Shahin 2010.

Methods	Double‐blinded (participant/outcome assessor), placebo/sham‐controlled, randomized clinical trial Sequence generation by computer‐generated random numbers Follow‐up: 8 months
Participants	Participants: parturients in a university setting in Assiut, Egypt Operation: caesarean section for delivery groups, size: 185/185 Age: 25 years (SD ± 1.5 ) Men/women (group 1, 2): 0/185, 0/185 Comorbidities (group 1/2/3): none reported Remarks:
Interventions	Group 1 (intraperitoneal lidocaine instillation): spinal (details not reported), postincision, preperitoneal closure single‐shot instillation of peritoneal lidocaine (2%, 10 mL) into the pelvis, post‐op paracetamol 1 g intravenously every 6 h for 36 h, rectal suppository of 10 mg followed by oral 400 mg ibuprofen for 72 h, plus intravenous morphine 2 mg for breakthrough pain Group 2 (intraperitoneal placebo/saline instillation): spinal (details not reported), postincision, preperitoneal closure single‐shot instillation of peritoneal saline (0.9%, 10 mL) into the pelvis, post‐op paracetamol 1 g intravenously every 6 h for 36 h, rectal suppository of 10 mg followed by oral 400 mg ibuprofen for 72 h, plus intravenous morphine 2 mg for breakthrough pain Adjuvants: none Immediate post‐op pain control: significantly improved
Outcomes	Dichotomous: overall pain/no pain at 8 months, differentiated also in wound, global abdominal and epigastric pain Continuous: at 8 months: NRS
Notes	Funding sources: "No ... funding acknowledgement was declared by either of the authors." Conflicts of interest: the study authors have no conflict of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐based random allocation
Allocation concealment (selection bias)	Low risk	Placed in sealed, opaque, consecutively numbered envelopes... just after providing consent the women were given the next number on the random list..., (allocation) was concealed from the residents and caregivers
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "the surgeon involved complied with the instruction but was not further involved" data "collection sheets with corresponding codes,.. a number of syringes equal in size;" "preparation and administration of the medication was carried out by a nurse not involved in the management of the patient", "access to randomization code was only available to the secretary of the statistics department", "randomization code was not broken until the completion of the study".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "access to randomization code was only available to the secretary of the statistics department", "randomization code was not broken until the completion of the study".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Analysis was per protocol, not ITT, but the low number of participants lost to follow‐up with almost equal attrition in both groups and the similar demographics in both groups make bias unlikely.
Selective reporting (reporting bias)	Low risk	No protocol available but all outcomes specified in the article were reported on.
Null bias	Low risk	Quote: "control group patients received significantly more morphine injections in the first 24 hours than lidocaine patients". Significantly more participants in the control group reported pain in all sites in the first 24 h than in the lidocaine group.