Effect Of Ropivacaine Combined With Low-Dose Naloxone Thoracolumbar Interfascial Plane Block On Postoperative Analgesia After Lumbar Spine Surgery

Objective:To compare the effect of the thoracolumbar interfascial plane block with ropivacaine combined with low-dose naloxone on analgesia in patients after lumbar spinal fusion.Methods:Sixty-four patients,40～70 years old,with BMI 18～30 kg/m²,ASA class I to III,undergoing posterior median approach lumbar fusion under general anesthesia were selected for elective surgery.Patients were randomly assigned to one of two groups（n=32）:the ropivacaine group（group R）and the ropivacaine combined with low-dose naloxone group（group RN）.Bilateral ultrasound-guided TLIP blocks were performed in both groups.The group R was injected with 20 m L of 0.375%ropivacaine on each side,and the group RN was injected with 20 m L of a mixture of0.375%ropivacaine combined with 10μg naloxone on each side.The dosage of sufentanil,the number of effective compressions on PCIA,the time to first request remedial analgesia,and the dosage of dezocine were recorded in the postoperative 48h.The VAS scores at rest and during turning at 2 h（T₁）、6 h（T₂）、12 h（T₃）、18 h（T₄）、24 h（T₅）and 48 h（T₆）postoperatively were observed and recorded for the occurrence of opioid-related adverse effects such as postoperative nausea,vomiting,respiratory depression,dizziness,skin pruritus and urinary retention.The Qo R-15 recovery quality scores at 1 day and 3 day postoperatively and the occurrence of nerve block-related complications such as puncture site infection,hematoma,lower extremity muscle weakness,extensive epidural block,and local anesthetic intoxication were recorded.Results:Compared with the group R,the differences in sufentanil dosage and the number of effective compressions on PCIA in the group RN from 0 to 24 h postoperatively were not statistically significant,the differences in sufentanil dosage and the number of effective compressions on PCIA in the group RN from 24 to 48 h postoperatively were significantly reduced（P<0.05）.Significantly longer time to first request remedial analgesia after surgery in the group RN compared with the group R（P<0.01）and significantly lower postoperative dezocine dosage in the group RN compared with the group R（P<0.05）.Compared with the group R,the postoperative pain scores at rest and during turning at T₄and T₅moments were significantly lower in the group RN（P<0.05）.There was no statistically significant difference in the incidence of opioid-related adverse reactions such as nausea,vomiting,respiratory depression,dizziness,skin pruritus and urinary retention between the two groups within 48 h postoperatively.Compared with the group R,the Qo R-15 recovery quality score was significantly higher in the group RN at 3 day postoperatively（P<0.01）.There were no postoperative nerve block-related complications such as puncture site infection,hematoma,lower extremity muscle weakness,extensive epidural block,and local anesthetic intoxication in either group.Conclusions:Ropivacaine combined with low-dose naloxone TLIP block effectively reduced the pain of patients after lumbar fusion,prolonged the postoperative analgesia time of TLIP block and the time of the first request for remedial analgesia after surgery,and reduced the dosage of postoperative opioids and remedial analgesics,which is worth further exploring and promoting the application in the clinic.