What is Post-Sepsis Syndrome (PSS)?

Sepsis is characterized by a systemic immune reaction to an infection. This can be potentially fatal and is one of the leading causes of death in the world. Those who survive often have life-changing alterations, such as amputations, as a result of sepsis. Around half of sepsis patients develop Post-Sepsis Syndrome (PSS), which is a condition comprising physical and psychological changes that occur because of sepsis.

PSS Characteristics

PSS effects include insomnia, nightmares, muscle and joint pains, extreme fatigue, worsened concentration, decreased cognitive functioning, and loss of self-esteem. While it can affect everyone, it seems to affect older demographics more. One study found it affects up to 60% of sepsis survivors in older adults. This does not appear to be due to general hospitalization, as the risk of developing moderate to severe cognitive impairment was 3.3 times more likely as a result of sepsis than other hospitalizations.

Studies done on the PSS effects found increased risk of physical and cognitive dysfunction. The dysfunctions were long term, continuing for the eight years the study took place over. The impairments, which were relatively more severe in initially healthy subjects than in those who previously had some dysfunction, increased three-fold from before to after sepsis.

When looking at general quality of life, studies have found this to be decreased in sepsis survivors. In addition to being lower than the general population, some studies have found it was lower in sepsis survivors than in survivors of other critical conditions, while other studies have said it was similar to other survivors. In addition to this, it was found that many work less or not at all after being afflicted with sepsis. This is likely partly due to retirement, given that older people are more likely to develop sepsis, but does still reflect changes in financial situation which can potentially influence quality of life.

While not included in the PSS, sepsis survivors have additional difficulties after surviving. Studies have found that they have increased risk of infection after release from hospital and doubled the risk of death in the long term. This is partly confounded by the increased risk of rehospitalization faced by sepsis survivors. Up to 32% of sepsis survivors are hospitalized within a month, rising up to 40% within a year. The most common cause for rehospitalization is infection.

Causes of PSS

Sepsis generally causes clotting of blood, due to dysregulated coagulation, and poor circulation, causing poor tissue oxygenation. Some cases may lead to gangrene in limbs, which will need to be amputated. Similarly, lung damage as a result of pulmonary edema or other factors can affect breathing and make survivors more at risk for contracting viral respiratory infections.

Sepsis can cause injury from inflammation, ischemia (insufficient blood flow to a tissue), and ischemia-reperfusion (blood flow returning after ischemia). These are believed to cause muscle dysfunction (myopathy) and neuropathy. Immobilization and drugs used in sepsis treatment, such as corticosteroids and neuromuscular blockers, will additionally aggravate myopathy, while the brain is vulnerable to inflammation, ischemia and ischemia-reperfusion damage. Inflammation is often sustained after recovery, which could give reason for the long-term cognitive impairments.

The psychological and cognitive impairments that occur as a result of sepsis are more difficult to explain. A significant portion of survivors develop post-traumatic stress disorder (PTSD) symptoms. This can be due to time spent in the ICU, which has been shown to cause PTSD symptoms in unrelated diseases. Researchers have hypothesized that post-ICU PTSD can be due to inflammation induced by sepsis, which can cause a breakdown in the blood-brain barrier. This may change the effect of ICU prescribed drugs, such as narcotics and sedatives.