Intraperitoneal Local Anesthetic in Bariatric Surgery Study (iLABS Study)
Condition: Overweight and Obesity; Bariatric Surgery Candidate
MeSH terms: Overweight
Study type: Interventional

Summary: 
      Obesity is a metabolic disorder that has gradually become a prevalent public health problem
      and is becoming one of the leading causes of death and disability worldwide. The most
      efficacious therapy for morbid obesity today is bariatric surgery. Bariatric surgery
      increases life expectancy by correcting the comorbidities associated with obesity, improves
      the quality of life, and is associated with reduced morbidity and mortality. There is an
      increase application of laparoscopic procedures as it is considered to cause less pain than
      traditional open surgery, smaller incision, reduced blood loss and shorter postoperative
      stay, which cuts down on hospital cost. However, postoperative pain still exists causing
      unpleasant experience for the patient and at times causes a delayed discharge. Pain after
      bariatric surgery is a result of many mechanisms such as tissue injury, abdominal distention,
      local trauma of the stomach, chemical irritation of the peritoneum, and the pneumoperitoneum
      and this pain potentially can prolong hospital stay and lead to increased morbidity, and
      bariatric surgeons are striving to minimize the morbidity of current procedures to improve
      patient outcomes and this gave rise to the use of intraperitoneal local anesthetics (LA). It
      was found that the use of intraperitoneal LA in laparoscopic cholecystectomy is safe, and it
      results in a statistically significant reduction in early postoperative abdominal pain. Many
      studies were done to evaluate the efficacy of intraperitoneal LA in laparoscopic
      cholecystectomy, gynecologic procedures and appendectomy but to date there are limited
      studies done to evaluate the role of intraperitoneal LA in bariatric surgery. The aim of this
      study is to evaluate the effectiveness of intraperitoneal instillation of local ropivacaine
      on postoperative abdominal pain after laparoscopic sleeve gastrectomy (LSG). We hypothesized
      that the administration of intraperitoneal instillation of local ropivacaine would help
      reduce postoperative pain.
    

Detailed description: 
      Recruitment will be a double-blind, placebo-controlled randomized study in patients age 18
      and above going for laparoscopic sleeve gastrectomy (LSG). The study will involve two groups
      with equal allocation of patients in the test group (local anaesthesia) and control group
      (normal saline) by randomization. All patient will need to be evaluated by our
      multidisciplinary team before randomization. Each patient going for an elective LSG will be
      informed regarding this research study, and the final decision will solely be made based on
      patients' willingness. All patients who agree to participate in this study will be randomized
      into one of the study groups. The patients will also be made aware that this is an
      experimental trial and both verbal and written informed consent will be taken before
      treatment. In addition, the patients will be informed regarding the use of the clinical and
      analytical data for publication purposes.

      Patients will not be given access to the study data however they will be informed regarding
      their progress during every follow-up visit. All research data will be kept in our hard disk
      as well as our web-based storage (i-cloud and i-drive) for two years. Study data will be held
      even after the study period as there will still be a continuous follow-up with the patients
      for life. However, all patients' information obtained from this study will be kept and
      handled in a confidential manner, by applicable laws and regulations. When publishing or
      presenting the study results, the identity of patients will not be revealed without patient's
      expressed consent. Participants will also be covered under clinical trial insurance from the
      institution during the study period. In the case of emergency, all patients will be given the
      contact number of the investigator as the investigator are contactable throughout the day.
      This study will begin after receiving the approval of Medical Research & Ethics Committee,
      Ministry of Health Malaysia.

      Computer generated randomization will be done using Interactive Web Response Technology.
      There will be equal chances for patients to be assigned to either one of the study groups.
      The result of the randomization will be kept in envelopes and viewed by the research
      assistant who did not otherwise participate in this study, were unknown to the investigators
      and the patients, and the answer will be contained in a set of sealed envelopes. After
      admitting the patient into the operating room and just before the surgery was done, the
      numbered envelope will be opened by the operating theater nurse and the card inside
      determined which group the patient would be placed. The operating theater nurse will then
      prepare either 20mL of 150mg ropivacaine in 180mL normal saline (for test group) or 200mL
      normal saline (for control group) using a standard syringe and the syringe will be given to
      the surgeon who then injects the solution through a catheter along the greater curvature and
      left subdiaphragmatic region of the stomach. The general anesthetic used for all patients
      will be a combination of 1gm IV Paracetamol, 40mg IV Parecoxib and IV Fentamyl prepared
      according to patient's adjusted body weight.

