Sepsis, also known as Systemic Inflammatory Response Syndrome (SIRS), is a serious medical condition caused by the body's response to a bacterial infection, which can lead to serious complications that affect the kidneys, lungs, brain, and hearing, and can even cause death. It is a condition in which the body is fighting a severe infection that has spread via the bloodstream.

If a patient becomes "septic," they will likely be in a state of low blood pressure termed "shock." This condition can develop either as a result of the body's own defense system or from toxic substances made by the infecting agent (such as a bacteria, virus, or fungus).

Sepsis is a serious infection usually caused by bacteria - which can originate in many body parts, such as the lungs, intestines, urinary tract, or skin - that make toxins that cause the immune system to attack the body's own organs and tissues.

Sepsis can affect people of any age, but is more common in:

• Infants under 3 months, whose immune systems haven't developed enough to fight off overwhelming infections
• Patients who are in the hospital
• People with a genetic tendency for sepsis
• People with chronic medical conditions
• People with pre-existing infections or medical conditions
• People with severe injuries, such as large burns or bullet wounds
• People with weakened immune systems
• Elderly people
• Very old or very young people
• People whose immune systems are compromised from conditions such as HIV

Causes of Sepsis
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.

• The most common cause of sepsis is Bacteria
• Sepsis can also be caused by fungal, parasitic, or viral infections.

The source of the infection can be any of a number of places throughout the body. Common sites and types of infection that can lead to sepsis include:

• Abdomen - Infection of the abdominal cavity , and gallbladder or liver infections
• Central nervous system - Infections of the brain or the spinal cord
• Kidneys - Urinary tract infections are especially likely if the patient has a urinary catheter to drain urine
• Lungs - Infections such as pneumonia
• Skin - Bacteria can enter skin through wounds or skin inflammations.

Signs & Symptoms of Sepsis
Symptoms of sepsis in newborns and young infants include:

• Changes in rate of heartbeat
• Decreased tone
• Decreased urination
• Difficulty in breathing
• Difficulty in feeding, or vomiting
• High Fever
• Increased crankiness
• Jaundice
• Lethargy
• Pale skin color
• Rash

Older children have might have following symptoms:

• Change in skin color
• Fever
• Lethargy
• Rash
• Trouble breathing
• Vomiting

Diagnosis of Sepsis
Symptoms of sepsis can be vague in an infant that is why laboratory tests play a crucial role in confirming or ruling out sepsis:

• Blood tests: Blood cultures may be taken to determine whether bacteria are present in the blood.
• Urine Test: Urine is usually collected by inserting a sterile catheter into the baby's bladder through the urethra for a few seconds to remove urine; this will be examined under a microscope and cultured to check for the presence of bacteria.
• A sample of cerebrospinal fluid will be tested and cultured to determine if the baby could have meningitis.
  X-rays: X-rays especially of the chest are sometimes taken.

A person may have sepsis if he or she has:

• A blood culture that is infected with bacteria
• A high or low white blood cell count
• A low platelet count
• Abnormal kidney or liver function
• Acidosis

Treatments of Sepsis

• Drug therapies: Some patients are given new drug therapies
• Intensive Care Unit: Patients diagnosed with severe sepsis are placed in the ICU for special treatment.
• IV fluids: The doctor manages IV fluids to prevent blood pressure from dropping too low.
• Vasopressor medications: Vasopressor medications are needed to achieve an adequate blood pressure. 
• Supportive care: If organ failures occur, appropriate supportive care is provided like dialysis for kidney failure, mechanical ventilation for respiratory failure, etc.

When to seek Medical Advice
Symptoms of sepsis can be very difficult to identify in newborns and young infants, so it is always better to call your health care provider immediately. Emergency medical care is necessary if your baby shows any severe symptoms of sepsis.

The signs don't necessarily mean a child has sepsis, but it's very important that a doctor should know about symptoms to make sure that the infection is sepsis or something else, before it becomes more severe.