Determination of Optimum Time for Intravenous Cannulation in Children With Dexmedetomidine Premedication
Condition: Cannulation; Sevoflurane Induction; Dexmedetomidine
Study type: Observational

Summary: 
      Inhalational induction with sevoflurane, nitrous oxide, and oxygen is accepted as a safe
      technique to avoid any movement during intravenous cannulation in children. In addition,
      intranasal dexmedetomidine could be used for premedication to reduce preoperative anxiety in
      preschool children. Early attempts to place, an intravenous line may result in movement and
      respiratory complications like coughing or laryngospasm. On the other hand delay in
      cannulation may prevent effective management of bradycardia and hypotension. There are a
      number of studies examining the optimum time for cannulation after sevoflurane induction.
      However, it is not known whether the addition of dexmedetomidine premedication affects the
      time for intravenous cannulation following induction with sevoflurane and nitrous oxide.
    

Detailed description: 
      All the children will be premedicated with intranasal 2mcg/kg dexmedetomidine 40 minutes
      before the surgery. Ramsay sedation scale and Turkish version of modified Yale Preoperative
      Anxiety Scale (mYPAS) will be measured at the time of arrival in the daycare unit and during
      anesthesia preparation in the operating room.

      The same anesthesia machine will be used in all children with the same circuit volume. The
      circuit will be emptied and then filled with sevoflurane (8%) and nitrous-oxygen (50:50) for
      30 seconds at a high fresh gas flow (6 liter/minute). The timer will be started when the face
      mask is placed on the child's face for inhalational induction.

      The exhaled gas concentrations will be measured continuously. After the loss of eyelash
      reflex, the fresh gas flow will be reduced to 3 liter/minute, the sevoflurane will be reduced
      to 5% and the timer will be restarted. Spontaneous respiration will be allowed until
      intravenous cannulation and ventilation will be gently assisted as required.

      For the first child, the gas flow settings will be maintained for 4 minutes from the loss of
      eyelash reflex before intravenous cannulation is attempted. All intravenous cannulation will
      be performed on the dorsum of the hand by an experienced anaesthesiologist, using a 24-gauge
      stainless steel guide cannula.

      At the time of intravenous cannulation attempt, an independent observer, who will be blinded
      about the predetermined cannulation time, will rate the movement according to a scale (0= no
      movement, 1= slight extremity tension, 2= extremity withdrawal, 3= generalized movement).

      The intravenous cannulation will be considered unsuccessful if there is any movement, cough,
      or laryngospasm, and the procedure will be considered successful in the absence of any
      reaction.

      The time for the subsequent patient's intravenous cannulation will be adjusted accordingly
      using Dixon's up-down sequential method (starting at 4 min with 15 s as the step size). The
      time for cannulation will be increased by 15 s if the time will be inadequate in the previous
      patient, and conversely, the time for cannulation will be decreased by 15 s if the time will
      be adequate in the previous patient.

      The aim of this study will be to determine the optimum time for intravenous cannulation after
      the induction of anesthesia with sevoflurane, oxygen, and nitrous oxide in children with
      intranasal dexmedetomidine premedication.
    

Intervention name(s): Optimum time for intravenous cannulation in children premedicated with dexmedetomidine
Intervention type(s): Procedure
Intervention description(s): The optimum time for intravenous cannulation after the induction of anesthesia with sevoflurane, oxygen, and nitrous oxide in children with intranasal dexmedetomidine premedication will be searched in children undergoing elective surgery.
Intervention MeSH terms: Dexmedetomidine
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Children aged 2-6 years, American Society of Anesthesiologists physical status 1 scheduled
        for elective procedures undergoing inhalational induction after dexmedetomidine
        premedication without intravenous access will be enrolled in the study.
      
Keywords: Induction of anesthesia; Sevoflurane; Nitrous oxide; Dexmedetomidine