Multiple organ dysfunction syndrome (MODS): Clinical sciences

Multiple organ dysfunction syndrome or MODS is a life-threatening condition that occurs in the setting of shock. Now, a condition that precedes MODS is a systemic inflammatory response syndrome, or SIRS for short, which can be triggered by both infectious and non-infectious causes, including burns and trauma.

Now, no matter what the initial trigger is, in SIRS, the immune system overproduces inflammatory cytokines and mediators, such as TNF-alpha, as well as IL-1, IL-6, and IL-8. This overproduction of inflammatory cytokines is often referred to as “cytokine storm”, and in combination with prolonged hypotension, it can lead to hypoperfusion of multiple organs, hypoxic damage, and progressive organ dysfunction.

Now, if you suspect MODS, immediately perform an ABCDE assessment and begin acute management.

Start by stabilizing their airway, breathing, and circulation, which means that you might need to intubate the patient. Next, obtain IV access, start IV fluids, and consider placing a central venous catheter for the administration of medications and hemodynamic monitoring.

Additionally, you can insert an arterial catheter for continuous monitoring of the mean arterial pressure or MAP; or you may also place a pulmonary artery catheter or PAC to measure hemodynamic parameters and guide the administration of IV fluids and even vasopressors. Finally, put your patient on continuous vital sign monitoring, including heart rate, blood pressure, and pulse oximetry.

Now, once you stabilize the patient, perform a focused history and physical examination and obtain labs, including a CBC, CMP, lactate, ABG, as well as cardiac enzymes and BNP.

Next, use physical exam findings and some of the lab values to perform the SIRS assessment, which is based on four main criteria. The first criterion is either leukopenia, defined as WBCs below 4,000, leukocytosis, defined as WBCs above 12,000, or bandemia, defined as bands greater than 10% bands. The second one is body temperature either below 36 ൦C or over 38൦C; while the third one is a heart rate above 90 beats per minute. Finally, the last criterion includes respiratory rate over 20 breaths per minute.

Now, the SIRS criteria is not met if your patient presents with less than 2 criteria, so you should consider an alternative diagnosis. On the flip side, SIRS criteria is met if there are 2 or more criteria present. In these individuals, your next step is to assess for signs and symptoms of hypoperfusion, primarily by checking their systolic blood pressure, peripheral pulses, and capillary refill time, and if available, labs to check lactate levels!

Systemic blood pressure over 90 mmHg, normal peripheral pulses, and normal capillary refill time, as well as normal lactate levels below 2 mmol/L are suggestive of normal organ perfusion, so in these individuals, you should consider alternative diagnoses. On the flip side, systemic blood pressure less than 90 mmHg, weak peripheral pulses, and prolonged capillary refill time, as well as elevated lactate levels above 2 mmol/L are usually associated with organ hypoperfusion, so your patient is likely experiencing shock!

Now here’s a high yield fact to keep in mind! MODS can be caused by almost any type of shock, but the most common ones include septic and hypovolemic shock! Suspect septic shock if your patient reports a fever, has a known or suspected infection, and if their labs reveal leukocytosis, but some cases may have leukopenia, neutropenia, or bandemia greater than 10%. Also, if initial blood lactate levels are twice above the normal limit, so above 4 mmol/L, you should be suspicious for severe sepsis.