SIPHRE

Shock Index in Pregnancy: Haemorrhage and sepsis Risk Evaluation. Shock index as a predictor of adverse outcome in maternal haemorrhage and sepsis.

THE PROBLEM TO ADDRESS

Bleeding and infection cause over half of maternal deaths worldwide. Most of these are preventable with simple interventions. But the majority of these deaths happen in lower-income settings where monitoring equipment is limited, and signs of deterioration are not detected in time to prevent the development of serious, life-threatening complications.

Our team found that shock index (SI), calculated by dividing heart rate into systolic blood pressure, is an early predictor of poor outcome in pregnant women.

We studied a group of women in South Africa with postpartum haemorrhage and sepsis and there were no maternal deaths, emergency hysterectomies or major surgical interventions in the group with SI <0.9 (green). SI 0.9 to 1.69 (amber) and SI ≥1.7 (red) indicated increased risk of all adverse outcomes with a four-fold greater risk of requiring blood transfusion ≥4IU in the red versus amber group (OR 4.2, 95% CI 1.3 to 14.4).

These SI thresholds have been incorporated into the CRADLE Vital Signs Alert device algorithm, and correspond to the green, amber and red traffic lights, with a downward-pointing arrow.

THE PROJECT

SIPHRE study prospectively evaluated whether these established SI thresholds maintain their predictive ability in pregnant and postpartum women with signs of sepsis or bleeding admitted to Princess Christian Maternity Hospital (PCMH) in Freetown, Sierra Leone.

Our main study objectives were to:

• Validate SI as a predictor of adverse outcome following obstetric haemorrhage or sepsis in PCMH.
• Evaluate the feasibility of implementation of the CRADLE VSA to reduce rates of maternal haemorrhage and sepsis through measurement of SI.
• Collect data that could inform a future prospective trial into the effects on adverse outcomes of incorporating SI into early warning scores used to assess women with sepsis and obstetric haemorrhage.