Effects of Esketamine Infusion by Patient-Controlled Intravenous Analgesia in Patients With Zoster-Associated Pain: A Retrospective Study

Background:Esketamine has been used for the management of acute and chronic pain.This study aimed to evaluate the effects of patient-controlled intravenous analgesia (PCIA) with esketamine on zoster-associated pain during the subacute stage.Material/Methods: This retrospective study analyzed 86 patients treated at Ningbo Medical Center Lihuili Hospital between January 1, 2024, and September 1, 2024.Patients were divided into an esketamine group (group ES, n=44) and a control group (group C, n=42).Group ES received intravenous esketamine via PCIA for 5 days, whereas group C received 0.9% saline.Both groups underwent pulsed radiofrequency treatment.Numeric rating scale (NRS) scores, Pittsburgh Sleep Quality Index (PSQI) scores, postoperative analgesic consumption, incidence of postherpetic neuralgia, Central Sensitization Index (CSI) scores, and adverse events were assessed before and after treatment.Results: Group ES demonstrated significantly lower NRS and PSQI scores at 1 week (NRS: Z=2.075, P=0.038; PSQI: Z=4.224, P<0.001) and 4 weeks (NRS: Z=2.117, P=0.034; PSQI: Z=5.775, P<0.001).Tramadol and pregabalin consumption did not differ between groups at 1, 4, 12, or 24 weeks (P>0.01).The postherpetic neuralgia rate was 25.00% in group ES and 42.86% in group C (c 2 =3.066,P=0.08).CSI scores differed at 12 weeks (t=2.591,P=0.011) and 24 weeks (t=2.135,P=0.036).Group ES had higher incidences of dizziness, nausea, and vomiting, but lower incidences of rebound pain and constipation. Conclusions:Esketamine was associated with reduced pain intensity and improved sleep quality in patients with zoster-associated pain during the early posttreatment period.