Comparison Between Blind And Ultrasound Guided Laryngeal Mask Airway Insertion

Beni-Suef University

Status and phase: Unknown; Phase 1

Conditions: the Position of Laryngeal Mask Airway

Treatments: Procedure: the fiberoptic laryngoscope (KARL STORZ 11301BN1, Germany) for confirmation of LMA position

Study type: Interventional

Funder types: Other

Identifiers

NCT04090944

Beni-suef Hospital

Details and patient eligibility

About

The Proper position of a laryngeal mask airway (LMA) requires confirmation to ensure the adequacy of laryngeal seal and pulmonary ventilation. This confirmation may help in prevention of the peri-operative airway complication and ventilation events associated with LMA placement

Full description

It is common practice to inflate the cuff of LMA with the maximum recommended volume (size 3, 20 ml; size 4, 30 ml; size 5, 40 ml), as illustrated in several studies , but it may become more rigid which may cause displacement of the LMA and decreases the airway sealing of LMA, more pressure on pharyngeal mucosa which might cause severe mucosal ischemia leading to post- operative sore throat, dysphagia or hoarseness.

Ultrasonography can reliably confirm correct placement of supraglottic devices like laryngeal mask airway (LMA) and rules out causes of inadequate ventilation , also it was found to be a sensitive in detecting rotational malposition of LMA in children.

the replacement of air with saline in LMA cuffs enable detection of cuffs in the airway allowing visualization of the surrounding structures and tissues as the ultrasound beam can be transmitted through the fluid-filled cuffs without being reflected from air mucosal interface.

the adequacy of LMA position will be confirmed by a fiberoptic laryngoscope (FOL)

Enrollment: 102 estimated patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients aged from 18- 60 years of either sex, ASA physical status I - II, weighting 50-100 kg, who will scheduled for elective surgery under general anesthesia.

Exclusion criteria

• • Patients whom LMA is contraindicated as patients who are at an increased risk of gastric aspiration as (obstetrics, hiatal hernia or esophageal reflux ), patients with high airway resistance e.g. (bronchospasm or pulmonary edema), patients with low pulmonary compliance e.g. (obesity), cases of an inability to open the mouth or an infection or pathologic abnormality within the oral cavity or pharynx and nonsupine position of operation .
• Patients with a known or predicted difficult airway as patients with class III and IV Modified Mallampati Score or with score > 5 wilson's risk score.
• Patients with cardiovascular disease (congestive heart failure, coronary artery disease), history of renal or hepatic insufficiency, and endocrinal Diseases will be excluded from the study.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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102 participants in 2 patient groups

1st group (group B)

Active Comparator group

Description:

The LMA LarySeal Multiple will be inserted using the blind technique which involves holding the LMA like a pen guided into the pharynx with the index finger of the operator at the junction of the tube and the bowl, with the operator at the head of the patient and the LMA facing caudally. The position of LMA will be assessed by another anesthetist (blinded assessor) using the fiberoptic laryngoscope (KARL STORZ 11301BN1, Germany) per the grading devised by Aoyama et al.

Treatment:

Procedure: the fiberoptic laryngoscope (KARL STORZ 11301BN1, Germany) for confirmation of LMA position

2nd group:(group U)

Active Comparator group

Description:

The LMA LarySeal Multiple will be inserted under the guide of B-mode US on the anterior neck . Transverse scans , Sagittal view and Parasagittal view. -The position of LMA will be assessed by another anesthetist (blinded assessor) using the fiberoptic laryngoscope (KARL STORZ 11301BN1, Germany) per the grading devised by Aoyama et al.

Treatment:

Procedure: the fiberoptic laryngoscope (KARL STORZ 11301BN1, Germany) for confirmation of LMA position