///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Delays in Administration of Antihypertensive Medication on Labor and Delivery for Severe Range Blood Pressures at a Tertiary Care Center

Abstract Number: T1H-468
Abstract Type: Original Research

Sara M. Seifert MD1 ; Rochelle J Molitor MD2; Erica Holland MD3; Brian T Bateman MD4; Julian N Robinson MD5; Michaela K Farber MD6

Introduction

Severe-range blood pressure (SRBP) in pregnancy (> 160/110 mmHg) can lead to significant maternal/fetal morbidity and mortality such as intracranial hemorrhage, cerebral and pulmonary edema, placental abruption, acute renal failure, liver rupture, seizures, and death (1-3). The National Partnership for Maternal Safety Severe Hypertension in Pregnancy bundle of 2016 recommends treatment of sustained SRBP within 15 minutes (4). We sought to quantify the frequency of delays in administration of antihypertensives for SRBP.

Methods

In this retrospective cohort study, we examined all patients with SRBP admitted to Labor and Delivery at a single large tertiary care center between 11/1/2018 and 1/31/2019. Patients were included if they received a rapid acting antihypertensive medication and had SRBP, defined as ≥ 160 mmHg systolic or 110 mmHg diastolic, for ≥ 15 minutes. Patients were excluded if they received nifedipine for preterm labor or were treated at other sites (e.g., intensive care unit or operating room). We report clinical characteristics and outcome variables using descriptive statistics and linear regression.

Results

A total of 71 patients had sustained SRBP and received 102 rapid acting antihypertensive medication doses. Patients were aged 21-48 and self-reported as 35.2% White, 30.0% Black, 5.6% Asian, and 21.1% Hispanic. Initial blood pressures ranged from 160-200 mmHg systolic and 77-116 mmHg diastolic (median 167/98 mmHg). The median time that patients’ blood pressure remained ≥ 160/110 was 77 minutes (range 18-450 minutes). The median time to receive an antihypertensive from first SRBP was 45.5 minutes (range of 0-232 minutes); only 9.9% of patients were given treatment within the recommended 15 minutes. There was no correlation in the severity of the initial blood pressure and the time to receive treatment (R2 = 0.0016). The most commonly used first line agent was labetalol (46.1%), followed by hydralazine (35.5%), and nifedipine IR (18.4%). Of the 102 antihypertensive medications administered, labetalol was up-titrated 14 times (max dose 60mg), hydralazine was up-titrated 11 times (max dose 20mg), nifedipine IR was up-titrated 0 times (max dose 10mg), and median time to up-titration was 40 minutes (range 15-100 minutes). Of the 25 times medication was up-titrated, a second rapid acting medication was added in 4 cases.

Conclusion

Most patients did not receive antihypertensive therapy within the recommended 15 minutes following recognition of SRBP or recommended up-titration, despite written protocols promoting this practice. Patients commonly had SRBPs for extended periods. Systems need to be developed to facilitate timely treatment of patients with SRBPs and for more rapid up-titration if initial treatments do not bring BP within a safe range.

References

1. J Obstet Gynaecol Can. 2014;36(7):575-576.

2. Obstet Gynecol. 2015;125(1):124-131.

3. Lancet.2010;376(741):631-644.

4. Anesth Analg. 2017; 125(2): 540-547.

SOAP 2019