Ultrasound-guided regional anesthesia is associated with fewer complications and has been reported to be useful in many patients who are likely to be high risk for general anesthesia [1]. However, there is also a risk of falls and injury to limb after surgery due to a prolonged anethestic effects and impaired motor or sensory function [2,3].

Although the considerations and risks of general anesthesia in smokers have been well-established, the relationship between smoking and regional anesthesia remains unclear [4]. Other than increased cardiovascular and pulmonary risks under general anesthesia, smoking affects the pharmacokinetics of common drugs used during general anesthesia as chemicals in cigarettes can induce liver enzymes and increase their metabolism. Chronic smokers also have higher analgesic requirements. The aim of the present study was to investigate the effect of smoking on the onset and duration of the effects of regional anesthesia. We hypothesized that the onset of regional anesthesia would be slower in smokers and that the duration of regional blockade would be shorter too [[5], [6], [7]]. If there is an association between smoking history and the effects of regional anesthesia, this would be an important consideration when planning the anesthetic technique of choice and for preoperative risk counseling.