Resuscitation Council UK (RCUK) Advanced Life Support (ALS) Practice Exam

A tension pneumothorax can lead to hypotension during an asthma arrest because it creates a buildup of pressure within the thoracic cavity. This pressure compresses the major blood vessels, particularly the inferior vena cava, which hampers venous return to the heart. When venous return is reduced, the heart's ability to fill and pump blood is compromised, resulting in decreased cardiac output and subsequent hypotension.

In scenarios of respiratory distress such as an asthma arrest, the presence of a tension pneumothorax exacerbates the situation by disrupting normal vascular physiology and further decreasing blood pressure, which can be critical for effective circulation and oxygen delivery to vital organs.

While hypercapnia can occur due to impaired gas exchange during respiratory crises, it is the compromised hemodynamic status caused by a tension pneumothorax that predominantly results in hypotension. Increased airway resistance can be influenced by other factors in an asthma attack but is not directly caused by tension pneumothorax. Likewise, coronary vasodilation is not typically a consequence of this condition; in fact, the pressure effects could lead to vasoconstriction in certain situations.