Septic shock is a life-threatening condition that happens when your blood pressure drops to a dangerously low level after an infection.
The infection will first cause a response from the body known as sepsis (see below). If sepsis isn't treated, it can lead to septic shock.
Symptoms of septic shock
Symptoms of septic shock include:
low blood pressure (hypotension) that makes you feel dizzy when you stand up
a change in your mental state, such as confusion or disorientation
nausea and vomiting
cold, clammy and pale skin
These symptoms usually follow on from sepsis, which begins with weakness, chills, and a rapid heart and breathing rate.
Septic shock is a medical emergency. Dial 999 to ask for an ambulance if you think that you or someone in your care has septic shock.
Treating septic shock
If you have septic shock, you'll usually be admitted to an intensive care unit (ICU) so your body’s functions and organs can be supported while the infection is treated.
Treatment may include:
fluids given directly through a vein (intravenously)
medication to increase your blood flow
surgery (in some cases)
Complications of septic shock
The chances of surviving septic shock will depend on:
the cause of infection
the number of organs that have failed
how soon treatment is started
Complications of septic shock can include:
inability of the lungs to take in enough oxygen (respiratory failure)
the heart not being able to pump enough blood around the body (heart failure)
kidney failure or injury
abnormal blood clotting
These are serious health conditions that will need to be treated urgently. Septic shock can be fatal because of complications such as these.
Sepsis occurs when an infection spreads through the blood, causing symptoms throughout the whole body. It's sometimes referred to as septicaemia or blood poisoning, but these terms aren't the same as sepsis.
Sepsis is where the body's defence mechanisms respond to an infection in some part of the body, resulting in symptoms such as a fever, raised pulse rate, raised breathing and confusion.
Septicaemia (another name for blood poisoning) is a bacterial infection of the blood that leads to the spread of infection and organ damage.
Causes of septic shock
Septic shock can be caused by an infection in any part of the body that's left untreated.
The infection will first cause a response from the body known as sepsis.
Bacterial infections are the most common cause of sepsis. Fungi, such as candida, and viruses can also sometimes lead to sepsis, although this is rare.
Bacterial infections happen if harmful bacteria enter the blood through the skin – for example, after an intravenous drip or catheter has been inserted. Sepsis can also occur after an infection in an organ, such as a urinary tract infection (UTI), or a lung infection (pneumonia).
How septic shock develops
Left untreated, the toxins produced by bacteria can damage the body’s cells. They attack the walls of the small blood vessels, causing them to leak fluid from the blood into the surrounding tissues. It can also decrease the heart's ability to pump blood to the organs, which lowers your blood pressure.
The fall in blood pressure means the heart can't supply the body’s vital organs with oxygen-rich blood. Without a blood supply, the brain, heart, kidneys and liver can't function properly.
The fall in blood pressure, which doesn't respond to treatment with fluids, is what distinguishes septic shock from severe sepsis.
Certain groups of people have an increased risk of developing septic shock. This is because they have weakened immune systems, which reduces their ability to fight serious infections, and includes:
people with long-term health conditions – such as diabetes, cirrhosis or kidney failure
people with lowered immune systems – such as those with HIV or AIDS, or those receiving chemotherapy
Treating septic shock
Sepsis and septic shock are medical emergencies and must be treated immediately.
If you have sepsis or septic shock, it's likely you'll be admitted to an intensive care unit (ICU) for urgent treatment and to carefully monitor your progress. In some cases, treatment may begin in the emergency department.
You may be connected to various tubes and machines to measure:
your blood pressure
how much urine you produce
how much oxygen is in your blood
To help you breathe more easily, you'll be given oxygen through a face mask, a tube inserted into your nose, or an endotracheal tube inserted into your mouth. If you have severe shortness of breath, a mechanical ventilator may be used.
Increasing blood flow
If you have septic shock, you'll probably be given fluids directly into a vein. This will help raise your blood pressure by increasing the amount of fluid in your blood.
To increase the blood flow to your vital organs, such as your brain, liver, kidneys and heart, you may be prescribed inotropic medicines or vasopressors.
Inotropic medicines (inotropes), such as dobutamine, stimulate your heart. They increase the strength of your heartbeat, which helps get oxygen-rich blood to your tissues and organs where it's needed.
These medicines will cause your blood vessels to narrow, increasing your blood pressure and the flow of blood around your body. This will allow your vital organs to start functioning properly.
Antibiotics are often used to treat sepsis and septic shock because they're usually caused by a bacterial infection.
The type of antibiotic that will be effective in treating the infection will depend on the type of bacterial infection and where in the body the infection started.
To increase your chances of survival, you may be started on antibiotics before the results of these tests are known. Initially, two or three types of antibiotics may be used. Once the results are known and the bacteria responsible for the infection have been identified, the most effective type of antibiotic can be used.
In severe cases of sepsis or septic shock, the large decrease in blood pressure and blood flow can cause organ tissue to die. If this happens, surgery may be required to remove the dead tissue.
You may also need surgery to remove the cause of your infection. For example, this may involve:
draining an abscess (a collection of pus)
removing infected tissue
removing a medical device – such as a heart valve