Introduction:
This study aims to compare the safety and efficacy of three commonly used non-steroidal anti-inflammatory drugs (NSAIDs) to reduce levels of serum tumour necrosis factor- (TNF-α) and substance P in children after orthopaedic hip surgery.

Material and methods:
Ninety children were randomised into three groups (A, B, and C) of 30 patients each. After surgery, ketorolac tromethamine injections were given to patients in group A, ibuprofen suspensions were given to patients in group B, and acetaminophen suppositories were given to patients in group C. Pain and sedation scores were determined after 30 min and at 1, 2, 3, 6, 12, and 24 h. Inflammatory factors, including serum TNF-α and substance P, were measured before, immediately after, and 24 h after surgery.

Results:
The treatment was effective for pain relief and sedation in all three groups. The venous blood levels of TNF-α and substance P in all groups increased after the operation but decreased after 24 h, and this was statistically significant (p < 0.05). These levels significantly decreased in group A, the ketorolac tromethamine group, when compared to groups B and C, but the difference was not statistically significant. In terms of the incidence of adverse reactions, the level in group C was lower than that in group A and group B (p < 0.05).

Conclusions:
NSAIDs are effective for analgesia after orthopaedic hip surgery in children 1 to 3 years old. However, ketorolac tromethamine is preferred because it can significantly and effectively reduce serum levels of TNF-α and substance P in patient serum and causes fewer adverse reactions.