Clinical trial NCT01960673: The Influence of Head and Neck Position About Oropharyngeal Leak Pressure and Sealing Between the Laryngeal Mask and Vocal Cord Using Different Types of Supraglottic Airway Device
Official title: The Influence of Head and Neck Position About Oropharyngeal Leak Pressure and Sealing Between the Laryngeal Mask and Vocal Cord Using Different Types of Supraglottic Airway Device
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
PHASE2
Conditions: the Influence of Oropharyngeal Leak Pressure and Sealing Between the Mask and Vocal Cord During Changing Patient's Head and Neck Position
Keywords: supraglottic airway,igel-LMA, ambu-LMA, changing position, head and neck position, oropharyngeal leak pressure,degree of rotation
Lead sponsor: National Taiwan University Hospital
Sponsor class: OTHER
First posted: 2013-10-10
Enrollment: 120
Sex: ALL
Minimum age (years): 20
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Generally, the laryngeal mask airway is not considered in the surgery which should be changing position in the perioperative period. The shape of the pharynx changes during the head and neck movement and there is probably also a change in the force transmitted to the cuff along the airway tube. Besides, there is evidence that supraglottic airway device can be displaced with rotation. In this article, the investigators want to discuss about that oropharyngeal leak pressure and sealing between the mask and vocal cord while changing head and neck position in perioperative period using different types of supraglottic airway device.

Detailed description: The investigators select adult patients,who are 20-80yrs old and ASA physical status I or II, receiving minor surgery, ex: breast surgery or cystoscope, participated in this randomized cross-over trial. Patients were excluded if they were in the above condition. The patient is at high risk of aspiration, ex:obesity, pregnancy upper GI bleeding or not enough fasting time. The patient could not open mouth or upper airway obstruction. The patient receive major surgery, ex: heart, brain, lung, liver, kidney surgery. The patient has abnormal heart and lung function.

The patient received different types of supraglottic airway device like proseal LMA,ambu LMA, air Q LMA or igel LMA by draw, then the patients will be divided into different groups.In the preoperative period, the investigators documented oropharyngeal leak pressure in these selected positions: neutral position( 0 degree),and rotation 15, 30,45, 60 degrees, etc. However, oropharyngeal leak pressure was measured by closing the expiratory valve of the circle system at fixed O2 flow 3L/min and 20 cm H2O. If the ambu bag is flattening, the investigators will think the leakage happened between the laryngeal mask and our vocal cord. Then the investigators use fiberscope to observe the condition between the epiglottis and the laryngeal mask.

The investigators wanted to compared the mean leak pressure at different head and neck rotation position,ex:neutral,30,45,60 degrees,by using many different types of supraglottic airway device.

The observers define the relationship between epiglottis and vocal cord to describe the condition when the patient is at different degree of head and neck position. Grade I is vocal cord completely visible. Grade IIA is only partially vocal cord visible and epiglottis noted. Grade IIB is no vocal cord visible and only epiglottis noted. Grade III is other condition, ex:trapped epiglottis or no epiglottis visible.

Eligibility criteria: Inclusion criteria:

* 20-80 yrs old and ASA physical status I or II,
* Receiving minor surgery, ex: breast surgery or cystoscope

Exclusion criteria:

* The patient is at high risk of aspiration, ex:obesity, pregnancy upper GI bleeding or not enough fasting time.
* The patient could not open mouth or upper airway obstruction
* The patient receive major surgery, ex: heart, brain, lung, liver, kidney surgery.
* The patient has abnormal heart and lung function.

Primary outcomes:
measure: the leakage happened between the laryngeal mask and our vocal cord
timeFrame: If the ambu bag is flattening during the surgery, the observers check the leak pressure between the laryngeal mask and our vocal cord
Secondary outcomes:
measure: Use fiberscope to observe the sealing between the mask and vocal cord while changing head and neck position in perioperative period using different types of supraglottic airway device.
timeFrame: During the surgery
Other outcomes:
Locations:
city: Taipei
country: Taiwan
facility: Department of anesthesiology,National Taiwan University Hospital
Study officials:
affiliation: anesthesiology department,National Taiwan University hospital
name: Cihmin Liu
role: PRINCIPAL_INVESTIGATOR
References: