Cannabinoid products for pain management: recommendations from the São Paulo State Society of Anesthesiology.

There is growing interest in using cannabinoids across various clinical scenarios, including pain medicine, leading to the disregard of regulatory protocols in some countries. Legislation has been implemented in Brazil, specifically in the state of São Paulo, permitting the distribution of cannabinoid products by health authorities for clinical purposes, free of charge for patients, upon professional prescription. Thus, it is imperative to assess the existing evidence regarding the efficacy and safety of these products in pain management. In light of this, the São Paulo State Society of Anesthesiology (SAESP) established a task force to conduct a narrative review on the topic using the Delphi method, requiring a minimum agreement of 60% among panelists. The study concluded that cannabinoid products could potentially serve as adjuncts in pain management but stressed the importance of judicious prescription. Nevertheless, this review advises against their use for acute pain and cancer-related pain. In other clinical scenarios, established treatments should take precedence, particularly when clinical protocols are available, such as in neuropathic pain. Only patients exhibiting poor therapeutic responses to established protocols or demonstrating intolerance to recommended management may be considered as potential candidates for cannabinoids, which should be prescribed by physicians experienced in handling these substances. Special attention should be given to individual patient characteristics and the likelihood of drug interactions.

Dor crônica inguinal, estamos atentos a essa complicação? / Chronic groin pain, are we aware of this complication?

A cirurgia de hérnia inguinal (HI) é um dos procedimentos mais comuns na prática do cirurgião geral. Estima-se que 20 milhões dessas operações sejam realizadas no mundo anualmente. Com o advento da técnica sem tensão e implante de tela sintética, as taxas de recidiva caíram expressivamente e a recidiva deixou de ser a principal complicação tardia após o reparo da hérnia inguinal. Hoje a principal complicação pós-operatória tardia da cirurgia de HI é a dor crônica inguinal pós-operatória (DCIP). A definição de DCIP é a dor pós-operatória da região inguinal após 3-6 meses da cirurgia. Relatamos o caso de um jovem paciente do sexo masculino que se apresentou com DCIP após ter sido previamente submetido a duas herniorrafias inguinais. Inicialmente apresentava dor inguinal a esquerda sem abaulamento evidente e na ocasião foi submetido a herniorrafia inguinal esquerda pela técnica de Lichtenstein. Não houve resolução da dor após a cirurgia. Após 1 ano foi novamente operado, dessa vez bilateralmente e infelizmente evoluiu com piora da dor apresentava dor predominantemente neuropática (em queimação e com irradiação para região testicular bilateralmente) e intensidade moderada (escala visual analógica 6), sem melhora com anti-inflamatórios não esteroidais ou analgésicos. Apresentava dor ao toque do anel inguinal externo bilateralmente, hiperestesia no teritório de nervos genito-femoral, ílio-hipogástrico e ílio-inguinal do lado esquerdo e hipoestesia no território dos três nervos do lado direito. Apresentou alívio temporário da dor após bloqueio anestésico inguinal bilateral. Paciente foi então submetido a triplo-neurectomia bilateral com remoção das telas de polipropileno. Em seguimento um ano após o tratamento cirúrgico, o paciente permanece sem dor inguinal. [au]

Inguinal hernia (IH) surgery is one of the most common procedures in the practice of the general surgeon. With adoption of tension-free technique and synthetic mesh implantation, recurrence rates decreased and recurrence is no longer the main late complication after IH repair. Currently, the main late postoperative complication of IH repair is chronic postoperative inguinal pain (CPIP). CPIP is defined as postoperative pain in the inguinal region persisting 3-6 months after surgery. We report the case of a young male patient who presented with CPIP after having undergone two inguinal hernia repairs. Initially, he had left inguinal pain without evident bulging and underwent left inguinal herniorrhaphy using the Lichtenstein technique. There was no relief of pain after surgery. After 1 year, he underwent surgery again, this time bilaterally and unfortunately the pain got worse. He had predominantly neuropathic pain (burning and irradiated to the testicular region bilaterally) and moderate intensity (visual analogue scale 6) refractory to medical management. He had hyperesthesia on the territory of the genitofemoral, iliohypogastric and ilioinguinal nerves on the left side and hypoesthesia in the territory of the three nerves on the right side. A local anesthetic inguinal block provided temporary relief. We performed a bilateral triple neurectomy with removal of the polypropylene mesh. Followed up one year after surgical treatment, the patient remains without inguinal pain. [au]

