Perioperative use of physostigmine to reduce opioid consumption and peri-incisional hyperalgesia: a randomised controlled trial.

BACKGROUND: Several studies have shown that cholinergic mechanisms play a pivotal role in the anti-nociceptive system by acting synergistically with morphine and reducing postoperative opioid consumption. In addition, the anti-cholinesterase drug physostigmine that increases synaptic acetylcholine concentrations has anti-inflammatory effects. METHODS: In this randomised placebo-controlled trial including 110 patients undergoing nephrectomy, we evaluated the effects of intraoperative physostigmine 0.5 mg h-1 i.v. for 24 h on opioid consumption, hyperalgesia, pain scores, and satisfaction with pain control. RESULTS: Physostigmine infusion did not affect opioid consumption compared with placebo. However, the mechanical pain threshold was significantly higher (2.3 [sd 0.3]) vs 2.2 [0.4]; P=0.0491), and the distance from the suture line of hyperalgesia (5.9 [3.3] vs 8.5 [4.6]; P=0.006), wind-up ratios (2.2 [1.5] vs 3.1 [1.5]; P=0.0389), and minimum and maximum postoperative pain scores at 24 h (minimum 1.8 [1.0] vs 2.4 [1.2]; P=0.0451; and maximum 3.2 [1.4] vs 4.2 [1.4]; P=0.0081) and 48 h (minimum 0.9 [1.0] vs 1.6 [1.1]; P=0.0101; and maximum 2.0 [1.5] vs 3.2 [1.6]; P=0.0029) were lower in the study group. Pain Disability Index was lower and satisfaction with pain control was higher after 3 months in the physostigmine group. CONCLUSIONS: In contrast to previous trials, physostigmine did not reduce opioid consumption. As pain thresholds were higher and hyperalgesia and wind-up lower in the physostigmine group, we conclude that physostigmine has anti-hyperalgesic effects and attenuates sensitisation processes. Intraoperative physostigmine may be a useful and safe addition to conventional postoperative pain control. CLINICAL TRIAL REGISTRATION: EudraCT number 2012-000130-19.

Neuraxial anesthesia in patients with multiple sclerosis - a systematic review / Anestesia neuraxial em pacientes com esclerose múltipla - uma revisão sistemática

Abstract Background and objectives: Current guidelines for neuraxial analgesia in patients with multiple sclerosis are ambiguous and offer the clinician only a limited basis for decision making. This systematic review examines the number of cases in which multiple sclerosis has been exacerbated after central neuraxial analgesia in order to rationally evaluate the safety of these procedures. Methods: A systematic literature search with the keywords "anesthesia or analgesia" and "epidural, peridural, caudal, spinal, subarachnoid or intrathecal" in combination with "multiple sclerosis" was performed in the databases PubMed and Embase, looking for clinical data on the effect of central neuraxial analgesia on the course of multiple sclerosis. Results and conclusions: Over a period of 65 years, our search resulted in 37 reports with a total of 231 patients. In 10 patients multiple sclerosis was worsened and nine multiple sclerosis or neuromyelitis optica was first diagnosed in a timely context with central neuraxial analgesia. None of the cases showed a clear relation between cause and effect. Current clinical evidence does not support the theory that central neuraxial analgesia negatively affects the course of multiple sclerosis.

Resumo Justificativa e objetivos: As diretrizes atuais para analgesia neuraxial em pacientes com esclerose múltipla (EM) são ambíguas e oferecem ao clínico apenas uma base limitada para a tomada de decisão. Esta revisão sistemática examina o número de casos nos quais a EM foi exacerbada após analgesia neuraxial central para avaliar racionalmente a segurança desses procedimentos. Métodos: Uma busca sistemática da literatura com as palavras-chave "anestesia ou analgesia" e "epidural, peridural, caudal, espinhal, subaracnóideo ou intratecal" em combinação com multiple sclerosis foi feita nas bases de dados PubMed e Embase à procura de dados clínicos sobre a efeito da analgesia neuraxial central sobre o curso da esclerose múltipla. Resultados e conclusões: Durante um período de 65 anos, nossa busca resultou em 37 relatos com um total de 231 pacientes. Em 10 pacientes, a esclerose múltipla foi agravada e, em nove, a esclerose múltipla ou neuromielite óptica foi diagnosticada pela primeira vez em momento concomitante com a analgesia neuraxial central. Nenhum dos casos apresentou uma clara relação entre causa e efeito. A evidência clínica atual não sustenta a teoria de que a analgesia neuraxial central afeta negativamente o curso da esclerose múltipla.

[Neuraxial anesthesia in patients with multiple sclerosis - a systematic review]. / Anestesia neuraxial em pacientes com esclerose múltipla ­ uma revisão sistemática.

BACKGROUND AND OBJECTIVES: Current guidelines for neuraxial analgesia in patients with multiple sclerosis are ambiguous and offer the clinician only a limited basis for decision making. This systematic review examines the number of cases in which multiple sclerosis has been exacerbated after central neuraxial analgesia in order to rationally evaluate the safety of these procedures. METHODS: A systematic literature search with the keywords "anesthesia or analgesia" and "epidural, peridural, caudal, spinal, subarachnoid or intrathecal" in combination with "multiple sclerosis" was performed in the databases PubMed and Embase, looking for clinical data on the effect of central neuraxial analgesia on the course of multiple sclerosis. RESULTS AND CONCLUSIONS: Over a period of 65 years, our search resulted in 37 reports with a total of 231 patients. In 10 patients multiple sclerosis was worsened and nine multiple sclerosis or neuromyelitis optica was first diagnosed in a timely context with central neuraxial analgesia. None of the cases showed a clear relation between cause and effect. Current clinical evidence does not support the theory that central neuraxial analgesia negatively affects the course of multiple sclerosis.