Laryngeal mask airway is inserted into the oral cavity and seals the upper esophagus and the surrounding tissue, effectively securing airway. Laryngeal mask airway has been widely adopted in the clinical practice. On the other hand, cricoid pressure has been used to reduce the risk of pulmonary aspiration of gastric contents during induction of general anesthesia. However, cricoid pressure might impede placement of the laryngeal mask airway, thereby preventing effective ventilation. Recently, left paratracheal pressure was introduced as an alternative to cricoid pressure and reported to be more effective than cricoid pressure in the prevention of gastric air insufflation during positive-pressure ventilation by facemask. Since this method compresses low left paratracheal level, it may affect the successful insertion of laryngeal mask airway. In this study, the investigators aimed to evaluate the effect of paratracheal esophagus pressure on the insertion of laryngeal mask airway compare to conventional cricoid pressure.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
TRIPLE
Enrollment
108
To apply paratracheal pressure, the thumb was placed over the left side of the trachea cephalad to the clavicle and medial to the sternocleidomastoid muscle.
To apply cricoid pressure, the cricoid cartilage is compressed by 30N force with a single-handed three finger maneuvre towards the vertebral bodies.
Ajou university hospital
Suwon, Gyeonggi-do, South Korea
The success rate of device insertion
Successful insertion of laryngeal mask airway in a maximum of three attempts
Time frame: During induction of anesthesia, an average of 60 seconds
The grade of fiberoptic bronchoscopic view
The fiberoptic bronchoscopic view is defined as Grade 1, larynx only seen; Grade 2, larynx and epiglottis posterior surface seen; Grade 3, larynx, and epiglottis tip or anterior surface seen-visual obstruction of epiglottis to larynx: \< 50%; Grade 4, epiglottis down-folded, and its anterior surface seen-visual obstruction of epiglottis to larynx: \> 50%; Grade 5, epiglottis downfolded and larynx cannot be seen directly.
Time frame: During induction of anesthesia, an average of 5 minutes
The time for successful insertion of the device
The total time is measured from the removal of the face mask until bilateral chest rise with the first capnogram upstroke.
Time frame: : During induction of anesthesia, an average of 60 seconds
Peak inspiratory pressure
Peak inspiratory pressure is recorded from mechanical ventilator.
Time frame: At 5 minute after insertion of laryngeal mask airway
The ease of insertion of device
The ease of placement was assessed using a subjective scale of 1-4 (1= no resistance, 2 = moderate resistance, 3 = high resistance, 4 = inability to place the device
Time frame: During induction of anesthesia, an average of 60 seconds
The number of attempts at insertion of device
The number of attempts for successful insertion of laryngeal mask airway
Time frame: During induction of anesthesia, an average of 60 seconds
Success rate in first attempt
Successful insertion of laryngeal mask airway in a first attempt
Time frame: : During induction of anesthesia, an average of 60 seconds
Incidence of intraoperative complications
Intraoperative complications including coughing, laryngospasm, bronchospasm, hypoxia (SpO2 \< 90%), regurgitation, aspiration, blood staining of the device.
Time frame: During the surgery, an average of 2 hours after anesthesia induction
Incidence of postoperative complications
Postoperative complications including sore throat, hoarseness/dysphonia, jaw, neck or ear pain, persistent cough, tachypnea, stridor, hypoxia (SpO2 \< 90%), nausea and vomiting.
Time frame: An average of 2 hours after extubation
The presence of gastric air insufflation after induction of anesthesia
The presence of gastric air insufflation is defined as an increase in antral cross-sectional area and/or presence of air artifacts in the antrum (comet tail, posterior acoustic shadow) confirmed by ultrasound.
Time frame: During induction of anesthesia, an average of 5 minutes
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