Inverse breathing, also known as paradoxical breathing or thoracoabdominal asynchrony, is an abnormal breathing pattern characterized by the reversal of the normal respiratory movements of the chest and abdomen.

Physiology of Normal Breathing

In normal breathing:

• During inhalation, the diaphragm contracts and moves downward, causing the abdomen to expand outward.
• The chest wall moves outward and upward.
• During exhalation, these movements are reversed.

Characteristics of Inverse Breathing

In inverse breathing:

• During inhalation, the abdomen moves inward instead of outward.
• The chest may still move outward and upward.
• During exhalation, the abdomen moves outward.

Causes

Respiratory distress:

• Acute respiratory failure
• Severe asthma exacerbations
• Chronic obstructive pulmonary disease (COPD)

Neurological disorders:

• Spinal cord injuries
• Muscular dystrophies

Diaphragmatic dysfunction:

• Phrenic nerve injury
• Diaphragmatic paralysis

Chest wall abnormalities:

• Flail chest
• Severe kyphoscoliosis

Psychological factors:

• Anxiety disorders
• Panic attacks

Clinical Significance

• Indicator of increased work of breathing
• Associated with respiratory muscle fatigue
• Can lead to respiratory failure if not addressed

Diagnosis

• Clinical observation of breathing pattern
• Respiratory inductance plethysmography
• Ultrasound evaluation of diaphragm movement

Management

• Treat underlying cause
• Respiratory physiotherapy
• Mechanical ventilation in severe cases
• Breathing retraining exercises