Accessory muscles of respiration

Skeletal muscles not normally active during quiet breathing, recruited to augment inspiratory or expiratory pump function during increased ventilatory load or respiratory distress (e.g., sternocleidomastoid, scalenes, pectoral and abdominal muscles). Their use at rest signifies increased work of breathing.

Possible causes:

• COPD

• Asthma

• Pnemonia

• Pulmonary embolism

• Airway obstruction

• Strenuous exercise

• Obesity

• Heart failure

• Anemia

• Acidosis

• Diaphragm paralysis/spinal cord injury