Common obstetrics and gynecologic topics in critical care: A narrative review

Abstract

The fields of Obstetrics and Gynecology and Critical Care often share medically and surgically complex patients. Peripartum anatomic and physiologic changes can predispose or exacerbate certain conditions and rapid action is often needed. This review discusses some of the most common conditions responsible for the admission of obstetrical and gynecological patients to the critical care unit. We will consider both obstetrical and gynecologic concepts including postpartum hemorrhage, antepartum hemorrhage, abnormal uterine bleeding, preeclampsia and eclampsia, venous thromboembolism, amniotic fluid embolism, sepsis and septic shock, obstetrical trauma, acute abdomen, malignancies, peripartum cardiomyopathy, and substance abuse. This article aims to be a primer for the Critical Care provider.

INTRODUCTION

Although the majority of obstetric patients are young and healthy, there are still convergences with the field of Critical Care. Every year, there are over 6 million pregnancies in the US,[1] and approximately 0.17%–1.1% of all pregnant patients require critical care admissions.[2] Pregnant women require intensive care unit (ICU) admission for a wide variety of reasons, including sepsis, hypertensive disorders, diabetic ketoacidosis, trauma, GI pathology, and peripartum cardiomyopathy. Viral illnesses such as influenza and COVID-19 put pregnant women at increased risk for severe respiratory compromise, and vaccines for these conditions are strongly recommended to prevent adverse outcomes.[3] This review will also discuss peripartum anatomy and physiology and how they can complicate diagnostic and therapeutic critical care interventions.

Nonpregnant patients are most commonly referred to Critical Care for hemorrhage, infection, and postoperative care from oncologic cytoreductive surgery. Occasionally, patients in the ICU require hormonal therapy or coordination of other outpatient routine gynecologic care.

METHODS

A literature search for English-language full-text articles was undertaken on PubMed and Google Scholar for studies and societal guidance on Critical Care in Obstetrics and Gynecology and for seminal articles on the chosen topics. Given breadth of topic, each subject was limited to key articles or guidance and recent changes in practice. Clinical guidelines and statistics were limited to the United States (US).

GENERAL OBSTETRIC CONSIDERATIONS

Maternal mortality in the US is increasing, and currently, about 700 women or 17 women per 100,000 live births die each year during pregnancy.[4] American Indian/Alaska Native and Black women are 2–3 times as likely to die from a pregnancy-related cause than white women.[4] Non-Hispanic Black women over the age of 40 have the highest risk of maternal mortality, 192 deaths per 100,000 live births.[5]

Pregnancy dating is critically important, as accurate estimation of gestational age predicts fetal viability and directs clinical interventions. The most accurate method of establishing or confirming gestational age is an early ultrasound (first trimester, based on crown-rump length).[6] Pregnancies at gestational ages between 20 0/7 and 25 6/7 weeks are considered periviable.[6] The uterine fundus generally reaches the umbilicus at approximately 20-week gestation.[7] Resuscitative hysterotomy, also known as perimortem cesarean delivery, is generally advised past 20–24 weeks for maternal benefit, and should ideally occur 4–5 min after initiating a code. This procedure requires minimal preparation (no skin cleansing) and instrumentation (scalpel alone will suffice).[8]

When admitted postpartum, if possible, it is recommended to have the mother and neonate together, and to consider breastfeeding and breast care. Pharmacists can assist in determining the safety of breastfeeding and certain medications. Postpartum patients who do not breastfeed or pump require supportive interventions to prevent breast engorgement or other complications.

The pregnant patient is often young and otherwise healthy, and, as such, can decompensate quickly when she becomes critically ill. Many first-line medications need to be given rapidly. A summary of some of the key obstetric medications is included in Table 1. These medications and conditions are reviewed more in depth below.

Table 1.

