What may indicate a patient is experiencing vigorous attempts to ventilate against closed vocal cords?

Indications of a patient experiencing vigorous attempts to ventilate against closed vocal cords typically manifest as sternal retractions. This occurs because the muscles involved in breathing, such as the intercostal and accessory muscles, become engaged more forcefully in an effort to draw air into the lungs when airflow is obstructed. When the vocal cords are closed, the negative pressure created during inhalation causes the chest wall to visibly retract, particularly at the sternum, as the body attempts to overcome the obstruction and facilitate ventilation.

Increased heart rate may occur due to various stressors or insufficient oxygenation, but it is not a direct physical sign of the mechanical struggle associated with closed vocal cords. Rapid eye movement does not relate to the mechanical breathing efforts or airway obstruction, and decreased blood pressure is more indicative of systemic hypoperfusion or other critical states rather than a direct response to ventilatory efforts. Thus, the presence of sternal retractions is the most specific sign of the struggle to ventilate against an obstructed airway.