Monday Morning Medical Director’s Message
Sepsis diagnosis can often be challenging. Since signs and symptoms may be subtle at first, emergency providers might miss these clues, which could delay definitive treatment. It is not uncommon for sepsis victims to complain of general weakness and fatigue, which are very nonspecific symptoms. Elderly patients often experience changes in mental status or difficulty ambulating. Sepsis should remain high on the list in the differential diagnosis of nonspecific symptoms, especially in high-risk patients.
Risk factors are a crucial component of a comprehensive history and can contribute to a more robust differential diagnosis. Risk factor assessment is important in patients with possible acute coronary syndrome, thoracic aortic dissection, cardiac tamponade, or pulmonary embolism. The same is true for sepsis. Patients with diabetes, chronic renal failure on dialysis, cancer, autoimmune diseases (Crohn’s, rheumatoid arthritis, psoriasis, lupus, etc.), indwelling devices, frequent hospitalizations, recent invasive procedures, and chronic exposure to healthcare facilities are among the high-risk patients.
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Since sepsis can affect anyone of all ages and has a multitude of presentations, the diagnosis can be difficult. A high index of suspicion, coupled with a concise history and physical examination, goes a long way in pointing to the diagnosis.
Ancillary testing can be a valuable adjunct in the diagnosis of sepsis, which results in organ dysfunction. The brain is often the target organ that reveals early signs of sepsis. A urinary tract infection in the susceptible chronic nursing home patient frequently manifests as “acute mental status change.” Glucose testing should be obtained in all patients with encephalopathy. Patients could experience hypoglycemia, especially if they are chronically malnourished or if they have had frequent vomiting and reduced food intake. The other extreme, hyperglycemia, can also be a consequence. Patients under the stress of sepsis have increased adrenal cortisol production, which increases blood glucose. Furthermore, endogenous epinephrine production (a consequence of the septic process) breaks down glycogen into glucose.
The 12 lead EKG may reveal tachyarrhythmias and signs of ischemia in patients with underlying heart disease. Lung dysfunction, as a result of sepsis, could manifest by impairment in oxygen exchange, resulting in a decrease in oxygen saturation on pulse oximetry.
As systemic perfusion decreases during the septic process, cells are impaired in their ability to produce ATP and carbon dioxide. CO2 reduction is detected by waveform capnography. As ATP energy diminishes, the cells and tissues break down and eventually die. Organ dysfunction is the consequence. Capnography remains a vital indicator of perfusion at the cellular level. Some squads have utilized pre-hospital point-of-care lactate testing. The cause of lactate excess in sepsis is still being debated by experts. Recently, many researchers have postulated that lactate (not lactic acid) is produced by the release of endogenous epinephrine, which breaks down glycogen into glucose. In the past, lactate was believed to be the product of anaerobic metabolism (without oxygen), but in fact, most patients with sepsis have adequate oxygen supplies and still produce lactate. Normally, glucose would be utilized in the metabolic pathway known as glycolysis to make pyruvate, which enters the Krebs cycle. When excess pyruvate is produced, the Krebs cycle pathway is overwhelmed. Some of the glucose excess is therefore converted into lactate. These scientists contend that lactate, not lactic acid, is the actual chemical (the difference is one hydrogen ion in lactic acid, which lactate lacks).
Regardless of how or why lactate accumulates, it remains an important indicator of sepsis severity, and serial lactate measurements provide insight into patient response to treatment. Thank you to all my EMS and ED colleagues!
Stay well,
Andrew Garlisi, MD
EMS Medical Director
University Hospitals EMS Training & Disaster Preparedness Institute