Circulatory Collapse

Circulatory collapse is a life-threatening condition where the body’s blood circulation system fails to deliver enough oxygen to tissues and organs. While some cases involve a brief, harmless blackout, others can lead to serious complications requiring immediate medical attention.

Table of contents

• What is circulatory collapse?
• Types of circulatory collapse
• Signs and symptoms
• Causes and triggers
• Who is at risk?
• How is it diagnosed?
• Treatment and management
• Outlook

What is circulatory collapse?

Circulatory collapse is defined as a general or specific failure of the circulation system, either affecting the heart or blood vessels throughout the body^[8]. When this happens, the circulatory system cannot maintain the supply of oxygen and other nutrients to the body’s tissues, and it cannot remove carbon dioxide and other waste products^[8].

Shock is a life-threatening form of circulatory failure that leads to problems at the cellular and tissue level^[2]. When cells and tissues don’t get enough oxygen, they can die, causing vital organs to stop working properly. If caught early, the effects of shock can be reversed. However, delays in diagnosis or treatment can lead to permanent damage, including failure of multiple organs and death^[2].

The condition is common in critically ill patients, occurring in about one-third of people admitted to intensive care units^[7]. More than 6 million people in the United States have conditions that can lead to circulatory collapse^[18].

Types of circulatory collapse

Circulatory collapse can be classified in different ways. A general failure occurs across a wide area of the body, such as when someone loses a large amount of blood and circulation systems throughout the legs collapse. A specific failure can be traced to a particular point, such as a blood clot blocking a single artery^[8].

Medical professionals also categorize circulatory collapse based on the underlying cause. There are four main types^[2]:

• Distributive shock: This happens when blood vessels become too wide, causing blood pressure to drop. This type includes septic shock (from severe infections) and shock from severe allergic reactions
• Hypovolemic shock: Also called low volume shock, this occurs when the body loses too much blood or fluid through bleeding, severe diarrhea, or vomiting^[6]
• Cardiogenic shock: This happens when the heart cannot pump blood effectively, often after a severe heart attack or due to heart failure^[6]
• Obstructive shock: This occurs when something physically blocks blood flow, such as a collapsed lung putting pressure on the heart or fluid around the heart preventing it from beating properly^[6]

Cardiac circulatory collapse affects the vessels of the heart, such as the main artery called the aorta, and is almost always fatal. This is sometimes called acute circulatory failure^[8]. Peripheral circulatory collapse involves blood vessels in the arms, legs, and other parts of the body. This can result in tissue death, organ failure, or other serious complications^[8].

Signs and symptoms

The symptoms of circulatory collapse can range from mild to severe, and they may appear suddenly without warning^[6].

In cases of brief, harmless circulatory collapse (known in medicine as vasovagal syncope), people black out for a few seconds because their blood pressure suddenly drops. This leads to a lack of blood flow and oxygen to the brain^[1]. Typical warning signs include^[1]:

• Dizziness
• Cold sweat
• A rising feeling of heat from the stomach
• Nausea

In more serious cases of shock, initial symptoms may include^[6]:

• Weakness
• Fast heart rate
• Rapid or irregular breathing
• Sweating
• Anxiety
• Increased thirst

As the condition worsens, people may experience^[6]:

• Confusion
• Loss of consciousness
• Very low blood pressure
• Decreased urine output
• Cardiac arrest (when the heart stops beating)

Some people may have only minimal symptoms, such as confusion and weakness. The general signs of all types of shock include low blood pressure, decreased urine output, and confusion, but these may not always be present^[6].

Causes and triggers

Circulatory collapse happens when the body cannot deliver enough oxygen to tissues. This can occur because oxygen delivery decreases, oxygen use increases beyond what the body can supply, or the body cannot use oxygen properly, even when it’s available^[2].

In many harmless cases, circulatory collapse is triggered by common situations. At large events like outdoor festivals, people often collapse because of standing for long periods in crowded spaces, being in hot weather, or forgetting to drink enough non-alcoholic fluids. Often, several of these factors combine to cause a collapse^[1].

Brief blackouts can be caused by an overreaction of the nervous system to pain. The collapse can also happen due to a sudden reduction in blood flow or low blood sugar^[1].

More serious medical conditions that can cause circulatory collapse include^[1][8]:

• Cardiac arrhythmia (irregular heartbeat)
• Epilepsy
• Pulmonary embolism (blood clot in the lungs)
• Heart attack
• Heart failure
• Severe infections leading to septic shock
• Major blood loss from injury or surgery
• Dengue fever
• Severe dehydration
• Certain heart conditions present from birth
• Kidney disease
• Diabetes
• Some medications, including certain cancer drugs

During medical procedures involving the spine, sudden unexpected circulatory collapse can occur. The most important factor causing severe low blood pressure, slow heart rate, and circulatory collapse during these procedures is decreased blood return to the heart^[9].

