Obstructive shock is when there are mechanical problems, such as an obstruction in the heart that prevents it from completely filling during diastole. In other words, although there is normal myocardial function and intravascular volume, there are physical obstructions that prevent the complete diastolic filling of the ventricles. The heart is pumping well and has normal volume and without chemical problems. As a result, the obstruction leads to a reduced amount of blood returning to the heart. Diastolic filling pertains to the time when the heart refills the ventricles with blood after systole (contraction).
When there is a reduced diastolic filling, it will also lead to decreased cardiac output. Consequentially, there is insufficient blood to be supplied to the various organs of the body. When the organs don’t receive their required oxygen and essential nutrients to function, it eventually leads to organ failure.
Complications from obstructive shock include gangrene of the extremities, permanent brain or kidney damage, and even damage to the heart.
Obstructive shock is fatal and is considered a medical emergency. It requires immediate medical attention.
Causes of Obstructive Shock
The following physical obstructions to the heart can prevent complete diastolic filling:
- Cardiac or pericardial tamponade
- Systemic or pulmonary hypertension (high blood pressure)
- Aortic dissection
- Vena cava syndrome
- Congenital or acquired outflow obstructions, e.g. heart lesions
- Tension pneumothorax
- Massive pulmonary thromboembolism
Signs and Symptoms of Obstructive Shock
Signs and symptoms of obstructive shock begin to show when the heart begins to fail pumping enough blood for the body. The extent of damage to the heart will determine the signs and symptoms. Obstructive shock has similar manifestations to those of cardiogenic shock:
- Pale, clammy skin
- Excessive sweating
- Cool fingers and toes
- Little or no urine output
- Loss of ability to concentrate
- Loss of consciousness
- Fast heartbeat
- Weak pulse
- Chest pain
- Rapid, shallow breathing
First Aid Management of Obstructive Shock
Obstructive shock requires immediate medical attention as it is life-threatening. Call for emergency medical services or bring the individual to the nearest hospital as soon as signs and symptoms begin to manifest. It is strongly recommended to do the following first aid tips while waiting for the paramedics to arrive.
- Check the casualty’s circulation, airway and breathing. Initiate rescue breathing and CPR if necessary.
- Check and monitor the casualty’s rate of breathing every 5 minutes even if the individual can breathe on their own.
- Help the casualty into shock position, assuming that there is no injury to the head, neck, spine or legs. Lay the person down flatly with the feet elevated at 12 inches. This will increase circulation. Do not elevate the head.
- Cover the casualty with a blanket or coat to keep the casualty warm. Loosen any tight clothing.
Understanding obstructive shock can help when taking First Aid Courses and CPR Training.
Obstructive shock occurs when there is something that prevents the heart from completely filling during diastole leading to reduced cardiac output. Obstructive shock is a medical emergency.