What ails 96-year-old Basu?

Veteran Marxist leader Jyoti Basu's condition deteriorated late on Friday night with five organs -- heart, lung, kidney, liver and brain -- malfunctioning.

The former West Bengal chief minister was admitted to Salt Lake's AMRI Hospital on New Year's Day with pneumonia and was shifted to the intensive care unit five days later as he developed sepsis.

To know more about what ails Basu, read on.

What is sepsis?

Sepsis, also known as systemic inflammatory response syndrome, is a serious medical condition caused by the body's response to an infection.

Sepsis can lead to widespread inflammation and blood clotting. Inflammation may result in redness, heat, swelling, pain, and organ dysfunction or failure.

Blood clotting during sepsis causes reduced blood flow to limbs and vital organs, and can lead to organ failure or gangrene (damage to tissues).

The body may develop this inflammatory response to microbes in the blood, urine, lungs, skin, or other tissues.

Severe sepsis often leads to organ dysfunction, low blood pressure, insufficient blood flow (hypoperfusion) to one or more organs. These cause lactic acidosis, decreased urine production or altered mental status.

What causes sepsis?

Bacterial infections are the most common cause of sepsis. Sepsis can also be caused by fungal, parasitic, or viral infections.

Common sites and types of infection that can lead to sepsis include:

• The abdomen: An inflammation of the appendix (appendicitis), bowel problems, infection of the abdominal cavity (peritonitis), and gallbladder or liver infections
• The central nervous system: Inflammation or infections of the brain or the spinal cord
• The lungs: Infections such as pneumonia
• The skin: Bacteria can enter skin through wounds or skin inflammations, or through the openings made with intravenous (IV) catheters (tubes inserted into the body to administer or drain fluids).
• Conditions such as cellulitis (inflammation of the skin's connective tissue) can cause sepsis.
• The urinary tract (kidneys or bladder): Urinary tract infections are especially likely if the patient has a urinary catheter to drain urine

Who are at risk?

Even otherwise healthy individuals who have a bacterial or other form of infection can fall victim to sepsis. However, the risk is greater in the case of the following conditions:

• A new born baby or infant
• Being over 35 and especially over 60
• Pregnant women
• Having certain chronic disorders such as diabetes or cirrhosis
• Having a weakened immune system because of use of immunosuppressant drugs (such as those used in chemotherapy) or corticosteroids, or because of certain diseases (such as cancer, AIDS, and immune disorders).

Twenty-five per cent of elderly and critically ill patients are known to fall prey to sepsis in ICU. In about 40-60 per cent of cases, deaths occur if there is severe sepsis.