Evaluation of the ease of mask ventilation and tracheal intubation using videolaryngoscope in sniffing versus head elevated laryngoscopy position in patients undergoing elective surgery under general endotracheal anaesthesia : A randomised controlled study

This study aims to compare two positioning techniques for endotracheal intubation under general anesthesia.

Procedure Summary:

1. **Enrollment & Consent**: After enrolling, patients will receive an information sheet and a verbal explanation of the study. Written informed consent will be obtained in the patient’s preferred language.

2. **Preoperative Setup**: ASA standard monitors will be applied, and baseline vital signs (heart rate, blood pressure, oxygen saturation) will be recorded. An intravenous (IV) line will be inserted.

3. **Positioning:**

• **Group A**: Patients’ heads will be placed in the "sniffing position" (flexed at the cervical spine and extended at the atlantooccipital joint).

• **Group B**: A preformed ramped pillow (72cm x 14cm, with a 30-degree angle) will be placed under the head and back, ensuring the alignment of the external auditory meatus and sternal notch in the same plane.

4. **Preoxygenation & Anesthesia Induction**: Preoxygenation will be done with 100% oxygen at 10 l/min for 3 minutes. Induction of anesthesia will involve midazolam (0.02 mg/kg), fentanyl (2 mcg/kg), and propofol (2 mg/kg), with ventilation checked before administering vecuronium (0.1 mg/kg). Mask ventilation will be performed using the one-handed E-C grip technique.

5. **Intubation Process**: Videolaryngoscopy will be performed using a NISCOMED version 2.0 Macintosh blade. Laryngeal visualization will be assessed with the POGO score (ranging from 0% to 100%, with 100% indicating complete visualization of the larynx). The time to intubate will be measured from the insertion of the videolaryngoscope until the sustained appearance of capnographic waveform (indicating successful endotracheal tube placement).

6. **Outcome Measures**:

• POGO score will be recorded to assess laryngeal visualization.

• The number of intubation attempts and the use of any additional equipment (e.g., oropharyngeal airway, alternative blades) will be documented.

• Time to intubate will be measured from insertion of the videolaryngoscope until sustained capnography waveforms are observed.

7. **End Point**: The successful placement of the endotracheal tube, confirmed by bilateral equal air entry and the appearance of a capnographic waveform on the EtCO2 monitor.

This study is designed to evaluate the effectiveness and ease of two different positioning methods in facilitating successful and efficient intubation.