the effect of transdermal tng on the level of spinal anesthesia inknee arthroscopic surgery

background and aims: one of the problems with the implementation of spinal anesthesia is not to achieve an appropriate sensory level and sensory level decline before the end of operation that can cause pain and stress for the patient and surgeon dissatisfaction.                                                                                              in this study, the effects of transdermal tng on the level of spinal anesthesia in knee arthroscopy patients were investigated. materials and methods: in a randomized clinical trial 46 patients randomly allocated in two groups of tng or placebo. all of patients  were premedicated with 10 mg diazepam before operation and then spinal anesthesia was performed with 1.5cc lidocaine 5%. after 20 minutes, one group received a transdermal placebo and the second group received transdermal tng.the level of sensory block was measured by a blunt needle and alcohol swab.                                                                findings: after 20 minutes a two level increase of sensory level in 82.6% of patients in the  tng group was observed but only 4.3%of the placebo group showed this raise. (p 0<0.05)                          conclusion: in spinal anesthesia, transdermal tng can increase the sensory level via some theoretical mechanisms.