
Introduction: 
ERAS programs (Enhance Recovery After Surgery) are based on the reduction of surgical aggression in  patients, and have already been proved to be safe and efficient as medical treatments. In order to achieve a good pain control with less opioids,  it is necessary to define an specific protocol of multimodal analgesia. Abdominal wall blocks are a key part of them, but there is no evidence of the best moment to perform it: before or after the surgery.

Material and methods:
We collected all the laparoscopic patients submitted to colorectal surgery with an ERAS program between January and November 2017. The study includes two groups of ERAS: in group A, we performed abdominal wall blocks before surgery incision. In group B, abdominal wall blocks were performed after surgical incision. Group A (80 patients) had an average age of 68 ± 13 years, 60% of men and average length of stay of 7.61 ± 4.38. Group B (10 patients) had an average age of 67 ± 7.02, 80% of men and average length of stay of 5.7 ± 1.49. 
The blocks performed in the first group were TAP block (transverses abdominal plane blockt) (86.2%), subcostal TAP block (6.2%) and rectus sheath block (7.5%). In the second group were performed TAP block (70%), subcostal TAP block (10%) and  rectus sheath block (20%). More than 90% of blocks were performed with levobupivacaine 0.33% in both groups.
We measured VAS score and morphine consumption in the day of surgery and postoperative days 1 to 3. Nausea, vomiting, length of stay and paralytic ileus were also recorded. 
Results:
Postoperative nausea / vomiting and ileus rates were 15,2% and 16.4% in the first group, while in the second group there were no cases of either of these complications. 

Conclusions:
It seems that there is no big difference in VAS and morphine consumption performing abdominal wall blocks pre or post surgery incision. Nausea, vomiting and ileus incidence cannot be absolutely reliable due to the small sample of group B. Bigger well designed studies should be carried out for evidence. 

Bibliography: 
-	Kim AJ, Young RJ, Urman RD. The Role of transversus abdominis plane blocks in enhanced recovery after surgery pathways for open and laparoscopic colorectal surgery.
-	Pirrera B, Alagna V, Lucchi A at al. Transversus abdominis plane (TAP) block versus thoracic epidural analgesia (TEA) in laparoscopic colon surgery in the ERAS program.
-	Matute M, Montero A. Avances farmacológicos en el manejo multimodal de la analgesia perioperatoria. 
-	Dunn K, Durieux M. Perioperative use of intravenous lidocaine.

08 / PERFORMING ABDOMINAL WALL BLOCKS: before or after the surgery?