title: Oximetry-derived perfusion index as an early indicator of CT-guided thoracic sympathetic blockade in palmar hyperhidrosis.
abstract: OBJECTIVE
  To test the hypothesis that the oximetry-derived perfusion index (PI) recorded in the index finger may provide earlier objective evidence for correct positioning of the needle tip during computed tomography (CT)-guided thoracic sympathetic blockade than skin temperature in palmar hyperhidrosis.
  
  
  METHODS
  Forty-four CT-guided thoracic sympathetic blockades were prospectively performed in both hands of 22 patients. Prior to chemical blockade, PI and skin temperature were recorded at 1 min intervals until 20 min after lidocaine injection. Repeated measures analysis of variance was used to assess the potency of PI and skin temperature over time. Using a 100% increase in the PI as the threshold and symptom relief within 20 min as the reference standard, the sensitivity and specificity for predicting a successful injection were calculated.
  
  
  RESULTS
  Thirty-seven (84%) sympathetic blockade procedures were clinically successful. For successful cases, the PI increased as early as 1 min after the blockade of the sympathetic chain (p < 0.05), whereas the skin temperature showed statistical significance 1 min later (p < 0.05). The PI can be used to indicate a successful CT-guided sympathetic blockade with 97% sensitivity and 100% specificity 3 min after lidocaine injection.
  
  
  CONCLUSIONS
  The PI, a more marked and sensitive indicator than changes in skin temperature, can be used to indicate a successful CT-guided sympathetic blockade with satisfying sensitivity and specificity, 3 min after lidocaine injection in palmar hyperhidrosis.
authors: Department of Anesthesiology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Department of Anesthesiology, First Hospital of Jiaxing, Jiaxing, China.
authors: B
authors: B
authors: Huang
authors: K
authors: K
authors: Sun
authors: Z
authors: Z
authors: Zhu
authors: C
authors: C
authors: Zhou
authors: Y
authors: Y
authors: Wu
authors: F
authors: F
authors: Zhang
authors: M
authors: M
authors: Yan
mesh_terms: D000293:Adolescent; D000328:Adult; D001340:Autonomic Nerve Block / Q000379:methods*; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods; D005260:Female; D005385:Fingers / Q000098:blood supply / Q000294:innervation; D006801:Humans; D006945:Hyperhidrosis / Q000601:surgery*; D008297:Male; D015641:Radiography, Interventional / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult