the effect of adding phentanil to lidocaine in sciatic nerve blockage of popliteal fossa on the period, extent and complications of nerve blockage in the patients underwent lower limb surgery

introduction: lower limb surgeries are commonly done by using general anesthesia, regional anesthesia and blockade nerve. patients who are exposed to danger such as cardiovascular and cardiopulmonary patients and hemodynamic instability, for reducing complications in below knee surgery, can use lower limb blockage nerve in popliteal region which is a safe method. materials & methods: in this experimental research 34 available patients, who were divided into two groups of 17, underwent lower limb surgery at taleghani hospital. dorsal anesthesia method was performed by using 40 milliliters lidocaine 1.5% in one group, and 20 milliliters lidocaine with 100 milligrams phentanil in another, then starting time, period of anesthesia and immobility, degree of senselessness and immobility at two groups were recorded, and eventually the two groups were compared by using appropriate statistical tests (t , χ 2 & fisher exact). results : most of the patients were men at the age 20-82. the onset of sensory blockade, in 64.7% of group one, was 1-2 minutes, and in the rest was 3 minutes (this time, for 84.2% of the patients in the second group, was 2-3 minutes). the difference of the starting time, between the two groups, was not statistically significant (p=0.724). the averages of the starting time of motor blockade in the two groups were 3.64 and 4.4 minutes respectively, and the difference was statistically significant (p=0.014). the period average for motor blockade in the two groups were 296.5 and 190.6 minutes respectively, which is statistically significant (p=0). conclusion: the results of this study revealed that using pure lidocaine or lidocaine with phentanil in sciatic nerve blockage of popliteal fossa has no significant effects on the period, extent and complications of nerve blockage in patients, so it is well recommended, instead of using a large amount of pure lidocaine, a little amount of it plus an appropriate amount of phentanil to be used.