Who is at risk?

Certain people are more likely to experience circulatory collapse. Young, small women or tall, slim men are often more susceptible to brief fainting episodes because their blood pressure is already naturally low, mostly due to their body type^[1].

Risk factors for more serious forms of circulatory collapse include^[5]:

• Being age 65 or older
• Depression
• Diabetes
• Excessive alcohol use
• Family history of heart disease
• High blood pressure
• High cholesterol
• High stress levels
• Obesity
• Poor nutrition or dietary habits
• Inactive lifestyle
• Smoking

More than 356,000 Americans each year experience sudden cardiac arrest outside of a hospital. This typically affects adults, but it can happen in children too^[12].

How is it diagnosed?

The diagnosis of circulatory collapse is generally based on a combination of symptoms, physical examination, and laboratory tests^[6].

Healthcare providers will examine patients and check for symptoms of circulatory collapse. They may ask about other health conditions, family history of heart problems, medications being taken, and symptoms experienced^[18].

A decreased pulse pressure (the difference between the top and bottom blood pressure numbers) or a fast heart rate raises concerns^[6]. Blood pressure that is lower than 90/60 mm Hg is generally considered low, though low blood pressure alone is not enough to diagnose circulatory collapse^[1].

Tests that may be performed include^[10]:

• Blood pressure check: Measures how hard blood pushes against artery walls
• Electrocardiogram (ECG or EKG): A quick test that shows how the heart is beating and can detect heart attacks or irregular rhythms
• Chest X-ray: Shows the size and shape of the heart and lungs and can reveal fluid in the lungs
• Blood tests: Can check for signs of organ damage, infection, and heart attack. These may measure oxygen levels in the blood and check for elevated lactate, which indicates tissues aren’t getting enough oxygen
• Echocardiogram: Uses sound waves to create pictures of the beating heart and check blood flow
• Cardiac catheterization: Involves threading a thin tube through an artery to look for blocked or narrowed blood vessels

Point-of-care ultrasound has become the preferred method for the initial evaluation of unexplained shock. It provides information to narrow down the diagnosis, assess whether the patient needs fluids, and evaluate how well treatment is working^[7].

Treatment and management

Circulatory collapse is a medical emergency that requires urgent care. If someone collapses and circulatory failure is suspected, emergency help should be called immediately. The faster someone gets help, the better their chances of survival with good health outcomes^[12].

While waiting for medical care, if it’s safe to do so, the person should be laid down (except if head or back injuries are suspected). The legs should be raised if possible, and the person should be kept warm. If the person is unresponsive, breathing should be monitored, and CPR (a method of keeping blood and oxygen flowing to vital organs) may need to be performed^[6].

Emergency treatment for sudden cardiac arrest includes CPR and shocks to the heart with a device called an automated external defibrillator (AED). CPR keeps enough oxygen in the lungs and gets it to the brain until an electric shock can restore a normal heart rhythm^[4].

The main goals when treating someone in circulatory collapse are to quickly restore blood flow to tissues and ensure they get enough oxygen^[7]. Treatment approaches include:

Fluid replacement: After the initial phase of treatment, which focuses on raising blood pressure to at least 65 mmHg, doctors use special tests to determine if the patient needs more fluids^[7]. Intravenous fluids may be given^[6].

Medications: Drugs called vasopressors may be used to help blood vessels tighten and raise blood pressure^[6].

Treating the underlying cause: Treatment depends on what caused the circulatory collapse^[6]. This might involve surgery to stop bleeding, antibiotics for infections, or procedures to open blocked blood vessels.

Mechanical support: In some cases, devices may be needed to help the heart pump blood or to support breathing.

For people with less serious, brief episodes of circulatory collapse, it’s important to have the causes checked by a healthcare provider, even though most cases are harmless^[1].

Outlook

The outlook for circulatory collapse varies greatly depending on the type and cause. Brief fainting episodes (vasovagal syncope) are usually harmless and people recover quickly without lasting effects^[1].

However, more serious forms of circulatory collapse carry significant risks. For shock in general, the risk of death ranges from 20 to 50 percent^[6]. About 1.2 million people per year in the United States experience shock^[6].

The effects of shock can be reversed if the condition is recognized and treated early. However, delays in diagnosis or starting treatment can lead to permanent changes, including failure of multiple organs and death^[2]. Even after surviving the initial shock episode, cellular damage from insufficient blood flow can lead to multiple organ problems that may cause death weeks or months later^[7].

Survival depends on how quickly treatment begins and how well the body responds. For sudden cardiac arrest, survival is possible with fast, appropriate medical care including CPR and defibrillation^[4].

vasovagal syncope, shock, cardiovascular collapse

• Heart
• Blood vessels (arteries and veins)
• Aorta
• Lungs
• Brain