lap-guided vs us-guided tap block in pediatric laparoscopy

Conditions: Postoperative Pain

Summary: transversus abdominis plane (tap) block is commonly used to control pain in laparoscopic procedures. it is usually administered with ultrasound guide but it can be also administered with laparoscopic assistance under direct visualization. aim of the present study is determining if the lap-assisted tap is superior to the us-guided tap block in pain control in the immediate postoperative phase as well at 1 and 6 hours post surgery.

although pain in laparoscopic procedures has been demonstrated to be inferior to that of laparotomic ones, it is still produced because of rapid distension of peritoneum, visceral manipulation, irritation and traction of vessels and phrenic nerves, presence of residual gas and inflammatory mediators. analgesia can be achieved with multimodal techniques, which include oral or intravenous drugs as well as loco-regional anesthesia techniques. the abdominal wall has three muscle layers: external and internal obliques, and transversus abdominis. they are innervated by mixed somatic nerves that course between the transversus abdominis and the internal oblique muscles. transversus abdominis plane block is a regional analgesia technique which consists of injecting local anaesthetics between the transversus abdominis and internal oblique muscles, providing analgesia to the parietal peritoneum, skin and muscles of the anterior abdominal wall. it can provide benefit in both open and laparoscopic procedures and it is a safe technique, with a very low reported rate of complications. three major techniques are used to perform the transversus abdominis plane (tap) block-a landmark-based, an ultrasound-guided, and a surgical- placed tap block. although the landmark technique is easy to perform, it might be complicated by inadvertent intraperitoneal organ damage. surgically administered transversus abdominis plane (tap) blocks have been performed by surgeons intraoperatively using the transperitoneal approach, accessing the transversus abdominis plane (tap) from the inside of the abdominal wall. direct visualization of the needle and local anaesthetic spread may help to increase the accuracy as well as eliminating the risk of intraabdominal organ injury and is technically less difficult. it is however necessarily placed after incision and pneumoperitoneum establishment. ultrasound-guided transversus abdominis plane (tap) block on the other side can be performed prior to incision and pneumoperitoneum, thus avoiding nociception from the very beginning. aim of the present prospective, randomised, single center controlled study is to compare postoperative analgesic efficacy of laparo-assisted vs ultrasound-guided transversus abdominis plane (tap) block in pediatric laparoscopic procedures. primary outcome will be the comparison of pain scores between groups upon arrival to post-anesthesia care unit (pacu). secondary outcomes are: * pain scores at 1 and 6 hours after surgery * general anesthesia requirements, as defined by minimum alveolar concentration-hour (mac_hour) * intraoperative opiod consumption * complication rates * time to block completion

Eligibility criteria:
inclusion criteria: * age\<= 18 yrs * elective or urgent laparoscopic surgical procedures including hernia repair, appendectomy, cholecystectomy, piloromyotomy, nissen fundoplication, varicocelectomy * asa status i and ii exclusion criteria: * absence of parental consent * asa status iii-vi * presence of neurological disability affecting spontaneous mobility * previous surgical procedures on the abdominal wall (e.g. gastroschisis repair) * foreseen surgical duration bigger than 4 hours * conversion to laparotomy * use of concomitant other regional anesthesia technique (e.g. neuraxial or peripheral)

Keywords: tap block laparoscopy pediatric surgery