Chapter 9. Direct Laryngoscopy
Regarding the mechanics of laryngoscopy all are true EXCEPT
A. A fully extended arm position permits binocular sighting of the larynx for most operators
B. A low grip, that is, where the blade meets the handle, provides greater control with less muscular effort
C. Morbidly obese patients require proper ear-to-sternal notch positioning before laryngoscope insertion, since dynamic lifting of the head during the procedure is impossible
D. The degree of lifting force applied during laryngoscopy is minimal when advancing the curved blade down the tongue and maximal after the blade is correctly positioned in the vallecula
(A) To maximize lifting efficacy with minimal muscular effort, it is important to keep the left elbow adducted to your side (roughly the anterior axillary line), not pointing outward. With the elbow in, the handle gripped down low, the forearm is kept straight and body weight can be used to rock forward slightly so that minimal arm strain occurs.
A. distinct from cricoid pressure because is applied by the laryngoscopist
B. distinct from cricoid pressure because it is done to improve laryngeal view
C. distinct from Backward Upward Rightward Pressure (BURP) because it is done by the operator, not an assistant
D. distinct from cricoid pressure because it is generally applied at the thyroid cartilage, not the cricoid ring
(E) All the statements are true with bimanual laryngoscopy.
The mechanical problem rail-roading an endotracheal tube over a tube introducer (or a flexible fiberscope)
A. can be overcome by rotating the tracheal tube counterclockwise (leftward) 90 degrees at 14 to 16 cm of insertion
B. is a consequence of the asymmetric left-facing bevel of a standard tracheal tube
C. is due to the gap between the outer diameter of the introducer (or scope) and the inner diameter of the tracheal tube
D. occurs at the laryngeal inlet, specifically at the right aryepiglottic fold and right posterior cartilages
(E) All the listed factors are potential causes of mechanical problem while rail-roading an endotracheal tube over a tube introducer into the trachea.