Letter to the Editor Regarding “Clinical Application of Different Doses of Hydromorphone Slow-Release Analgesia in Lumbar Fusion in Elderly Patients”

• Guanyu Yang,
• Qinjun Chu

Affiliations

Guanyu Yang

Department of Anesthesiology and Perioperative Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University

Qinjun Chu

Department of Anesthesiology and Perioperative Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University