# The effect of scheduled metamizole on opioid consumption after cardiac surgery

## TL;DR

Using a scheduled dose of metamizole after heart surgery reduces opioid use without compromising pain control or safety.

## Contribution

Demonstrates that scheduled metamizole use in multimodal analgesia reduces opioid consumption post-cardiac surgery.

## Key findings

- Scheduled metamizole reduced opioid consumption from 119.51 mg to 95.91 mg morphine equivalents.
- Pain scores improved significantly from 1.12 to 0.89 on the Numeric Rating Scale.
- No clinically relevant agranulocytosis or renal issues were observed with metamizole use.

## Abstract

This retrospective study evaluates the impact of implementing a standardized scheduled metamizole dosing protocol within a multimodal analgesia approach after cardiac surgery. The results showed that scheduled metamizole administration was associated with lower opioid consumption, while maintaining adequate pain control and safety. Pain scores measured by the Numeric Rating Scale improved from 1.12 pre-protocol to 0.89 post-protocol (p < 0.0001). Mean opioid consumption decreased from 119.51 mg morphine equivalents to 95.91 mg (p < 0.0001). No cases of clinically relevant agranulocytosis or persistent neutropenia were observed. Renal function, assessed by changes in serum creatinine, showed no significant differences between groups, suggesting renal safety. Despite improved analgesia and reduced opioid use, hospital length of stay increased slightly, potentially due to confounding factors. Our findings support scheduled metamizole as a safe and effective opioid-sparing agent in postoperative cardiac surgery pain management. Further prospective randomized trials are warranted to confirm these results and establish optimal protocols.