Shock index thresholds to predict adverse outcomes in maternal hemorrhage and sepsis : a prospective cohort study
Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
Introduction: Shock index (SI) is a predictor of hemodynamic compromise in obstetric
patients. The SI threshold for action is not well understood. We aimed to evaluate SI
thresholds as predictors of outcomes in obstetric patients.
Material and methods: We undertook a prospective cohort study at three South
African hospitals of women with postpartum hemorrhage (n = 283) or maternal sepsis
(n = 126). The “first” and “worst” SI following diagnosis were recorded. SI was
compared with conventional vital signs as predictors of outcomes. The performance
of SI <.9, SI .9‐1.69 and SI ≥1.7 to predict outcomes (maternal death; Critical Care Unit
admission; major procedure; hysterectomy) and hemorrhage‐specific outcomes (lowest
hemoglobin <70 g/l; blood transfusion ≥4 IU) were evaluated.
Results: “First” SI was one of two best performing vital signs for every outcome in
postpartum hemorrhage and sepsis. In hemorrhage, risk of all outcomes increased with
increasing “first” SI; for blood transfusion ≥4 IU odds ratio was 4.24 (95% confidence interval
1.25‐14.36) for SI ≥1.7 vs SI .9‐1.69. In sepsis, risk of all outcomes increased with
increasing “worst” SI. Sensitivity, specificity, positive and negative predictive values of
“first” SI <.9 vs SI ≥.9 for maternal death were 100.0%, 55.2%, 4.6% and 100.0%, respectively,
in hemorrhage and 80.0%, 50.4%, 12.3% and 96.7%, respectively, in sepsis.
Conclusions: The shock index was a consistent predictor of outcomes compared
with conventional vital signs in postpartum hemorrhage and sepsis. SI <.9 performed
well as a rule‐out test and SI .9‐1.69 and SI ≥1.7 indicated increased risk of all outcomes
in both cohorts. These thresholds may alert to the need for urgent intervention
and prevent maternal deaths.
Description
CITATION: Nathan, Hannah L., et al. 2019. Shock index thresholds to predict adverse outcomes in maternal hemorrhage and sepsis : a prospective cohort study. Acta Obstetricia et Gynecologica Scandinavica, 98(9):1178-1186, doi:10.1111/aogs.13626.
The original publication is available at https://obgyn.onlinelibrary.wiley.com
The original publication is available at https://obgyn.onlinelibrary.wiley.com
Keywords
Blood pressure, Heart rate, Postpartum hemorrhage, Sepsis, Vital signs
Citation
Nathan, Hannah L., et al. 2019. Shock index thresholds to predict adverse outcomes in maternal hemorrhage and sepsis : a prospective cohort study. Acta Obstetricia et Gynecologica Scandinavica, 98(9):1178-1186, doi:10.1111/aogs.13626