Airway management and Anaesthesia
Obstruction of the upper airway is common in anaesthesia, which is caused by the loss of muscle tone. The narrow segment known as the hypopharynx is vulnerable during anaesthesia and sedation. Identifying high risk patients is essential in addition to seeking a history of upper airway compromise. According to Dr. Rowan Molnar, currently the Staff Specialist Anaesthetist at Launceston General Hospital, Tasmania with extensive clinical experience in anaesthesia at a tertiary referral hospital level, factors such as obesity, manipular recession, and nasal obstructions or just a few risk areas that must be identified. Such conditions make intubation difficult and increases vulnerability to upper airway obstruction during anaesthesia or sleep.
Importance of risk identification
Dr. Rowan Molnar, who is also Head of Discipline, Anaesthesia, at University of Tasmania Clinical School says that risk identification and caution are the keys to airway management even while the use of aids such as the laryngeal mask airway is initiated. The airway must be secured prior to administering anaesthesia when doubt exists. In addition, it is essential for every anaesthetist of plan for failed intubation or failed ventilation. For anaesthetists, one of the major indicators of the likely behaviour of the upper airway is the behaviour of the upper airway during sleep.
During sleep and anaesthesia, upper airway obstruction increases due to narrowing of the pharynx and the increased pressure around it. Factors outside the pharynx include narrowing of skeletal confines, and the lateral pharyngeal fat pads in obese patients, loss of traction on the pharynx and reduction in lung volumes due to obesity. There are primarily three reasons why a narrow airway is vulnerable to collapse. A small radius of curvature and greater expanding force is required to maintain adequate tension on the wall of the airway to prevent collapse according to Laplace’s law. If the calibre is small the absolute change in calibre is less prior to airway closure. Habits such as smoking, alcohol consumption, sleeping pills, and certain medications can also have an effect on muscle tone and airway calibre. Tracheal intubation is the standard way of control of the airway in which the lower airway and regions where the exchange of gas takes place in the lungs are directly accessed.
Written by a professional author who describes the detail of Dr. Rowan Molnar.