Blood poisoning is the colloquial term often used to describe sepsis or septicemia. We have all heard of blood poisoning but what does it actually mean?
Sepsis is a potentially deadly condition in which an individual experiences a 'whole body' inflammatory state as the result of an infection of bacteria in the blood, urine, lungs, skin and other tissue (bacteremia). This whole body response is a result of the immune system responding to the bacteria and is called 'systemic inflammatory response syndrome' or 'SIRS'. This can lead to organ failure (due to changes in blood flow) and death if not treated. In general the term 'sepsis' is used to describe this response (SIRS) while septicemia is used to describe bacteremia and the symptoms (though they are generally used interchangeably).
Blood poisoning then is used to describe the presence of bacteria in the blood – not actually a poison or toxin as the name might suggest. While it is used interchangeably, it is perhaps best used to describe bacteremia or septicemia.
Symptoms of Blood Poisoning
The early symptoms and indicators of blood poisoning can include:
• High fever OR sudden low body temperature
• Increased heart rate
• Rash (reddish discoloration)
• Pain in the joints and knees
• Stomach pain
As this progresses into sepsis this can include:
• Elevated white blood cell count AKA leukocytosis
• Inflammation throughout the entire body
• Drop in blood pressure
• Problems associated with organ damage
• Breathing difficulties
The cause of blood poisoning is any infection – such as an infection of a wound etc. In most cases your body's immune system is able to localize the infection to one place and this is what's called a 'localized infection'. Your body creates white blood cells which then destroy that localized infection and the tissue swelling etc all help prevent spreading.
However in the case of severe infection, or where the immune system is already weak, this infection can spread via the blood around the whole body. This then of course results in full-body response that is sepsis.
There are many potential causes for infection which can lead to blood poisoning and they include:
• Lung infection (pneumonia)
• Flu AKA influenza
• Urinary tract infections
• Skin infections as a result of a wound or the use of an intravenous drip/catheter
• Post surgical infections
• Nervous system infections such as meningitis/encephalitis
• In some cases the source of the infection remains unidentified
Diagnosis and Treatment
The diagnosis of bacteremia uses a blood culture along with identification of the symptoms. Treatment requires hospitalization and it is highly important that it is carried out promptly to prevent sepsis and organ failure. Blood poisoning can be treated with intravenous antibiotics – antibiotics delivered directly into the blood stream. These will normally be administered for around 7-10 days. In other cases it can be treated with medications such as insulin or steroid, a blood transfusion and dialysis.
The prognosis for severe sepsis is relatively poor with 20-35% of patients dying within 30 days. If this progresses to 'septic shock' that number increases to 40-60%. Other deaths can occur within the following 6 months as a result of poorly controlled infection or immunosuppression.