Using lactate testing to improve maternal sepsis identification: a multi-country test accuracy study: LACTate in mATernal sEpsis
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Date
2022-03-16
Authors
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Journal ISSN
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Publisher
Kamuzu University of Health Sciences
Abstract
Type of study
This is a prospective, multi-site, phase III test accuracy study.
Problem
Maternal infections left untreated may lead to sepsis and consequently death. Maternal sepsis can
develop in pregnant women and women who have recently experienced pregnancy and is defined as
a life-threatening condition with organ dysfunction resulting from infection during pregnancy,
childbirth, post-abortion, or the post-partum period”(1) . Multiple studies have tested the accuracy
of blood lactate for the early identification of people likely to experience worsening sepsis in high
income adult populations. The evidence suggests that lactate levels are informative, and a tiered
recommendation was made of different actions based on the lactate measurement. A raised lactate
level (>2 mmol/L) can be used as a triage tool to prompt initiation of urgent treatment and the
patients can be identified as more severe (lactate level of >4 mmol/L) prompting more intensive
treatment and monitoring. The need for high quality evidence of diagnostic accuracy for this test has
been highlighted as a research priority. Currently there is no high-quality test accuracy study of
lactate testing for maternal sepsis. After multiple systematic reviews we concluded there is no
reliable evidence of test accuracy in the pregnant population. There is need to investigate if a lactate
measurement has incremental benefit over conventional maternal vital sign assessment in the
diagnosis of sepsis and identification of women at risk of severe morbidity or mortality in low
resource settings. This study can help determine the diagnostic and prognostic accuracy of venous
lactate measurement in the maternity populations, in low resource settings, which is unknown.
Broad objective
The broad objective purpose of the Lactate test accuracy study is to determine the diagnostic
accuracy of maternal venous lactate measurement in addition to maternal vital sign thresholds, in
maternal sepsis in low-resource health facility settings in Malawi, Uganda and Pakistan.
Specific objectives
The specific objectives are to assess the immediate diagnostic value of lactate testing by comparing
the baseline index test with baseline reference standard; to assess short-term predictive value of
lactate testing, by comparing the baseline index test with 24-hour reference standard, in those
without sepsis at baseline; to explore if baseline venous lactate, in addition to vital sign
measurements, improves prediction of severe morbidity and mortality from infection; to explore if
the test accuracy of lactate in addition to maternal vital sign monitoring alone varies by the prespecified
subgroups of pregnancy status (pregnant or post-delivery / post miscarriage / postabortion)
and recruitment country; to explore and examine the effects of adjusting the threshold
values for both vital sign and lactate assessment on the sensitivity and specificity of the index tests;
and finally to explore and validate the use of an alternative reference standard in which the SOFA
score is modified to use maternity specific ranges for creatinine and platelet concentration.
Methods
The study will be conducted in the maternity wards at Queen Elizabeth Central Hospital in Blantyre,
Malawi. Women will be recruited to have an additional blood sample taken at two time points
during admission; at day 0 and day one for lactate testing. There will be no additional clinical
procedures or interventions conducted with eligible women by members of the study team or by
hospital staff for other reasons than those of their usual clinical practice. We will estimate
diagnostic accuracy to detect sepsis as defined by comparison with the reference standard diagnosis
of sepsis, at baseline and at 24 hours. We will compare (a) baseline index test with baseline
reference standard to determine immediate diagnostic value, (b) baseline index test with 24-hour
reference standard in those without sepsis at baseline to determine short-term predictive value and
(c) baseline index test with occurrence of infection related “severe maternal outcome” (near miss or
maternal mortality) prior to hospital discharge to determine predictive value for severe morbidity or
mortality
Expected findings
If lactate testing in this population is found to offer incremental benefit over the standard sepsis
triggering approach, and is feasible to implement in an integrated approach, then this has the
potential to improve maternal sepsis outcomes.
Dissemination
The study report will be submitted to College of Medicine Research and Ethics committee
(COMREC). Research findings will be disseminated via download on relevant websites and will also
be shared with both local (QECH, Blantyre DHO, community gatekeepers and participants) and global
stakeholders through research dissemination conferences, peer reviewed publications and via
participant and public information groups, national and international forums and conferences and.
Data will be retained and be supported to produce additional secondary outputs as appropriate.
Description
Keywords
Lactate testing for maternal sepsis diagnosis