Evidence based switch to perianal block for ano-rectal surgeries

Evidence suggests that switch from spinal/general anaesthesia (SA/GA) to perianal block (PAB) may prove advantageous for proctologic surgeries. This study evaluates the practicability of this evidence based switch.

Feasibility and efficacy of PAB for proctologic surgeries was prospectively evaluated on 100 consecutive patients over 11 months. Thirty ml of local anesthetic (0.25% bupivacaine+1% lignocaine with adrenaline) was infiltrated into the anal sphincter and perianal skin, under sedation, for achieving PAB. Time taken for onset of anesthesia; success/failure of block; conversion rate to GA; operative ease; operative time; post operative recovery; duration of analgesia; post operative pain based on verbal response score (VRS; scale: 0-100); and complications were analyzed.

54 open haemorrhoidectomies; 27 fistulectomies and 19 lateral sphincterotomies were performed. Average of 3 min (range 2-5 min) was needed for onset. Block was successful in 97% of cases. 3% needed conversion to GA. Good anesthesia and sphincter relaxation ensured operative ease. Median operative time was 20 min (range 10-35 min). Analgesia lasted a median of 5 hours (range 3-10 hrs). Subsequent pain ranged between VRS 10-40, tapering off, along with analgesic requirement, over a week. Trivial injection site hematoma (1%) and reactionary bleeding (1%) were the complications observed. Post operative recovery was uniformly smooth in all patients.

Perianal block is a safe, feasible, reliable, and reproducible mode of anesthesia for ano-rectal surgeries. Its evident efficacy justifies its adoption as anesthesia of choice.