Fassoulaki 2016.

Methods	Triple‐blind (participant, provider, and outcome assessor), placebo controlled, randomized clinical trial Sequence generation by computer‐generated random number tables Follow‐up: 3 months
Participants	Participants 110 adults in a university setting in Greece Operation: laparoscopic cholecystectomy 2 groups, size: 55/55 Age (± SD), group 1, 2: 51 years (11.2), 48 (SD ± 12.5) Men/women, group 1, 2: 17/38, 14/41 Exclusion criteria: central nervous system, kidney, or liver disease, chronic pain, or consumption of analgesics and/or calcium channel blockers during the last month
Interventions	Group 1 (ropivacaine): premedication was omitted in all cases. In the operating room an 18‐G catheter was inserted in a peripheral vein on the dorsum of the left hand and metoclopramide 10 mg, ranitidine 50 mg, and droperidol 0.75 mg were injected IV before induction of anaesthesia. Pulse oximetry, electrocardiogram, noninvasive blood pressure, inspired and end tidal oxygen concentration, capnography, inspired and end tidal sevoflurane concentration, and neuromuscular block were monitored (Datex Ohmeda S/5TM, Anesthesia Monitor, Helsinki, Finland) (Multistim VARIO, Pajunk, Geisingen, Germany). Participants were preoxygenated for 3 min. Thiopental (5‐6 mg/kg) and fentanyl (2 mg/kg) were administered to induce anaesthesia, followed by rocuronium (0.6 mg/kg) to facilitate tracheal intubation. Anaesthesia was maintained with sevoflurane 2%‐3% inspired concentration in an oxygen nitrous oxide mixture of 1:1 L/min. Diclophenac (75 mg IV) was infused slowly within 30 min before pneumoperitoneum. After induction of anaesthesia and before beginning the operation the surgeon inserted SC a “PAINfusor” multihole catheter 75 mm long (PLAN 1 Health, Baxter, Amaro‐UD, Italy) below and parallel to the subcostal area under aseptic conditions. The catheter was connected to a 130 mL elastomeric pump (Baxter Health‐Care Corporation, Deerfield, IL) delivering fluid at 2 mL/h. The pump was filled with 48 mL of 0.75% ropivacaine under sterile conditions by an anaesthetic nurse not participating in the study and having access to the randomization sets. The infusion was maintained for the first 24 h. Laparoscopic cholecystectomy using the 4‐port technique was performed by the same surgeon in all participants. During the pneumoperitoneum the intra‐abdominal pressure ranged between 12 and 14 mmHg. The total amount of CO2 used was recorded. At the end of the procedure each of the 4 holes was infiltrated with 2 mL of ropivacaine 0.75%. After skin closure residual neuromuscular block was reversed with sugammadex (2 mg/kg), and the participant was extubated and transferred to the PACU. In the PACU, the participants were asked to score their pain using the VAS and received paracetamol IV 1 g if VAS was > 40 mm or if the participant asked for analgesia. If paracetamol was not effective then tramadol (100 mg IV) was administered. Participants who experienced vomiting were given ondansetron 4 mg IV. During the first 48 h postoperatively participants were given paracetamol (400 mg) and codeine (10 mg) (Lonarid tablets) on demand or when the VAS scores exceeded the 40 mm in the VAS 100 mm scale. If the participant experienced nausea/vomiting, then ondansetron (4 mg IV) was given. Group 2 (control): the same intervention as above was used except 0.9% saline was substituted for ropivacaine Adjuvants: none Immediate post‐op pain control: no difference
Outcomes	Dichotomous: pain vs no pain Continuous: VAS scores Other reported: pain at rest and pain during cough recorded 2, 4, 8, 24, and 48 h postoperatively, paracetamol and tramadol consumption in the PACU and cumulative Lonarid tablets consumption during the first postoperative 48 h, incidence of shoulder pain
Notes	Funding sources: source of funding not stated Conflicts of interest: "the authors declare no conflicts of interest."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization was carried out by means of a computer‐generated table with 1 set of 55 numbers for the range 1‐110. In a second set the remaining 55 numbers were included corresponding to the control group.
Allocation concealment (selection bias)	Low risk	Each number for the ropivacaine and the control group remained unique.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The pump was filled with 48 mL of 0.75% ropivacaine or equal volume of saline 0.9% under sterile conditions by an anesthetic nurse not participating in the study and having access to the randomization sets."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Sham block was used to maintain blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition rates were low and ITT analysis was performed.
Selective reporting (reporting bias)	Unclear risk	Not discussed
Null bias	Low risk	Quote: "Subcutaneous ropivacaine ...was associated with less pain in the PACU and 4 hours after surgery."