Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01099969 |
| Other study ID # |
HSC-MS-09-0456 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
March 2010 |
| Est. completion date |
January 2012 |
Study information
| Verified date |
May 2018 |
| Source |
The University of Texas Health Science Center, Houston |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The purpose of this study is to compare the safety and efficacy of Endotrol Tube compared to
the conventional endotracheal tube in conjunction with the GlideRite stylet (Verathon Medical
Inc, USA) during videolaryngoscopy assisted endotracheal intubation using a McGrath (Aircraft
Medical Ltd., and distributed in the US by LMA North America, Inc.) video laryngoscope or a
GlideScope (Verathon Medical Inc, USA). The investigators hypothesize that using the Endotrol
tracheal tube, (Covidien, Colorado, USA) is safer and more efficacious than using the
conventional endotracheal tube during McGrath video laryngoscope and/or GlideScope aided
endotracheal intubation.
Description:
It is estimated that endotracheal intubation is performed on some 8 million patients per year
in the United States. Of these endotracheal intubations, approximately 80% are performed by
direct laryngoscopy with transoral placement of the endotracheal tube (ET) into the trachea.
There is fairly uniform reporting of the incidence of failed intubation in the literature; it
occurs in approximately 0.05% or 1:2230 of surgical patients and in approximately 0.13% to
0.35%, or 1:750 to 1:280, of the obstetric patients.1,2 The incidence of unsuspected
difficult intubation is estimated to be higher at 3%. One factor that contributes to
difficult intubation is poor visualization of the airway. Video laryngoscopes are a
relatively new edition to the armamentarium of airway devices available to the airway
manager. Although these instruments are more expensive than traditional direct laryngoscopes,
they offer several advantages that may justify their expense. Although some clinicians may
espouse the routine use of video laryngoscopy, most providers reserve it for anticipated
difficult situations or as "plan B" after failed intubation by direct laryngoscopy (DL).
There are several advantages of a video intubation technique as compared to direct
laryngoscopy. The video laryngoscopes have been shown to provide superior views to
traditional laryngoscopy as well as in difficult intubations.3-5 Video intubation techniques,
by allowing tracheal intubation monitoring, have been shown to improve the safety of the
procedure and increase intubation success. The GlideScope consists of a digital camera,
called a video baton, which fits into a plastic laryngoscope blade and a light source on the
side to provide a video image of airway structures on a screen, which can be conveniently
located directly in front of the anesthesiologist. The GlideRite rigid stylet conforms to the
GlideScope blade angulation, which,eliminates the need to manually shape the stylet to fit
down the airway and improves maneuverability in endotracheal tube placement.
It should be noted that several reports have been published describing trauma to the upper
airway (anterior tonsillar pillar, soft palate) during intubation with video laryngoscopes.
Recently, several reports using endoflex tube (which is similar to the endotrol tube) showed
that there is considerable usefulness in normal direct laryngoscopy and video laryngoscopy
(using glidescope) as well. The purpose of this study is to compare the safety and efficacy
of Endotrol Tube (Covidien, Colorado, USA) compared to the conventional endotracheal tube in
conjunction with the GlideRite stylet during videolaryngoscopy assisted endotracheal
intubation.
INSTRUMENTS:
McGrath Video Laryngoscope (MVL) - A video-based system for tracheal intubation that utilizes
a video camera embedded into a "camera stick". The resulting video image is displayed on a
small color Liquid Crystal Display (LCD) attached to the top of the handle of the device,
which can be adjusted to obtain the best view. The unit is powered with a single
easily-replaced AA battery and features a single electronic control: an on/off switch located
on the top of the unit. The device is available with an adjustable curved MAC blade (sizes 3
to 5). Also,the device features a sterile disposable transparent blade sheath preventing
cross infection.
GlideScope Video Laryngoscope (GVL)- The GlideScope was commercially introduced in 2001. The
1- piece handle and blade is made of medical- grade plastic. It has a vertical profile of
14.5 mm, a midblade bend of 50-60 degrees, and a video camera with a light-emitting diode
housed toward the distal end of the blade. The image captured by the camera is transferred by
the attached cable to a color liquid crystal display (LCD). A heating element covers the
camera lens and ensures effective antifogging after the device has been turned on for 15- 30
seconds. The blades can be sterilized and reused, and are available in 3 sizes: large
(adult), midsize (pediatric), and small (neonatal). As the image is transferred to the LCD
display, anesthesiologists are able to view key anatomical landmarks at the earliest possible
time, facilitating navigation. Also, in cases requiring external laryngeal manipulation, the
assistant can see the effect of the maneuver on the monitor simultaneously with the
anesthesiologist for quicker, more efficient intubation. Endotrol Tracheal Tube (ETT)
(Covidien, Colorado, USA) - A sterile, single lumen, disposable ET with a built- in flexing
mechanism with a standard 15 mm connector. The tube provides directional tip control via an
operator- activated ring loop and incorporates a self- sealing valve with attached pilot
balloon. The ETT is specifically designed for use in cases where difficult intubation can be
aided with directional tip control. Due to the Hi-Lo cuff design, the ETT is acceptable for
oral/nasal intubation of the trachea for anesthesia and in cases where the intubation
duration is expected to be more than 24 hours or unpredictable. The special way to hold the
ETT is to place the thumb of the right hand against the end of the 15 mm connector and the
index finger in the ring loop. Pulling on the ring loop causes the tip to turn anteriorly
towards the tracheal opening.
METHODOLOGY:
A. General Study Design- The study will include a total of 60 patients. Patients will be
randomized into 2 groups and 2 subgroups in each group, through a computer generated
randomization schedule.
Patients in group A (N= 30) will be intubated using MVL and patients in group B (N= 30) will
be intubated using GVL. Patients in each group will be divided into 2 subgroups.
Group A (N= 30) - Subgroup A1 (N=15) - Patients will be intubated using Endotrol Tracheal
Tube without stylet (Covidien, Colorado, USA). Subgroup A2 (N= 15) - Patients will be
intubated using styletted endotracheal tube the Gliderite (Teleflex Medical, Hudson RCI/
Sheridan/ HBT). Group B (N= 30) - Subgroup B1 (N=15) - Patients will be intubated using
Endotrol Tracheal Tube without stylet (Covidien, Colorado, USA).
. Subgroup B2 (N= 15) - Patients will be intubated using styletted endotracheal tube the
Gliderite (Teleflex Medical, Hudson RCI/ Sheridan/ HBT). In the operating room, standard
monitoring devices will be applied including a pulse oximeter, 3 lead (at least), ECG and
blood pressure cuff; the latter could be invasive or non-invasive depending on the nature of
the surgery. Baseline measures of BP, pulse, oxygen saturation, and CO2, will be made. The
time will be noted before any sedation or anesthesia is administered. Vital signs will be
recorded every minute from the time that induction of anesthesia is begun until five minutes
after the patient has been intubated, and then at five-minute intervals thereafter for
fifteen minutes. General anesthesia will be induced by bolus administration of propofol
(2mg/kg) and fentanyl (1mcg/kg), and maintained with an inhalational agent. Rocuronium (0.6
mg/kg) will be administered to provide muscle relaxation and a mixture of sevoflurane or
isoflurane and nitrous oxide will be utilized for maintenance of anesthesia once the ability
to mask ventilate is confirmed. The lungs will be mechanically ventilated with a semi-closed
circle system to maintain an end-tidal CO2 near 35 mmHg. Patients' lungs will be ventilated
via anesthesia mask 100% oxygen until the patient is completely relaxed. All investigators
will be trained based on manufacturer recommendations and each resident will perform at least
3 intubations with McGrath laryngoscope and 3 intubations with Cobalt GlideScope (total of 6
intubations) prior to enlisting any patients for the study. The CA-2 and CA-3 residents will
be performing the intubations. The external neck pressure may be applied by an assistant in
an attempt to improve exposure of the larynx. The ease of intubation will be recorded in
terms of the number of attempts (measured as either the reinsertion of the blade or
endotracheal tube) and the intubation time (time the laryngoscope blade enters the mouth
until 1st capnograph breath) will be recorded. If more than 2 attempts were needed, a third
attempt can be made with the device used in the other group. If still unsuccessful, the
direct laryngoscopy/ flexible fibreoptic laryngoscopy will be performed to intubate the
trachea and the case will be deemed a failure. The subjective level of difficulty (from 0 =
Extremely Easy to 5 = Extremely Difficult) in the performance of intubation will also be
recorded. An alternative technique will be used in case the intubation fails. 1. Use of the
Glideride stylet if using an Endotrol tracheal tube, if the Endotrol tracheal tube is not
able to get towards the cords. 2. Use of a regular stylet instead of the Glideride especially
with McGrath if Glideride not able to help with intubation 3. Use of macintosh or miller
appropriate blade with styletted or Endotrol tube if intubation with videolaryngoscope is
difficult 4. Use of LMA or similar device in case intubation is difficult with any of the
previous devices and application of a difficult airway protocol. B. Measurements- We will
record morphometric characteristics of all patients. The quality of the airway will be
evaluated using the Mallampati and Wilson scoring system, thyromental scoring system of
Patil, interincisor gap distance, neck mobility and sternomental distance.
Additionally, the anesthesiologist will provide a personal, subjective opinion of a possible
difficult intubation. Intubation: We will measure the time and number of attempts required
for successful endotracheal intubation in each group. An attempt is defined as an attempt at
placement of an ET through the glottic opening and into the trachea. Removal/reinsertion of
the laryngoscope or the switching of the laryngoscopist will constitute as a new attempt. The
subjective level of difficulty (0-5) in the performance of intubation will also be recorded.
Once an optimal positional has been confirmed, position of the ET will not be further
altered. Degree of irritation: Following intubation in either group, the appearance of
oropharynx, pharynx, epiglottis, and arytenoids will be checked. The presence of abrasions,
bleeding, redness, perforation or other signs of tissue or dental injury will be recorded.
SUBJECTS:
The subjects will be adult surgical candidates age 18-80, ASA I- III, presenting for elective
surgery who require general anesthesia. Patients will be chosen if it is determined that
endotracheal intubation is required. Patients will be excluded if they are considered so
difficult (i.e. Mallampatti IV, < 2 FB or 4 cm mouth opening), that an awake fibreoptic
intubation should be performed. ASA IV and V patients will also be excluded.
RECRUITMENT METHODS/ INFORMED CONSENT:
Physician investigators will interview all potential subjects to determine if subjects are
suitable for the study. Both English and Spanish speaking subjects will be enrolled for the
study. Written consent will be obtained by an anesthesiology resident or research assistant.
PROCEDURES TO MAINTAIN CONFIDENTIALITY:
All information recorded on the anesthetic records will be kept strictly confidential and all
data will be kept in a data logbook locked in the office of the principal investigator. We
will record patients only by study code number.
DATA ANALYSIS:
Data will be compared using two- tailed paired t- tests, repeated measures of ANOVA, or
Fisher Exact test, as appropriate. Results will be presented as means ± SD. P < 0.05 will be
considered as statistically significant.
