RESULTS: No significant difference in pain intensity was observed between G1 and G2. Significant decreases in pain at rest and during movement and significant increases in mean flexion and extension angles were observed in both groups, with no significant difference between the two groups. The mean total amount of paracetamol used over a seven-day period was 3578 mg in G1 and 5333 mg in G2 (P = 0.2355; Mann-Whitney test). CONCLUSION: The analgesic effects of 1 mg of morphine and 25 mg of 0.25% bupivacaine were similar among patients with osteoarthritis of the knee.

Avaliação do efeito da cetamina associada à remifentanila na dor pós-operatória / Assessment of the effect of ketamine in combination with remifentanil on postoperative pain / Evaluación del Efecto de la Cetamina Asociada con el Remifentanilo en el Dolor Postoperatorio

JUSTIFICATIVA E OBJETIVOS: A associação de cetamina com remifentanila parece estar relacionada à analgesia de melhor qualidade e duração. O objetivo deste estudo foi avaliar se a cetamina associada à remifentanila promove melhora da analgesia pós-operatória. MÉTODO: Estudo prospectivo, aleatório, duplo encoberto em 40 pacientes submetidos à colecistectomia videolaparoscópica. A anestesia foi feita com remifentanila, propofol, atracúrio, 50% de oxigênio. Os pacientes do G1 receberam remifentanila (0,4 mcg.kg-1.min-1) e cetamina (5 mcg.kg-1.min-1); os do G2, remifentanila (0,4 mcg.kg-1.min-1) e solução salina. Foi administrado 0,1 mg.kg-1 de morfina no final da operação e a dor pós-operatória foi tratada com morfina, através de analgesia controlada pelo paciente (PCA). A intensidade da dor pós-operatória foi avaliada pela escala numérica de 0 a 10, durante 24 horas. Foram anotados o tempo para primeira complementação analgésica, a quantidade de morfina usada durante 24 horas e os efeitos adversos. RESULTADOS: Ocorreu diminuição da intensidade da dor entre a desintubação e os outros momentos avaliados no G1 e no G2. Não foi observada diferença significante na intensidade da dor entre os grupos. Não houve diferença entre G1 (22 ± 24,9 min) e G2 (21,5 ± 28,1 min) no tempo para a primeira dose de morfina e dose complementar de morfina consumida no G1 (29 ± 18,4 mg) e no G2 (25,1 ± 13,3 mg). CONCLUSÕES: A associação de cetamina (5 mcg.kg-1.min-1) a remifentanila (0,4 mcg.kg-1.min-1) para colecistectomia não alterou a intensidade da dor pós-operatória, o tempo para primeira complementação ou a dose de morfina em 24 horas.

BACKGROUND AND OBJECTIVES: The combination of ketamine and remifentanil seems to be associated with better analgesia and duration. The aim of this study was to evaluate whether a ketamineremifentanil combination promotes improved postoperative analgesia. METHODS: Prospective, randomized, double blind study of 40 patients undergoing video laparoscopic cholecystectomy. Anesthesia was performed with remifentanil, propofol, atracurium, and 50% oxygen. Group 1 (GI) patients received remifentanil (0.4 mcg.kg-1.min-1) and ketamine (5 mcg.kg-1.min-1) and Group 2 (G2) received remifentanil (0.4 mcg.kg-1.min-1) and saline solution. Morphine 0.1 mg.kg-1 was administered at the end of the procedure, and postoperative pain was treated with morphine via PCA. We evaluated the severity of postoperative pain by a numerical scale from zero to 10 during 24 hours. We registered the time to the first analgesic supplementation, amount of morphine used in the first 24 hours, and adverse effects. RESULTS: There was a decrease in pain severity between extubation and other times evaluated in G1 and G2. There was no significant difference in pain intensity between the groups. There was no difference between G1 (22 ± 24.9 min) and G2 (21.5 ± 28.1 min) regarding time to first dose of morphine and dose supplement of morphine consumed in G1 (29 ± 18.4 mg) and G2 (25.1 ± 13.3 mg). CONCLUSION: The combination of ketamine (5 mcg.kg-1.min-1) and remifentanil (0.4 mcg.kg-1.min-1) for cholecystectomy did not alter the severity of postoperative pain, time to first analgesic supplementation or dose of morphine in 24 hours.

