Colorectal cancer is the second most common tumor in women and the third most common tumor in men, accounting for approximately 10% of tumors diagnosed and tumor-related deaths worldwide each year. Laparoscopic resection has become the standard of colorectal cancer surgery, and its main advantages are to shorten the length of hospital stay, reduce postoperative pain, and accelerate patient recovery. However, it has been reported that about 49% of patients undergoing laparoscopic colorectal cancer surgery still have moderate to severe postoperative pain. The insertion of abdominal drainage tube will increase the degree of postoperative pain, especially when patients take deep breaths, exercise or cough, which will increase the demand for postoperative opioids and reduce the quality of postoperative recovery. How to further reduce the postoperative pain of patients, reduce the dosage of opioids, shorten the length of hospital stay, promote the rapid recovery of patients and improve patient satisfaction are our concerns. Intrathecal morphine can provide a good analgesic effect on visceral pain. At present, intrathecal morphine has become a new method of postoperative analgesia, which is used in thoracic, abdominal and obstetrics and gynecology operations. The objective of this study was to investigate the effect of intrathecal morphine on the quality of recovery after laparoscopic colon cancer surgery.

Colorectal cancer is the second most common tumor in women and the third most common tumor in men, accounting for approximately 10% of tumors diagnosed and tumor-related deaths worldwide each year. Laparoscopic resection has become the standard of colorectal cancer surgery, and its main advantages are to shorten the length of hospital stay, reduce postoperative pain, and accelerate patient recovery. However, it has been reported that about 49% of patients undergoing laparoscopic colorectal cancer surgery still have moderate to severe postoperative pain. The insertion of abdominal drainage tube will increase the degree of postoperative pain, especially when patients take deep breaths, exercise or cough, which will increase the demand for postoperative opioids and reduce the quality of postoperative recovery. How to further reduce the postoperative pain of patients, reduce the dosage of opioids, shorten the length of hospital stay, promote the rapid recovery of patients and improve patient satisfaction are our concerns.

The anesthesia scheme was endotracheal intubation general anesthesia combined with bupivacaine liposome plane block of transverse abdominal muscle, experimental group combined with intrathecal morphine, control group injected with intrathecal saline. Heart rate, electrocardiogram, pulse oxygen saturation, noninvasive blood pressure, and end-expiratory partial carbon dioxide pressure (ETCO2) were routinely monitored after entry. Before anesthesia induction, the experimental group received lumbar morphine (L3/4). Based on the literature and our previous clinical application, the intrathecal morphine was 3ug/kg. Control group received intrathecal injection of normal saline. General anesthesia was induced by intravenous injection of dexmedetomidine (0.5ug/kg), cyclopofol (0.4mg/kg), remifentanil (TCI4ng/ml) and rocuronium (0.6mg/kg), followed by tracheal intubation. Bupivacaine liposome plane block of transverse abdominal muscle was performed in both groups, bupivacaine liposome injection (20ml: 266mg) was diluted with 0.9% sodium chloride solution from 20ml to 40ml, and 10ml diluent solution was injected into the left and right abdominal subcostoal approach and lateral approach under ultrasound guidance. Anesthesia was maintained with 1-1.3MAC desflurane, remifentanil, sufentanil, cis-atracurium, and vasoactive agents as needed. Intraoperative opioid dosage was recorded. Patients in both groups received intravenous controlled analgesia, 150mg morphine with 0.9% sodium chloride solution to 150ml intravenous analgesia pump. The background dose is 0ml/h, the single patient-controlled analgesia dose is 1ml, and the locking time is 6 minutes to manage fulminant pain. When adverse events such as hypotension occur, appropriate accelerated fluid rehydration is given while makingWith vasoactive drugs, the nurse (who did not participate in the study) was asked to reduce the parameters of the intravenous analgesic pump to 1/2 of the original, and if the symptoms persisted, the analgesic pump was turned off and the study was terminated. The main outcome was QoR15 score 24 hours after operation.

Inclusion Criteria:

• Laparoscopic colorectal cancer surgery under tracheal intubation and general anesthesia is intended
• Agreed to use intravaginal morphine injection and bupivacaine liposomal plane block of transversal muscle after surgery
• ASA Grade I - III
• Over 18 years of age

Exclusion Criteria:

• Preoperative accident or subjective refusal of surgery
• Nervous system dysfunction
• Contraindications to intraspinal anesthesia
• Preoperative opioid use history
• Patients with abnormal preoperative pain and pain score (NRS) >3