What organs can fail with sepsis?

Sepsis is a life-threatening condition that arises 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. With sepsis, organs throughout the body can be affected and begin to deteriorate.

Table of Contents

How does sepsis cause organ failure?

Sepsis occurs when chemicals released into the bloodstream to fight an infection trigger inflammation throughout the body. This inflammation can damage multiple organ systems, causing them to fail. Some reasons why sepsis can lead to organ failure include:

The widespread inflammation triggers leaky blood vessels, leading to poor blood flow to organs.
Injured blood vessels and abnormal clotting further blocks blood flow, depriving organs of oxygen and nutrients.
The drop in blood pressure seen in septic shock also reduces blood flow.

Chemicals released by the immune system damage organs directly.
Abnormal oxygen metabolism due to the infection damages cells.

When organs do not get enough oxygen and nutrients, they start shutting down and failing to perform their normal functions. The type and severity of organ failure depends on factors like the site of infection, underlying health conditions, and how early sepsis is caught and treated.

Which organs are most affected by sepsis?

While sepsis can impact all organs, those most likely to fail include:

Lungs

Acute respiratory distress syndrome (ARDS) is a common complication of sepsis where inflammation causes fluid leakage and reduced oxygen uptake in the lungs. As a result, oxygen levels fall dangerously low. Respiratory failure is one of the most common causes of death in sepsis.

Kidneys

The kidneys are very vulnerable to low blood pressure, inadequate oxygenation, and inflammatory damage in sepsis. Kidney injury occurs early and can progress rapidly to complete failure without prompt treatment. Sepsis is the most common cause of acute kidney failure.

Liver

The liver helps fight infections but is susceptible to reduced blood flow and inflammatory damage in sepsis. Impaired liver function affects blood clotting and the body’s ability to fight infections.

Heart

Sepsis can stun the heart, reducing its ability to pump enough blood to meet the body’s needs. Heart damage may be reversible if sepsis is recognized and treated quickly. Delayed treatment increases the risk of permanent injury and cardiovascular collapse.

Brain

In sepsis, delirium and other changes in mental status occur due to inflammation, reduced blood flow, and abnormal oxygen metabolism in the brain. Permanent brain damage is possible if sepsis is not treated promptly.

How common is organ failure in sepsis?

Multiple organ failure is seen in about one-third to one-half of all sepsis cases. The more organs that fail, the higher the risk of death. Some statistics on organ failure in sepsis include:

About 35% of sepsis patients develop acute kidney injury.
ARDS occurs in over 40% of sepsis cases.

Up to 50% of sepsis patients develop liver dysfunction.
Cardiovascular failure is seen in over 60% of septic shock cases.
Delirium due to brain dysfunction occurs in 70-80% of patients with sepsis.

In severe sepsis, multiple organ failure often develops, affecting two or more organs. The failure of three or more organ systems is associated with around an 80% risk of mortality.

How does organ failure increase sepsis mortality?

Organ failure significantly increases the risk of death from sepsis. Reasons include:

Failing organs are unable to keep the body’s processes and systems working.

Toxins build up as organs like the kidneys and liver fail.
Infections are harder to fight with impaired immune function.
Fluid imbalances and respiratory failure make shock and death more likely.

Delirium and multiple organ dysfunction make recovery more difficult.

Mortality rates vary based on the number of organs affected. Some estimates include:

10-20% mortality with single organ failure

20-40% mortality with two organ failure
Over 50% mortality with three organ failure
Over 80% mortality with four or more organ failure

The onset of septic shock also sharply increases the risk of death to over 40%. Full-blown septic shock carries a mortality rate of up to 60-80%.

What is the sequence of organ failure in sepsis?

While sepsis can damage any organ, multiple organ failure tends to occur in a predictable progression:

Lungs – Respiratory alterations and ARDS often occur first.

Brain – Delirium and related neurological changes follow soon after.
Kidneys – Acute kidney injury is seen within hours after the onset of sepsis.
Liver – Impaired liver function and jaundice may be seen next.

Heart – Cardiac dysfunction can occur within days.
Clotting – Disseminated intravascular coagulation arises later.

Understanding this usual sequence of events allows doctors to anticipate complications and initiate supportive therapies to try to prevent organ failure progression and irreversible damage.

What treatments help prevent organ failure in sepsis?

Early interventions are vital, as every hour that treatment is delayed increases mortality in sepsis. Key treatments include:

Antibiotics – Broad-spectrum antibiotics are given immediately to treat the underlying infection.
IV fluids – Aggressive fluid resuscitation helps improve organ blood flow.

Vasopressors – Medications are given to increase blood pressure.
Treatment of organ dysfunction – This may include kidney dialysis, mechanical ventilation, medications, and other organ supports.

In addition, good general critical care helps prevent complications and further deterioration:

Treating low oxygen levels with supplemental oxygen.
Nutritional support with feeding tubes if needed.
Prevention of hospital-acquired infections.

Thromboprophylaxis to lower clotting risk.
Sedation and pain management if on a ventilator.

What is the prognosis for organ failure in sepsis?

When treated aggressively, organ failure in sepsis may be reversible, especially if caught early. Overall, about 25-30% of patients with severe sepsis or septic shock will die. Prognosis depends on:

Number and extent of organ failure – More organs failing and higher severity of dysfunction increase mortality.
Speed of onset – Acute, rapid-onset failure is more deadly than gradual failure.
Cause and site of infection – Certain organisms and infected body sites have higher death rates.

Pre-existing illnesses – Chronic diseases like diabetes, kidney disease, cancer, etc. worsen outcomes.
Age – Mortality rates double above age 65 and are over 60% above 85.
Timeliness and effectiveness of treatment – This is key, as every hour without treatment increases mortality.

Some organs have a better prognosis for recovery than others. For example, acute kidney injury is often reversible if treated early, while sepsis-induced ARDS has a mortality rate around 40%. Long-term impacts like neurocognitive deficits may persist after organ function improves.

Conclusion

Sepsis can cause dysfunction and failure in virtually every organ due to the bodywide effects of severe infection. Lungs, kidneys, brain, liver, and heart are most commonly affected. Multiple organ failure increases sepsis mortality substantially, with death rates of 50% or higher when three or more organ systems are involved. Early recognition and rapid, aggressive treatment of sepsis is key to prevent irreversible organ damage and give patients the best chance of recovery.