Management of Hypertension on the Labor and Delivery Unit: Delivering Care in the Era of Protocols and Algorithms


Lauren O’Brien, MD; Jennifer Duong, MPH; Tessa Winterton, MD;
Anna Haring, MD; Zachary Kuhlmann, DO

Perm J 2018;22:17-170 [Full Citation]
E-pub: 09/13/2018


Introduction: Preeclampsia with severe hypertension, which occurs in 5% to 8% of pregnancies, is a leading cause of maternal and perinatal morbidity and mortality in the US. Early recognition and treatment of hypertensive crises can significantly reduce poor outcomes. A protocol to ensure prompt treatment with antihypertensive medication (intravenous labetalol) was implemented at our institution.
Objective: To determine adherence to this protocol on the Labor and Delivery Unit.
Design: Retrospective chart review was performed for patients admitted to the Labor and Delivery Unit between April 2015 and June 2015. Charts were reviewed if the patient had a diagnosis of chronic hypertension, gestational hypertension, superimposed preeclampsia, preeclampsia with severe features, eclampsia, or stroke in pregnancy. Only patients with confirmed severe blood pressures, in which the protocol would be initiated, were included in the final analysis.
Main Outcome Measure: Overall compliance with the entire protocol.
Results: Of 178 cases reviewed, 58 (32.6%) had confirmed severe blood pressures. Most patients (n = 46, 79.3%) received a diagnosis of preeclampsia with severe features, and most delivered via cesarean delivery (n = 38, 65.5%). No cases were compliant with the entire labetalol protocol. Of 58 patients, 2 (3.5) adequately repeated a confirmation blood pressure within 5 minutes, and 34 (58.6%) were adequately treated with intravenous labetalol according to protocol requirements.
Conclusion: Labetalol treatment was appropriately initiated in many cases; however, protocol adherence could greatly improve. Potential factors affecting protocol compliance include shift changes, communication issues, and conflicting protocols. Institutions should review protocol compliance to improve care.


Care of the pregnant woman in her third trimester can be met with unexpected and challenging complications. This is especially true of hypertensive disorders, which account for 17% of maternal mortality in the US.1 The American College of Obstetricians and Gynecologists (ACOG)2 defines preeclampsia as hypertension with new-onset proteinuria occurring in the second and third trimesters of pregnancy (after 20 weeks). Approximately 5% to 8% of pregnancies are affected by preeclampsia with severe hypertension.3 Of more concern, approximately 50,000 to 60,000 deaths worldwide were preeclampsia related, and the US saw a 25% rise in diagnoses during the past 2 decades.2 Later in life, women who had preeclampsia have a 4-fold increased risk of heart failure and an increased risk of cardiovascular disease.4 As research continues to better understand the exact mechanism underlying the disease, efforts to decrease the morbidity and mortality have been instituted in the US and globally. According to ACOG,5 the focus of decreasing hypertensive crises at initial presentation has been shown to significantly improve morbidity and mortality for both the mother and the neonate.

The ability to respond with appropriate treatment, and in a timely manner, is critical to reducing morbidity and mortality associated with hypertensive disorders.6 Severe hypertension in pregnancy is characterized by a systolic blood pressure greater than or equal to 160 mmHg or a diastolic blood pressure greater than or equal to 110 mmHg, or both.5 Hypertension is manifested in association with multiple clinical syndromes such as chronic hypertension; preeclampsia; eclampsia; gestational hypertension; HELLP (hemolysis, elevated liver enzyme levels, low platelet count) syndrome; chronic hypertension with superimposed preeclampsia or eclampsia; and stroke in pregnancy. First-line treatment for immediate control of blood pressure includes intravenous (IV) administration of labetalol, IV hydralazine, or oral nifedipine.5 

In South Africa, Moodley and Ngene7 recommend that in cases of severe hypertension, health care professionals must be aware of the “5 Rs: Recognition, Responding, Responsibility, Reviewing, and Realising.” The authors describe how clinical protocols and checklists have been implemented to standardize care and management of hypertensive crises.7 Many institutions have implemented clinical protocols to reduce maternal and perinatal morbidity and mortality as a result of hypertensive disorders. A study by Menzies et al8 found the incidence of adverse maternal outcome decreased from 5.1% to 0.7% after the implementation of a standardized assessment tool for evaluating preeclampsia. Similarly, in 2010 von Dadelszen et al9 detailed how maternity hospitals in British Columbia actively implemented standardized guidelines for treatment of hypertensive disorders of pregnancy, which resulted in a decline in adverse maternal outcomes (3.1%-1.9%).

