Chinese Association for the Study of Pain: Expert consensus on chronic postsurgical pain

Table 1 Risk factors for chronic postsurgical pain[7-14]

Risk factors for CPSP[7-14]
Preoperative factors	Preoperative chronic pain; psychological factors (depression, anxiety, pain catastrophizing and fear of surgery); smoking; younger age; female gender; genetic susceptibility
Surgical factors	Type and site of surgery (amputation, breast cancer, thoracotomy, hysterectomy, inguinal hernia repair, cesarean section); surgical technique (open surgery > laparoscopy and thoracoscopy, traditional hernia repair > tension-free hernia repair); extensive use of electric knife; long operation time; infection on incision site; nerve damage or compression
Postoperative factors	Severe acute postoperative pain; opioid use (high doses of opioids can cause hyperalgesia and may be related to NMDA receptor activation); neuropathic pain (early postoperative neuropathic pain is prone to chronic); complication (cardiovascular, respiratory, renal/gastrointestinal, wound, thrombotic or neural)

CPSP: Chronic post-surgical pain; NMDA: N methyl D aspartate.

Table 2 Algorithm for pharmacotherapy of chronic post-surgical pain

Algorithm for pharmacotherapy of CPSP
First-line therapy	Gabapentin; pregabalin; duloxetine; venlafaxine; tricyclic antidepressants
Second-line therapy	Capsaicin cream/patch; lidocaine cream/patch; tramadol; paracetamol dihydrocodeine
Third-line therapy	Strong opioids; botulinum toxin type A

CPSP: Chronic post-surgical pain.

Table 3 Oxford Centre for Evidence-Based Medicine levels of evidence

Level	Therapy/prevention, etiology/harm
1a	Systematic review of RCTs
1b	RCT
1c	“All-or-none”
2a	Systematic review of cohort studies
2b	Cohort study or poor RCT
2c	“Outcomes” research; ecological studies
3a	Systematic review of case-control studies
3b	Individual case-control study
4	Case series
5	Expert opinion without critical appraisal, or based on physiology, bench research or “first principles”

RCT: Randomized controlled trial.

Table 4 Division and cooperation between surgeons, anesthesiologists and pain physicians

Division and cooperation between surgeons, anesthesiologists and pain physicians
Surgeon	(1) Optimize surgical methods based on the principle of minimizing tissue trauma; (2) Communicate with the anesthesiologist before surgery to negotiate the best anesthesia plan; and (3) Provide preventive medication and necessary psychological intervention for patients at high risk of CPSP
Anesthesiologist	(1) Carefully evaluate the patient’s medical history, including chronic pain, opioid use, drug abuse and mental illness. Screen for patients at high risk of CPSP; (2) Educate patients and their families. Inform them about the possible challenges of perioperative analgesia and the risks of CPSP; (3) Communicate with the surgeon before the operation to understand the surgical method and discuss the best anesthesia plan; (4) Establish perioperative pain management files; (5) Based on a comprehensive assessment of the patient’s condition, an individualized multimodal analgesic plan is formulated; (6) Carefully evaluate and record the analgesic effect on the patient; (7) If the patient does not have good postoperative analgesia and uses high-dose opioids, the pain management file should be transferred to the pain physician 1 wk after the operation; and (8) Based on the follow-up results and the latest progress on research, continue to summarize and optimize the analgesia schemes for different surgical operations
Pain physician	(1) Review the perioperative pain management files after taking over the patient; (2) Carefully analyze the nature and source of pain and develop a corresponding treatment plan; (3) Establish a follow-up mechanism; (4) If CPSP occurs, provide pain management in time; and (5) Regularly discuss difficult cases of CPSP with surgeons and anesthesiologists. Summarize risk factors and feedback treatment effect. Discuss further optimization of perioperative analgesia plan and preventive measures

CPSP: Chronic post-surgical pain.