Multiple organ dysfunction syndrome

The condition results from infection, injury (accident, surgery), hypoperfusion and hypermetabolism. The primary cause triggers an uncontrolled inflammatory response.

Sepsis is the most common cause of multiple organ dysfunction syndrome and may result in septic shock. In the absence of infection, a sepsis-like disorder is termed systemic inflammatory response syndrome (SIRS). Both SIRS and sepsis could ultimately progress to multiple organ dysfunction syndrome. In one-third of the patients, however, no primary focus can be found.[1] Multiple organ dysfunction syndrome is well established as the final stage of a continuum: SIRS + infection → sepsis → severe sepsis → Multiple organ dysfunction syndrome.

Currently, investigators are looking into genetic targets for possible gene therapy to prevent the progression to multiple organ dysfunction syndrome. Some authors have conjectured that the inactivation of the transcription factors NF-κB and AP-1 would be appropriate targets in preventing sepsis and SIRS.[2] These two genes are pro-inflammatory. They are essential components of a normal healthy immune response, however, so there is risk of increasing vulnerability to infection, which can also cause clinical deterioration.

A definite explanation has not been found. Local and systemic responses are initiated by tissue damage. Respiratory failure is common in the first 72 hours. Subsequently, one might see liver failure (5–7 days), gastrointestinal bleeding (10–15 days) and kidney failure (11–17 days).[1]

The European Society of Intensive Care organized a consensus meeting in 1994 to create the "Sepsis-Related Organ Failure Assessment (SOFA)" score to describe and quantitate the degree of organ dysfunction in six organ systems. Using similar physiologic variables the Multiple Organ Dysfunction Score was developed.[1]

Four clinical phases have been suggested:

• Stage 1: the patient has increased volume requirements and mild respiratory alkalosis, which is accompanied by oliguria, hyperglycemia and increased insulin requirements.
• Stage 2: the patient is tachypneic, hypocapnic and hypoxemic; develops moderate liver dysfunction and possible hematologic abnormalities.
• Stage 3: the patient develops shock with azotemia and acid–base disturbances; has significant coagulation abnormalities.
• Stage 4: the patient is vasopressor dependent and oliguric or anuric; subsequently develops ischemic colitis and lactic acidosis.

At present, there is no drug or device that can reverse organ failure that has been judged by the health care team to be medically and/or surgically irreversible (organ function can recover, at least to a degree, in patients whose organs are very dysfunctional, where the patient has not died; and some organs, like the liver or the skin, can regenerate better than others),- with the possible exception of single or multiple organ transplants or the use of artificial organs or organ parts, in certain candidates in specific situations. Therapy, therefore, is usually mostly limited to supportive care, i.e. safeguarding hemodynamics, and respiration. Maintaining adequate tissue oxygenation is a principal target. Starting enteral nutrition within 36 hours of admission to an intensive care unit has reduced infectious complications.[1]

Mortality, though it has lessened to a limited degree, at least in developed countries with timely access to initial and tertiary care, varies where the chance of survival is diminished as the number of organs involved increases. Mortality in MODS from septic shock (which itself has a high mortality of 25–50%), and from multiple traumas, especially if not rapidly treated, appear to be especially severe. If more than one organ system is affected, the mortality rate is still higher, and this is especially the case when five or more systems or organs are affected. Old age is a risk factor in and of itself, and immunocompromised patients, such as with cancer or AIDS or a transplant, are at risk. Prognosis must take into account any co-morbidities the patient may have, their past and current health status, any genetic or environmental vulnerabilities they have, the nature and type of the illness or injury (as an example, data from COVID-19 is still being analyzed, whereas other cases from long-existing illnesses are much better understood), and any resistance to drugs used to treat microbial infections or any hospital-acquired co-infection. Earlier and aggressive treatment, the use of experimental treatments, or at least modern tools such as ventilators, ECMO, dialysis, bypass, and transplantation, especially at a trauma center, may improve outcomes in certain cases, but this depends in part on speedy and affordable access to high-quality care, which many areas lack. Measurements of lactate, cytokines, albumin and other proteins, urea, blood oxygen and carbon dioxide levels, insulin, and blood sugar, adequate hydration, constant monitoring of vital signs, good communication within and between facilities and staff, and adequate staffing, training, and charting are important in MODS, as in any serious illness.[6][7][8][9][10]

In patients with sepsis, septic shock, or multiple organ dysfunction syndrome that is due to major trauma, the rs1800625 polymorphism is a functional single nucleotide polymorphism, a part of the receptor for advanced glycation end products (RAGE) transmembrane receptor gene (of the immunoglobulin superfamily) and confers host susceptibility to sepsis and MODS in these patients.[11]

For many years, some patients were loosely classified as having sepsis or the sepsis syndrome. In more recent years, these concepts have been refined – so that there are specific definitions of sepsis – and two new concepts have been developed: the SIRS and MODS.[1]

• The ICU Book by Marino
• Cecil Textbook of Medicine
• The Oxford Textbook of Medicine
• Harrison's Principles of Internal Medicine