Common obstetric medications and treatments

Condition	Diagnostic assessment	Medication or treatment
PPH	Fundal check for uterine tone Rapid bedside ultrasound or pelvic exam for retained products Laboratory evaluation for DIC or coagulation defect	Atony: Uterotonics: Oxytocin, misoprostol, methergine, carboprost Antifibrinolytics: TXA 1 g IV Uterine tamponade: Balloon or vacuum device Surgical intervention
Antepartum hemorrhage	Evaluation for abnormal placentation Clinical signs of placental abruption (painful contractions, vaginal bleeding, nonreassuring fetal heart tracing) Evaluation of Rh status	Consideration for delivery Rhogam administration pending clinical scenario
Preeclampsia	Evaluation of blood pressure (elevated 140/90, severe 160/110) Evaluation for proteinuria Evaluation for thrombocytopenia, transaminitis, renal insufficiency, pulmonary edema, or clinical signs	Treatment of severe blood pressures within 15 min: IV labetalol, hydralazine, PO nifedipine, or nicardipine or sodium nitroprusside Prevention of seizures
Eclampsia	New-onset seizures in a patient with preeclampsia Usually self-limiting	Magnesium 4 g or 6g IV loading dose with 2 g/h continuous to prevent further seizures
Amniotic fluid embolus	Cardiorespiratory arrest or compromise and DIC at time of labor	Supportive ACLS, with MTP and fluid support A OK regimen (anecdotal): 1 mg atropine, 8 mg ondansetron, 15 mg ketorolac
Sepsis	Evaluation for cause, including endometritis or chorioamnionitis on differential	Surviving sepsis treatment Ampicillin/gentamicin for chorioamnionitis Ampicillin/gentamicin/metronidazole for endometritis

DIC: Disseminated intravascular coagulation, TXA: Tranexamic acid, MTP: Massive transfusion protocol, PPH: Postpartum hemorrhage, IV: Intravenous, ACLS: Advanced cardiac life support, PO: Per os

DIAGNOSES

Obstetric hemorrhage

There are several causes of hemorrhage in pregnancy that can necessitate massive transfusion protocols (MTPs). Associated complications of hemorrhage, such as shock, disseminated intravascular coagulation (DIC), acute kidney injury, pituitary necrosis, and acute respiratory distress syndrome (ARDS), may also benefit from Critical Care management.[9]

Postpartum hemorrhage (PPH) is defined as a cumulative blood loss of >1 L or blood loss with signs or symptoms of hypovolemia in the 24 h after birth. PPH is the leading cause of maternal morbidity and mortality worldwide. In the US from 2011 to 2016, PPH accounted for 11% of maternal mortality.[10] Uterine atony is the most common cause of PPH, accounting for over 75% of cases, with other common causes being retained placenta (8.4%), delayed or secondary hemorrhage (8.1%), and coagulation defects (7.4%).[11]

Management of PPH requires a multidisciplinary and multifaceted approach to maintain hemodynamic stability while treating the cause of blood loss. Pharmacologic interventions with uterotonics (such as oxytocin, methergine, carboprost, or misoprostol) can be combined with antifibrinolytics (such as tranexamic acid [TXA]), as well as mechanical interventions such as uterine tamponade (balloon or vacuum), correction of coagulopathy, surgical correction of laceration, percutaneous embolization, laparotomy with surgical control of bleeding, or hysterectomy [Table 1].[9] Hysterectomy occurred in 2014 at a rate of 10.7 per every 10,000 delivery hospitalizations, an increase of 55% from 1993.[12]

Antepartum hemorrhage (second/third trimester) is another consideration in acute obstetric care. Abnormal placentation, such as placenta or vasa previa, could cause bleeding ranging in volume from scant spotting requiring expectant management, or in contrast, massive antepartum hemorrhage requiring combined cesarean hysterectomy. Placenta previa is associated with placenta accreta spectrum disorders, which necessitate interdisciplinary cesarean hysterectomies. Another potential cause is a placental abruption, or premature separation of the placenta. Placental abruption is a clinical diagnosis, suspected in cases with painful contractions and nonreassuring fetal heart tracing, and may be accompanied by vaginal bleeding. It can occur spontaneously, in the context of a hypertensive disorder, following trauma, or substance use. The strongest risk factor is a prior abruption. Placental abruption is responsible for up to 17% of cases of MTPs in pregnancy.[9] Early recognition of this condition is key. Rh status must be determined in pregnant patients with vaginal bleeding or trauma, with Rh immunoglobulin given in certain clinical scenarios. Ideally, all uncross-matched blood in pregnancy should be O negative, to avoid potential alloimmunization.

Blood transfusions in pregnancy have increased by 400% from 1993 to 2014.[12] However, practice may be shifting with the widespread blood shortages during the COVID-19 pandemic. Transfusion reactions are rare but may be lethal in 1 per 100,000 units. Women who receive a postpartum transfusion have a doubled risk of a transfusion reaction (odds ratio: 2.0, 0.8% incidence) compared with nonpregnant women. Treatment of these reactions in pregnancy follows standard of care guidelines outside of pregnancy.[13] Transfusion-related acute lung injury and transfusion-associated circulatory overload are rare clinical diagnoses that require Critical Care intervention. These reactions are more likely to occur in patients with hypertensive disorders of pregnancy, especially preeclampsia.

