Study of Accuracy of Placement and Performance Test in Detecting Supraglottic Airway Placement Compared to Fiberoptic View. Recruited Patients in University Malaya Medical Center, Malaysia, Undergoing General Anesthesia With Supraglottic Airway.

Accuracy of gastric test in evaluating optimal SGA placement.

Lubricant gel applied over gastric outlet of SGA. Positive test(abnormal) indicated when presence of gel movement seen during positive pressure ventilation.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of suprasternal notch test in evaluating optimal SGA placement.

Lubricant gel applied over gastric outlet of SGA. Downward pressure applied over patient's suprasternal notch. Positive test(abnormal) indicated absent of movement with suprasternal notch pressure.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of Maximal minute ventilation test in evaluating optimal SGA placement.

After general anesthesia and SGA insertion, manual positive pressure ventilation bagging done with APL valve set at 30cmH20 by providing 4 maximal insufflation breaths within 15 seconds and extrapolate to calculate minute ventilation(ml/min). Positive test(abnormal) indicated when \<12L/min.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of subjective assessment(chest rise) in evaluating optimal SGA placement.

After general anesthesia and SGA placement, chest rise observed visually with positive pressure ventilation Positive test(abnormal) is indicated when no chest rise observed.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of subjective assessment(expired tidal volume) in evaluating optimal SGA placement.

After general anesthesia and SGA placement, using volume controlled ventilation from GA machine, expired tidal volume is measured (ml). Positive test(abnormal) is indicated when tidal volume is less than 6ml/kg of predicted body weight of patients.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of subjective assessment(end tidal CO2 waveform) in evaluating optimal SGA placement.

After general anesthesia and SGA placement, while using Volume controlled ventilation via GA machine, end tidal CO2 waveform is observed. Positive test(abnormal) is indicated when absence of square waveform pattern of et-CO2.

Time frame: from enrollment until end of surgery, in recovery.

Accuracy of subjective assessment(audible leak) in evaluating optimal SGA placement.

After general anesthesia and SGA placement, stethoscope placed near oral cavity to appreciate for presence of leakage. Positive test(abnormal) is when leakage heard with stethoscope.

Time frame: from enrollment until end of surgery, in recovery.