A successful peripheral nerve block not only involves a proper technique, but also a thorough knowledge and understanding of the physiology of nerve conduction and pharmacology of local anesthetics (LAs). This article focuses on what happens after the block. Pharmacodynamics of LAs, underlying mechanisms of clinically observable phenomena such as differential blockade, tachyphylaxis, C fiber resistance, tonic and phasic blockade and effect of volume and concentration of LAs. Judicious use of additives along with LAs in peripheral nerve blocks can prolong analgesia. An entirely new group of drugs-neurotoxins has shown potential as local anesthetics. Various methods are available now to prolong the duration of peripheral nerve blocks.

Background: The prospect of undergoing surgery under anaesthesia can induce significant anxiety in patients. Excess anxiety can lead to several deleterious effects like perioperative cardiac events, increased anaesthetic requirements, higher postoperative pain scores and prolonged hospital stay. Various factors can influence the anxiety levels during surgery. The aim of the study was to estimate the prevalence of anxiety in adult patients scheduled for surgery in a suburban teaching institute in India where the majority of patients belong to lower socioeconomic strata.Methods: One hundred consecutive patients scheduled for various elective surgeries were asked 6 questions according to the Amsterdam preoperative anxiety and information scale to assess their anxiety levels just before shifting into the Operating room. Probable contributing factors noted were age, sex, socioeconomic status, type of surgery, duration of hospital stay, and history of previous surgery. Any specific factors causing anxiety like failure or complications of surgery, recovery from anaesthesia, needle pricks were also asked with leading questions.Results: The overall prevalence of anxiety was 31%. The prevalence in male patients and female patients were 21.2% and 39.5% respectively. There was a moderate correlation between the anxiety scores and need to know scores. The effects of sex, previous surgery, the length of hospital stay were not significant upon the anxiety scores.Conclusion: The overall prevalence of anxiety in the southern part of India was lower when compared to many of the reported studies; however, the prevalence was higher among the female patients.