This post was co-authored with Cheryl Holub BSN, CCRN-CSC at Legacy Emanuel Hospital in Portland, OR.
If you are a maternity nurse, most likely February doesn’t register as American Heart Month for you. But cardiovascular disease (CVD) is the leading cause of pregnancy-related mortality in the United States and has gradually increased over time (from 7.2 to 17.2 deaths per 100 000 live births from 1987–2015). There’s several reasons for this, both from pre-existing conditions as well as the SERIOUS cardiovascular situation that transpires during pregnancy, regardless of health status. It’s a high flow, low resistance state where the heart increases in size, blood volume increases by 50%, heart rate increases, blood-pressure and systemic vascular resistance drops, and vascular tissue integrity is challenged from hormonal effects. Yikes! Even if all you did for heart month was review the normal cardiovascular adaptations of pregnancy, it would be time well spent.
Racial and ethnic disparities (cough-injustices-cough) in pregnancy-related mortality, especially CVD are significant, peaking among black non-Hispanic women (42.8/100 000) followed by American Indian/Alaskan Native women (32.5), Asian/Pacific Islander women (14.2), white non-Hispanic women (13.0), and Hispanic women (11.4). This is most likely due to something called ‘weathering’. This term, first defined in 1992 (yet I learned it in neither nursing school nor grad school) describes the differences in chronic morbidity and worsening health deterioration of some ethnic and racial groups. It's the accumulation and manifestation of daily stressors related to discriminatory treatment. So her illness is not anything your individual patient is likely to be able to control and explains why these differences persist even when you control for socio-economics, education, weight, etc etc (etc).
But let’s go one step further. With more cardiovascular disease, that means more of our patients are likely rolling over for a stay in the ICU/CVICU, pre- and post-delivery. What used to be fairly rare, even if you work in a higher level center, is now becoming more common. If you’ve ever had to go to manage fetal monitoring in an antepartum patient or the uterus postpartum (ICU nurses are NOT into funduses. Fundi?), you’ve likely noticed it is a different environment with lines, monitors, etc that we aren’t used to. It can be pretty intimidating. But just like we will happily manage a labor, ICU nurses LOVE monitoring cardiac and respiratory status, dialing in drips and reading those invasive monitor printouts. So what are the main diagnoses of these maternity ICU patients? And what happens once they are over there? Luckily, one of my oldest friends, Cheryl Holub, is a CVICU nurse and is helping answer these questions. It used to be that our patients could not be more different. Now, sometimes they are the very same person.
Peripartum Cardiomyopathy (Heart Failure)-
In the last month of pregnancy and up to 5 months postpartum, the heart chambers enlarge causing the cardiac muscle to weaken. With a weaker muscle, the amount of blood able to be ejected from the left ventricle (ejection fraction) is decreased. This means less blood flow and if severe enough, the heart is no longer able to meet the oxygen demands of the organs. The symptoms of peripartum cardiomyopathy (PPCM) include fatigue, palpitations, increased nocturia, shortness of breath, swollen ankles and swollen neck veins. So besides the neck veins, this is your basic pregnant person, which is why so many people don’t seek care until they are quite sick and can be easily dismissed in triage. It is important to take these concerns seriously instead of dismissing them, as they are often the warning signs that something serious is brewing. PPCM is a complicated phenomenon and the underlying cause is multifactorial.. Diagnosis occurs when the ejection fraction is less than 45% (normal is 55-70%) and when clinicians are unable to come up with another identifiable cause of heart failure. These patients are at a higher risk of developing a left ventricular thrombus, which puts them at risk for stroke or a pulmonary embolism.
If your patient is transferred to the ICU with PPCM, the focus will be on close cardiac and respiratory monitoring of the patient. This will mean continuous EKG and respiratory monitoring. They will likely receive an echocardiogram (ultrasound of the heart) to assess for heart function, value function, fluid status, and to rule out presence of thrombus.These patients are treated similar to typical, non peripartum heart failure patients, which usually includes supplemental oxygen, occasionally mechanical ventilation, fluids or medications to optimize preload (the ability of the ventricle to stretch), and inotropes or vasopressors which also maximize cardiac function. Sometimes these patients will have invasive monitoring with a pulmonary artery catheter, also known as a Swan Ganz catheter, to assess fluid status, heart function and the pressures within the heart.
