Alfentanil and the Elimination of Sympathetic Responses to Tracheal Intubation During Rapid Sequence Induction of Anesthesia: A Probability-based Approach
Condition: Anesthesia Intubation Complication
Study type: Interventional
Phase: Phase 4

Summary: 
      Induction of anesthesia:

      After 3 minutes pre-oxygenation with 100% oxygen, a blinded dose alfentanil (0,10,20,30,40,50
      or 60 µg/kg, followed by thiopental 4 mg/kg and rocuronium 0.6 mg/kg will be administered
      over 15 sec. Laryngoscopy will be performed 40 s. after injection of rocuronium, with the
      goal being to have the endotracheal tube passed through the patients vocal cords and the cuff
      inflated within the following 15 s . The investigator performing the tracheal intubation is
      blinded to the dose of alfentanil administered.

      Blood samples:

      As part of the study efficacy, blood samples, will be collected prior to induction and 30 s.,
      1 min. 3 min. and 5 min postintubation to determine blood concentrations of alfentanil and
      catecholamines.
    

Detailed description: 
      Introduction:

      Autonomic responses (blood pressure and heart rate increases) secondary to tracheal
      intubation are probably not harmful to healthy individuals(1). However, in certain groups of
      patients (cardiac/neurosurgical/ophthalmic surgery), strict control of these responses during
      anesthesia may add to the safety of patient care (2-6).

      Traditionally, rapid sequence induction (RSI) of anesthesia is performed with combined
      administration of pentothal and suxamethonium. Significant increases in blood pressure and
      heart rate will be observed in most patients when this drug regimen is used(7-9). Opioid
      drugs may obtund autonomic responses to tracheal stimulation(10), but at present there is no
      consensus regarding the use of opioids as an integral part of the RSI of anesthesia.

      AIMS & OBJECTIVES:

        -  Define guidelines for proper care of cardiac/neurosurgical/eye surgery patients during
           induction of anesthesia when rapid airway control is needed.

        -  Determine the dose of alfentanil needed to prevent blood pressure and heart rate
           increases > 10% secondary to tracheal intubation performed in a rapid-sequence fashion
           (intubation completed within 70 s after start of drug administration:
           alfentanil-pentothal 4 mg/kg-rocuronium 0.6 mg/kg).

        -  Determine the optimal dose of alfentanil to obtain perfect conditions for tracheal
           intubation in healthy surgical patients when laryngoscopy is initiated within 55 s after
           start of drug administration (alfentanil-pentothal 4 mg/kg-rocuronium 0,6 mg/kg).

      Induction of anesthesia:

      After 3 min pre-oxygenation with 100% oxygen, a blinded dose of alfentanil (0, 10, 20, 30,
      40, 50 or 60 mcg/kg), followed by thiopental 4 mg/kg and rocuronium 0.6 mg/kg will be
      administered over 15 s. Cricoid pressure will be applied when the patient is unconscious.

      Laryngoscopy and intubation:

      Laryngoscopy will be performed 40 s after injection of rocuronium, with the goal being to
      have the endotracheal tube passed through the patients vocal cords and the cuff inflated
      within the following 15 s. The investigator performing the tracheal intubation will be
      blinded to the dose of alfentanil administered.

      Maintenance of anesthesia:

      The study ends 5 min post intubation. At this time sevoflurane and fentanyl will be
      administered according to the patient's needs. Ventilation will be adjusted to pCO2-values in
      the range 4.5-6 kPa, and body temperature maintained at > 36 degree ºC with a forced-air
      warmer.

      Monitoring:

      Routine monitoring of blood pressure, ECG, and pulse oximetry, according to standard of
      anaesthesia, approved by the Society of the Norwegian Anaesthesiologists. An arterial line
      will be inserted in one of the radial arteries for accurate beat-to-beat recording of blood
      pressure and heart rate, and for collection of blood samples.

      Statistical analysis plan:

      In the present study a nonlinear logistic regression analysis will be used to determine the
      optimal dose of alfentanil based on the success rates of optimal blood pressure control
      (blood pressure increase < 10%)and the success rates of perfect intubation conditions in all
      alfentanil dose groups.
    

Intervention name(s): Alfentanil 0.5mg/ml (Rapifen , Janssen-Cilag)
Intervention type(s): Drug
Intervention description(s): Induction dose(0µg/kg,10µg/kg,20µg/kg,30µg/kg,40µg/kg,50µg/Kg,and 60µg/kg) 12 patients in each dose group.
Pentothal 4mg/kg Rocuronium 0.6 mg/kg
Intervention MeSH terms: Alfentanil
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: Alfentanil; Tracheal intubation; Rapid sequence induction