Efficiency of I-gel Supraglottic Airway Device in Supine and Lateral Decubitus Position in Obese Patient

Obesity is linked to many complications of respiratory care which are directly related to the obstructive apnea syndrome: difficult airway management including difficult mask ventilation, difficult intubation and obstruction of the upper airway.

I gel which is a non inflatablesupraglottic airway device with a gastric channel is gaining popularity in anesthesia practice because of its ease of insertion and stable positioning.

There are many studies evaluating I-gel for airway managment during different head and necks position ,in prone and lateral position showing both successeful results. Morover, it was evaluated during spontanous and mechanically ventilated patients.

There are limited number of studies evaluating the efficacy of I- gel in mild to moderate obese patients.

The primary aim of this study is to Measure the oropharyngeal airway leak pressure in both supine and lateral position and to determine laryngeal glottic view grade by the fibreoptic bronchoscope.

prospective observational cohort study. Induction of anethesisa will be started after pre-oxygenating the patient for 3min , with administerating Propofol (2mg/kg)(lean body weight)), Fentanyl (2μg/kg) and Atracurium (0.5mg/kg)(based on ideal body weight.The patient will to be ventilated by a 100% oxygen and 1.2% isoflurane with fresh gas flow 6L/min for 5 min.immediately after induction heart rate , blood pressure and oxygen saturation will be recorded.

A proper sized I-gel according to the patient's weight and manifacturer instructions (Intersurgical Ltd, UK) ( 4 or 5 adult sizeI-gel) will be lubricated with a water based lubricant from the front and back sides of the device, will be inserted after compelete muscle relaxation (Train of four = zero) In case of insertion problem various adjuvant manoeuvres will be used such as such as head flexion or extension, or slightly pulling or pushing the device. Any additional manoeuvres will be recorded. If insertion or ventilation fails three times in succession, Endotracheal tube will be immediately inserted and the patient will be excluded from the study. The number of excluded cases will be recorded The circut will be connected to the device,Capnograph will be attached and end tidal carbon dioxide will be recorded.

The ventilator parameters will be set with tidal volume (4-6 ml/kg) at a respiratory rate(12-15 breath/min) to maintain ETCO2 from 30-35 mmHg.

Anaethesia will be maintanied by a mixture of 50% oxygen and 50% medical air,Isoflurane 1.2% and Atracurium (0.01 mg/kg) will be given according to train of four . Analgesia of pethidine 100mg IV will be given as intraoperative analgesia.

In order to confirm proper positioning of the I-gel,a fiberoptic bronchoscope will be pass through the device and pushed forward up to1 cm proximal to it to obtain a glottic view.

Afterwards the same patient will be placed in the lateral decubitus position.Blood pressure,Heart rate ,Oxygen saturation and End tidal CO2 will be recorded immedialy. After confirming proper ventilation as before ,confirmation of I-gel position using fiberoptic bronchoscope will be done and recorded.The leak air way pressure test will be done as previously done in supine position and recorded.

The patient will be returned to supine position where a proper size Orogastric tube will be inserted.The surgery can be started and Heamodynamics and ventilation will be monitored.

By the end of the surgery the patient will be reversed from general anaesthesia by administrating Neostigmine (0.04mg/kg) and Atropine (0.01mg/kg). intravenously at (TOF=3) and the I-gel will be removed at the end.The presence of blood on the I-gel device, or the occurrence of any complications, will be recorded.

The patient will be transfered to the post operative care unit

Eligibility Criteria:
Inclusion Criteria:

BMI: ≥30 - \<40. Surgery: short time procedures \>60 minutes and ≤. 120 minutes

Exclusion Criteria:

Patientswith neck or upper airway pathologies or other contraindications to supraglottic decives.

Patients at risk of stomach contents regurge e.g. pregnant ,GIT Ulcer, Symptomatic reflux disease or Hiatus hernia ...etc Patients with risk of pulmonary aspiration e.g. Full stomach or incompetent gastro-oesophageal sphincter.

History of gastric band or gastric bypass surgeries. Pregnant females. Laparotomy or laparoscopic procedures. Obstructive sleep apnea Patients with risk of bleeding.