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 the box on
this page). If sepsis is not treated, it can lead to severe sepsis and septic
shock.
Infective microorganisms can infect the blood, causing septicaemia and leading to septic shock.
Symptoms of septic
shock include:
- low blood pressure that makes you feel dizzy when you stand up
- a change in your mental state, such as confusion or disorientation
- diarrhoea
- nausea and vomiting
- cold, clammy and pale skin.
These symptoms
usually follow on from sepsis, which begins with weakness, chills, a rapid
heart rate and rapid breathing rate. Septic shock is a
medical emergency. If you think that you or someone in your care has this,
phone 999 and ask for an ambulance.
If you
have septic shock, you will usually be admitted to an intensive care
unit (ICU) as an emergency so your body’s functions and organs can be
supported while the infection is treated. Treatment may
include:
- oxygen therapy
- fluids given directly through a vein (intravenous)
- medication to increase your blood flow
- antibiotics
- surgery, in some cases.
Schematic diagram demonstrating the cascade of Septic Shock.
A person's chance of
surviving septic shock will depend on the cause of infection, the number of organs
that have failed and how soon treatment is started. Complications of
septic shock can include:
- lungs not being able to take in enough oxygen (respiratory failure)
- the heart not being able to pump enough blood around the body (heart failure)
- kidney injury or failure
- 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.
Causes
Septic
shock can be caused by an infection in any part of the body that is
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
occur if harmful bacteria enter the blood through the skin – for example, when
an intravenous drip or catheter has been inserted. Sepsis can also
happen after an infection in one of the organs – for example, a urinary tract
infection or lung infection.
If left untreated,
the toxins produced by bacteria can severely 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. This is called acute circulatory failure,
or shock. It significantly lowers your blood pressure.
The fall in blood
pressure means the heart cannot supply the body’s vital organs with oxygen-rich
blood. Without an oxygen-rich blood supply, the brain, heart, kidneys and liver
cannot function properly. The fall in blood
pressure, which does not respond to treatment with fluids, is what
distinguishes septic shock from severe sepsis.
Certain groups
of people are more at risk of developing septic shock. This is because their
immune systems are weaker, which reduces their ability to fight serious
infections. People who are
particularly at risk of developing septic shock include:
- newborn babies
- elderly people
- pregnant women
- people with long-term health conditions such as diabetes, cirrhosis or kidney failure
- people with lowered immune systems, such as people with HIV or AIDS or people receiving chemotherapy.
Treatment of Septic
Shock
Sepsis and septic
shock are medical emergencies and must be treated immediately. If you have sepsis,
it is likely you will 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 will be given oxygen through one of the following:
- a face mask
- a tube inserted into your nose
- an endotracheal tube inserted into your mouth.
If you have severe
shortness of breath, a mechanical ventilator may be used.
If you have septic
shock, you will 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
- vasopressors.
Inotropic
medicines
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 is needed.
Vasopressors
include:
- dopamine
- adrenaline
- noradrenaline.
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 as these are 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:
- draining a collection of pus (an abscess)
- removing infected tissue
- removing a medical device, such as a heart valve.
Source: NHS Choices.