Gynecologic hemorrhage

A normal menstruation occurs every 21–35 days, lasting around 5 days, and can be considered excessive by the patient's perception. The etiology of gynecologic hemorrhage can be structural or nonstructural. Structural causes are related to abnormal anatomy of the uterus/cervix and include benign, premalignant, and malignant conditions. Nonstructural causes can include coagulopathy or ovulatory dysfunction. Treatment depends on the cause and may require hormonal management, antifibrinolytics (TXA), embolization, and conservative or definitive surgical interventions. Significant hemorrhage might require ICU care for MTPs and hemodynamic stabilization.[14]

Preeclampsia/eclampsia

Preeclampsia and eclampsia caused 6.9% of all maternal deaths in the US from 2011 to 2016.[10] Preeclampsia is characterized by new-onset hypertension after 20-week gestation, accompanied by proteinuria or other clinical features of organ damage. Preeclampsia can develop rapidly and can be superimposed on other hypertensive disorders. Severe features include otherwise unexplained thrombocytopenia, transaminitis, renal insufficiency, pulmonary edema, severe persistent right upper quadrant or epigastric pain, visual changes, or new-onset headache unresponsive to acetaminophen. Severe range blood pressures (systolic ≥160 mmHg or diastolic ≥110 mmHg) meet criteria for preeclampsia with severe features. All severe features increase morbidity and mortality and require immediate intervention. Other severe forms of preeclampsia include hemolysis, elevated liver enzymes, low platelet count syndrome, and eclampsia (seizures). Vasogenic edema from preeclampsia can also progress to posterior reversible encephalopathy syndrome, a range of clinical neurologic signs and symptoms that requires control of hypertension, antiepileptic medications, and long-term neurologic follow-up. Laboratory values associated with severe features should be monitored regularly for progression. Ob/Gyn, Maternal Fetal Medicine, and Neonatal providers should be consulted early to assist with counseling and evaluation for possible urgent delivery in the case of antepartum preeclampsia. Postpartum preeclampsia should be managed clinically using the aforementioned tenets.[15]

Physiologic changes in preeclampsia include significant capillary leak and decreased colloid oncotic pressure resulting in increased risk for pulmonary edema, necessitating volume restriction. Acute renal deterioration may also occur, resulting in oliguria, so strict monitoring of intake and output is crucial. The changes in blood flow may result in uteroplacental insufficiency or ischemia, causing fetal growth restriction, oligohydramnios, placental abruption, and spontaneous or indicated preterm delivery.[15]

Treatment includes blood pressure control, prevention of eclamptic seizures, and symptomatic relief. Blood pressure control can be achieved with medications such as labetalol, nifedipine, hydralazine, nicardipine, or sodium nitroprusside [Table 1]. Goal pressures are below the severe range. Eclamptic seizures are usually self-limiting, but IV magnesium sulfate is used to prevent further seizures, with loading dose of 4–6 g, with a subsequent continuous dose of 2 g/h [Table 1]. This dosage is used for any severe features for prevention of initial seizure activity. There is a risk for magnesium toxicity, especially with impaired renal function. Clinical signs of toxicity include loss of deep tendon reflexes, respiratory depression, or cardiac arrest.[15]

Embolism

Deep vein thromboses (DVTs) in pregnancy occurred at 4.3 per 10,000 delivery hospitalizations in 2014.[16] They are often left-sided and proximal due to pregnancy physiology, and best diagnosed with compression ultrasound.[17] Critical Care support is indicated when thrombectomy is required, with evidence of arterial compromise, or for hemodynamic instability. In these cases, standard practices should be continued, with modifications such as fetal monitoring or avoidance of teratogenic anticoagulants such as warfarin.[8]

Pulmonary emboli (PE) occurred in 2014 at a rate of 2.2 per 10,000 delivery hospitalizations,[16] and caused 9.0% of maternal deaths in the US from 2011 to 2016.[10] Noninvasive screening for DVT or PE in pregnancy with D-dimer is not recommended, although studies are investigating appropriate interpretation of D-dimer in pregnancy. Both ventilation-perfusion scan and computed tomography angiography are associated with low radiation to fetus and maternal breast, but a chest X-ray may be used for initial evaluation, depending on local resources. Treatment follows standard protocol, with hemodynamic stabilization and medical or procedural intervention as needed.[17]

