O5 Dose mean opening pressure predominantly assess internal anal sphincter function

Abstract Introduction We have suggested that mean Opening Pressure (Op) recorded during Anal Acoustic Reflectometry (AAR) predominantly represents IAS function however, the extent remains unknown. The aim was to investigate this by excluding external anal sphincter general anaesthetic (GA) with confirmed neuromuscular blockade (NMB). Method Patients undergoing elective abdominal surgery requiring GA+NMB were approached. had pre-operative (awake) and GA + NMB (asleep) AAR measurements performed. rectoanal inhibitory reflex (RAIR) assessed permitting Op value also be when inhibited. at prerectal distension then after 100 mls of air inflated within a balloon in rectum (post-rectal distension). Result 19 patients included. values (cmH20) reductions observed RAIR awake/asleep are as follows: Awake Op: (64.94) post-rectal (35.35) therefore change 29.59 cmH2O i.e. 44.6% reduction Asleep (37.64) (15.55) 22.1 55.3% contribution is calculated (Mean awake x 100)/% asleep = (29.59cmH20 100)/55.3 53.51cmH20 Total awake—IAS EAS 64.94cmH20–53.51cmH20 (82.4%) 11.43cmH20 (17.6%) Conclusion accounts for 82.4% rest it our hypothesis primarily function. Take-home Message pressure internal