The Utility of Gastro-laryngeal Tube During Transesophageal Echocardiography: Prospective Randomized Clinical Trial
Phase: NA
Conditions: Anesthesia, Sedation, Analgesia, Airway Complication of Anesthesia
Sponsor: Bezmialem Vakif University

01.10.2015 
Title page 
 
The Utility of Gastro-laryngeal Tube during Transesophageal Echocardiography: 
Prospective Randomized Clinical Trial 
 
Muhittin Calim (mcalim@bezmialem.edu.tr) 
M.D. Department of Anesthesiology and Reanimation, Bezmialem Vakif University School of 
Medicine, Istanbul, Turkey. ORCID ID: 0000-0003-0231-3636 
Harun Uysal (drharunuysal@hotmail.com) 
Assist. Prof. Dr. Department of Anesthesiology and Reanimation, Bezmialem Vakif University 
School of Medicine, Istanbul, Turkey. ORCID ID: 0000-0003-0426-8525 
Nuray Kahraman Ay (drnuraykahraman@hotmail.com) 
Assoc. Prof. Dr. Department of Cardiology, Bezmialem Vakif University School of Medicine, 
Istanbul, Turkey. ORCID ID: 0000-0003-3355-0925 
Kazim Karaaslan (kazimkaraaslan@gmail.com) 
Prof. Dr. Department of Anesthesiology and Reanimation, Bezmialem Vakif University School 
of Medicine, Istanbul, Turkey. ORCID ID: 0000-0003-0582-8723 
Hayrettin Daskaya (h.daskaya@gmail.com) 
Assoc. Prof. Dr. Department of Anesthesiology and Reanimation, Bezmialem Vakif University 
School of Medicine, Istanbul, Turkey. ORCID ID: 0000-0002-0155-1387 
 
Address all correspondence to: 
Muhittin Calim, M.D. Department of Anesthesiology and Reanimation, Bezmialem Vakif 
University School of Medicine, Istanbul, Turkey 
Mail: mcalim@bezmialem.edu.tr 
Phone Number: +905057734267 
 
 
 
 
 
 
 

01.10.2015 
Study Protocol 
After approval from the Ethics Committee of Bezmialem Vakif University School of Medicine, study was 
performed for 42 patients scheduled for TEE under sedation and analgesia or general anesthesia. Patients with 
American Society of Anesthesiology (ASA) physical status I-II and aged 20-75 years old were included in this 
study. ts who were under 20 to over 75 years old, an allergy to anesthetic drugs, emergent procedure, uncontrolled 
cerebrovascular disease, drug and alcohol addiction, performed oropharyngeal surgery were excluded, as were all 
patients who refused written informed consent. 
Preoperative evaluations were performed on all patients a day before procedure. Age, gender, height, weight, and 
ASA physical status were recorded. On the day of procedure, patients were taken to the procedure room after 
premedication with 0.003 mg/kg IV midazolam (Dormicum, Deva Holding Cor., Istanbul, Turkey). Standard 
monitoring procedures were used, including heart rate (HR), noninvasive blood pressure, electrocardiogram, 
peripheral oxygen saturation (SpO2). 
Forty two patients were randomly assigned to either the Group 1 (n=22, sedation and analgesia without any airway 
instrumentation) or Group 2 (n=20, airway control provided by GLT after inducing sedation and analgesia). Also, 
randomization (1:1) was based on a computer generated random numbers table, using MedCalc v. 16 statistical 
software for Windows (medcalc.com.tr). All patients received standard intervention procedures determined by the 
same team of cardiologists and an anesthesiologist with experience in TEE. Standard intervention procedure 
protocol was not change in any way. 
All patients received preoperative midazolam (0.01-0.02 mg/kg) before being taken to the procedure room. For 
patients in Group 1, a standardized sedation and analgesia was administered by an experienced anesthesiologist. 
After administration of lidocaine (1 mg/kg) and atropine sulfate (0.01 mg/ kg), and also preoxygenation (100% 4 
L/min O2 for 3 min), patients were induced with propofol (1-2 mg/kg) and fentanyl (1-2 mcg/kg) via intravenous 
(IV) route at doses calculated according to ideal body weight. Anesthesia was maintained with propofol infusion 
(4 mg/kg/h). Repetitive IV boluses of propofol (0.1 mg/kg) were administered, if necessary. Patients received 
oxygen (100%, 3 L/min) through a nasal cannula during sedation and analgesia.  
For patients in Group 2, after administration of lidocaine (1 mg/kg) and atropine sulfate (0.01 mg/ kg), and also 
preoxygenation (100% 4 L/min O2 for 3 min), patients were induced with propofol (1-2 mg/kg) and fentanyl (1-2 
mcg/kg). After induction of anesthesia, supraglottic airway device named GLT (VBM Medizintechnik GmbH, 
Sulz, Germany) was inserted (Figure 3). Patients were ventilated mechanically with a tidal volume of 6–8 mL/kg 

01.10.2015 
based on ideal body weight and a frequency of 12–14 breaths/min using a Dräger Primus ventilator (Dräger AG, 
Lübeck, Germany) after inserting the GLT. Repetitive IV boluses of propofol (0.1 mg/kg) were administered, if 
necessary. Also, GLT was then removed at the end of TEE procedure. 
The anesthesiologist was responsible for patient comfort, hemodynamic stability, immobility, adequate analgesia 
and airway management. 
We hypothesized that GLT, allowing passage of the TEE probe and ensuring supraglottic airway control, would 
provide more advantages in terms of hemodynamic stabilization, complications related airway management, 
cardiologist and patient satisfactions when used in a clinical setting. To date, there has been no detailed prospective 
clinical study analyzing the performance of the GLT during TEE. The present study sought to address this gap by 
performing a prospective clinical study to analyze the performance of the GLT during TEE. Our primary outcome 
measures were safety of airway management, and cardiologist and patient satisfactions. Our study also recorded 
demographic characteristics, intraoperative and postoperative hemodynamics, level of hypoxemia, and duration of 
procedure as secondary outcome measures. 
Statistical Analysis 
Data were analyzed using the Statistical Package for the Social Sciences program (SPSS 22.0; IBM). The Shapiro 
Wilk normality test was used to test whether quantitative variables showed a normal distribution. Differences 
between variables in two groups with normal distribution were compared with the paired t-test. Continuous 
variables distributed abnormally were compared between the groups using a Mann–Whitney U test. Differences 
between variables within the same group at different times were tested with the Friedman test, and significant 
variables had pairwise comparisons performed with the Dunn test. Categorical variables were summarized using 
frequencies and percentages, and were compared between the groups using a chi-square test or Fisher’s exact test. 
Descriptive statistics are given as mean, standard deviation, median, Q1 (1st quartile), Q3 (3rd quartile), frequency 
and percentage (%). Results were evaluated at a 95% confidence interval at a significance level of p < 0.05. Consent 
to conduct the study was obtained from Local Ethic Committee of Bezmialem Vakif University.