Amniotic fluid embolism is a rare (0.2 out of every 10,000 delivery hospitalizations)[12] and devastating obstetrical emergency that is usually unpredictable and unpreventable. It caused 5.6% of all maternal deaths in the US from 2011 to 2016.[10] It presents with systemic shock, DIC, and is often associated with PPH from coagulopathy. Proposed criteria for diagnosis include sudden onset of cardiorespiratory arrest or both hypotension and respiratory compromise, documentation of overt DIC, clinical onset during labor or within 30 min of delivery, and no fever during labor.[18] It should be managed with aggressive volume replacement, typically MTPs.[9] Some have proposed the emergent use of “A O K” (1 mg atropine, 8 mg ondansetron, and 30 mg ketorolac) for these patients [Table 1].[18]

Sepsis/septic shock

Obstetrical sepsis caused 12.5% of all maternal deaths in the US from 2011 to 2016.[10] Common etiologies of sepsis in pregnancy include chorioamnionitis, endometritis, or urologic sources. Treatment guidelines remain standard with other sepsis guidelines, with prompt source control and, when possible, avoidance of teratogenic antibiotics [Table 1]. Chorioamnionitis and endometritis can be initially treated with ampicillin and gentamicin, with addition of metronidazole for endometritis.[19] Pregnant patients with sepsis/septic shock have an increased risk of developing ARDS. If intubation is required in a pregnant patient, ICU teams should be prepared for a difficult airway or intubation failure due to upper airway changes related to physiologic changes of pregnancy.[8] Pregnant patients often have a physiologic leukocytosis which can confound a sepsis work-up. Normal respiratory physiology in pregnancy includes an increased respiratory rate, minute volume, tidal volume, decreased arterial PCO2 (normally under 30), and a compensated respiratory alkalosis that can all lead to decreased buffering capacity. The normal pH in pregnancy changes from the baseline of 7.40 in the nonpregnant woman to 7.42–7.46.[8] Considerations for delivery should be made with a multidisciplinary team approach.

Gynecologic causes of sepsis include endometritis, postoperative abscess, and tubo-ovarian abscesses (TOAs), a severe complication of untreated pelvic inflammatory disease. Sepsis associated with TOAs, especially ruptured TOAs, can have a mortality rate as high as 5%–10%. As with all causes of sepsis, early recognition, resuscitation, and initiation of broad-spectrum antibiotic therapy including coverage for mixed flora (gonorrhea, chlamydia, mycoplasma genitalia, or bowel flora) can reduce potential adverse sequelae. Surgical or radiological drainage for source control is usually necessary.[20]

Obstetrical trauma

Trauma occurs in 1 in 12 pregnancies, from motor vehicle crashes, assaults, falls, and intimate partner violence (more common in pregnancy).[21] Some of the physiologic changes of pregnancy can complicate trauma evaluation. Intestinal compartmentalization means that pregnant women are more susceptible to penetrating injuries. The diaphragm is elevated by 4–7 cm, and internal organs can be displaced to varying degrees based on gestational age.

Positioning of pregnant patients in the left lateral decubitus for evaluation will avoid inferior vena cava compression and hypotension. This positioning should be maintained should cardiopulmonary resuscitation (CPR) be required. During pregnancy, there are increased circulation demands due to the increased cardiac output and heart rate, and there is also increased blood sequestration due to decreased systemic vascular resistance. Increased CPR compression force should be used due to the decreased chest wall compliance secondary to breast hypertrophy.[21]

All Rh-negative patients with abdominal trauma should receive Rhogam. In viable and periviable pregnancies (over 20-week gestation), fetal monitoring should be rapidly instituted once the patient has been stabilized. A FAST scan is a useful rapid assessment for possible intra-abdominal hemorrhage and can be coordinated with sonographic evaluation in those trained to assess fetal well-being and placental status.[21]

Trauma in pregnancy can result in devastating outcomes, including placental abruption, preterm delivery, intrauterine fetal demise (60%–70% occurred after a minor trauma), uterine rupture, or amniotic fluid embolus.[21] Continuous fetal monitoring and cardiotocography should be continued for at least 4 h during evaluation. It should continue in the setting of nonreassuring fetal heart tracing, presence of concerning symptoms, positive Kleihauer-Betke test (surrogate marker for placental abruption), or presence of regular contractions.[21]

Acute abdomen in Gynecology

Women of reproductive age with an acute abdomen should have a urine pregnancy test, regardless of contraception use or regularity of menstruation to rule out ectopic pregnancy. If the urine pregnancy test is positive, a transvaginal ultrasound and a serum beta-human chorionic gonadotropin (hCG) will assist in discussion of evaluation and treatment options.

