Obstructive Shock Overview:
Obstructive shock occurs when adequate oxygen and nutrient delivery to the organs and tissues of the body is compromised as a direct result of an obstruction to blood flow into or out of the heart.
If blood flowing INTO the heart is obstructed, it causes a decrease in cardiac output because of impaired diastolic filling. If blood flowing OUT of the heart is obstructed, it causes a decrease in cardiac output because of excessive afterload.
The most common causes of obstructive shock in children are tension pneumothorax, pulmonary embolism, and cardiac tamponade. There are also several congenital abnormalities that can cause obstructive shock. Examples include critical aortic stenosis and coarctation of the aorta.
Both signs and symptoms of obstructive shock and the management and treatment of obstructive shock are dependent upon the cause. Click each cause to review the signs, symptoms, and management of each major cause is reviewed.
Review signs, symptoms, and mgt.
Tension pneumothorax is the accumulation of air within the pleural space.
Causes of tension pneumothorax in children include trauma, asthma, cystic fibrosis, pneumonia and excessive positive pressure during manual or mechanical ventilation.
Once a tension pneumothorax occurs air can continue to accumulate within the pleural space but cannot escape. This continued accumulation of air increases pressure and ultimately obstructs venous blood return to the heart. The obstruction results in decreased diastolic filling.
Signs and Symptoms:
The following list provides other signs and symptoms of tension pneumothorax using the primary assessment model (ABCDE).
- Airway: tracheal deviation toward the contralateral side
- Breathing: increased work of breathing, increased respiratory rate, respiratory distress, and diminished lung sounds on the affected side
- Circulation: neck vein distention, rapid and severe hypotension, tachycardia rapidly degrades into bradycardia, and PEA
- Disability: decreased level of consciousness
- Exposure: pale and cool extremities
Management of Tension Pneumothorax:
The definitive treatment for obstructive shock caused by tension pneumothorax is needle decompression and chest tube placement to the affected area.