Hemodynamic Responses of Different Laryngoscopes
Condition: Heart Rate and Rhythm Disorders; Blood Pressures; Oxygen Disorders
Study type: Interventional
Phase: Phase 4

Summary: 
      During laryngoscopy and endotracheal intubation, stimulation of supraglottic regions leads to
      an increase in the plasma catecholamine concentrations due to the activation of the
      sympatho-adrenal system. Prevention or reduction of this increment is important for
      hemodynamic control. Therefore, various methods such as providing adequate depth of
      anesthesia and shortening the time of laryngoscopy were used. On the other hand; alternative
      laryngoscopy devices and techniques have recently started to be used.

      In this randomized single blind study, the aim is to compare the hemodynamic responses of
      four different laryngoscopy techniques with Macintosh laryngoscope, McCoy laryngoscope, C-Mac
      videolaryngoscope and McGrath videolaryngoscope in patients with normal predictive airway.
    

Detailed description: 
      During laryngoscopy and endotracheal intubation, stimulation of supraglottic regions leads to
      an increase in the plasma catecholamine concentrations due to the activation of the
      sympatho-adrenal system. Prevention or reduction of this increment is important for
      hemodynamic control. Therefore, various methods such as providing adequate depth of
      anesthesia and shortening the time of laryngoscopy were used. On the other hand; alternative
      laryngoscopy devices and methods have recently started to be used.

      In this randomized single blind study, our aim is to compare the hemodynamic responses of
      four different laryngoscopy techniques with Macintosh laryngoscope, McCoy laryngoscope, C-Mac
      videolaryngoscope and McGrath videolaryngoscope in patients with normal predictive airway.

      After obtaining Institutional Ethics Committee approval and patient consents, 170 patients
      (18-65 years old) with ASA I-II status requiring general anesthesia with endotracheal
      intubation, were enrolled to this prospective randomized study.

      Besides routine monitorization (noninvasive blood pressure (NIBP), electrocardiography (ECG),
      heart rate (HR), peripheral oxygen saturation (SPO2)), continuous BIS monitorization was also
      performed. Sedation was performed using a standard dose of IV fentanyl (1.5 μg/kg) and
      midazolam (0.05 mg/kg). Baseline systolic, diastolic and mean arterial blood pressures, HR
      and SPO2 values were recorded as T0. After a stabilization period of 10 minutes, propofol 2-3
      mg/kg IV bolus was applied incrementally until a clinically desirable sedation level was
      achieved. If necessary, additional propofol boluses were given to maintain a BIS level of 60.
      As soon as BIS level was reduced to 60, patients were put on 0.6 mg/kg IV rocuronium. 100%
      oxygen was applied with a facemask for a period of 3 minutes. Then, post induction values
      (T1) were recorded.

      One hundred seventy patients were randomly allocated equally to Macintosh laryngoscope,
      Mc-Coy laryngoscope, C-Mac videolaryngoscope and McGrath videolaryngoscope groups.
      Endotracheal tube (ETT) of 7.0 mm and 7.5 mm were placed to female and male patients,
      respectively. All intubation procedures were performed by a single experienced
      anesthesiologist. Intubation stylet was provided, if necessary. Cuff pressures of
      endotracheal tubes were standartized to 30 cmH2O via a manometer. The following measurements
      were recorded immediately after intubation (T2) and at one minute intervals for 5 minutes
      (T3, T4, T5, T6 and T7).

      Moreover; the number of intubation attempts, stylet needs, Cormack-Lehane scales, and the
      complications occurred during intubation procedures were recorded as the second outcomes.
      Patients were also questioned for possible sore throat at postoperative 2 hours. Patients
      requiring more than one attempt to achieve successful intubation were excluded from
      statistical analysis of data.
    

Intervention name(s): Macintosh laryngoscope; Mc-Coy laryngoscope; C-Mac videolaryngoscope; McGrath videolaryngoscope
Intervention type(s): Device; Device; Device; Device
Intervention description(s): Hemodynamic parameters after endotracheal intubation with Classic laryngoscope (Macintosh); Hemodynamic parameters after endotracheal intubation with Mc-Coy laryngoscope; Hemodynamic parameters after endotracheal intubation with C-Mac videolaryngoscope; Hemodynamic parameters after endotracheal intubation with McGrath videolaryngoscope
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Screening
Keywords: Macintosh laryngoscope; McCoy laryngoscope; C-Mac videolaryngoscope; McGrath videolaryngoscope; Hemodynamic parameters