Previously, treatment of hypertensive crises was highly dependent on each individual clinician’s clinical practice. In 2011, our institution, in concordance with recommendations from ACOG Committee Opinion No. 623 (Box 3),5 established its own antihypertensive protocol for prompt treatment of hypertension. This protocol established guidance for treatment of hypertension: Timely, periodic evaluation of blood pressures, followed by administration of IV labetalol to treat persistent severe hypertension or IV hydralazine if labetalol treatment was inadequate.

Monitoring adherence to evidence-based guidelines and recommendations is imperative; numerous studies have demonstrated that treatment of hypertensive emergencies have reduced the incidence of adverse maternal and fetal outcomes. Since the implementation of the protocol, no formal assessment had been conducted to assess compliance at our institution. We conducted this study to assess compliance with the protocol at our institution during a 3-month period.


This descriptive study is a retrospective review of patients admitted to the Labor and Delivery Unit at a Midwestern teaching hospital. A local institutional review board reviewed this project and deemed this study as quality improvement.

To minimize confounding variables related to new resident physicians entering the institution, we included only patients admitted during April 2015 to June 2015. Patients were included if they had a clinical diagnosis of severe hypertension and the electronic medical record documented any of the following: Preeclampsia, chronic hypertension, chronic hypertension with superimposed preeclampsia, gestational hypertension, eclampsia, and stroke in pregnancy. At our institution, blood pressures in the severe range were defined as systolic blood pressure greater than or equal to 160 mmHg and/or diastolic blood pressure greater than or equal to 105 mmHg. Blood pressures were taken with the patient in the “dangling position” (defined as the patient sitting on the edge of the bed with her feet dangling from the bed). Patients with documented contraindications to labetalol were excluded.

Maternal data were collected from the electronic medical record. Variables included gestational age at initial presentation and timing of the first severely elevated blood pressure and the repeated blood pressure assessment, whether nursing staff contacted the resident physician to notify the start of the protocol, whether IV labetalol was administered, timeliness of blood pressure reassessments, and administration of additional antihypertensive agents.

Three different resident physicians served as auditors to manually review the cases, with each step of the protocol evaluated as a binary outcome in terms of compliance with the labetalol protocol (Figure 1). If at any point the case deviated from the hypertensive treatment protocol, the auditor indicated where in the protocol the case was found to be noncompliant. The primary outcome of this study was overall compliance, which was defined as the number of cases that were compliant with the entire labetalol protocol from the first severe blood pressure assessment. Additional outcomes of interest included frequent points where deviations from the labetalol protocol occurred and whether treatment was provided.

Data were managed using Microsoft Excel (Microsoft Corp, Redmond, WA). All statistical analyses were conducted using SPSS Statistics for Windows, Version 23.0 (IBM Corp, Armonk, NY). Descriptive statistics were presented as frequencies and proportions for categorical variables.


A total of 178 patients presented to the Labor and Delivery Unit during the specified time frame. A total of 120 cases were excluded from the analysis for the following reasons: No severe hypertension was documented or the case did not meet diagnostic criteria for severe hypertension (82.5%, n = 99), no diagnosis of preeclampsia with severe features was made by symptoms or laboratory test results (8.3%, n = 10), the diagnosis of severe hypertension was made postpartum (4.2%, n = 5), or the case had a single documented severe blood pressure followed by normal or mild blood pressures for the remaining evaluation (5%, n = 6). Of the 178 cases reviewed, 58 (32.6%) had 2 confirmed severe blood pressures at initial evaluation and were included in the final analysis (N = 58).

