Clinical trial NCT02790099: Comparison of Surgical Rectus Sheath Block and Intrathecal Morphine
Official title: Double-blinded Randomized Controlled Study for Comparison of Surgical Rectus Sheath and Intrathecal Morphine for Postoperative Pain Control After Caesarean Section
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Pain
Keywords: Pain
Postoperative pain control
Rectus sheath block
Intrathecal morphine
Caesarean section
Lead sponsor: Queen Mary Hospital, Hong Kong
Sponsor class: OTHER
First posted: 2016-06-03
Enrollment: 144
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Pain is the main obstacle in delaying postoperative recovery and leads to prolonged hospital stay. Administration of intrathecal morphine during spinal anaesthesia can provide effective pain control. However, it is associated with significant side effects including nausea, vomiting and itchiness. Also, it is not suitable in all patients, for example, those with morphine allergy, or severe respiratory disease. Surgical rectus sheath block involves injection of local anaesthetic agents into the rectus sheath space before closure of the wound. It has been shown to provide adequate pain control with less systemic side effects. The aim of the study is to evaluate the effectiveness of surgical rectus sheath block and intrathecal morphine in post-Caesarean section pain control.

Detailed description: The incidence of Caesarean section is increasing worldwide. Adequate post-operative analgesia is becoming an essential expectation of patients after Caesarean section. The process of recovery will be hindered by suboptimal pain control and eventually it will leads to immobilization and prolonged hospital stay.

Spinal anesthesia is usually the mode of anesthesia in pregnancy in view of increase general anesthetic risks. Intrathecal morphine can provide good pain control. However, pruritus can occur in up to 51% of patient, nausea and vomiting in up to 21%. Despite its significant side effects, there is an overall better patient satisfactory over use of intrathecal morphine. Due to its concern on respiratory depression, intrathecal morphine is not recommended in patients with severe respiratory disease, obstructive sleep apnoea or those receiving central nervous system depressants. As a result, there were numerous studies on alleviating the adverse effect and to search for other alternatives.

Rectus sheath block aims at blocking the terminal branches of 9th -12th intercostals nerve within the rectus sheath. They form rectus sheath plexus after piercing the posterior aspect of the rectus sheath and then branch into muscular and cutaneous branches. It can be given by anesthetist with or without ultrasound guidance. However, it involved additional time for administration of rectus sheath block and possibility of incorrect placement of catheter leading to ineffective analgesia.

On the contrary, surgical rectus sheath block was administrated by surgeon before closure of rectus sheath. It involves injection of local anesthetic in the rectus sheath space before closure of the wound under direct visual control. Surgical rectus sheath block was shown to be effective in postoperative pain control after transverse laparotomy in paediatrics patients. It was shown to be effective in postoperative pain control in Caesarean section without intrathecal morphine.

Surgical rectus sheath block may be a simple and safe alternative for intrathecal morphine. However, the evidence on its use in Obstetrics and Gynaecology was sparse and there is no study directly comparing the two different mode of analgesia. The aim of the study is to evaluate the use of surgical rectus sheath and intrathecal morphine for postoperative pain in Caesarean section; and its side effects profile.

Eligibility criteria: Inclusion Criteria:

* Planned for elective lower segment Caesarean section, using suprapubic transverse incision
* Willing and able to participate after the study has been explained
* Those understand either Cantonese, Putonghua or English

Exclusion Criteria:

* Patient with treatment for chronic pain
* History of narcotic abuse/ recreational drug use
* Allergy to opioids/ local anesthesia/ paracetamol/ tramadol/ non-steroidal anti-inflammatory drugs
* Patient with pre-eclampsia

Primary outcomes:
measure: Pain score
timeFrame: at 12 hours postoperatively
Secondary outcomes:
measure: Requirement of oral analgesics
timeFrame: within 24hours postoperatively
measure: Time of mobilization
timeFrame: 3days postoperatively
measure: Side effect
timeFrame: 3days postoperatively
measure: Pain score
timeFrame: Immediate postoperative
measure: Pain score
timeFrame: 4hours postoperatively
measure: Pain score
timeFrame: 8hrs postoperatively
measure: Pain score
timeFrame: 24hrs postoperatively
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Department of Obstetrics and Gynaecology, Queen Mary Hospital
Study officials:
affiliation: Queen Mary Hospital, Hong Kong
name: Ernest H. Y. Ng
role: STUDY_CHAIR
References:
citation: Uchiyama A, Nakano S, Ueyama H, Nishimura M, Tashiro C. Low dose intrathecal morphine and pain relief following caesarean section. Int J Obstet Anesth. 1994 Apr;3(2):87-91. doi: 10.1016/0959-289x(94)90175-9.
citation: Dahl JB, Jeppesen IS, Jorgensen H, Wetterslev J, Moiniche S. Intraoperative and postoperative analgesic efficacy and adverse effects of intrathecal opioids in patients undergoing cesarean section with spinal anesthesia: a qualitative and quantitative systematic review of randomized controlled trials. Anesthesiology. 1999 Dec;91(6):1919-27. doi: 10.1097/00000542-199912000-00045. No abstract available.
citation: Sawi W, Choy YC. A comparative study of post operative analgesia, side effects profile and patient satisfaction using intrathecal fentanyl with and without morphine 0.1 mg in caesarean section. Middle East J Anaesthesiol. 2013 Feb;22(1):21-6.
citation: Rozen WM, Tran TM, Ashton MW, Barrington MJ, Ivanusic JJ, Taylor GI. Refining the course of the thoracolumbar nerves: a new understanding of the innervation of the anterior abdominal wall. Clin Anat. 2008 May;21(4):325-33. doi: 10.1002/ca.20621.
citation: Willschke H, Bosenberg A, Marhofer P, Johnston S, Kettner SC, Wanzel O, Kapral S. Ultrasonography-guided rectus sheath block in paediatric anaesthesia--a new approach to an old technique. Br J Anaesth. 2006 Aug;97(2):244-9. doi: 10.1093/bja/ael143. Epub 2006 Jun 23.
citation: Niklasson B, Borjesson A, Carmnes UB, Segerdahl M, Ohman SG, Blanck A. Intraoperative injection of bupivacaine-adrenaline close to the fascia reduces morphine requirements after cesarean section: a randomized controlled trial. Acta Obstet Gynecol Scand. 2012 Dec;91(12):1433-9. doi: 10.1111/j.1600-0412.2012.01480.x. Epub 2012 Nov 1.
citation: Crosbie EJ, Massiah NS, Achiampong JY, Dolling S, Slade RJ. The surgical rectus sheath block for post-operative analgesia: a modern approach to an established technique. Eur J Obstet Gynecol Reprod Biol. 2012 Feb;160(2):196-200. doi: 10.1016/j.ejogrb.2011.10.015. Epub 2011 Nov 21.