Do we still need to restrict preoperative fluid administration in ambulatory anorectal surgery under spinal anaesthesia?

Background: This study was undertaken to determine the effect of a restricted versus a standard intravenous fluid regimen on urinary retention and readiness for discharge after surgery for benign anorectal disease. Methods: A total of 41 ASA I-II patients were randomized into a standard fluid regimen group (group S, n=21) or a restricted fluid regimen group (group R, n=20). Spinal anaesthesia was performed with hyperbaric ropivacaine. Haemodynamic variables were noted. Hypotension, headache, analgesia requirement, nausea and vomiting, thirst and urinary retention were evaluated postoperatively. The Mann-Whitney U and chi-squared tests were used. Results: Patient demographics were comparable between the groups. The area under heart rate versus time curve was higher in group R than in group S (p=0.002). Additional fluid and ephedrine requirements were similar between the groups. First voiding time was longer in group R (p=0.045). Conclusion: In minor anorectal surgery under spinal anaesthesia with ropivacaine, standard fluid regimen provides stable haemodynamic variables without urinary retention.