Evaluation of Supraglottic Airway Devices in Children and Comparison to Historic Control

The supraglottic airway device LMA Supreme has recently been introduced for pediatric patients. The investigators will prospectively evaluate success rate and airway leak pressure in everyday's clinical pediatric anesthesia practice. Primary hypothesis is that the LMA Supreme has a leak pressure with a 95% confidence interval of 18-22cmH2O. Leak pressures will be compared to results from other pediatric supraglottic airway devices previously studied by the investigators group. Secondary Hypothesis: The primary success rate of the LMA-S is higher than 90%; therefore, performance is similar to the performance of the Ambu Aura Once™ and of the i-gel™. Study design: Prospective controlled observational cohort study.

In a second step, we will include more pediatric supraglottic airway devices. Each new arm will be handled exactly the same, assuming the same hypothesis being justified.

The induction of anesthesia will follow the standard operating procedures of the pediatric anesthesia division at the children's hospital for the use of supraglottic airway devices. After loss of eyelash reflex and proper bag-mask ventilation provided, the SGA will be introduced into the mouth under standardized anesthesia to guarantee the same depth of anesthesia. This includes either propofol 2.5 mg/kg for older children, or sevoflurane inhalation in younger children at an end-tidal sevoflurane concentration of 6%. The time necessary to insert the airway device and the success rate will be recorded. We will also check at what airway pressure the SGA starts leaking. A fiberscope will be inserted through the airway port and through the gastric tube to obtain a view of the vocal cords and evaluate the position of the SGA. The gastric catheter will then be placed after insertion; the size will be according manufacturers' recommendations. After surgery, the SGA will be checked for evidence of mucosa lesions (blood stains on device). One day after surgery, the patient (and/or the parents) will be interviewed about sore throat, hoarseness, dysphagia, postoperative nausea and vomiting (PONV), rescue medication, pain, time of hospital discharge and any unscheduled re-hospitalization.

Before and during the operation, the following data will be recorded: Sex, age, weight, surgical procedure and duration, medications needed, cardiovascular parameter, depth of anesthesia. Secondary outcome data include:

* The insertion time necessary to airway device placement.
* Success rate of SGA device to ventilate patient
* Fiberscope view through the airway port on the glottis opening (1 full vision on the vocal cords - 4 no structure distinguishable)
* Fiberscope view through the airway gastric tube channel on the upper esophageal sphincter (rating 1-4)
* Placement of the gastric catheter (yes, no)
* Postoperative: Device will be checked for evidence of mucosa lesions (blood stains on device).

Eligibility Criteria:
Inclusion Criteria:

* Patients of both genders, ages 0-18 years, ASA physical status I-III, scheduled at the University Hospital of Bern for elective surgery under general anesthesia in supine position with planned operation time \<4 hours and planned airway management including a supraglottic airway, written informed consent.

Exclusion Criteria:

* Exclusion criteria are high risk of aspiration of gastric content into the lungs, body mass index \>35kg/m2, cervical spine disease, known difficult airway, upper respiratory tract symptoms in the previous 10 days, preoperative sore throat, poor dentition with high risk of damage, patients not speaking German or refusing to participate.