Patients’ clinical characteristics are presented in Table 1. Most patients were at 34 weeks to 38 weeks of gestation at the time of admission (range = 26 weeks to 41 weeks). The mode of delivery was predominantly cesarean, with 38 of the 58 cases (65.5%) undergoing either a primary or repeated cesarean delivery. Preeclampsia with severe features was diagnosed in 43 patients (74.1%).

Compliance with repeating blood pressure assessment within 5 minutes after the first documented severe blood pressure is illustrated in Figure 2. Blood pressures were confirmed with the patient in the dangling position approximately 53.4% of the time (n = 31). Appropriate repeated blood pressure assessment after the initial severe blood pressure was completed in 2 cases (3.4%). In 5 cases (8.6%), the blood pressure assessment was repeated less than 5 minutes after the first documented severe blood pressure. More than half of cases (56.9%, 33 of 58) had the repeated blood pressure assessment taken more than 10 minutes after the first initial severe blood pressure. Mean duration of time (standard deviation) between the initial severe blood pressure and repeated blood pressure was 19.2 (20.9) minutes, with a range of 1 to 94 minutes.

Of the 58 patients with severe blood pressures, 57 (98.3%) had severe blood pressures that qualified them for IV labetalol treatment. There was 1 case in which blood pressures normalized after magnesium sulfate was instituted, therefore not requiring IV antihypertensive medications. Magnesium sulfate for seizure prophylaxis was instituted in 53 (91.4%) of the cases.

Of the 57 patients who required labetalol treatment, 34 (59.6%) of the cases were treated adequately with IV labetalol. Labetalol was not administered or no documentation was found in 21 (36.8%) of cases. In 2 cases (3.5%), the IV labetalol dosage was documented incorrectly or the improper dose was administered.

Both patients with compliant blood pressure assessment (reassessment within 5 minutes after the first documented severe blood pressure) received labetalol treatment. Neither had a follow-up blood pressure assessment 10 minutes after treatment documented. One case had all other blood pressure assessments taken with various timing of assessment not compliant with the institutional protocol. The other case had no follow-up blood pressure assessments documented.

No cases were compliant with the entire labetalol protocol. Table 2 shows compliance with major initial steps of the protocol. Figure 3 illustrates drop-off with protocol compliance after blood pressure assessment.

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Our study demonstrates that among cases in which hypertensive crises should be treated with initiation of the labetalol protocol, compliance at our institution is inadequate. Only 3.4% of cases had documented severe blood pressures in the time frame allowable by the protocol, signifying that our institution is failing to recognize acute onset of severe hypertension in a timely manner. The implementation of standardized assessments, protocols, and checklists has demonstrated a reduction in adverse hypertensive events7-9; however, our study results reveal that barriers exist at our institution that may result in a delay of care, or that the protocol should be reassessed for implementation feasibility. Although clinical guidelines and recommendations are meant to systematically reduce practice variation, our study findings clearly demonstrate obstacles our institution faces when putting evidence into practice, specifically with adherence to complex protocols.

Disregarding critical evaluation at each step of the protocol, our study demonstrates that most cases requiring treatment with IV antihypertensive agents received IV labetalol. Most cases deviated from the protocol beginning with the follow-up blood pressure assessment; what Moodley and Ngene7 would consider as “Recognition.” There are some possible explanations for low compliance with blood pressure assessments. First, when preeclampsia with severe features is diagnosed, the standard of care is to start magnesium sulfate for seizure prophylaxis to prevent the progression to eclampsia.2 At our institution, the IV labetalol protocol and the magnesium sulfate treatment protocol have conflicting timing requirements for blood pressure reassessment. Second, depending on the gestational age, the recommendation may be to proceed with delivery, which requires an induction or cesarean delivery. Each procedure has its own established guidelines for blood pressure assessment. Anesthesia protocol requires additional blood pressure measurements to be taken every 5 minutes during the administration of an epidural or spinal anesthetic. Depending on which protocol is being used, variance in blood pressure assessments makes compliance with the labetalol protocol difficult to obtain.

