title: The optimal succinylcholine dose for intubating emergency patients: retrospective comparative study.
abstract: BACKGROUND
  Succinylcholine remains the drug of choice for satisfactory rapid-sequence tracheal intubation. It is not clear from the literature why the 1 mg/kg dose of succinylcholine has been traditionally used. The effective dose (ED95) of succinylcholine is less than 0.3 mg/kg. The dose of 1 mg/kg represents 3.5 to 4 times the ED(95).
  
  
  OBJECTIVE
  To compare the effect of the traditionally used 1 mg/kg of succinylcholine with lower doses of 0.6 mg/kg and 0.45 mg/kg on intubation condition regarding the onset time, duration of action, duration of abdominal fasciculation, and the intubation grading.
  
  
  METHODS
  This retrospective comparative study was carried into three groups of ASA III & IV (American Society of Anesthesiologist's Physical Status III and IV) non-prepared emergency patients who were intubated at emergency department of Hamad General Hospital, Doha, Qatar during January 1st 2007 to August 31, 2010. The Institutional Research Board (IRB) approval was obtained. This study was limited to 88 patients who received fentanyl 1µg/kg followed by etomidate 0.3 mg/kg intravenously as induction agents and succinylcholine as a muscle relaxant agent in doses of 0.45 mg/kg, 0.6 mg/kg, or 1 mg/kg.
  
  
  RESULTS
  Increasing the succinylcholine dosage shortened the onset time, prolonged the duration of action, and prolonged the duration of abdominal fasciculation significantly (P<.001). Tracheal intubation was 100% successful in the three groups of patients.
  
  
  CONCLUSIONS
  Succinylcholine dose of 0.45 mg/kg provides an optimal intubation condition in ASA III & IV emergency non-prepared patients. Duration of action of succinylcholine is dose dependent; reducing the dose allows a more rapid return of spontaneous respiration and airway reflexes.
authors.affiliation: Anesthesia, ICU & Pain Management, Hamad General Hospital, Doha, Qatar.
authors.forename: Alaa
authors.initials: A
authors.lastname: Ezzat
authors.forename: Essam
authors.initials: E
authors.lastname: Fathi
authors.forename: Ahmad
authors.initials: A
authors.lastname: Zarour
authors.forename: Rajvir
authors.initials: R
authors.lastname: Singh
authors.forename: M Osama
authors.initials: MO
authors.lastname: Abusaeda
authors.forename: M Magdy
authors.initials: MM
authors.lastname: Hussien