Original Article
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jun 16, 2014; 6(6): 240-247
Published online Jun 16, 2014. doi: 10.4253/wjge.v6.i6.240
Monitoring salivary amylase activity is useful for providing timely analgesia under sedation
Masaya Uesato, Yoshihiro Nabeya, Takashi Akai, Masahito Inoue, Yoshiyuki Watanabe, Daisuke Horibe, Hiroshi Kawahira, Hideki Hayashi, Hisahiro Matsubara
Masaya Uesato, Takashi Akai, Daisuke Horibe, Hisahiro Matsubara, Department of Frontier Surgery, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan
Yoshihiro Nabeya, Division of Gastroenterological Surgery, Chiba Cancer Center, Chiba 260-8717, Japan
Masahito Inoue, Yoshiyuki Watanabe, Department of Endoscopic Diagnostics and Therapeutics, Chiba University Hospital, Chiba 260-8670, Japan
Hiroshi Kawahira, Hideki Hayashi, Research Center for Frontier Medical Engineering, Chiba University, Chiba 263-8522, Japan
Author contributions: Uesato M, Nabeya Y, Matsubara H designed the study; Uesato M, Akai T, Inoue M, Watanabe Y, Horibe D, Kawahira H performed the research; Uesato M, Nabeya Y, Hayashi H, Matsubara H wrote the manuscript; all authors have approved the final version.
Supported by Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science, Japan, No. C: #23591018
Correspondence to: Masaya Uesato, MD, Department of Frontier Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba 260-8670, Japan. uesato@faculty.chiba-u.jp
Telephone: +81-43-2262110 Fax: +81-43-2262113
Received: January 4, 2014
Revised: April 2, 2014
Accepted: May 28, 2014
Published online: June 16, 2014
Processing time: 163 Days and 0.8 Hours
Abstract

AIM: To detect the criteria and cause of elevated salivary amylase activity (sAMY) in patients undergoing endoscopic submucosal dissection (ESD) under sedation.

METHODS: A total of 41 patients with early gastric cancer removed via ESD under deep sedation (DS) were enrolled. The perioperative sAMY, which was shown as sympathetic excitements (SE), was measured. The time at which a patient exhibited a relatively increased rate of sAMY compared with the preoperative baseline level (IR, %) ≥ 100% (twice the actual value) was assumed as the moment when the patient received SE. Among the 41 patients, we focused on 14 patients who exhibited an IR ≥ 100% at any time that was associated with sAMY elevation during ESD (H-group) and examined whether any particular endoscopic procedures can cause SE by simultaneously monitoring the sAMY level. If a patient demonstrated an elevated sAMY level above twice the baseline level, the endoscopic procedure was immediately stopped. In the impossible case of discontinuance, analgesic medicines were administered. This study was performed prospectively.

RESULTS: A total of 26 episodes of sAMY eruption were considered moments of SE in the H-group. The baseline level of sAMY significantly increased in association with an IR of > 100% at 5 min, with a significant difference (IR immediately before elevation/IR at elevation of sAMY = 8.72 ± 173/958 ± 1391%, P < 0.001). However, effective intervention decreased the elevated sAMY level immediately within only 5 min, with a significant difference (IR at sAMY elevation/immediately after intervention = 958 ± 1391/476 ± 1031, P < 0.001). The bispectral indices, systolic blood pressure and pulse rates, which were measured at the same time, remained stable throughout the ESD. Forceful endoscopic insertion or over insufflation was performed during 22 of the 26 episodes. Release of the gastric wall tension and/or the administration of analgesic medication resulted in the immediate recovery of the elevated sAMY level, independent of body movement.

CONCLUSION: By detecting twice the actual sAMY based on the preoperative level, the release of the gastric wall tension or the administration of analgesic agents should be considered.

Keywords: Salivary amylase activity; Endoscopic submucosal dissection; Analgesia; Anesthesia; Sedation; Sympathetic excitement; Gastric wall tension

Core tip: The analgesia in patients during endoscopic submucosal dissection (ESD) under deep sedation (DS) has not yet been developed. There was no way of measuring the degree of the pain in those patients. This study revealed that the salivary amylase activity (sAMY) shown as sympathetic excitement (SE) sometimes was elevated during ESD without any change in circulatory dynamics or consciousness. We suggest that sAMY is elevated when patients feel pain during ESD under DS. By detecting twice the actual sAMY based on the preoperative level, the release of gastric wall tension or the administration of analgesic agents should be considered.