Use of gabapentin in management of postoperative pain after crosslinking / Uso da gabapentina no manejo da dor pós-operatória do crosslinking

ABSTRACT Objective: The objective was to evaluate the efficacy of gabapentin in the management of neuropathic pain in patients with keratoconus, who were treated with fast (10 minutes) epi-off corneal crosslinking (CXL). Methods: This was a prospective, double-blind, randomized study. The sample comprised patients with bilateral progressive keratoconus, aged 12 years or older, who underwent a bilateral epi-off corneal CXL (fast - 10 minutes) procedure. One group was given placebo orally, and the other group received gabapentin 600 mg orally, both preoperatively. The visual analogue scale (VAS) was applied to record postoperative pain up to 48 hours after procedure. The study was conducted at the Belotto Stock Centro Oftalmológico, in the city of Joaçaba, Santa Catarina, Brazil, from June 2018 to September 2019. Results: At no point in the study significant differences were observed between groups, in terms of pain intensity measured by means of the VAS questionnaire, or of opioid use (Paco®), though opioid consumption was 21% lower in the group receiving gabapentin. Conclusion: We concluded gabapentin has no efficacy in postoperative pain control after epi-off corneal CXL (fast - 10 minutes). Although there was no statistically significant difference, the group that received gabapentin suffered less pain, resulting in lower opioid consumption. UTN number: U1111-1256-0330.

RESUMO Objetivo: Avaliar a eficácia do uso da gabapentina no manejo da dor neuropática em pacientes portadores de ceratocone submetidos ao tratamento de crosslinking corneano epi-off fast de 10 minutos. Métodos: Tratou-se de pesquisa prospectiva, duplo-cega, randomizada. A amostra foi composta de pacientes com ceratocone progressivo bilateral, a partir dos 12 anos de idade, submetidos ao procedimento de crosslinking corneano acelerado epi-off fast de 10 minutos bilateral. Um grupo recebeu placebo via oral e o outro, gabapentina 600mg, via oral, ambos no pré-operatório. A Escala Visual Analógica foi aplicada para registrar a dor pós-operatória até 48 horas após o procedimento. A pesquisa foi realizada no período de junho de 2018 a setembro de 2019 em um centro oftalmológico. Resultados: Não foram observadas diferenças estatísticas significativas para ambos os grupos, tanto na intensidade da dor medida pela Escala Visual Analógica, como na redução do uso do opioide (Paco®), em qualquer horário analisado durante um período de 48 horas. No entanto, houve redução de 21% no consumo de opioides pelo grupo que fez uso da gabapentina. Conclusão: A gabapentina não demonstrou eficácia no controle da dor no pós-operatório do crosslinking corneano epi-off fast de 10 minutos. No entanto, observou-se que, mesmo não havendo diferença estatisticamente significativa, houve diminuição da dor no grupo em que foi usada a gabapentina, resultando na redução do consumo de opioides. Número UTN: U1111-1256-0330.

Synergistic effect of the association between lidocaine and magnesium sulfate on peri-operative pain after mastectomy: A randomised, double-blind trial.

BACKGROUND: Recently, the use of venous adjuvants, such as lidocaine and magnesium sulfate, has been gaining ground in multimodal analgesia. However, no study has evaluated the impact a combination of the two drugs. OBJECTIVES: To evaluate the efficacy of venous adjuvants in reducing opioid consumption and pain scores after mastectomy. DESIGN: Randomised, double-blind, parallel-group, noninferiority clinical trial with a 1 : 1 : 1 : 1 allocation ratio. SETTING: Hospital de Base do Distrito Federal, Brasilia, Federal District, Brazil from November 2014 to December 2017. PATIENTS: One-hundred and ninety-eight patients were electively scheduled for mastectomy. Seventy-eight were excluded. INTERVENTIONS: Intra-operative infusions of remifentanil (0.1 µg kg min), lidocaine (3 mg kg h), magnesium sulfate (50 mg kg + 15 mg kg h) or lidocaine with magnesium sulfate were used. All patients received standard general anaesthesia. MAIN OUTCOME MEASURES: Peri-operative opioid consumption and pain scores. RESULTS: The patients who received both lidocaine and magnesium sulfate group (n=30) consumed less alfentanil during surgery (P < 0.001) and less dipyrone (P < 0.001) and morphine (P < 0.001) in the postoperative period. Only two patients (6.7%) in the lidocaine and magnesium sulfate group needed morphine (P < 0.001). These requirements were significantly lower when compared with patients who received remifentanil (n=30; 76.6%) and magnesium sulfate (n=30; 70%; odds ratio 46.0, 95% confidence interval 8.69 to 243.25, P < 0.001, and odds ratio 32.66, 95% confidence interval 6.37 to 167.27, P < 0.001, respectively). The patients of the lidocaine and magnesium sulfate group had lower pain scores in the first 24 h postoperatively using the numerical rating scale and verbal rating scale at discharge from the postanaesthesia care unit (P < 0.001), after 12 h (P < 0.001) and after 24 h (P < 0.001) when compared with the other three groups. CONCLUSION: Our findings suggest a synergistic effect of the use of both lidocaine and magnesium in peri-operative pain. This may be another potential strategy in the multimodal analgesia regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02309879.