Comparing Hemodynamic Changes for Intubation With Shikani Intubating Stylet and Macintosh Laryngoscope

Study Overview
=================
Brief Summary
-----------------
Because of its simplicity of function and reliability, direct laryngoscopy it is routinely used for endotracheal intubation during general anesthesia. However, direct laryngoscopy is fraught with concerns for cardiovascular stimulation during induction of general anesthesia. This can be attributed to the placement of the laryngoscope blade into the vallecula and then applying force in an upward direction to expose the glottic opening. The average force necessary for visualization of the glottic opening is approximately 5.4kg. This can lead to significant pressor responses and tachycardia though stimuli to supraglottic region. An alternative airway management device is the Shikani optical stylet (SOS). It is an effective, safe and reusable intubation device that has been shown to be effective in cases of difficult intubation. It consists of a fiberoptic bundle within a J - shaped malleable stainless steel sheath. At the proximal end of the sheath is an eyepiece with an attachment to a light source. An adjustable tube stop firmly affixes the endotracheal tube to the stylet, and has a port to be able to deliver oxygen. (4) The operator inserts the tip of the stylet with the loaded endotracheal tube into the patient's oropharynx and under direct visualization through the eyepiece, is able to visualize the vocal cords. Because the end of the stylet is at the end of the endotracheal tube, it can be directly visualized to be entering trachea past the vocal cords. The investigators hypothesize that endotracheal intubation performed by the aid of SOS by minimizing oropharyngolaryngeal stimulation will result in fewer hemodynamic changes in patients with normal airways as compared with the MacIntosh laryngoscope.

Conditions
-----------------
Anesthesia

Intervention / Treatment
-----------------
* Device: Endotracheal Intubation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 18 - 75 years, ASA I and II, normotensive, Mallampati class: I and II, thyromental distance > than 6.5 cm, interincisor distance > than 3 cm, BMI < 35 Kg/m2 Exclusion Criteria: Exclusion criteria: pregnant patients, known or expected difficult airway, gastroesophageal reflux, esophageal pathology, pulmonary pathology, cardiovascular pathology.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: MacIntosh group<br> | Device: Endotracheal Intubation<br>* General anesthesia will be induced with fentanyl 1-2 mcg/kg, 2-3 mg/kg propofol and maintained with 50% air /50% oxygen and isoflurane. Neuromuscular blockade will be obtained with rocuronium 0.5 mg/kg. Laryngoscopy will be performed with Shikani optical stylet (SOS) (one size) or MacIntosh laryngoscope blade size 3 for women and size 4 for men. Endotracheal intubation will be performed with an endotracheal tube of internal diameter of 7.0 mm l for female patients and 8 mm for male in both groups. Noninvasive blood pressure and heart rate will be recorded preinduction, preintubation, and every min for the first 5 min after successful intubation. The patients will be questioned post-operatively about symptoms of a sore throat, hoarseness, dysphonia or dysphagia in the Post Anesthesia Care Unit and again 24 hours after surgery.<br>|
| Experimental: Shikani optical stylet<br> | Device: Endotracheal Intubation<br>* General anesthesia will be induced with fentanyl 1-2 mcg/kg, 2-3 mg/kg propofol and maintained with 50% air /50% oxygen and isoflurane. Neuromuscular blockade will be obtained with rocuronium 0.5 mg/kg. Laryngoscopy will be performed with Shikani optical stylet (SOS) (one size) or MacIntosh laryngoscope blade size 3 for women and size 4 for men. Endotracheal intubation will be performed with an endotracheal tube of internal diameter of 7.0 mm l for female patients and 8 mm for male in both groups. Noninvasive blood pressure and heart rate will be recorded preinduction, preintubation, and every min for the first 5 min after successful intubation. The patients will be questioned post-operatively about symptoms of a sore throat, hoarseness, dysphonia or dysphagia in the Post Anesthesia Care Unit and again 24 hours after surgery.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart Rate and Blood Pressure Double Product | The double product was measured. The double product is calculated by multiplying the heart rate with the systolic blood pressure. It is also known as the rate pressure product and it is used to measure hemodynamic response.The double product is calculated from the values obtained preinduction, during intubation and after intubation.(5 minutes after intubation)The double products from each time point are averaged to get one mean double product value. | Noninvasive blood pressure and heart rate will be recorded preinduction, preintubation, and every min for the first 5 min after successful intubation. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to Complete Laryngoscopy and Successful Intubation |  | Noninvasive blood pressure and heart rate will be recorded preinduction, preintubation, and every min for the first 5 min after successful intubation. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Comparison of hemodynamic, endotracheal intubation, changes induced by, performed, the aid of the SOS, as compared to the Macintosh Laryngoscope