Analgesic Effect of Intraoperative Intravenous S-Ketamine During Total Knee Arthroplasty Surgery

Analgesic Effect of Intraoperative Intravenous S-Ketamine During Total Knee Arthroplasty Surgery:A Randomized Controlled Clinical Trial

Severe acute pain after total knee arthroplasty surgery has multiple implications for hospitals and patients, monopolising resources and affecting the quality of life. S-ketamine inhibits N-methyl-d-aspartate (NMDA) receptor activation and attenuates central sensitization associated with hyperalgesia, opioid tolerance.Therefore, the primary aim of this trial was to investigate whether s-ketamine decreases pain and opioid consumption postoperatively in adult individuals undergoing total knee arthroplasty surgery.

Total knee arthroplasty surgery is considered a cost-effective therapy for end-stage knee osteoarthritis (KOA). With an ageing population and rising rates of obesity in the world, knee joint replacements are estimated to escalate. While joint replacement is a cost effective intervention,approximately 20% of people experience persist pain postoperatively. The surgical injury triggers a myriad of responses in the pain matrix, from sensitization of peripheral and central pain pathways to feelings of fear, anxiety and frustration. Opioids are effective for acute postoperative pain but have numerous adverse effects. In addition, postoperative opioid treatment may pose a risk of opioid addiction. Numerous publications state that adjuvant s-ketamine reduces pain and opioid consumption postoperatively . Whether intraoperative intravenous s-ketamine alleviates postoperative acute pain after total knee arthroplasty surgery still unclear . Therefore, a randomized, controlled, clinical study was designed to observed analgesic effect intraoperative intravenous a lower doses of s-ketamine(0.3mg/kg/h) with patients after total knee arthroplasty surgery .

For patients in the control group,anaesthesia will be maintained with intravenous sodium chloride (NaCl; 0.9%) infusion.while anaesthesia will be maintained with propofol infusion(4-12mg/kg/h),analgesia will be maintained with remifentanil(0.15-0.3ug/kg/min).The sufentanil dose at induction and the rate of intraoperative remifentanil and propofol infusions were at the discretion of the anesthesiologist in charge of the patient. The assessment of the depth of anesthesia was based on clinical evaluation,placebo-controlled infusion will be stopped 15 minutes before the end of surgery.Propofol and remifentanil infusion will be stopped at the end of surgery.

For patients in the s-ketamine group, anaesthesia will be maintained with s-ketamine infusion（0.3mg/kg/h),while anaesthesia will be maintained with propofol infusion(4-12mg/kg/h) ,analgesia will be maintained with remifentanil(0.15-0.3ug/kg/min).The sufentanil dose at induction and the rate of intraoperative remifentanil and propofol infusions were at the discretion of the anesthesiologist in charge of the patient.The assessment of the depth of anesthesia was based on clinical evaluation.S-ketamine infusion will be stopped 15 minutes before the end of surgery.Propofol and remifentanil infusion will be stopped at the end of surgery.

For patients in the control group,anaesthesia will be maintained with intravenous sodium chloride (NaCl; 0.9%) infusion.while anaesthesia will be maintained with propofol infusion(4-12mg/kg/h),analgesia will be maintained with remifentanil(0.15-0.3ug/kg/min).The sufentanil dose at induction and the rate of intraoperative remifentanil and propofol infusions were at the discretion of the anesthesiologist in charge of the patient.The assessment of the depth of anesthesia was based on clinical evaluation,placebo-controlled infusion will be stopped 15 minutes before the end of surgery.Propofol and remifentanil infusion will be stopped at the end of surgery.

For patients in the s-ketamine group,anaesthesia will be maintained with s-ketamine infusion（0.3mg/kg/h),while anaesthesia will be maintained with propofol infusion(4-12mg/kg/h),analgesia will be maintained with remifentanil(0.15-0.3ug/kg/min).The sufentanil dose at induction and the rate of intraoperative remifentanil and propofol infusions were at the discretion of the anesthesiologist in charge of the patient.The assessment of the depth of anesthesia was based on clinical evaluation.S-ketamine infusion will be stopped 15 minutes before the end of surgery.Propofol and remifentanil infusion will be stopped at the end of surgery.

NRS = (numerical rating scale) is widely used to measure pain intensity after surgery.NRS is evaluated on a 11-point NRS (0 = no pain, 10 = worst pain imaginable)

NRS = (numerical rating scale) is widely used to measure pain intensity after surgery.NRS is evaluated on a 11-point NRS (0 = no pain, 10 = worst pain imaginable)

NRS = (numerical rating scale) is widely used to measure pain intensity after surgery.NRS is evaluated on a 11-point NRS (0 = no pain, 10 = worst pain imaginable)

The number of patients who required additional analgesics such as opioids(demerol,sufentanil,morphine)or non-steroid anti-inflammatory drugs(acetaminophen,diclofenac).

The Opioids or non-steroid anti-inflammatory drugs total consumption during the first 48h after operation

The opioids (such as demerol,sufentanil,morphine) or non-steroid anti-inflammatory drugs (such as acetaminophen,diclofenac)total consumption.

(Postoperative nausea and vomiting)Nausea is defined as subjective,unpleasant sensation associated with awareness of the urge to vomit. Retching is defined as the laboured, spastic, rhythmic contraction of the respiratory muscles without expulsion of the gastric contents.Vomiting is defined as the forceful expulsion of gastric contents from the mouth.The adverse central nervous system (CNS) events(such as nightmares, hallucinations, dizziness, itchy skin) were recorded (yes/no) at the patient leaves the PACU and at 24, 48hours in the surgical ward.

Inclusion Criteria: ASA physical statusI-III; Patients understood the study in detail and voluntarily signed the informed consent before the study; Patients to be treated with total knee arthroplasty Surgery under General anesthesia; Elderly patients(≥65y),regardless of gender; Patients can communicate normally; Patients who have no contraindications to drugs such as midazolam,fentanyl,s-ketamine. 7.18 kg/m2 ≤BMI≤30 kg/m2; Exclusion Criteria: Increased intracranial or intraocular pressure; severe hypertension; unwillingness the study; severe psychiatric disease and mental system diseases; severe respiratory diseases; hyperthyroidism; liver and kidney dysfunction; alcohol or drug abuse; allergy to midazolam,fentanyl,s-ketamine.