Airway Devices MCQs

Ans. D. Increased thyromental distance Decreased thyromental distance predicts difficult airway (not increased TM distance).

Explanation: Measurement for Size Selection: The appropriate size of the oropharyngeal airway (OPA) is determined by measuring the vertical distance from the patient's incisors to the angle of the mandible . This ensures that the OPA fits correctly, allowing for optimal airway patency without causing obstruction. Consequences of Incorrect Sizing: Too small: Can kink the tongue, leading to obstruction of airflow. Too large: May push the epiglottis backward, causing further obstruction or trauma to the larynx. Key Takeaways: Accurate sizing of the oropharyngeal airway is crucial for maintaining a patent airway. Proper measurements help prevent complications associated with incorrect airway adjunct sizing.

Brain demonstrated the first commercially made silicone model of LMA . First commercial devices were made available in the UK Reference : E Book of Baheti's Understanding Anesthetist Equipments and Procedures a Pratical Approach First Edition Chapter 16 Page No 197 to 204

A Guedel airway maintains upper airway patency by keeping the mouth open and preventing the tongue falling backwards. The airway is available in a range of sizes from neonate to adult. To determine the correct size, the airway is held up to the patient's face. The size that is most appropriate for the patient can be estimated in two ways: the 'hard-to-hard' method, where the flange is placed at the level of the incisors and the tip at the angle of the mandible, or the 'soft-to-soft' method, from the angle of the mouth to the tragus of the ear. Reference: Equipment in Anaesthesia and Critical Care, Daniel Aston, Angus Rivers, Asela Dharmadasa, pg 28

The mean pressure at which gastric insufflation occurs is 28cm H 2 O. When airway pressures with an LMA exceed this limit, there is a possibility of gastric insufflation because of raised pressure as the LMA doesn't form a watertight seal around the larynx and hence cannot be relied upon for protection against aspiration of gastric contents. Reference: Understanding Anaesthesia Equipment (Jerry A. Dorsch, Susan E. Dorsch) 5th edition pg 488

Incidence of sore throat is minimal with face mask, as compared to supraglottic airway devices or intubation with an endotracheal tube, since there is no airway instrumentation in facemask ventilation. With face mask, when a positive pressure ventilation is provided, gases are likely to enter the stomach. So it is recommended that inspiratory pressure be kept below 20 cm H 2 O. Mask ventilation moves the cervical spine, sometimes even more than commonly used methods of tracheal intubation. This may be of significance in the patient with an unstable cervical spine injury. Face mask is associated with greater operating room pollution with anesthetic gases and vapors than with a tracheal tube or supraglottic airway device. Reference: Understanding Anaesthesia Equipment (Jerry A. Dorsch, Susan E. Dorsch) 5th edition pg 450

The nasopharyngeal airway is a simple airway adjunct that can be used to facilitate ventilation and removal of secretions. A nasopharyngeal airway can be used in patients with an intact gag reflex, unstable fractures of the mandible, trismus (lockjaw), or oral trauma, complications include soft tissue damage of the nasal mucosa and bleeding. Reference: Clinical Application of Mechanical Ventilation, Fourth Edition by David W. Chang, page no 130

Esophageal-tracheal combitube (ETC): An airway that may be inserted into the esophagus or trachea. The ETC is inserted blindly either into the trachea or esophagus. Both lumens on the ETC can be used to provide ventilation. Lumen 1 is used when the tube enters the esophagus and lumen 2 is used when it is in the trachea. Reference: Clinical Application of Mechanical Ventilation, Fourth Edition by David W. Chang, page no 139