The Consensus Bundle on Hypertension in Pregnancy and the Anesthesiologist: Doing All the Right Things for All the Patients All of the Time

Hypertensive disorders of pregnancy and their associated complications are a major source of maternal morbidity and mortality in contemporary obstetrical practice in the United States, accounting for a substantial fraction of pregnancy-related intensive care unit admissions, cardiac arrests, and deaths.1–4 The prevalence of these disorders in pregnancy are increasing, potentially driven by rising rates of obesity and increasing numbers of patients of advanced maternal age.1 It is thus timely that the National Partnership for Maternal Safety (NPMS) is publishing the obstetric bundle on severe hypertension in this month’s Anesthesia & Analgesia. The NPMS is a multidisciplinary interprofessional collaboration between 19 core organizations, including the American Society of Anesthesiologists and the Society for Obstetric Anesthesia and Perinatology. The partnership strives to generate a culture of change by creating and disseminating patient safety bundles that promote development of protocols and practices that should be implemented in all hospitals that provide obstetric care. The NPMS has identified 3 major contributors to maternal morbidity and mortality amenable to interventions that can improve outcome: hemorrhage, pulmonary embolism, and severe hypertension. Bundles focused on hemorrhage were published in 20155 and venous thromboembolism in 2016.6 The goal of the safety bundles is to facilitate doing “all the right things for all the patients all the time.” Recognizing the diverse characteristics of hospitals performing deliveries in the United States, the goal is to lay out a set of guidelines to be adapted to local circumstances and create systems so that any hospital can optimally manage a condition. The bundle is organized in 4 action domains: readiness, recognition, response, and reporting and system learning. Each action domain describes key practices that should be put in place on labor and delivery units. Implementation of the bundle on labor and delivery units will require multidisciplinary and intraprofessional collaboration between anesthesiologists, obstetricians, midwives, and nurses. As such, the bundle is being simultaneously published in Obstetrics and Gynecology, Journal of Midwifery and Women’s Health, and Journal of Obstetric, Gynecologic and Neonatal Nursing, in addition to Anesthesia & Analgesia. KEY CONSIDERATIONS FOR THE ANESTHESIOLOGIST Publication of this bundle will prompt labor and delivery units across the country to develop new guidelines and protocols for the treatment of severe hypertension. As these are developed and implemented, anesthesiologists should take advantage of the opportunity to engage with or even lead this process. There are 6 areas that will be particularly important for anesthesiologists to be attentive to as labor and delivery unit protocols are developed. 1. Management of hypertensive emergency: Systolic blood pressure of ≥160 mm Hg or a diastolic blood pressure of ≥110 mm Hg in pregnant or postpartum women accurately measured and persistent over 15 minutes is a hypertensive emergency and requires prompt treatment (within 30–60 minutes). This threshold is based largely on data suggesting that risk for hemorrhagic stroke increases when blood pressures exceed these values.7 The bundle recommends intravenous labetalol or hydralazine as first-line medications, with oral nifedipine as an alternative if the patient does not have intravenous access or has contraindications to the other first-line agents. If elevations in blood pressure are refractory to first-line agents, then anesthesiologists or intensivists may be consulted to evaluate the patient for treatment with a second-line agent administered by infusion, such as nicardipine, esmolol, or nitroprusside, potentially with invasive arterial blood pressure monitoring.8 Prolonged use of nitroprusside should be avoided due to the potential risk of cyanide and thiocyanate toxicity. In general, nitroglycerine infusions should also be avoided around the time of delivery due to the drug’s effect on uterine tone and risk for postpartum hemorrhage. 2. Management of eclamptic seizures: Anesthesiologists have an important role in management of eclamptic seizure given their expertise in airway and crisis management. Unit protocols for responding to eclamptic seizures should include calling an anesthesiologist to the patient’s bedside where they can immediately attend to the patient’s airway, breathing, and circulation. The bundle appropriately identifies magnesium as the first line of treatment for eclamptic seizures (recommending a 4–6 g bolus of magnesium sulfate), followed by a magnesium infusion. While magnesium is rarely harmful at these doses, it may not be sufficient; optimal management depends on a timely and accurate diagnosis. Not all seizures on the labor and delivery unit are due to eclampsia, and seizure is not the only serious complication of preeclampsia. If a patient’s seizure activity is refractory to repeat doses of magnesium, or if she demonstrates