During a severe asthma episode, what unusual vital sign change may occur during inhalation?

During a severe asthma episode, the phenomenon known as pulsus paradoxus may be observed. This refers to a significant drop in blood pressure during inhalation compared to exhalation, typically exceeding 10 mmHg. In the context of asthma, the obstruction of airways can lead to increased intrathoracic pressure during inhalation, which affects the heart's ability to fill properly. This can result in a reduced stroke volume and subsequently a decrease in blood pressure that can be detected during inhalation.

The presence of pulsus paradoxus is indicative of severe respiratory distress and can suggest that the patient is experiencing significant airflow obstruction. This is an important clinical sign that healthcare professionals look for when assessing the severity of an asthma exacerbation and the need for urgent intervention.

Other vital sign changes that occur during respiratory distress may include increased heart rate or blood pressure, but these would not specifically characterize the inhalation phase the way pulsus paradoxus does. Understanding this unusual vital sign change is essential for timely assessment and treatment in managing severe asthma exacerbations.