Sepsis is a life-threatening condition that occurs when the body’s response to an infection damages its own tissues and organs. Sepsis leads to shock, multiple organ failure and death, especially if not recognized early and treated promptly. Sepsis is a medical emergency that requires rapid treatment and close monitoring.
What causes sepsis?
Sepsis typically occurs when chemicals released into the bloodstream to fight an infection trigger inflammation throughout the body. This inflammation can trigger a cascade of changes that damage multiple organ systems, causing them to fail.
Almost any type of infection can lead to sepsis. The most common causes include:
- Lung infections, such as pneumonia
- Kidney infections
- Bloodstream infections (bacteremia)
- Bacterial infections
- Abdominal infections, such as appendicitis
Infections that most commonly result in sepsis include:
1. Pneumonia
Pneumonia is the most common cause of sepsis. Pneumonia is a lung infection that can be caused by bacteria, viruses or fungi. Pneumonia triggers an inflammatory immune response in the lungs that can spill over systemically, potentially leading to sepsis.
2. Urinary tract infections
Urinary tract infections (UTIs) are the second most frequent cause of sepsis. UTIs occur when bacteria enter the urinary tract and multiply in the bladder. UTIs can spread to the kidneys and enter the bloodstream, causing sepsis.
3. Intra-abdominal infections
Infections in the abdominal cavity (peritonitis) are the third leading cause of sepsis. Sources include appendicitis, perforated bowel, diverticulitis and gallbladder infections. Bacteria can spread from the infected site into the blood.
4. Soft tissue infections
Infections of soft tissues, including muscles and skin, can result in sepsis. Common causes are cellulitis, necrotizing fasciitis, pyomyositis and gangrene. The infection can invade blood vessels and release bacteria into circulation.
5. Infective endocarditis
This infection of the inner lining of the heart (endocardium) can release bacteria into the bloodstream. Risk factors include congenital heart defects, rheumatic heart disease and hypertrophic cardiomyopathy.
Who is at risk of sepsis?
While anyone can get sepsis, some people are at higher risk. Groups at increased risk of sepsis include:
- Adults 65 years or older
- Children younger than 1
- People with weakened immune systems or chronic illnesses (diabetes, cancer, kidney or liver disease)
- Patients who have experienced a severe burn or physical trauma
- People with indwelling medical devices, such as intravenous (IV) catheters or urinary catheters
Additional risk factors for sepsis include:
- Recent surgery or hospitalization
- Prior sepsis
- Residence in a long-term care facility
- Taking immunosuppressive drugs
- Malnutrition
How does sepsis start?
Sepsis develops in response to an existing infection in the body. When bacteria, fungi or viruses invade the body, the immune system mounts an inflammatory response. Chemicals called cytokines and leukotrienes are released into the blood to target the infection.
In some people, this normal immune response goes into overdrive. The inflammation extends beyond the local site of infection and spreads systemically. This triggers widespread inflammation and blood clotting. Blood flow to organs is impaired, causing multiorgan damage. Blood pressure drops severely, resulting in septic shock.
What are the symptoms of sepsis?
The early signs and symptoms of sepsis are often subtle and nonspecific, which can make early diagnosis challenging. Symptoms generally start with the infection that triggered sepsis. As sepsis worsens, other signs and symptoms can develop, including:
- Fever above 101°F or temperature below 96.8°F
- Heart rate higher than 90 beats per minute
- Fast breathing (tachypnea)
- Confusion or disorientation
- Extreme pain or discomfort
- Clammy or sweaty skin
As sepsis progresses to severe sepsis and septic shock, symptoms may include:
- Decrease in urination
- Cold, clammy arms and legs
- Pale or discolored skin
- Sleepiness, difficulty to rouse, or unconsciousness
- Rapid heart rate
- Rapid breathing
- Abdominal pain
- Diarrhea
- Nausea and vomiting
- Poor blood circulation
- Organ dysfunction (kidney failure, acute respiratory distress syndrome)
- Dramatic decrease in blood pressure
When to see a doctor
Sepsis is a medical emergency that requires rapid treatment. Seek immediate medical care if you or a loved one develops any of the following:
- A probable or confirmed infection accompanied by fever above 101°F or below 96.8°F
- Fast heart rate, rapid breathing or extreme pain
- Decrease in urination
- Unusual drowsiness, confusion or disorientation
- Skin that is clammy or unusually pale
Call 911 or emergency medical services if you or a loved one:
- Is experiencing symptoms of shock, such as passing out or breathing problems
- Is struggling to stay awake
- Appears confused
- Cannot be awakened or aroused
How is sepsis diagnosed?
Doctors will diagnose sepsis based on symptoms, medical history and test results. Tests used to help confirm sepsis include:
- Blood tests to check white blood cell count, to identify bacteria and viruses and to measure markers of inflammation (procalcitonin, C-reactive protein and lactate)
- Urine tests to look for bacteria, blood and kidney dysfunction
- Imaging tests such as X-rays, CT scans or echocardiograms to locate infection sites
- Cultures of blood, urine, wounds or respiratory secretions to identify infectious organisms
How is sepsis treated?
Sepsis requires rapid, aggressive treatment in the hospital, often in an intensive care unit. Treatment aims to:
- Eliminate and control the source of infection
- Maintain adequate blood flow and pressure
- Stabilize oxygen levels
Treatments may include:
- Antibiotics – Broad-spectrum antibiotics are given intravenously to treat the underlying infection.
- IV fluids – Large amounts of intravenous fluids help increase blood pressure and improve blood flow.
- Oxygen – Extra oxygen by mask may be given to maintain normal oxygen levels.
- Medications – Vasopressor medications improve blood pressure and heart function.
- Diuretics – Diuretics eliminate excess fluid overload.
- Dialysis – Dialysis removes fluids and waste products if kidney function is impaired.
- Surgery – Surgery may be needed to remove sources of infection or infected tissue.
If organ damage is severe, supportive treatment in an intensive care unit may be needed. Mechanical ventilation, drugs, machine assistance and even dialysis might be required temporarily to support normal function.
What complications can result from sepsis?
Sepsis can trigger potentially life-threatening complications, including:
- Septic shock – Dramatic decrease in blood pressure reduces blood flow to vital organs and can result in multiple organ failure. Septic shock has a mortality rate as high as 50%.
- Respiratory failure – Fluid in the lungs (pulmonary edema) or damage to the lungs impairs ability to exchange oxygen and carbon dioxide. Mechanical ventilation may be required.
- Kidney failure – Decreased blood flow damages the kidneys. Dialysis may be needed temporarily or long-term.
- Heart failure – The heart is unable to pump adequate blood. Medications or mechanical support may be needed.
- Liver failure – Reduced perfusion to the liver causes significant dysfunction. Dialysis can provide temporary support.
- Encephalopathy – Altered mental status can occur due to inflammation of brain tissue.
- Coagulation problems – Impaired coagulation leads to bleeding or clotting disorders.
Long-term complications of sepsis may include amputation of limbs damaged by poor perfusion, cognitive impairment, insomnia, post-traumatic stress disorder (PTSD), chronic kidney disease and increased risk of future infections.
How can sepsis be prevented?
While sepsis cannot always be prevented, the following precautions can lower sepsis risk:
- Preventing infections – Practice good hygiene and get recommended vaccinations.
- Managing chronic conditions – Follow treatment plans for medical conditions like diabetes that increase infection risk.
- Caution with IVs and catheters – Ensure proper insertion and remove promptly when no longer needed.
- Wound care – Clean and treat wounds properly to prevent infection.
- Avoiding pathogens – Take precautions when handling raw meat, fish and eggs or when in contact with those who are sick.
- Controlling spread – Isolate or avoid others with serious infections like pneumonia or the flu.
- Early treatment – Seek prompt medical care for infections before they progress.
Conclusion
Sepsis is a life-threatening complication of an infection. Pneumonia, urinary tract infections, intra-abdominal infections and tissue infections are frequent triggers. High risk groups include older adults, very young, immunocompromised and hospitalized populations. Rapid heart rate, high fever, confusion and extreme pain can signal sepsis. Aggressive hospital care with IV fluids, antibiotics, oxygen and treatment of organ failure may be required. Preventing infections, managing chronic illnesses and prompt treatment of infections can help reduce sepsis risk.
