Anesthetic considerations and postoperative pain management in radical penectomy: Case report / Penectomía radical, consideraciones anestésicas y manejo del dolor postoperatorio: Reporte de un caso

Abstract Radical penectomy (RP) is infrequently performed as it is reserved for specific cases of penile cancer, hence the paucity of reports regarding surgical and anesthetic considerations. Acute postoperative pain, chronic post-surgical pain, concomitant mood disorders as well as a profound impact on the patient's quality of life have been documented. This case is of a patient with diabetes and coronary heart disease, who presented with advanced, over infected penile cancer, depressive disorder and a history of pain of neuropathic characteristics. The patient underwent radical penectomy using a combined spinal-epidural technique for anesthesia. Preoperatively, the patient was treated with pregabalin and magnesium sulphate, and later received a blood transfusion due to intraoperative blood loss. Adequate intra and postoperative analgesia was achieved with L-bupivacaine given through a peridural catheter during one week. Recovery was good, pain was stabilized to preoperative levels and the patient received pharmacological support and follow-up by psychiatry and the pain team.

Resumen La penectomía radical (PR) es una cirugía infrecuente, reservada para casos específicos de cáncer de pene, por lo que hay escasos informes sobre sus consideraciones quirúrgicas y anestésicas. Se ha documentado dolor agudo postoperatorio, dolor crónico posquirúrgico y alteraciones del estado de ánimo concomitantes, así como un profundo impacto en la calidad de vida posterior del paciente. Se presenta el caso de un paciente diabético y cardiópata coronario con cáncer de pene avanzado y sobreinfectado, trastorno depresivo y dolor previo de características neuropáticas, que recibe técnica combinada espinal-peridural para cirugía de penectomía radical. Se le trata también con pregabalina preoperatoria, sulfato de magnesio y transfusión por sangrado quirúrgico. Se otorgó una adecuada analgesia intra y postoperatoria, mediante catéter peridural con L-bupivacaína hasta por una semana. El paciente tuvo una buena recuperación, estabilización del dolor a niveles preoperatorios, controles y apoyo farmacológico por psiquiatría de enlace y equipo del dolor.

Dexmedetomidine preventive chronic post-hysterectomy pain / 临床麻醉学杂志

Objective To investigate the effects of dexmedetomidine preventive on chronic postsurgical pain (CPSP) in patients undergoing hysterectomy.Methods Eighty patients scheduled for elective abdominal hysterectomy,aged 18-65 years,ASA physical status Ⅰ or Ⅱ were recruited,and randomly divided into dexmedetomidine group (group D) and the control group (group C).All patients received total intravenous anesthesia with propofol and remifentanil.The patients in group D were administered intravenously dexmedetomidine 0.5μg·kg-1 ·h-1 from anesthesia induction to extubation at the end of surgery,while the patients in group C were administered normal saline 0.125 ml·kg-1· h-1.All patients received patient-controlled analgesia with fentanyl postoperatively.Intraoperative vital signs,the dose of analgesic and sedatives,and adverse reactions were recorded.CPSP and neuropathic pain (NP) were evaluated through the telephone follow-up in 3,6 and 12 months postoperatively.Results The peri-operative vital signs of both groups were stable,and no obvious adverse reaction were observed.The dosage of tramadol used for resue analgesia in group D was lower than that in group C [(58.8±15.4) mg vs (78.9±24.5) mg,P＜0.05].Seventy-one of eighty patients completed all follow-up (37 in group D,34 in group C).The incidence of CPSP in postoperative 3,6 and 12 months were 10.8％,5.4 ％,2.7 ％ in group D,significantly lower than 35.3 ％,26.5 ％,17.6％ in group C,respectively (P＜0.05).The incidence of NP in postoperative 3 and 6 months were 2.7％,0％,significantly lower than 17.6％,14.7％ in group C,respectively (P＜0.05).Conclusion Dexmedetomidine preventive analgesia alleviate chronic post-hysterectomy pain.

Mechanisms of postoperative pain

Good pain control after surgery is important to facilitate overall recovery, improve patient satisfaction, decrease morbidity, and reduce health care cost. However, despite heightened awareness and development of new guidelines in recent decades, we have failed to make major improvements in postoperative pain control. Currently available analgesic therapies have limited efficacy, and pain after surgery continues to be a significant clinical problem. Our goal is to develop more effective and safer clinical strategies that will eliminate or greatly reduce postoperative pain, and a better understanding of the mechanisms of pain induced by surgery would be essential to achieve this goal. Evidence suggests that the pathophysiological mechanisms and optimal treatment of postoperative pain are different from many other painful conditions. Recognizing the necessity and importance of relevant pre-clinical models, we have developed and characterized rodent incision models that have close similarities to postoperative pain in patients. Previous studies have demonstrated the clinical relevance and translatability of these pre-clinical models of postoperative pain. In this review, we describe the rodent incision pain models, and summarized our current understanding of the mechanisms of postoperative pain, highlighting key findings from our previous studies using these models.

Fisiopatologia da dor pós-operatória / Pathophysiology of the post-surgical pain

Foi realizada revisão dos mecanismos fisiopatológicos da dor aguda pós-operatória, envolvendo fibras nervosas, estímulos e neurotransmissores. A lesão tecidual provoca liberação de mediadores inflamatórios com sensibilização periférica. Os estímulos atingem a medula espinal, com alterações da plasticidade e sensibilização central.