title: Effect of equivalent doses of fentanyl, sufentanil, and remifentanil on the incidence and severity of cough in patients undergoing abdominal surgery: A prospective, randomized, double-blind study.
abstract: BACKGROUND
  Fentanyl congeners have been found to induce cough during induction of general anesthesia. Studies of fentanyl and sufentanil have found incidence rates of 28% to 65% and 15%, respectively. However, no study has assessed the occurrence of cough induced by remifentanil.
  
  
  OBJECTIVE
  The aim of this study was to assess the effect of equivalent doses of fentanyl, sufentanil, and remifentanil on cough.
  
  
  METHODS
  Patients rated American Society of Anesthesiologists class I or II of either sex, aged 18 to 60 years, who were scheduled for elective abdominal surgery with general anesthesia were randomly and equally assigned to 3 groups using a computer-generated table of random numbers. The patients received equivalent doses of fentanyl 2 μg/kg, sufentanil 0.2 μg/kg, or remifentanil 2 μg/kg via IV push. Vital signs (systolic blood pressure [SBP], heart rate [HR], and oxygen saturation via pulse oximetry [SpO2]) and the occurrence and severity of cough were recorded for 2 minutes after drug administration by an anesthesiologist who was blinded to the drug treatment. The severity of cough was graded as none (0), mild (1-2), moderate (3-5), or severe (>5).
  
  
  RESULTS
  A total of 315 Chinese patients (197 women, 118 men; mean [SD] age, 37.9 [10.4] years) were approached for enrollment and assigned to 3 groups of 105 patients each; all patients completed the study protocol. The 3 treatment groups were similar in terms of demographic characteristics and type of abdominal surgery. The incidence of cough was significantly greater in the remifentanil group (57 [54.3%] patients) than in the fentanyl group (35 [33.3%]; P < 0.01) or the sufentanil group (32 [30.5%]; P < 0.01). The severity of cough was significantly greater in the remifentanil group (severe, moderate, mild, none: 24, 7, 26, 48) than in the fentanyl (7, 9, 19, 70; P < 0.01) or sufentanil group (4, 2, 26, 73; P < 0.01). In all 3 groups, when the patients coughed, significant increases were observed in their SBP (128 [12]-139 [16] mm Hg; P < 0.01) and HR (74 [10]-87 [16] beats/min; P < 0.01). Within 2 minutes after drug administration, 62 patients (59%) in the remifentanil group experienced hypoxemia (SpO2 <90%) necessitating manually assisted mask ventilation, while no patients experienced hypoxemia in the fentanyl or sufentanil group. Three patients (2.9%) in the remifentanil group experienced muscle rigidity and deterioration of SBP, HR, and SpO2. No other adverse events were recorded. Cunclusion: Remifentanil was associated with a significantly greater incidence and severity of cough than equivalent doses of fentanyl or sufentanil. Fentanyl and sufentanil appeared comparable in these Chinese patients undergoing abdominal surgery.
authors.affiliation: Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.
authors.forename: Jin-Chun
authors.initials: JC
authors.lastname: Shen
authors.affiliation: Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Xu
authors.affiliation: Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.
authors.forename: Hong-Jun
authors.initials: HJ
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Yang
keywords: cough; fentanyl; incidence; remifentanil; severity; sufentanil