Background: Inguinal hernia repair involves more than 20 million patients annually worldwide. Most of the inguinal hernia surgical procedures are performed on outpatients. Prilocaine has a relatively rapid onset and short duration of action which makes it more suitable for outpatient surgeries with relatively fewer effects on hemodynamics.
Aim of the work: The primary outcome of this study is to evaluate hemodynamic changes and the secondary outcomes is to compare the efficacy of block [onset of sensory block, onset and intensity of motor block and duration of action], using three different doses of Prilocaine.   
Patients and methods: A prospective randomized comparative double-blind clinical trial included 60 patients underwent elective inguinal hernia repair. Patients were randomly classified into three groups [20 patients in each] and received spinal anesthesia with three different doses of Prilocaine [low dose 40 mg, medium dose 60 mg and high dose 80 mg]. Hemodynamics and efficacy of the block were measured.
Results: There was a statistically significant decrease of systolic [p-value =0.001] and diastolic blood pressure [p-value =0.033] with high dose Prilocaine. Also, a statistically significant drop in heart rate [p-value=0.017] and early reduce of oxygen saturation [p-value=0.027] with high dose Prilocaine compared to low and medium doses. On the other hand, high dose Prilocaine was associated with faster sensory and more block and was faster to reach maximum block level.
Conclusion: From this study, we can conclude that the use of low and medium doses of Prilocaine [40 and 60 mg] was associated with more hemodynamic stability. In spite of high dose of Prilocaine [80 mg] associated with less hemodynamic stability, it showed better motor and sensory block.