title: Swallowing action immediately before intravenous fentanyl at induction of anesthesia prevents fentanyl-induced coughing: a randomized controlled study.
abstract: OBJECTIVE
  Fentanyl is a strong µ-opioid analgesic which attenuates the stimulation of surgical invasion and tracheal intubation. However, intravenous fentanyl often induces coughing [fentanyl-induced coughing (FIC)] during induction of anesthesia. We found that the swallowing action, when requested at induction of anesthesia, attenuated FIC. In the current study, we investigated the relationship between the occurrence of FIC and the swallowing action.
  
  
  METHODS
  The study included American Society of Anesthesiologists physical status I or II patients, aged 20-64 years, who were undergoing elective surgery. They were divided into two groups-one group was urged to perform the swallowing action immediately before intravenous fentanyl (S group), and the other group performed no swallowing action (non-S group). The patients first received intravenous fentanyl and were observed for 90 s. Each patient's background, dose of fentanyl and occurrence of coughing were investigated from their records and a motion picture recording. The incidence of FIC was evaluated by chi-squared test, and severity was tested by Wilcoxon rank-sum test. P < 0.05 was considered statistically significant.
  
  
  RESULTS
  The incidence of FIC in the S group and non-S group was 14.0 and 40.4%, respectively. The risk of FIC was reduced in the S group by 75%; risk ratio (95% confidence interval) was 0.35 (0.20, 0.60). The number of coughs in the S group were less than in the non-S group (P < 0.001).
  
  
  CONCLUSIONS
  The swallowing action immediately before intravenous fentanyl may be a simple and clinically feasible method for preventing FIC effectively. Clinical trial number: UMIN000012086 ( https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=Rn000014126&language=J ).
authors.affiliation: Department of Dental Anesthesiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Sako
authors.affiliation: Medical Information Center, Kyushu University Hospital, Fukuoka, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Tokunaga
authors.affiliation: Department of Dental Anesthesiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi higashi-ku, Fukuoka, 812-8582, Japan. tsukamoto@dent.kyushu-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Tsukamoto
authors.affiliation: Department of Anesthesiology, St. Mary's Hospital, Fukuoka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshino
authors.affiliation: Department of Anesthesiology, St. Mary's Hospital, Fukuoka, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Fujimura
authors.affiliation: Department of Dental Anesthesiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yokoyama
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000627:therapeutic use; D003371:Cough / Q000139:chemically induced / Q000517:prevention & control*; D003679:Deglutition / Q000502:physiology*; D017558:Elective Surgical Procedures; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D005283:Fentanyl
keywords: Analgesics; Cough; Deglutition; Fentanyl; Opioid; Swallowing