Comparison of face mask ventilation before and after neuromuscular blockade in patients under general anaesthesia

This study aims to compare face mask ventilation before and after giving a muscle relaxant in adult patients under general anaesthesia. All patients will be assessed before surgery with a medical history clinical examination and relevant investigations. Demographic data such as age ,sex, height ,weight and American Society of Anaesthesiologiats status will be recorded. Patients who are pregnant under 18 years old ,have a Body Mass Index over 30 or have anticipated difficulty with face mask ventilation will be excluded.

In the operating room standard monitoring including Electrocardiogram,Non invasive blood pressure and Saturation prbe will be applied and patients will be positioned supine with their head in a sniffing position. Premedication with intravenous Midazolam 1 milligram and Fentanyl 2 microgram per kilogtam will be administered. After preoxygenation anaesthesia will be induced with intravenous Propofol 2 milligram per kg .Face mask ventilation will be performed using a standard technique and ventilator settings of inspiratory pressure 10 centimeter of water, Positive end expiratory pressure of 5 centimeter of water, Inspiratory to Expiratory ratio 1 to 2 ,gas flow 6 litres per minute .respiratory rate 12 per minute and Sevoflurane 2 to 3 percent in 100 percent oxygen. Expired tidal volumes and Han scale grading for face mask ventilation will be recorded

One minute later intravenous Vecuronium 0.1 milligram per kg will be administered and face mask ventilation will be reassessed at 1minute ,2 minute, 3minute and 4 minutes after its administration. The primary objective is to evaluate changes in face mask ventilation before and after the neuromuscular blockade.