Comparison of the Baska Mask Airway to a Single-use LMA Device in Low-risk Female Patients

The purpose of this study is to compare the performance of the Baska mask supraglottic airway device with a single use laryngeal mask device (LMA) in low-risk female patients.

The investigators have performed a number of studies on novel airway devices, including 3 studies on the Baska mask. This trial will compare some performance characteristics of the studied devices, including airway seal pressures, insertion success rates, device use difficulty scores. Additional performance and device safety data will be accumulated.

The investigators have two primary hypotheses, namely 1.Non-inferiority of first placement attempt success rate of the Baska mask vs LMA; and 2.greater seal pressure of the Baska mask vs LMA.

Supraglottic airway devices have established place in the airway management in patients undergoing general anesthesia.

The Baska mask is a new supraglottic airway device. It's features include:

1. Non pressurized cuff designed to reduce the risk of oropharyngeal tissue damage.
2. Improved cuff seal during the inspiratory phase of positive pressure ventilation
3. An improved system for drainage of oropharyngeal contents intended to reduce the rate of lung aspiration.
4. Integrated bite-block to reduce the risk of patients biting and blocking the airway.

This study is randomized, single-blinded, controlled trial. The participants will be allocated to two groups, in which either the Baska mask or the single use LMA will be the primary airway management device.

Clinical Research Ethics Committee approval has been obtained. Suitable participants will be recruited after written informed consent.

Standard anesthetic preassesment and anesthesia will be provided.

Consenting patients will be randomly allocated to either of the 2 study groups.

Protocol for airway size selection and attempts at placement will be followed.

The investigators will monitor a number of parameters, including time and ease of insertion, airway seal pressure, airway leak, complications related to device use and other.

Follow up will be performed.

The investigators have two primary hypotheses:

1. That the Baska mask is non-inferior to LMA in respect if first placement attempt success rate. A greater than 15% difference in success rate will be considered a clinically important difference and will disprove this hypothesis.
2. The Baska mask is superior in respect of seal pressure. A 20% higher seal pressure with Baska as compared to the LMA device seal pressure will be considered a clinically important difference.

Interim analysis will be performed once 75 patients are recruited per group. This is reasonable as this figure exceeds that required to prove or disprove the primary hypothesis regarding the seal pressure. The study will only be stopped at this stage if the non-inferiority hypothesis is disproven with P value \< 0.01

In addition to the above the investigators will evaluate a number of secondary outcomes.

Eligibility Criteria:
Inclusion Criteria:

* Female
* Written informed consent
* ASA 1-3
* No relevant allergies
* Body-mass index (BMI) 35 or less
* Age 16-85
* Non-urgent surgery of planned duration under 4 hours

Exclusion Criteria:

* Inability of patient/parent to understand or consent for the trial
* Neck pathology
* Previous or anticipated problems with the upper airway or upper GI tract
* BMI \>35
* Predicted or previously documented difficult airway
* Live Pregnancy
* Increased risk for Gastric Aspiration