How to Evaluate Sepsis

Sepsis cannot be diagnosed by a single trustworthy laboratory test. The following extra testing is still regarded as crucial even though the presumptive diagnosis is based on the history and physical examination.

1. Laboratory studies:

a) Blood cultures and site-specific cultures (e.g., sputum, urine, cerebrospinal fluid [CSF]) should be obtained before initiating empiric antibiotic therapy.

b) Gram staining of samples from a particular location is advised.

c) Serologic studies (e.g., counter-immune electrophoresis, latex agglutination) are useful when infection with pneumococcus, Haemophilus influenza, meningococcus, or group B streptococcus is suspected.

d) Complete blood count (CBC): Findings compatible with a diagnosis of sepsis include anemia, leukopenia, leukocytosis, eosinopenia, and thrombocytopenia.

e) Urinalysis: A result that confirms the diagnosis of sepsis is proteinuria.

f) Urine Legionella antigen: Positive results imply either a recent or historical infection. May already be visible in the urine three days after the onset of symptoms.

g) The most common cause of community-acquired pneumonia is the urinary Streptococcus pneumoniae antigen.

h) Coagulation profile: The presence of thrombocytopenia and a prolonged prothrombin time are signs that sepsis is present.

i) Arterial blood gas profile: Hypoxemia and metabolic acidosis could be detected in a sepsis patient.

j) Serum biochemical profile: Supportive findings would include hypoferremia, hypocalcemia, hyperbilirubinemia, hyper- or hypoglycemia, and azotemia.

k) Lactic acid: Mostly made anaerobically in the red blood cells and muscles. Elevated levels (>1mmol/L) can be a manifestation of organ hypoperfusion in the presence or absence of hypotension and is an important component of initial sepsis workup. Keep in mind that increased levels can also be found in heart, liver, and lung diseases in addition to sepsis.

l) A very unwell patient's procalcitonin level can be used to check for a systemic bacterial infection. This test is best used during the first day of the presentation of illness and subsequently to monitor the response to treatment.

2. Imaging studies: It may be necessary to do site-specific radiographs, ultrasonograms, computed tomography (CT) scans, or magnetic resonance imaging scans.

3. Other studies: It may be useful to analyze site-specific samples taken via biopsy or aspiration.