title: Dose requirements of alfentanil to eliminate autonomic responses during rapid-sequence induction with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.
abstract: OBJECTIVE
  Opioids are integral part of anesthesia induction, but information on optimal dosing is limited. We aimed to determine doses of alfentanil needed to eliminate increases in 5 autonomic response variables (plasma concentrations of epinephrine, norepinephrine and vasopressin, arterial blood pressure [ABP], and heart rate) during rapid-sequence induction of anesthesia with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.
  
  
  METHODS
  Prospective, randomized, observer-blinded, interventional clinical study.
  
  
  METHODS
  Large academic institution.
  
  
  METHODS
  Eighty-four healthy patients, aged 18 to 55 years, received 1 of 7 assessor-blinded doses of alfentanil (0, 10, 20, 30, 40, 50, and 60 μg/kg) together with thiopental 4 mg/kg and rocuronium 0.6 mg/kg, administered in rapid succession (15 seconds). Laryngoscopy was initiated 40 seconds after rocuronium, and tracheal intubation was concluded within 15 seconds thereafter.
  
  
  METHODS
  An indwelling radial artery catheter was used for hemodynamic monitoring and blood sampling. Relationships between alfentanil dose and response variables were tested with linear regression, and the influence of covariates (sex, body weight, and age) was determined. Alfentanil dose needed to prevent increases in ABP >10% above baseline with 95% probability was estimated with logistic regression.
  
  
  RESULTS
  Significant relationships were determined between alfentanil dose and response variables. Clinically interesting influence of covariates was not found. Alfentanil 55 μg/kg was needed to prevent increases in ABP postintubation >10% above baseline with 95% probability. One individual needed a bolus of vasopressor postintubation.
  
  
  CONCLUSIONS
  Optimal control of autonomic responses during rapid-sequence induction was achieved with clinically relevant doses of alfentanil in healthy patients anesthetized with thiopental 4 mg/kg and rocuronium 0.6 mg/kg.
authors.affiliation: Department of Anesthesia, Division of Emergencies and Critical Care Medicine, Oslo University Hospital, Oslo, Norway.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Abou-Arab
authors.affiliation: Department of Acute Medicine, and Section of Cardiovascular and Renal Research, Division of Medicine, Oslo University Hospital, Oslo, Norway.
authors.forename: Morten
authors.initials: M
authors.lastname: Rostrup
authors.affiliation: Department of Anesthesia, Division of Emergencies and Critical Care Medicine, Oslo University Hospital and University of Oslo, Oslo, Norway. Electronic address: tom.heier@medisin.uio.no.
authors.forename: Tom
authors.initials: T
authors.lastname: Heier
mesh_terms: D000293:Adolescent; D000328:Adult; D015760:Alfentanil / Q000494:pharmacology*; D000732:Androstanols / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D001341:Autonomic Nervous System / Q000187:drug effects* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D011446:Prospective Studies; D000077123:Rocuronium; D013874:Thiopental / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000732:Androstanols; D018686:Anesthetics, Intravenous; D003473:Neuromuscular Nondepolarizing Agents; D015760:Alfentanil; D013874:Thiopental; D000077123:Rocuronium
keywords: Alfentanil; Arterial blood pressure; Catecholamines; Heart rate; Rapid sequence; Vasopressin