JUSTIFICATIVA Y OBJETIVOS: La asociación de la cetamina con el Remifentanilo parece estar asociada con una analgesia de mejor calidad y duración. El objetivo de este estudio fue evaluar si la cetamina asociada al Remifentanilo genera una mejoría de la analgesia postoperatoria. MÉTODO: Se hizo un estudio prospectivo, aleatorio y doble ciego en 40 pacientes sometidos a la colecistectomía videolaparoscópica. La anestesia se realizó con de Remifentanilo, propofol, atracurio y 50% de oxígeno. Los pacientes del G1 recibieron Remifentanilo (0,4 mcg.kg-1.min-1) y cetamina (5 mcg.kg-1.min-1); los del G2, Remifentanilo (0,4 mcg.kg-1.min-1) y solución salina. Fue administrado 0,1 mg.kg-1 de morfina al final de la operación y el dolor postoperatorio se trató con morfina por medio de analgesia controlada por el paciente (PCA). La intensidad del dolor postoperatorio fue mensurada por la escala numérica de 0 a 10, durante 24h. Se anotó el tiempo para la primera complementación analgésica, la cantidad de morfina utilizada durante 24 h y los efectos adversos. RESULTADOS: Ocurrió una reducción de la intensidad del dolor entre el momento de la desentubación y los otros momentos calculados en el G1 y en el G2. No fue observada ninguna diferencia significativa en la intensidad del dolor entre los grupos. No hubo diferencia entre G1 (22 ± 24,9 min.) y G2 (21,5 ± 28,1 min.) en el tiempo para la primera dosis de morfina y dosis complementaria de morfina consumida en el G1 (29 ± 18,4 mg) y en el G2 (25,1 ± 13,3 mg). CONCLUSIONES: La asociación de la cetamina (5 mcg.kg-1.min-1) con el Remifentanilo (0,4 mcg.kg-1.min-1) para la colecistectomía no alteró la intensidad del dolor postoperatorio, el tiempo para la primera complementación o la dosis de morfina en 24h.

Assessment of oral S+ ketamine associated with morphine for the treatment of oncologic pain.

BACKGROUND AND OBJECTIVES: Morphine is used frequently to treat oncologic pain. However, tolerance may develop with prolonged use. The association of a NMDA receptor antagonist may reduce or delay the onset of tolerance. S(+) ketamine seems to be more potent and with fewer side effects. The aim of this study was to evaluate the association of S(+) ketamine and morphine in the treatment of oncologic pain. METHODS: Thirty patients, randomly divided in two groups, participated in this double-blind study. Patients in G1 received 10 mg of morphine PO every 6 hours and 10 mg of S(+) ketamine PO every 8 hours. Patients in G2 received 10 mg of morphine PO every 6 hours and placebo PO every 8 hours. The dose of morphine was adjusted by 5 mg increments whenever necessary. Pain severity was evaluated through a verbal scale. RESULTS: The percentage of no pain and mild pain was similar in both groups (G1 = 0 and G2 = 0 at M0; G1 = 22.2 and G2 = 53.8 at M1; G1 = 22.2 and G2 = 61.5 at M2; G1 = 44.6 and G2 = 61.5 at M3; and G1 = 44.5 and G2 = 53.8 at M4); Chi-square test. The percentage of moderate relief and complete relief was similar in both groups (G1 = 33.4 and G2 = 53.9 after one week; G1 = 44.4 and G2 = 69.2 after two weeks; G1 = 66.6 and G2 = 69.2 after three weeks; and G1 = 55.6 and G2 = 53.9 after four weeks); Chi-square test. The need to increase the dose of morphine was also similar in both groups (G1 = 2.22 and G2 = 2.15); Mann-Whitney test. CONCLUSIONS: We did not observe an increase on the analgesic effects of morphine with the association of 10 mg of S(+) ketamine PO in the treatment of oncologic pain.