“Well, that escalated quickly!” If you’ve had a HELLP patient go to the ICU, you know this phrase is appropriate. We see lots of patients with pre-eclampsia (2-8% of all pregnant people) who labor, birth, recover and go home with pre-eclampsia signs and symptoms totally resolved. But not all...and that is important to remember. During pregnancy, if your patient has severe pre-eclampsia and is over 34 weeks, delivery is indicated. Prior to 34 weeks, if magnesium sulfate and anit-hypertensive therapy aren’t adequate, the risks of preterm delivery for the fetus are weighed with the risk of maintaining the mother’s pregnant state.
But once postpartum (even once the patient has discharged home! aaaahhhh!), a host of complications can occur, including DIC, acute respiratory distress syndrome, pulmonary edema, stroke, acute renal failure, hepatic dysfunction with hepatic rupture or liver hematoma and infection/sepsis. As a perinatal nurse, these are all good reasons that I want this patient off my unit and in the ICU. In the ICU, supportive care is the focus- hemodynamic management, volume management, pain management, and venous thromboembolism (see below) prophylaxis are all common therapies. You will often see diagnostic imaging such as liver ultrasounds being utilized based on how the patient’s labs are trending and how they are presenting clinically. These patients will be receiving EKG monitoring, frequent blood pressure monitoring and close monitoring of their respiratory status. There is the possibility that they may require an ‘escalation of oxygen support’. This is a method of supporting oxygenation using different devices sequentially, with the goal of avoiding endotracheal intubation. It can be weird to see these various devices on your postpartum patient, but the ICU team (RN, RT, MD) are experts at this.
Pregnancy-associated pulmonary thromboembolism (VTE) remains a leading cause of direct maternal mortality. It’s what Serena Williams had. Look that story up if you haven’t heard the deets. Pregnancy is by design a hyper-coagulable state and embolism is 10 times more likely than in non-pregnant humans. And because of delays in timing of pregnancy, older maternal age means the risk is further increased. But diagnosis of one type of VTE, pulmonary embolism (PE) in pregnancy remains difficult. Just like with cardiomyopathy, the signs can mimic those of pregnancy (out of breath, tired, etc). That said, you will often see additional signs, like sharp, stabbing chest pain, cough and diaphoresis, which should cue you as the bedside RN into being suspicious of a pulmonary embolism.
Investigations for a PE can be tricky, because you want to minimize the amount of radiation exposure to the mother and baby. That said, every labor nurse knows that oxygen and carbon dioxide exchange is crucial for the mother and baby, so the benefits of imaging might outweigh the risks. Chest x-rays can be helpful in determining other factors that could be contributing to respiratory distress, like a pneumothorax or pneumonia but the gold standard for a PE diagnosis is a CT scan. The American College of Obstetrics and Gynecology’s official Guidelines for Diagnostic Imaging During Pregnancy and Lactation outlines their recommendations on various forms of imaging and they endorse a CT of the chest if medically necessary to diagnose and treat a pregnant patient. They report that the dose of radiation from a chest CT is at a much lower level than the exposure associated with fetal harm.
Once a VTE is diagnosed, they will receive Lovenox and Heparin therapy and close respiratory and hemodynamic monitoring. The Journal of the American Medical Association (JAMA) published an article discussing advanced treatments of massive PEs in pregnant patients, such as embolectomies and thrombotic therapy, however they are associated with a high rate of fetal loss and the mother’s risk of hemorrhage is significantly increased, so generally they are not a realistic option when managing a pregnant patient.
The OB/ICU Relationship
At the end of the day, OB patients that end up in the ICU are a unique group of individuals that need critical care. Suddenly, instead of one specialty team, there are at least two (and sometimes more) teams of specialists. In an effort to leave you with some actionable steps, we’d like to make the following recommendations:
Let us know below in the comments what your favorite takeaway is or what you learned from this post. We’ll be hosting an IG Live on 2/22 @ 4 pm PST (also known as happy hour), so submit your questions here for us to answer! Come follow myself @jenatkisson and Cheryl @holitala on Instagram where you’ll be able to tune in to the IG Live.
Next month Cheryl and I will be continuing our ICU collaborative series, discussing the three main things your ICU nurse needs your help with.