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The Scientific World Journal
Volume 2013, Article ID 183493, 6 pages
Clinical Study

Assessment of Pulse Oximeter Perfusion Index in Pediatric Caudal Block under Basal Ketamine Anesthesia

Department of Anesthesiology, Shanghai First People’s Hospital, Shanghai Jiaotong University, 650 Xin Songjiang Road, Shanghai 201620, China

Received 29 July 2013; Accepted 20 August 2013

Academic Editors: S. Lang and E. O. Martin

Copyright © 2013 Zifeng Xu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Whether pulse oximeter perfusion index (PI) may be applied to detect the onset of caudal block in pediatric patients under ketamine intravenous basal anesthesia is investigated. 40 ASA I, 2–8-year-old boys scheduled for elective circumcision surgery were randomized into two groups. Group I: 20 patients were anesthetized by 2 mg·kg−1 ketamine intravenous injection (IV) followed by caudal block using 1 mL·kg−1 lidocaine (1%); Group II: 20 patients were anesthetized by 2 mg·kg−1 ketamine IV only. PI on the toe in Group II decreased by 33 ± 12%, 71 ± 9% and 65 ± 8% at 1 min, 15 min, and 30 min after ketamine injection. The maximum increase in MAP and HR after ketamine IV was 11 ± 6% at 3 min and 10 ± 6% at 2 min. Compared to the PI value before caudal injection of lidocaine, PI in Group I increased by 363 ± 318% and 778 ± 578% at 5 min and 20 min after caudal block, while no significant changes in MAP and HR were found compared to the baseline before caudal block. Thus, PI provides an earlier, more objective, and more sensitive indicator to assess the early onset of caudal block under basal ketamine anesthesia.