Our systematic review had several limitations, including
those that relate to the general use of a systematic review
and others that pertain specifically to surgical analgesia
studies. In only 5 of 16 studies did the acetaminophen
group size exceed 40 patients. Small sample sizes studies
are unlikely to identify rare but clinically relevant
adverse effects. Because the best analgesic approach
needs to be individualized to the specific surgical procedure,
results from a specific study may not be applicable
to other surgery types or when other analgesic interventions
such as nerve blocks are added to a multimodal
approach.12 In addition, the studies used different
systems for reporting the severity and duration of pruritus,
nausea, and vomiting. Publication bias also cannot
be excluded. Also, none of the active comparator studies
included often used nonsteroidal anti-inflammatory
drugs such as ketorolac, ketoprofen, or diclofenac.