CLN - The Sample

Lactate Testing Underutilized in Sepsis Care

The Sample: July 2018

Only about 60% of patients who met Severe Sepsis and Septic Shock Early Management Bundle (SEP-1) criteria for severe sepsis had an initial lactate level drawn within the SEP-1-indicated timeframe. Yet in patients with elevated baseline lactate results >2.0 mmol/L, each hour of delay was associated with a 2% increase in the risk of in-hospital mortality (Chest 2018; doi.org/10.1016/j.chest.2018/03.025).

Researchers at the University of Chicago assessed whether initial lactate levels were drawn within the SEP-1-mandated timeframe—6 hours before to 3 hours after a patient presents with sepsis based on meeting two of four systemic inflammatory response criteria, experiencing at least one new organ dysfunction, and having documented suspected infection. The SEP-1 criteria, issued in 2015 by the Centers for Medicare and Medicaid Services, also call for repeat lactate measurements within 6 hours of presentation if the initial level is elevated.

Of nearly 150,000 admissions during the 8-year study period, 5,762 met all three SEP-1 criteria and were included in the final analysis. Patients treated in the emergency department (ED) were most likely to receive SEP-1-recommended lactate measurements (79%), compared with 55% in the intensive care unit (ICU) and 32% in care wards. Overall, 41% of lactate values across ED, ICU, and ward settings were ≤2.0 mmol/L and 78% were ≤4.0 mmol/L.

The mortality for patients who first met SEP-1 criteria while in the ED was 12% for those who had a baseline lactate value ≤2.0 mmol/L, 15% for values >2.0 mmol/L but ≤4.0 mmol/L, and 34% for values >4.0 mmol/L. In comparison, mortality rates at these initial lactate levels for patients in ICU and wards were 35%, 52%, and 62%, and 25%, 38%, and 55%, respectively.

Length of stay (LOS) and time to first dose of antibiotics lengthened with delayed lactate testing.

If all patients who met SEP-1 criteria had recommended lactate testing, there would be a “significant increase in lactate measurements, with uncertain consequences as to how providers would react to many additional normal lactate values,” the authors cautioned.

Fine-Tuning Glucose Challenge Testing Thresholds Might Obviate Some Oral Glucose Tolerance Testing for Gestational Diabetes Mellitus

Anonfasting 50g glucose challenge test (GCT) has “moderate diagnostic accuracy” in a universal two-step screening strategy for gestational diabetes mellitus (GDM) using criteria adopted in 2013 by the World Health Organization (WHO) (Diabetes Care 2018; doi.org/10.2337/dc18-0556). Belgian researchers conducted a prospective cohort study to assess the sensitivity and specificity of GCT among patients who also took a 75g oral glucose tolerance test (OGTT), which WHO endorsed in 2013 as a means of diagnosing GDM.

Although WHO and other organizations have endorsed a one-step 75g OGTT screening strategy, this practice remains controversial and has not been adopted worldwide. Some professional associations still recommend a two-step strategy, with 50g GCT followed by OGTT in patients with GCT results above a certain threshold.

In their study of 1,811 women tested with both GCT and OGTT between 24 and 28 weeks of pregnancy the authors assessed the sensitivity and specificity of GCT thresholds ranging from ≥120 mg/dL to ≥140 mg/dL.

Sensitivity for GCT rose from 59.6% with a ≥140 mg/dL threshold to 82.0% with a ≥120 mg/dL threshold. Specificity for GCT varied from 81.0% at a ≥140 mg/dL threshold to 56.0% at a ≥120 mg/dL threshold. Using a GCT with a ≥130 mg/dL threshold would enable 65.1% of all OGTTs to be avoided.

Low HCV Testing Prevalence for Infants Exposed in Utero

Just 30% of infants exposed in utero to hepatitis C virus (HCV) and who subsequently received well-child care at University of Pittsburg Medical Center (UPMC) facilities were screened as recommended for HCV (Pediatrics 2018;141:e20173273). The findings point to the need to evaluate and possibly implement universal HCV screening during pregnancy, particularly in areas with high HCV prevalence, according to the authors.

This retrospective study covering women who delivered at UPMC between 2006 and 2014 found that the HCV prevalence increased 60% during this period.

The researchers identified babies who received well-child services at UPMC as those for whom hemoglobin and/or lead testing had been conducted at or after age 9 months. Of 87,924 women who gave birth, 1,043 had documented HCV infection. Nearly one-third (32%) of the babies born to these patients received well-child care at UPMC, and of these, just 30% received any form of HCV testing.

Most infants had HCV antibody tests (74%), while 23% had polymerase chain reaction (PCR) testing for HCV RNA, and 3% had both HCV antibody and PCR tests. Of all the children screened, 76% had optimal testing, defined as HCV RNA testing in children younger than 18 months, an HCV antibody test in those older than 18 months, or simultaneous HCV RNA and HCV antibody testing.

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