Sedación en anestesia neuroaxial

introduction. sedation observed in patients with regional anesthesia for cesarean section is a phenomenon not yet clear. in studies that attempt to answer this question, has been found that these patients have low requirements for intravenous hypnotic and inhaled agents. objective: to this review it is proposed that the sedation is a side effect to the action of endogenous opioids under the influence of descending inhibitory pathways. methods. was searched pubmed with the following mesh terms: conscious sedation, deep sedation, spinal and epidural anesthesia.was performed a manual search of reviews of regional anesthesia and the snowball technique, was found items related to sedation and regional anesthesia. articles were reviewed and were confronted with conflicting theories proposed hypothesis. results. were obtained and evaluated 10 articles related to the effects of neuraxial anesthesia sedation. it found that although no specific mechanism is known, however, there is an association between the level of blockade, a mechanism of "down regulation" in the activation of brain stem, and the effect of inhibitory descending pathways in the onset of these effects. conclusions. previously described a causal relationship between inhibition of somatosensory afferents and decreased alertness, measured by auditory evoked potential level. it is proposed an additional mechanism to explain this phenomenon: the predominant action of descending inhibitory system.