      Patients will need to be admitted to the hospital one day before the scheduled surgery date.
      Participating patients that are allergic to local anesthetic ropivacaine will be excluded
      from this study. However, if patients have allergy due to the medication after surgery,
      anti-allergic medication will be administered to the patients upon investigation. After the
      surgery, the medical doctors or nurses in the ward that is not otherwise involved in this
      research will assess and record the pain score using visual analog scale (VAS) (0-10). A
      score of 0 means no pain, whereas a score of 10 equals the worst pain ever experienced.
      Post-operative pain will be rated on a VAS at rest and cough. The time of arrival in the
      postoperative recovery room will be defined as zero hours postoperatively. The patients will
      be asked about the location of pain, whether at the shoulder, incision sites, and/or inside
      the abdomen by the medical doctors or nurses. The abdomen and shoulder tip pain intensity
      will be rated at two, four, six, eight, 24 and 48 hours postoperatively. The analgesic
      requirement during the 48 hours after the surgery will also be noted by the medical doctor or
      nurses in the ward. The duration of patients' participation in the study will only be for two
      days postoperative. However, patients still need to come for follow-up after surgery. The
      standard follow-up includes a visit to the outpatient clinic at 1, 2, 3, 4 weeks after
      surgery, then 3, 6, 9, 12, 18, 24 months and after that, a life-long annual visit. Adverse
      events (eg. post-operative bleeding and stapler leak) will be monitored closely at 1, 2, 3,
      and 4 weeks after surgery. In any occurrence of an adverse event, it will be documented and
      reported within 14 days.

      Sample Size Estimation The sample size was estimated with the help of PS software (power and
      sample size calculation software) 3.0.43 with a power of 80% and a significant level of 0.05.
      The estimation was based on Visual Analog Score (VAS) with assuming 50% of difference in mean
      postoperative pain score. The total estimated sample size is 22 patients in each arm for our
      study. However, with the inclusion of 20% drop out rate, the total number of patients needed
      for this study is 27 patients in each arm.

      Data Analysis Statistical calculations will be performed using the standard statistical
      software package, IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. All
      data will be expressed as mean values and standard deviation, with the exception of rescue
      analgesic treatment and the occurrence of shoulder tip pain that will be in percentages (%).
      Median and interquartile range (IQR) will be calculated for all not normally distributed
      continuous variables. Non-parametric tests such as Mann-Whitney U test and/orKruskall-Wallis
      test will be used for non-normal distribution of variables. Associations between qualitative
      variables will be determined by Chi-square test, Fisher's exact test and SAS Exact
      Contingency Table. In all statistical analyses, p-value of < 0.05 (95% confidence interval)
      was considered to be statistically significant.

      Study Ethics Ethical clearance will be obtained from the Medical Research Ethic Committee of
      the Faculty of Medicine, Universiti Putra Malaysia and Kuala Lumpur General Hospital. This
      study will be submitted for National Medical Research Register (NMRR). Respondent consent
      will be obtained from each participant of study.

      Conflict of Interest There is no conflict of interest among the investigators.
    

Intervention name(s): Ropivacaine; Normal saline
Intervention type(s): Drug; Drug
Intervention description(s): Patient undergo elective laparoscopic sleeve gastrectomy will receive 20mL of 150mg ropivacaine (0.75%) diluted in 180mL normal saline to be injected through a catheter along the greater curvature and left subdiaphragmatic region of the stomach at the end of the surgical procedure. After the surgery, the medical doctors or nurses in the ward that is not otherwise involved in this research will assess and record the pain score using visual analog scale (VAS) (0-10). The abdomen and shoulder tip pain intensity will be rated at two, four, six, eight, 24 and 48 hours postoperatively.; Patient undergo elective laparoscopic sleeve gastrectomy will receive 200mL normal saline to be injected through a catheter along the greater curvature and left subdiaphragmatic region of the stomach at the end of the surgical procedure. After the surgery, the medical doctors or nurses in the ward that is not otherwise involved in this research will assess and record the pain score using visual analog scale (VAS) (0-10). The abdomen and shoulder tip pain intensity will be rated at two, four, six, eight, 24 and 48 hours postoperatively.
Other intervention name(s): Test group; Control group
Intervention MeSH terms: Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The study will involve two groups with equal allocation of patients in the test group (local anaesthesia) and control group (normal saline) by randomization. All patients who agree to participate in this study will be randomized into one of the study groups.
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Intraperitoneal local anesthetic; Ropivacaine; Postoperative pain; Bariatric surgery; Sleeve gastrectomy