Khalili 2013.
Methods | Randomized, double‐blind placebo‐controlled, single dose, over 24 h IV acetaminophen was administered before skin closure versus a control group that received normal saline as placebo; preemptive group receiving 15 mg/kg 0.5 h preoperatively, not reported here |
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Participants | Type of surgery: orthopedic, lower extremity Paracetamol group Entered/completing: 25/25 Age (mean, SD): 36.8 +/‐ 14.8 Sex (male, %): 21 (84%) Placebo group Entered/completing: 25/25 Age (mean, SD): 37.8 +/‐ 12.9 Sex (male, %): 17 (68%) |
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Interventions | Paracetamol: 15 mg/kg in 100 ml of IV normal saline prior to skin closure Placebo (normal saline) 100 ml prior to skin closure |
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Outcomes | Primary: pain intensity according to VRS Secondary: Timing, # participants requesting and dose of rescue medication (pethidine) Adverse effects (sedation, hypotension, etc.) |
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Source of funding | Not mentioned | |
Were treatment groups comparable at baseline? | Yes: demographics; duration of surgery; site of surgery; postoperative VRS scores | |
Details of preoperative pain | Patients with a history of opioid use in the past 48 h or chronic pain were excluded; baseline pain scores not significantly different | |
Notes | — | |
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | Computerized (random number generator) |
Allocation concealment (selection bias) | Low risk | Opaque envelopes |
Blinding (performance bias and detection bias) All outcomes | Low risk | Participants and anesthesiologists were blinded by “creating treatments that looked identical” |
Incomplete outcome data (attrition bias) All outcomes | Low risk | No dropouts or protocol violations – complete data set obtained for both groups |
Selective reporting (reporting bias) | High risk | Not all outcomes from Methods section reported in Results section (e.g., sedation scores, patient satisfaction) |
Size | High risk | Fewer than 50 participants per arm of the study (25 paracetamol, 25 placebo) |