Our study findings revealed that despite ACOG recommendations, duration between the initial severe blood pressure and the follow-up assessment ranged from 1 minute to 94 minutes, which causes some concern. Multiple protocols with conflicting blood pressure assessment requirements may be a reason for noncompliance. It is imperative that checklists and protocols are reviewed to ensure protocol requirements do not conflict with one another and that protocols facilitate close monitoring of patient status to allow for early treatment of hypertensive crises.

Potential factors affecting protocol compliance at our institution include shift changes, multiple handoffs, and communication issues. Communication failures, specifically lack of communication regarding treatment timeline and which protocol the nurse was following to recheck blood pressures, may have occurred. Proper documentation and assessment are essential to curb mistakes that can arise from shift changes and communication failures. Moroz et al6 suggest that an episode of severe hypertension or a change in disease status warrants documentation of blood pressure at least every 30 minutes until the patient’s blood pressure has been stabilized.

Limitations of this study include a small population, but this can be easily corrected by expanding on the number of charts included in the review. We found early, in a small set of patients, a key failure in care in our treatment protocol. Our results are also limited by potential selection bias, because less than one-third of the initially included patients had confirmed severe blood pressures at the time of evaluation. Misclassification bias may have also resulted from the use of multiple auditors. Furthermore, the study is limited by its retrospective design and reliance on the electronic medical record, which may have been incomplete.

The labetalol protocol, although adapted from ACOG recommendations, may not be consistent across all hospitals; thus, our study describes the experience of one facility. Although the results of this study may be limited to our institution, our study gives insight to problems that may occur as a result of implementing new clinical protocols, especially when competing protocols are not taken into consideration. The results of our project suggest that when an institution adopts a protocol to address hypertensive crises, potentially competing protocols should be reviewed to assess any conflicting clinical procedures. Although some institutions have described success with implementation of hypertension guidelines,8,9 it is also important to highlight struggles with implementation. We suggest that institutions consider reviewing their compliance with hypertensive protocols and whether there are conflicts or problems with implementation. Other clinical protocols related to magnesium sulfate treatment, labor, and cesarean delivery should be reviewed and revised to decrease potential confusion among staff. Many protocols are managed using computerized physician order entry systems, which have allowed clinicians to properly treat patients in a systematic manner. However, competing order sets in computerized physician order entry systems, especially for patients with complex conditions, will default to clinician decision making, which is often not standardized. Clinicians should consider whether their institutional protocol allows them to recognize and respond7 to hypertensive crises.

Future directions can include implementing a systemwide education and training system to reintroduce the current protocols for management of hypertensive crises. Additionally, it may be beneficial for institutions to incorporate nursing staff into development of protocols because they may have insight about treatment procedures. Interventions should include multidisciplinary teams composed of labor and delivery nurses, postpartum nurses, anesthesia staff, attending and resident physicians, pharmacists, and information technology specialists. A systematic review of all protocols, especially reviewing order sets in computerized physician order entry systems, may expose conflicts in treatment. Meetings with hospital representatives, such as an institutional implementation officer, should be held to address a system-based change to care protocols and to explore improved implementation processes.


Research continues to investigate the pathophysiology of preeclampsia, but health care facilities should focus on implementing methods to decreasing the morbidity and mortality associated with the disease. In addition to instituting protocols, such as the one established at our institution, regular assessment of implementation feasibility will ensure that protocols allow patients to be treated adequately. Although most patients requiring IV antihypertensive medications did receive proper administration of labetalol in our study, adherence to the protocol could be much improved.

Disclosure Statement

The author(s) have no conflicts of interest to disclose.


Kathleen Louden, ELS, of Louden Health Communications provided editorial assistance.

Author Contributions

Lauren O’Brien, MD, contributed to the study design, data collection, and manuscript preparation. Jennifer Duong, MPH, contributed to study design, data analysis, and manuscript preparation. Tessa Winterton, MD, contributed to data collection and manuscript preparation. Anna Haring, MD, contributed to data collection and manuscript preparation. Zachary Kuhlmann, DO, contributed to study design, data collection, and manuscript preparation.

How to Cite this Article

O’Brien L, Duong J, Winterton T, Haring A, Kuhlmann Z. Management of hypertension on the labor and delivery unit: Delivering care in the era of protocols and algorithms. Perm J 2018;22:17-170. DOI:

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