Appendix A

by Vanessa Hrvatin

Making a Sepsis Diagnosis

A physician must run several of the following tests in order to make a definitive sepsis diagnosis.

  1. Testing for an infection:
  • Can include urine tests (for example testing for a UTI) and blood cultures to look for any signs of bacteria. These are often considered the most definitive tests when diagnosing sepsis.
  • This can include a variety of different tests, ranging from x-rays (to test for something like pneumonia) to MRI’s.
  • Can include testing for procalcitonin (PCT), a precursor to the hormone calcitonin. It is typically produced by the thyroid gland but starts being produced by immune cells as well after a bacterial infection has been detected. Higher than normal levels of PCT are therefore indicative of a bacterial infection.
  • Can test for C-reactive protein (CRP). This tests for inflammation in the body, which can be indicative of an infection.
  1. If an infection is diagnosed (sepsis always stems from an infection), then physicians will start running the following general tests:
  • Temperature (fever or extremely low temperature)
  • Respiratory rate (low is concerning)
  • White blood cell count (low is concerning)
  • Heart rate (high is concerning)
  1. Physicians will run a variety of tests looking for organ dysfunction, based on SOFA guidelines:
  • Kidney function by testing creatinine levels
  • Liver function by testing bilirubin levels
  • Coagulation by testing platelet levels
  • Cardiovascular function by testing mean arterial pressure
  • Nervous system function by using the Glasgow coma scale to test the patient’s conscious state
  • Respiratory system function by testing the ratio of arterial oxygen partial pressure to fractional inspired oxygen

4.  Physicians will also test for lactate. High lactate levels mean the patient isn’t getting enough oxygen to their organs. However, this is typically only indicative of septic shock. Most patients who are in the early stages of sepsis won’t have elevated lactate levels. It’s interesting to note that some physicians consider this to be one of the most important tests when it comes to identifying a sepsis patient, while others consider it to provide the exact same information as qSOFA, rendering it useless.

5.  The physician will take into consideration the patient’s history and the overall clinical picture they present.