Mowafi 2012.

Methods	Randomized, investigator‐blinded, parallel‐group study with active and placebo control, first dose at skin closure, outcomes X 24 h
Participants	Type of surgery: variety of lower abdominal surgery (bowel resection, abdominal hysterectomy, abdominal myomectomy, radical prostatectomy) Paracetamol group Entered/completing: 20/20 Age (mean, SD): 49.4 ± 18.4 Sex (male, %): 20% Placebo group Entered/completing: 20/19 Age (mean, SD): 48.5 ± 14.4 Sex (male, %): 25% Lornoxicam group Entered/completing: 20/20 Age (mean, SD): 52.8 ± 16.1 Sex (male, %): 30%
Interventions	Paracetamol: 1 g every 6 h in 100 cc IV x 24 h Placebo: 100 cc IV every 6 h x 24 h Lornoxicam: 16 mg in 100 cc saline at time 0 and 8 mg at time 12 h All: PCA pump containing morphine was attached to the participant in a separate IV cannula. The pumps were programmed to administer morphine 1 mg boluses at 10 min intervals and total of 20 mg through 4 h limits.
Outcomes	Primary: pain score via VPS during rest and coughing at 1st, 2nd, 4th, 8th, 12th and 24th postoperative h Secondary: heart rate, blood pressure, respiratory rate, and morphine consumption of the participants were assessed at 1st, 2nd, 4th, 8th, 12th and 24th postoperative h Adverse effects, including nausea, vomiting, itching, sweating, urinary retention, sedation, respiratory depression, hypotension, tachycardia, bradycardia, gastric irritation, increased bleeding from the wound, hematemesis, and melena were recorded and managed accordingly. The Ramsay sedation score [16] was used to evaluate the level of sedation.
Source of funding	Deanship of Scientific Research of Dammam University
Were treatment groups comparable at baseline?	Reports no significant differences for study groups including operative time but states P value < 0.05 for all demographics, likely an error
Details of preoperative pain	Patients who received pain medications on the day prior to surgery and chronic drug abusers were excluded
Notes	Sample size based on internal pilot and VPS difference of 3
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Online research randomizer (www.randomizer.org)
Allocation concealment (selection bias)	Unclear risk	No information reported
Blinding (performance bias and detection bias) All outcomes	Low risk	No mention of participants blinding. “The anesthetist who provided anesthesia and the on who followed up with the patients in the ward for assessment were blinded to the study drug given. Sealed and enclosed 100 ml bags containing either normal saline or the study drugs were used. The color of lornoxicam solution is yellow; to maintain blinding, the containers for all solutions were covered with aluminium foil during administration”.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only one dropout in entire study
Selective reporting (reporting bias)	Unclear risk	Opioid consumption measured at 1, 2 and 4 h, but not reported No results available on clinicaltrials.gov
Size	High risk	Fewer than 50 participants per arm of the study (20 paracetamol, 20 placebo, 20 lornoxicam)