Ultrasound is the preferred methodology for diagnosis of most gynecologic pathologies. Incidental adnexal sonographic findings are exceedingly common. A simple appearing cyst under 10 cm is likely benign, and can often be observed, unless symptomatic. Acute symptoms from cysts can include cyst rupture, intra-abdominal hemorrhage, or adnexal torsion. If imaging and patient presentation are suggestive of torsion, emergent surgical intervention with detorsion and cystectomy/oophorectomy is warranted.[22]

Malignancies

Patients with metastatic gynecologic carcinomas can decompensate from their disease process, therapeutic interventions, and paraneoplastic syndromes. Treatment is typically supportive and requires multidisciplinary collaboration including palliative care. Approximately 7% of patients who have aggressive cytoreductive surgery for ovarian cancer require ICU admission,[23] and 20% experience major morbidity including postoperative hemorrhage, venous thromboembolism, sepsis, and in some cases, anastomotic leaks.[24] These surgeries are complex and often involve colon resections, diaphragm stripping, or splenectomy. Patients may be immunocompromised from neoadjuvant chemotherapy or heated intraperitoneal chemotherapy at the time of surgery. Treatment is supportive.

Gestational trophoblastic neoplasia is rare but considered in any female patient with high hCG without an intrauterine pregnancy. Metastases often occur in the lung, liver, brain, spleen, or intestines.[25] Metastases cause bleeding, respiratory compromise, and neurologic symptoms, which can necessitate Critical Care management. Tissue biopsy is rarely necessary. Rapid and aggressive treatment with chemotherapy is indicated, even if the patient is critically ill. Cure is possible in more than 90% of patients even with widespread metastatic disease. Surgical intervention is sometimes necessary for cessation of internal bleeding from metastases.[25]

Peripartum cardiomyopathy

Physiologic changes in pregnancy include increase in cardiac output and heart rate, electrocardiogram left axis deviation from the dextrorotation of the heart, increased predisposition of supraventricular arrhythmias secondary to the effects of estrogen, and increased susceptibility to third spacing of fluid and pulmonary edema from the decreased colloid oncotic pressure and decreased pulmonary capillary wedge pressure.[8] Peripartum cardiomyopathy affects about 1000 patients in the US every year[26] and accounted for 11.0% of all maternal mortality in the US from 2011 to 2016.[10] It most commonly affects Black women (3–4 times more than non-Hispanic whites). It is characterized by a dilated cardiomyopathy with reduced ejection fraction, resulting in congestion, pulmonary edema, and pleural effusions. Severe cases can progress to cardiogenic shock, requiring the use of mechanical circulatory support or even cardiac transplantation. Evaluation for other potential diagnoses, including preexisting cardiac conditions, valvular disease, drug or toxin-induced disease, pulmonary or amniotic fluid embolism, or changes of normal pregnancy should be undertaken.[26] Standard treatments for heart failure with reduced ejection fraction are recommended, with avoidance of teratogenic medications and maternal hypotension. Most (50%–80%) patients will recover systolic function.[26]

Substance abuse in pregnancy

Substance abuse is common in pregnancy. Supportive care for these patients is crucial, and consideration for detoxification, lifesaving treatment such as naloxone, or maintenance therapy can assist in decreasing morbidity.[8] Here, we will discuss some of the most common substances.

Per a 2012 survey, 8.5% of pregnant women in America consumed at least one alcoholic drink in the previous month, and use has been related to many fetal anomalies and pregnancy complications. Pharmacologic treatments for alcohol use disorder in pregnancy are limited, with Naltrexone, disulfiram, and acamprosate all classified as category C. Acute withdrawal can cause hypertension and a hypercortisol state which can affect the mother, placenta, and fetus. There are limited data on the short-term administration of benzodiazepines for alcohol withdrawal in pregnancy.[27]

Cocaine, ecstasy, methamphetamines, and other stimulants are the second most widely used substances in the US.[28] The use of stimulants in pregnancy can have adverse outcomes, including preterm labor, low birth weight, infections, fetal anomalies, maternal death, and placental abruption. The only effective treatment for stimulant use disorders is psychosocial treatment – there are no Food and Drug Administration-approved pharmacotherapies.[29]

Opioid use disorder can have risks of neonatal abstinence syndrome, fetal growth restriction, and placental changes. Buprenorphine and methadone are the mainstays of treatment. Breastfeeding while using long-acting opioid agonist medication-assisted treatment is safe and can promote maternal–infant bonding.[30]

CONCLUSIONS

Ob/Gyn and Critical Care can overlap in the treatment of a number of conditions, some of which are outlined in brief in this article. Ongoing discussions between providers for multidisciplinary care can be key to treatment of these complex patients in this rapidly evolving field.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.