Indian Journal of Clinical Anaesthesia

A comparative study to evaluate the effectiveness of timing principle and priming principle for tracheal intubation using rocuronium

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Author Details: M. Kamalakannan, P. Sunder

Volume : 4

Issue : 4

Online ISSN : 2394-4994

Print ISSN : 2394-4781

Article First Page : 512

Article End Page : 517


The present study is to compare the "Timing principle" and the "Priming principle" for tracheal intubation using rocuronium during balanced anesthesia by assessing the Intubating conditions and Hemodynamic changes during intubation. The succinylcholine is considered to be the best drug for rapid tracheal intubation because of its rapid onset and ultrashort duration of the action. The “priming technique” uses a sub-paralyzing dose of non-depolarizing muscle relaxant where 20% of ED 95 or 10% of the intubating dose was administered 2 to 4 min before administering an intubating dose. This technique has been proved to accelerate the onset of action by 30 to 60 seconds.(5) In “timing principle” a single bolus of non-depolarizing muscle relaxant was given followed by the administration of the induction agent after the first sign of the onset of clinical weakness. The “high – dose regimen” was used when tracheal intubation has to be accomplished in less than 60 – 90 seconds.(6) The study was conducted in Madras Medical College, Chennai The groups were comparable based on age and weight. Males were more in Group RP. Using the “Timing principle” with rocuronium 0.6 mg/kg consistently provides good to excellent intubating conditions at 60 seconds after the induction of anesthesia. Using the "Priming principle" with rocuronium 0.06 mg/kg followed by rocuronium 0.54 mg/kg consistently provides fair to good intubating conditions at 60 seconds after induction of anesthesia.

Keywords: Rocuronium, Tracheal Intubation, Priming Principle and Timing principle