Pain Management After Day Surgery

Pain Control After Outpatient Surgical Procedures

Adequate postoperative analgesia for patients undergoing day surgery faces two main issues. Patients must self-manage pain at home, and the method of administration is limited compared to options available during hospitalization. Despite advances in pain therapy in recent years, 9-40% of patients report moderate to severe pain after discharge.  

For day surgery procedures, it is recommended to administer a combination of oral paracetamol, NSAIDs, mild opioids, and local anesthetics. However, NSAIDs are not suitable for up to 25% of patients due to contraindications. Metamizole can be a potential substitute. It is a non-opioid compound with analgesic, antipyretic, and spasmolytic effects. Its administration can, in very rare cases, cause agranulocytosis, which is why this modality is not widely used currently. While the effectiveness of metamizole (when administered intravenously or intramuscularly) in reducing postoperative pain is well documented, there is less data available on its combination with paracetamol.

Study Methodology and Progress

The cited study was conducted at a single site in Belgium and included 200 patients aged 18-70 years. Participants underwent elective day surgery procedures: hemorrhoid surgery (n = 50), arthroscopic shoulder surgery (n = 50), knee surgery (n = 50), or inguinal hernia repair (n = 50). Patients were randomized 1:1 to receive a combination of paracetamol (1 g four times daily) with metamizole (1 g three times daily) or paracetamol (1 g four times daily) with ibuprofen (600 mg three times daily) for 4 days. The first dose was administered 30 minutes before the procedure. Rescue therapy consisted of tramadol 50 mg up to three times daily. Pain intensity was measured using a visual analog scale in the postoperative unit, and daily on the first to third postoperative day. A difference of <1 point was considered non-inferiority. The occurrence of adverse effects and patient satisfaction with analgesic treatment were also monitored via telephone.

Results

In the postoperative unit, the average pain score difference (± SD) between the paracetamol/metamizole and paracetamol/ibuprofen combinations was 0.85 ± 0.78 points. A difference of <1 was also observed on each of the three postoperative days.

There was no difference in the use of rescue therapy in the postoperative unit and on the first and third day after surgery between the groups. On the second postoperative day, a significantly higher use of rescue medication was observed in the group using the paracetamol/ibuprofen combination (p = 0.042).      

In the ibuprofen group, 48 patients reported adverse effects, compared to 56 patients in the metamizole group. No significant difference in treatment safety was observed between the groups (p = 0.252). No cases of agranulocytosis or serious adverse effects were reported during the study. Patient satisfaction with treatment was comparable between the groups. 

Conclusion

The combination of paracetamol/metamizole and paracetamol/ibuprofen showed comparable efficacy in treating postoperative pain in patients after day surgery within the first three postoperative days. 

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Source: Stessel B., Boon M., Pelckmans C. et al. Metamizole vs. ibuprofen at home after day case surgery: a double-blind randomized controlled non-inferiority trial. Eur J Anaesthesiol 2019; 36 (5): 351−359, doi: 10.1097/EJA.0000000000000972.

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