Objective:

To evaluate the effectiveness and safety of subcutaneous PCA hydromorphone for refractory cancer pain in hospitalized older patients, emphasizing the retrospective nature of the study and identifying clinical factors associated with 24-h pain reduction.

Key Findings:

• Mean pre-PCA current NRS decreased from 4.43 to 2.21 at 24 h (mean reduction of 2.18 points, p < 0.001).
• Response rates at 24 h were 57.3% (95% CI needed) for ≥30% improvement and 45.2% (95% CI needed) for ≥50% improvement.
• Median time to satisfactory analgesia was 0.6 h.
• Adverse events included somnolence (0.4%) and constipation (0.2%), with no documented respiratory depression.

Interpretation:

Subcutaneous PCA hydromorphone was associated with rapid and clinically meaningful short-term pain improvement and a low rate of documented adverse events, suggesting implications for clinical practice.

Limitations:

• Retrospective design limits causal inferences and may introduce biases.
• Findings may not be generalizable beyond the studied population.

Conclusion:

Subcutaneous PCA hydromorphone is a pragmatic rescue option for selected older patients with refractory cancer pain, but further prospective studies are needed to validate these findings.