Maternal Early Warning System and Severe Hypertension Safety Bundle: A Quality Improvement Initiative
Hypertensive disorders of pregnancy are a leading cause of pregnancy-related morbidity and mortality. Timely treatment of a hypertensive emergency has the potential to reduce preeclampsia-related morbidity and mortality. The American College of Obstetricians and Gynecologists (ACOG) defines acute-onset severe hypertension (SHTN) (i.e., hypertensive emergency) as systolic blood pressure of 160mmHg or more, and/or diastolic blood pressure of 110mmHg or more, that is confirmed as persistent (15min or more), and recommends that antihypertensive agents be administered within 30–60 min of persistent SHTN. Recent reports, however, demonstrate a quality gap between the recommended expeditious treatment of SHTN and the actual performance. Maternal early warning systems (MEWS) have been proposed to facilitate timely recognition, diagnosis and treatment for women developing critical illness and may be a pathway to ensuring timely treatment of a hypertensive emergency.
The Alliance for Innovation on Maternal Health (AIM) has a patient safety bundle for SHTN in pregnancy in an effort to reduce its associated morbidity and mortality. The readiness and recognition domains include having standards for early warning signs as well as a standard response to them. In 2021, Texas DSHS launched a statewide initiative to implement an adapted version of the AIM SHTN patient safety bundle (Texas AIM) and invited all Texas birthing hospitals to participate. Texas AIM's adaptation incorporated disparity-focused structure, process and outcome measures, given the known disparities in hypertension associated maternal mortality and morbidity in Texas, with NH Black women having the highest rates. The primary process measure for bundle implementation was the rate of timely treatment of a hypertensive emergency. Since much of the morbidity and mortality associated with hypertensive disorders of pregnancies is related to SHTN, authors’ project sought to evaluate the impact of our MEWS combined with the implementation of the SHTN patient safety bundle on the Texas AIM process metric of timely treatment of a hypertensive emergency in pregnancy and any associated racial and ethnic disparities. The focus on racial and ethnic disparities aligned with the 2022 Texas MMMRC's recommendation for implementation of statewide maternal health and safety initiatives with incorporation of health equity principles to reduce maternal mortality, morbidity and health disparities.
A retrospective chart review of all hospital deliveries with a hypertensive emergency was conducted from 1 January 2017 through 31 December 2024. During the study period, the hospital implemented a maternal early warning system (MEWS) and a patient safety bundle for severe hypertension (SHTN) in pregnancy. All deliveries ≥ 20 0/7 weeks were included.
There was a statistically significant improvement in the rate of timely treatment of SHTN with implementation of MEWS (69.5% at baseline/phase 1 vs. 79.9% with MEWS/phase 2, p<0.001, 15% improvement) and then again with implementation of the SHTN bundle/phase 3 (88.8% in phase 3, 11% improvement compared to phase 2 and 27.8% improvement compared to phase 1, p <0.001). Changes over time within each racial and ethnic group indicated that the rate of timely treatment of a hypertensive emergency increased significantly for NH-Black, NH-White and Hispanic patients from phase 1 to phase 2 and for all groups from phase 1 to phase 3. The disparity in treatment fallouts and timely treatment was eliminated with MEWS modifications and the patient safety bundle in the final phase.
This study demonstrated an association between the implementation of a MEWS and SHTN patient safety bundle and an improved rate of timely treatment of a hypertensive emergency during pregnancy and postpartum. Over the course of implementation, authors observed a 15% improvement in the rate of timely treatment from the implementation of MEWS alone and an additional 11.2% improvement with the implementation of a SHTN bundle as compared to MEWS alone, which represented a 27.8% improvement in rate of timely treatment as compared to the baseline period. The study also demonstrated an association between a robust MEWS process with the elimination of racial and ethnic disparities in the rate of treatment fallouts for a hypertensive emergency. Additionally, this study illustrates the significant differences in timely treatment rates based on whether or not spontaneous resolution of a SHTN episode is considered timely treatment.
This study suggests that the use of a MEWS combined with implementation of the AIM SHTN patient safety bundle improves early recognition and response to an obstetric hypertensive emergency and reduces racial and ethnic disparities. This may lead to a reduction in preventable morbidity and mortality from hypertensive disorders of pregnancy. These findings also suggest that the adoption of the SMFM quality metric definition for timely treatment of SHTN, which considers spontaneous resolution of SHTN as timely treatment and captures patients with hypertensive emergencies who have intervening non-SHTN, will more appropriately identify patients who would benefit from acute-acting anti-hypertensive medication.
