Comparison of Two Insertion Techniques of Proseal Laryngeal Mask Airway by Unskilled Personnel in Children

Study Overview
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Brief Summary
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The ProSeal laryngeal mask airway (PLMA) is one of the alternative methods for effective airway management. It is an advanced form of laryngeal mask airway(LMA) with a softer and larger cuff to improve sealing and a drain tube to permit venting of the stomach. However, the larger cuff is more difficult to save space for insertion in the mouth and is more likely to fold over. Particularly, a relatively large tongue, a floppy epiglottis, a cephalad and more anterior larynx and frequent presence of tonsillar hypertrophy may disturb PLMA insertion in pediatric patients. The manufacturer recommends inserting PLMA using digital manipulation or with an introducer, but these techniques have lower success rates compared to those of LMA insertion. McIvor blade is a tongue retractor with a thin and curved blade and a flat handle. It is used to secure the operating field by pressing tongue during tonsillectomy. The investigators hypothesized that McIvor blade would provide more space in the mouth for PLMA insertion, and therefore it could improve the PLMA insertion as well as reducing injuries to the pharyngeal wall. The investigators compared the success rate and the incidence of complications of the digital technique with those of McIvor blade-guided insertion by unskilled anesthesia residents.

Detailed Description
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Rapid and successful airway management is important for the patient's outcome in emergency care. Tracheal intubation with an endotracheal tube is the gold standard for airway management, but tracheal intubation by paramedical staff in pre-hospital setting can be time-consuming and difficult. The ProSealTM laryngeal mask airway (PLMA) is one of the alternative methods for effective airway management. It is an advanced form of laryngeal mask airway(LMA) with a softer and larger cuff to improve sealing and a drain tube to permit venting of the stomach. However, the larger cuff is more difficult to save space for insertion in the mouth and is more likely to fold over. Particularly, a relatively large tongue, a floppy epiglottis, a cephalad and more anterior larynx and frequent presence of tonsillar hypertrophy may disturb PLMA insertion in pediatric patients. The manufacturer recommends inserting PLMA using digital manipulation or with an introducer, but these techniques have lower success rates compared to those of LMA insertion. The first attempt success rate of PLMA insertion by inexperienced personnel was reported to be 83%. Several techniques have been introduced to improve the insertion success rate; the use of fiberoscopy, gum-elastic bougie, and a suction catheter. However, all of them can not save enough oral space for PLMA insertion and it would not be easy for the unskilled personnel to use them in emergency situations. A larger space between tongue and retropharynx, not being accompanied with an index finger for insertion would make make it easier for the unskilled personnel to insert the PLMA. McIvor blade is a tongue retractor with a thin and curved blade and a flat handle. It is used to secure the operating field by pressing tongue during tonsillectomy. We hypothesized that McIvor blade would provide more space in the mouth for PLMA insertion, and therefore it could improve the PLMA insertion as well as reducing injuries to the pharyngeal wall. We compared the success rate and the incidence of complications of the digital technique with those of McIvor blade-guided insertion by unskilled anesthesia residents.

Official Title
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Comparison of Two Insertion Techniques of Proseal Laryngeal Mask Airway by Unskilled Personnel in Children

Conditions
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Airway Management

Intervention / Treatment
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* Procedure: McIvor retractor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy pediatric patients undergoing surgery under general anesthesia Exclusion Criteria: pediatric patients with a known or predicted difficult airway, recent sore throat, mouth opening less than 2.5 cm, or at risk of aspiration

Ages Eligible for Study
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Minimum Age: 3 Years
Maximum Age: 9 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: McIvor group<br>groups in which proseal laryngeal mask airway is inserted with McIvor retractor. | Procedure: McIvor retractor<br>* The Mclvor blade- guided technique (McIvor group) involved the following steps. The PLMA was lubricated on the posterior aspect of the deflated mask with a water-based lubricant. The McIvor blade was fully inserted beneath the tongue of the patients. The tongue was lifted gently with the McIvor blade and PLMA was introduced into a space between the McIvor blade and maxillary incisors holding the bite block of the PLMA. The PLMA was advanced into the hypopharynx until definite resistance was felt and McIvor blade was removed.<br>* Other names: McIvor group;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the success rate of proseal laryngeal mask airway (PLMA) insertion | immediately after the insertion of PLMA | at the time of insertion of PLMA | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the incidence of complications following PLMA insertion | blood staining: after the removal of PLMA; sore throat: 1 day after surgery | after the removal of PLMA, and 1 day after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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McIvor retractor, Proseal laryngeal mask airway