title: Comparative study between effect of pre- versus post-incisional transversus abdominis plane block on acute and chronic post-abdominal hysterectomy pain.
abstract: BACKGROUND
  The prevalence of persistent chronic pain after abdominal hysterectomy is 5-32%. Our objectives were to determine the influence of transversus abdominis plane (TAP) block on the incidence of acute and chronic post-hysterectomy pain and to examine potential associations between time of block administration, either before surgical incision (preemptive) or after end of surgical procedure and its effect.
  
  
  METHODS
  Seventy-five patients undergoing elective total abdominal hysterectomy under general anesthesia were allocated randomly to receive TAP block either pre-incisional, or before emergence from anesthesia or sham block (just a needle puncture, control group). Pain was evaluated postoperatively at rest and movement by visual analogue scale. Peri-operative analgesic requirements, sedation, postoperative nausea and vomiting scores were recorded. Patients were questioned at three, and six months after surgery for type and severity of chronic pain.
  
  
  RESULTS
  Pain scores were significantly higher in Group II versus Group I (P<0.05), but both demonstrated significantly lower pain scores than control Group. Analgesic requirements decreased significantly in patients received TAP block (P<0.0001) with more significant decrease in the pre-incisional group. The incidence of chronic pain was significantly reduced in the pre-incisional group than others. The incidence of sedation was noted to be higher in the control group (61%) versus other groups (18% and 32% respectively), at time point 12 h postoperatively but was comparable between 12, 48 h (awake and alert). Incidence of postoperative nausea and vomiting (PONV) was reduced in patients who received TAP block (16% and 29%) in Group I and II respectively versus 66.5% in Group III. There were no complications attributed to the TAP block.
  
  
  RESULTS
  Pain scores were significantly higher in Group II versus Group I (P<0.05), but both demonstrated significantly lower pain scores than control Group. Analgesic requirements decreased significantly in patients received TAP block (P<0.0001) with more significant decrease in the pre-incisional group. The incidence of chronic pain was significantly reduced in the pre-incisional group than others. The incidence of sedation was noted to be higher in the control group (61%) versus other groups (18% and 32% respectively), at time point 12 h postoperatively but was comparable between 12, 48 h (awake and alert). Incidence of postoperative nausea and vomiting (PONV) was reduced in patients who received TAP block (16% and 29%) in Group I and II respectively versus 66.5% in Group III. There were no complications attributed to the TAP block.
  
  
  CONCLUSIONS
  TAP block seems to be an acceptable choice for postoperative analgesia; pre-incisional TAP block appeared to reduce the severity of acute pain, analgesic requirements with its undesirable side-effects and incidence of chronic pain in comparison with blockade before emergence from anesthesia.
authors.affiliation: Department of Anesthesia, Tanta University Hospital, Tanta University, Tanta, Egypt.
authors.forename: Yasser Mohamed
authors.initials: YM
authors.lastname: Amr
authors.affiliation: Department of Anesthesia, Tanta University Hospital, Tanta University, Tanta, Egypt.
authors.forename: Sabry M
authors.initials: SM
authors.lastname: Amin
keywords: Abdominal hysterectomy; TAP block; pain