When organs fail one by one

By Jennifer L. Duhon, RN, MSN

JENNIFER DUHON is assistant professor of nursing at Illinois Central College in East Peoria, IL. The author has no financial relationships to disclose.

It's important to know who's at risk for organ failure after infection or injury. Your early intervention can prevent the development of the often-fatal syndrome known as MODS.When his safety belt broke, a 27-year-old construction worker I'll call Matt Sherman fell from scaffolding and fractured his left tibia-fibula and femur. A set of X-rays done during his initial trauma workup in the ED revealed multiple left rib fractures, a large hemopneumothorax, and a left vertical shear fracture of the pelvis.1After surgeons repaired a splenic laceration and stabilized his pelvis, femur, and tibia, Mr. Sherman was transferred to the ICU in critical condition. For the next three days, he had numerous problems with his hemodynamic parameters, urine output, and temperature.

His oxygenation saturation level dropped, his respiratory rate increased, and chest X-rays showed diffuse, fluffy white infiltrates. His blood pressure was below 90 mm Hg systolic and he looked like he was going into shock. After studying Mr. Sherman's clinical, hemodynamic, and laboratory data, physicians diagnosed early sepsis with multiple organ dysfunction syndrome (MODS).

A progressive impairment of two or more organ systems, MODS is caused by the immune system's uncontrolled inflammatory response to a severe illness or injury.2,3It's a common cause of death for patients in the ICU. Mortality rates for MODS range from an estimated 50% to just under 100%, with the outcome dependent upon the underlying cause, the number of organ systems involved, and the degree of organ damage.2,4Identifying those at risk for MODS and acting quickly to stop its progression can keep your patient from becoming a statistic. Knowing what to look for and how to respond is crucial, whether you work in the ED, on a med/surg unit, or in the ICU.

Defenses take a destructive turn

MODS can develop quickly following major surgery, trauma, or severe burns, or slowly as in the case of an infection that turns into sepsis. While it's not clear why some patients develop MODS while others don't, there are predisposing factors that increase the likelihood. Risk factors include:

Age (very young or very old),

Chronic disease, such as diabetes, cancer, or renal insufficiency,

Immunosuppressant therapy, and

Multiple blood transfusions.1Regardless of whether the insult to the body is infectious or not, it is the body's own defenses the immune system and stress responsethat together damage organs one by one.4 The immune system triggers inflammation that's supposed to contain the intruder, injured area, or irritant, get rid of dead tissue, and restore balance. But as inflammation progresses from a local to a systemic response, it gathers intensity and can end up doing the body more harm than good.3,4This systemic reaction to injury or infection has its own name: systemic inflammatory response syndrome. SIRS can lead to organ damage independent of the trigger that sets it off. That's because the powerful inflammatory mediators (cytokines and chemokines) that drive the process cause both direct and indirect tissue damage, which in turn triggers the release of more inflammatory mediators in a self-perpetuating downward spiral.5,6And what happens when these mediators run amok? The mediators that promote peripheral vasodilation end up causing severe hypotension. Those that increase capillary permeability cause the body's fluids to shift out of the vascular bed and into the interstitial spaces, causing pulmonary and generalized edema. Those that activate the clotting cascade create microemboli that lodge in capillary beds all over the body. The result: global tissue hypoxia.5Without oxygen, organs rapidly fail. The body tries to defend itself by activating the sympathetic nervous systemthe stress response. But like the immune system, it too ends up doing more harm than good. Catecholamines (adrenaline and norepinephrine) boost the falling cardiac output by increasing the heart rate and shunting the blood supply back toward the heart.2,5 Unfortunately, they do so at the expense of the gut and kidneys.

Taking blood from the gut leads to necrosis and allows gut bacteria to translocate into the bloodstream, exacerbating or causing sepsis.7 Taking blood from the kidneys impairs their ability to eliminate toxins and maintain acid-base balance. Stress hormones (glucagon, cortisol, glucocorticoids, others) block inflammation and bolster the body's energy needs by pulling glucose out of storage.2,5 But their side effects cause numerous problems, including insulin resistance, hyperglycemia, sodium and water retention, and stress-induced ulcers.2Starved for oxygen, the body's tissues turn to anaerobic metabolism for energy; lactate is a byproduct. Without intervention, lactic acidosis leads to death.

Since the lungs are highly sensitive to mediator-induced inflammation, they are often the first system to show signs of failure in the progression of SIRS to MODS.5,8 Damage to lung tissue can occur within 90 minutes of the onset of SIRS. That's why there's no time to waste in detecting SIRS and providing targeted intervention.5,8(For the signs and symptoms of SIRS, see the box at the end of this article.)Once the lungs start failing, the liver, kidneys, and gut follow.3 The sequence of organ failure is not set in stone, however. (The table below lists the signs of dysfunction and failure for each system.) As dysfunction progresses to failure, organs become so significantly altered that homeostasis can't be maintained without intensive medical support.1,3,7

When organs malfunctionTreating the cause, providing support

Eliminating or minimizing potential triggers for SIRS by treating the underlying cause takes top priority. Thus, the physician may drain an abscess or remove an infected invasive line, vascular graft, or orthopedic device, for example.1,2Nursing care is mainly supportive, and geared toward preventing or limiting further destruction of each system. Controlling infection is paramount. Meticulous line care, thorough handwashing, and scrupulous attention to sterile technique is a must. Since more than half of all cases of MODS are triggered by a pathogen, patients should get broad-spectrum antibiotics, as ordered and without delay.3 Culture and sensitivity tests of sputum, blood, catheter tips, and urine must be done for all patients who are febrile.1 The physician will adjust the antibiotic regimen if a pathogen is discovered.

Supporting oxygenation is critical: This involves increasing oxygen delivery with supplemental oxygen and fluid resuscitation.9 While noninvasive positive pressure ventilation can be used, most SIRS patients require mechanical ventilation. The goal of ventilator therapy is to maintain an SpO2 >90% and a PaO2 >60 mm Hg.9 But achieving this in a patient whose lungs are failing without causing further injury can be tricky.

To protect the lungs, the patient should be given the lowest tidal volumes (6 ml/kg and end inspiratory plateau pressure