Sepsis Testing

Lactic Acid Test Ordering Pattern

In patients with suspected sepsis, serum lactate testing should be performed as soon as possible to determine the need for immediate goal-directed therapy. If an initial test indicates elevated lactate (>2mmol/L) and therapy is initiated, the Surviving Sepsis Campaign (SSC) recommends repeating the test within 2 to 4 hours to monitor therapeutic response  or at least 1 to 2 hours after starting resuscitation, according to the American College of Emergency Physicians (ACEP).  Remeasuring lactate too soon is not beneficial. 

In addition to recommending immediate serum lactate testing and repeat testing within 2 to 4 hours, SSC recommends two sets of blood cultures (aerobic and anaerobic) from two different sites in cases in which lactate is elevated before initiating antibiotics. 

Procalcitonin Testing

Procalcitonin (PCT) measurements may provide supportive evidence that systemic inflammation is due to bacterial infection. They also can help differentiate blood-culture contaminants and guide antibiotic stewardship. In addition, PCT can be used to predict 28 day cumulative mortality risk for patients diagnosed with sepsis.  PCT testing should not take the place of serum lactate testing to indicate the severity of sepsis and to monitor therapeutic response.

According to the American Society for Clinical Pathology (ASCP) through the Choosing Wisely initiative, the rapid adoption of PCT testing has sometimes outpaced proper utilization, which results in a significant expense to hospital laboratories with mixed outcomes. ASCP recommends that institutions using PCT adopt protocols to ensure appropriate use of the test. 

PCT testing can be useful in decreasing unnecessary use of antibiotics, but it should not take the place of serum lactate testing.

Recommendations

Preorder

Provider Education

The Surviving Sepsis Campaign (SSC) offers a variety of materials aimed at emergency and critical care physicians, as well as clear guidelines and checklists for treating septic patients.

Emergency-Based Protocols for Procalcitonin Testing

The rapid adoption of PCT testing has at times outpaced physician education and establishment of evidence-based protocols to encourage proper utilization. Establish protocols about when testing is appropriate and algorithms that indicate which actions to take based on the test results.

Order

Computerized Physician Order Entry Interval Check

Implement an interval check in the Computerized Physician Order Entry (CPOE), based on supporting evidence, for guidance on the appropriate frequency for lactic acid. This alert will generate an advisement to the ordering provider if the test is repeated earlier than recommended.

Ordering Protocol Standardization

Identify standard uses and contexts of lactic acid testing and establish ordering protocols to improve the efficiency and standardization of order placement.

Post Order

Positive Results Automated Repetition

Establish a process to trigger tests with positive results to repeat when certain criteria are met, such as results being above a given threshold.

Interval Guidance

In cases of suspected sepsis, lactic acid measurements should be taken immediately, and repeat testing should occur within 2 to 4 hours of the initial measurement.