Obstructive shock
[2] Causes include pulmonary embolism, cardiac tamponade, and tension pneumothorax.
Symptoms may include shortness of breath, weakness, or altered mental status.
[3][9] In response to low blood pressure, heart rate increases.
Because of poor blood flow to the tissues, patients may have cold extremities.
Less blood to the kidneys and brain can cause decreased urine output and altered mental status, respectively.
For example, jugular venous distension is a significant finding in evaluating shock.
The triad includes hypotension, jugular vein distension, and muffled heart sounds.
[10] Low-voltage QRS complexes and electrical alternans are signs on EKG.
Other findings may include decreased chest mobility and air underneath the skin (subcutaneous emphysema).
There are multiple, including pulmonary embolism, cardiac tamponade, and tension pneumothorax.
Other causes include abdominal compartment syndrome, Hiatal hernia, severe aortic valve stenosis, and disorders of the aorta.
Masses can grow to press on major blood vessels causing shock.
When severe enough to cause these shifts and hypotension, it is called a tension pneumothorax.
The veins supplying the heart are compressed, in turn decreasing venous return.
Most commonly, this is from a deep vein thrombosis (DVT) in the legs or pelvis.
The lack of blood flow to vital organs can cause death.
[19] Whether an effusion causes tamponade depends on the amount of fluid and how long it took to accumulate.
[20] Acute effusions can cause tamponade when small because the tissue does not have time to stretch.
Diagnosis requires a thorough history, physical exam, and additional tests.
[22] Vital signs in obstructive shock may show hypotension, tachycardia, and/or hypoxia.
[3] Labs including a metabolic panel can assess electrolytes and kidney and liver function.
Lactic acid rises due to poor tissue perfusion.
This may even be an initial sign of shock and rise before blood pressure decreases.
[3][25] Measurement of the vena cava during the breathing cycle can help assess volume status.
Other findings include paradoxical septal motion or clots in the right heart or pulmonary artery.
In tamponade, collapse of the right atrium and ventricle would be seen due to pressure in the pericardial sac.
[24] A chest X-ray can rapidly identify a pneumothorax, seen as absence of lung markings.
[7] For example, tamponade prevents normal cardiac filling due to pressure compressing the heart.
[19][26] However, in other causes of obstructive shock, too much fluid can worsen cardiac output.
Catheter-directed therapy involves giving tPA locally in the pulmonary artery.
