A patient experiencing increased work of breathing is likely using which muscles?

When a patient is experiencing increased work of breathing, they often engage the accessory muscles of respiration. These muscles are recruited when the body needs to enhance ventilation, especially in situations of respiratory distress or when normal breathing is insufficient. Accessory muscles, which include the sternocleidomastoid, scalene, and pectoralis major among others, help to increase the thoracic cavity's volume more effectively during inhalation.

In typical breathing, the diaphragm and intercostal muscles perform the majority of the work. However, during periods of increased respiratory demand, such as in cases of asthma, pneumonia, or other respiratory diseases, the body compensates by activating accessory muscles to support and facilitate deeper or more forceful breathing. This is an important mechanism because it allows for greater airflow and gas exchange under challenging conditions.

The abdominal muscles are generally more involved in exhalation rather than increasing the effort for inhalation, and while intercostal muscles play a crucial role, they are part of the regular breathing process in conjunction with the diaphragm. If respiration becomes particularly labored, accessory muscles become critical for augmenting ventilation efficiency.