focal neurologic deficits or her confusion extends beyond the postictal period, the differential diagnosis should be broadened to consider other etiologies (Box). Emergency computerized tomography or magnetic resonance imaging in a postictal or confused patient will require anesthesia services to ensure that she holds still, to protect her airway, and to monitor for further decompensation.Box.: Differential Diagnosis of Peripartum Seizure 3. Promotion of the use of regional anesthesia: Protocols should encourage the use of regional anesthesia for hypertensive patients whenever possible because preeclampsia increases the risks of general anesthesia. In particular, airway edema may exacerbate difficult intubation, and an exaggerated hypertensive response to laryngoscopy may lead to hemorrhagic stroke.9,10 Nevertheless, coagulopathy must be excluded to ensure safe neuraxial blockade. Units need processes in place to obtain frequent platelet counts for preeclamptic patients, particularly for those with severe features, so that a count is available at a time point proximate to the placement of the neuraxial block. Systems to obtain point-of-care viscoelastic monitoring or rapid coagulation studies, or both, are also needed to facilitate optimal decision-making and clinical care for the rare patient with severe thrombocytopenia or suspected abruption. Absent coagulopathy, spinal anesthesia is generally safe for this population,11 despite historical concerns about hemodynamic change and fetal perfusion. 4. Safe administration of general anesthesia when necessary: If general anesthesia is required either to facilitate emergent delivery or due to coagulopathy, maternal blood pressure should be stabilized prior to the anesthetic induction. The target systolic blood pressure should be between 140 and 160 mm Hg, recognizing that normotension or hypotension may impair placental or maternal cerebral perfusion. Preparations should be made for a potential difficult airway (eg, summoning additional providers, using videolaryngoscopes). A medication should be administered to blunt the hypertensive response to laryngoscopy; a variety of drugs have been demonstrated to be effective in this setting including remifentanil, esmolol, or nitroglycerin boluses.12 Hemodynamic instability may also accompany emergence, so careful attention to blood pressure at this time is also critical. 5. Management of magnesium in the peridelivery period: Unit protocols should recommend that magnesium be continued during cesarean deliveries and not stopped out of concern for the impact on uterine tone or anesthetic drug interactions. The half-life of magnesium sulfate is about 4 to 5 hours in women with normal renal function,13 so stopping at the time of incision will not significantly change the levels during the intraoperative period but will increases the likelihood of subtherapeutic magnesium levels in the postpartum period, placing the patient at risk for eclampsia. Magnesium infusions in the operating room increase risk for a drug error if other medications (eg, oxytocin, phenylephrine, azithromycin) are also infused on pump, and systems are needed as part of the handoff process to ensure safe transfer of responsibility for the magnesium infusion from the labor nurse to the anesthesiologist at the time of transport to the operating room and from the anesthesiologist to the nurse in the postanesthesia care unit. 6. Postdelivery care: The postpartum period is a particularly vulnerable time for preeclamptic patients; over 50% of strokes7 and as many as 75% of deaths secondary to hypertension occur following delivery.14 Protocols should ensure that preeclamptic patients are carefully monitored well into the postpartum period. Anesthesiologists should be involved in defining a safe disposition for the patient based on the degree of blood pressure control and respiratory status. Additionally, postdelivery analgesic regimens will need to be tailored for circumstances when nonsteroidal anti-inflammatory medications or acetaminophen are contraindicated. Opioid monotherapy and magnesium infusions increase the risk for respiratory depression, so appropriate systems for monitoring are advised. CONCLUSIONS The Consensus Bundle on Hypertension in Pregnancy was written for an intraprofessional audience and addresses key actions that have the potential to reduce maternal morbidity and mortality associated with hypertensive diseases of pregnancy. This editorial expands on the intraprofessional bundle to detail the specific role that anesthesiologists can play in ensuring safe peripartum care for women with hypertensive disorders. Given that hemodynamic monitoring and administration of cardiovascular drugs are so central to role of anesthesiologists, we should play a key role in facilitating the implementation of the bundle on labor and delivery units and, with this, expand our role in the care of these patients. DISCLOSURES Name: Mihaela Podovei, MD. Contribution: This author helped write the manuscript. Name: Brian T. Bateman, MD, MSc. Contribution: This author helped write the manuscript. This manuscript was handled by: Jill M. Mhyre, MD.