Intraoperative use of methadone improves control of postoperative pain in morbidly obese patients: a randomized controlled study.

OBJECTIVES: Surgical patients still commonly experience postoperative pain. With the increasing prevalence of obesity, there is a growing demand for surgical procedures by this population. Intraoperative use of methadone has not been well assessed in this population. MATERIALS AND METHODS: Patients with a body mass index of 35 kg/m2 or more undergoing bariatric surgery were randomly assigned to receive either fentanyl (group F) or methadone (group M) in anesthesia induction and maintenance. The primary outcome was morphine consumption during the first 24 hours after surgery through a patient-controlled analgesia device. Secondary outcomes were pain scores at rest and while coughing, opioid related side effects, and patient satisfaction. The patients were also evaluated 3 months after surgery for the presence of pain, dysesthesia, or paresthesia at surgical site. RESULTS: Postoperative morphine consumption was significantly higher for patients receiving fentanyl than methadone during the postoperative period at 2 hours (mean difference [MD] 6.4 mg; 95% CI 3.1-9.6; P<0.001), 2-6 hours (MD 11.4 mg; 95% CI 6.5-16.2; P<0.001), 6-24 hours (MD 10.4 mg; 95% CI 5.0-15.7; P<0.001), and 24-48 hours (MD 14.5 mg; 95% CI 3.9-25.1; P=0.01). Patients from group F had higher pain scores until 24 hours postoperatively, higher incidence of nausea and vomiting, lower satisfaction, and more evoked pain at surgical scar at the 3-month postoperative evaluation than group M. CONCLUSION: Intraoperative methadone can safely lower postoperative opioid consumption and improve postoperative pain scores compared with fentanyl in morbidly obese patients.

Colitis generates remote antinociception in rats: the role of the L-arginine/NO/cGMP/PKG/KATP pathway and involvement of cannabinoid and opioid systems.

OBJECTIVE AND DESIGN: The aim of this study was to investigate the possible involvement of the NO/cGMP/PKG/KATP+ pathway, cannabinoids and opioids in remote antinociception associated with 2,4,6-trinitrobenzene sulph onic acid (TNBS)-induced colitis. METHODS: TNBS-induced colitis was induced by intracolonic administration of 20 mg of TNBS in 50% ethanol. After induction, carrageenan (500 µg/paw) or prostaglandin (PG) E2 (100 ng/paw) was injected in the rat's plantar surface and hypersensitivity was evaluated by the electronic von Frey test. Rats were pre-treated with L-Noarg one hour before carrageenan injection. L-Arginine was given 10 min before L-Noarg injections. ODQ, KT 5823, glibenclamide (Glib), naloxone and AM 251 or AM 630 were administered 30 min prior to carrageenan or PGE2 treatments. RESULTS: Colitis induction by TNBS reduced PGE2 or carrageenan-induced hypersensitivity. Antinociception produced by TNBS-induced colitis was reversed significantly (P<0.05) by L-Noarg, ODQ, KT 5823, glibenclamide, naloxone, AM251 and AM630 treatments. CONCLUSIONS: TNBS-induced colitis causes antinociception in the rat paw. This disorder appears to be mediated by activation of the NO/cGMP/PKG/KATP pathway, endocannabinoids and endogenous opioids. This information may contribute to a better understanding of peripheral neurological dysfunctions occurring in Crohn's disease.