Effects Of The Different Doses Of Esketamine On Postoperative Quality Of Recovery In Patients Undergoing Modified Radical Mastectomy

Objective The objective of this study was to investigate the effect of intraoperative intravenous infusion of esketamine at different doses on postoperative recovery quality of patients undergoing modified radical mastectomy,so as to provide a reliable basis for better clinical application of esketamine.Methods Ninety-nine patients who were hospitalized in Thyroid and Breast Surgery Department from June 2021 to June 2022 and underwent elective modified radical mastectomy under tracheal intubation under general anesthesia were selected.Patients were randomly allocated to three groups:low-dose esketamine group（group E₁）;high-dose esketamine group（group E₂）and normal saline control group（group C）,with33 cases in each group.All patients in the three groups were given intravenous dexamethasone 10 mg,penehyclidine 0.5 mg before anesthesia,midazolam 0.05 mg/kg,sufentanil 0.4μg/kg,etomidate 0.3 mg/kg,cis-atracurium 0.15 mg/kg for anesthesia induction,and propofol 4～6 mg·kg^-1·h^-1and remifentanil 0.15μg·kg^-1·min^-1were injected continuously during the operation.Patients in group E₁and group E₂received bolus infusion of esketamine 0.5 mg/kg before surgical excision,followed by continuous esketamine infusion at 2μg·kg^-1·min^-1and 4μg·kg^-1·min^-1until the suture began,respectively;patients in group C received the equal volume normol saline until the suture began.The primary outcome of the quality of recovery-15（Qo R-15）scores were recorded on the postoperative day 1（POD1）,postoperative day 3（POD3）and sleep quality scores on the postoperative day 1.The numeric rating scale（NRS）pain scores within 24 h after surgery,bispectral index（BIS）value at 10,30,and 60 min after the operation,side effects（nausea,vomiting,drowsiness,nightmare,intraoperative awareness）and remedial treatments were regarded as the secondary outcomes.Results There was no significant difference in general data among the three groups（P>0.05）.The total Qo R-15 scores on POD1 and POD3 and sleep quality scores on POD1 were higher in group E₁and group E₂than in group C（P<0.05）;the total Qo R-15 scores were the highest in group E₂on POD1 and POD3;there were no significant differences with regard to total Qo R-15 scores at POD1 and POD3 in group E₁and group E₂（P>0.05）.The sleep quality scores were higher on POD1 in group E₁and group E₂compared to group C（P<0.05）;the sleep quality scores were no significant differences between group E₁and group E₂（P>0.05）.The NRS scores were lower at 2,4 and 6 hours after surgery in group E₁than in group C（P<0.05）;the NRS pain scores were lower at 2,4,6,12 and 24 hours after surgery in group E₂than in group C（P<0.05）;the NRS pain scores were lower at 6,12 and 24 hours after surgery in group E₂than in group E₁（P<0.05）;the NRS scores were no significant differences at 2 and 4 hours after operation in group E₁and group E₂（P>0.05）;the NRS scores were also no significant differences at 12 and 24 hours after surgery in group C and group E₁（P>0.05）.The BIS values were higher in group E₁and group E₂than in group C at 10,30,and 60 min after surgical incision（P<0.05）;the BIS values were no significant differences in group E₁and group E₂at 10,30,and 60 min after surgical incision（P>0.05）.The incidence of drowsiness was higher in group E₁and group E₂than in group C（P<0.05）;there were no significant differences with respect to drowsiness between the group E₁and group E₂（P>0.05）.Compared with group C,postoperative nausea,vomiting,nightmares,intraoperative awareness,rescue analgesia,and anti-emetics required were not statistically significant in groups E₁and E₂（P>0.05）.Conclusion The different doses of esketamine infusion especially 4μg·kg^-1·min^-1esketamine improved to some extent the quality of recovery 1 and 3 days after surgery,decreased the intensity of postoperative pain in patients undergoing modified radical mastectomy.However,esketamine administration could increase intraoperative BIS values and the incidence of postoperative drowsiness.