key: cord-257729-s0vo7dlk
authors: Bauer, Melissa; Bernstein, Kyra; Dinges, Emily; Delgado, Carlos; El-Sharawi, Nadir; Sultan, Pervez; Mhyre, Jill M.; Landau, Ruth
title: Obstetric Anesthesia During the Coronavirus Disease 2019 Pandemic
date: 2020-04-20
journal: Anesth Analg
DOI: 10.1213/ane.0000000000004856
sha: 
doc_id: 257729
cord_uid: s0vo7dlk

With increasing numbers of Coronavirus Disease 2019 (COVID19) cases due to efficient human-to-human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United States, preparation for the unpredictable setting of labor and delivery is paramount. The priorities are 2-fold in the management of obstetric patients with COVID-19 infection or persons under investigation (PUI): (1) caring for the range of asymptomatic to critically ill pregnant and postpartum women; (2) protecting health care workers and beyond from exposure during the delivery hospitalization (health care providers, personnel, family members). The goal of this review is to provide evidence-based recommendations or, when evidence is limited, expert opinion for anesthesiologists caring for pregnant women during the COVID19 pandemic with a focus on preparedness and best clinical obstetric anesthesia practice.

T he management of obstetric patients infected with Coronavirus Disease 2019 (COVID- 19) due to human-to-human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires quite unique considerations-from caring for critically ill pregnant and postpartum women to protecting health care workers from exposure during the delivery hospitalization (health care providers, personnel, family members, and beyond). The goal of this review is to provide evidence-based recommendations or, when evidence is limited, expert opinion for anesthesiologists caring for pregnant women during the COVID 19 pandemic with a focus on preparedness and best clinical obstetric anesthesia practice.

In principle, the clinical characteristics reported in pregnant women with confirmed COVID-19 infection in China have been consistent with those reported among nonpregnant adults, with better maternal and neonatal outcomes with COVID-19 infection compared with the 2002-2003 severe acute respiratory syndrome (SARS) outbreak from SARS CoV 1 infection. [1] [2] [3] The signs and symptoms of COVID-19 infection in a large data set in nonpregnant patients from China were fever (99%), fatigue (70%), cough (59%), shortness of breath (31%), myalgias (35%), headache (6.5%), sore throat (17%), diarrhea (10%), nausea (10%), and vomiting (4%). 4 An additional manifestation noted among patients with COVID-19 infection is the sudden loss (or reduction) of the sense of smell and taste, which is currently recommended by the American Academy of Otolaryngology-Head With increasing numbers of Coronavirus Disease 2019 (COVID 19) cases due to efficient human-to-human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the United States, preparation for the unpredictable setting of labor and delivery is paramount. The priorities are 2-fold in the management of obstetric patients with COVID-19 infection or persons under investigation (PUI): (1) caring for the range of asymptomatic to critically ill pregnant and postpartum women; (2) protecting health care workers and beyond from exposure during the delivery hospitalization (health care providers, personnel, family members). The goal of this review is to provide evidence-based recommendations or, when evidence is limited, expert opinion for anesthesiologists caring for pregnant women during the COVID 19 pandemic with a focus on preparedness and best clinical obstetric anesthesia practice. and Neck Surgery as part of screening for COVID-19 infection. 5 In pregnancy, presentation of COVID-19 infection appears similar, but many of these nonspecific symptoms may be attributed to symptoms of pregnancy and labor. 2 For example, signs of latent labor may include myalgias and diarrhea; preeclampsia can present with headache; shortness of breath is perceived during pregnancy and labor; and chorioamnionitis may cause tachycardia and fever, thus, leading clinicians to overlook COVID-19 infection as a possible diagnosis. In addition, women infected with COVID-19 may be asymptomatic until their admission in labor and beyond, 6 which in itself poses a significant risk of exposure for their family members (including the newborn) and all providers involved in their clinical care.

Screening criteria for COVID-19 infection usually include the following: (1) fever, (2) cough or shortness of breath, (3) diarrhea, and (4) any possible exposure to COVID-19. However, because women with COVID-19 infection may be asymptomatic at the time of admission and because some may present with overlapping pregnancy symptoms, universal screening may miss pregnant women infected with SARS-CoV-2 in communities with a high prevalence or high projected infection rate (eg, New York, New Orleans, Detroit, Chicago, Miami). 7, 8 Universal testing with real-time reverse transcriptase-polymerase chain reaction (RT-PCR) tests for SARS-CoV-2 viral ribonucleic acid (RNA) may improve case detection in high prevalence communities. However, current assays may return false-negative results if the viral load is low or if specimen collection is incomplete.

The goals of COVID-19 testing specific to pregnant patients admitted to labor and delivery units are 2fold: (1) to prevent vertical transmission and ensure separation of the neonate after birth and (2) to protect health care workers by ensuring use of appropriate personal protective equipment (PPE). Besides the unclear sensitivity of RT-PCR testing, the time for nucleic acid detection varies between 6 and 8 hours or longer depending on availability. Therefore, management of women on Labor and Delivery Units located in a community with a high prevalence of COVID-19 infection should err on the side of caution.

For purposes of clinical management and PPE use, women may therefore be categorized as follows (1) COVID-19 negative, (2) asymptomatic, (3) symptomatic (persons under investigation [PUI]), and (4) personally positive for COVID-19 testing. This information should be made available to all health care providers and updated at all times as it may change during the course of labor (from asymptomatic to symptomatic or, if tested, once the result becomes available).

Women who are COVID-19 positive (or high-risk PUI) should ideally be placed in an isolation room. Airborne infection isolation rooms (single-patient negative-pressure rooms with a minimum of 6 air changes per hour), if available, should be used if performance of aerosolizing procedures is anticipated. In general, isolation rooms suitable for droplet and contact precautions are recommended. 9 Strategies for exposure mitigation and cohorting, as well as considerations for transportation of patients who are PUI or COVID-19 should follow the same recommendations as for general patient cases. 10 

A multidisciplinary team of anesthesiologists, obstetricians, labor and delivery nurses, neonatologists, critical care experts, infectious disease and infection control experts, employee health services, environmental health services, and telemedicine services should create and implement protocols to support the management of patients with COVID-19 infection in the setting of a Labor and Delivery Unit. A sideby-side comparison of recommendations from many professional societies for labor and delivery units is presented in Table 1 . For institutions with multiple labor and delivery sites, consideration should be given to designating 1 institution to care for patients with COVID-19 infection. This proved useful in managing patients during the SARS epidemic and for cases in the recent COVID-19 outbreak in Wuhan, China. [11] [12] [13] Resource allocation within the Labor and Delivery Unit as well as other units (including intensive care unit) should be proactively addressed. It is imperative to establish a back-up team to care for patients without COVID-19 infection due to the time-intensive tasks of donning/doffing PPE, transporting the patient, providing anesthetic care, and performing surgery in patients with active COVID-19 infection.

From a logistical standpoint, a designated operating room within the Labor and Delivery Unit should be prepared. Dedicated trays (or carts) containing the most commonly used supplies and drugs for both neuraxial labor analgesia and cesarean delivery should be available to minimize traffic and contamination of anesthesia workstations and other anesthesia equipment.

A pregnant woman who is PUI or COVID-19 positive should be evaluated (limiting unnecessary encounters) including vital signs, physical examination, and review of laboratory tests (complete blood count, comprehensive metabolic panel, and arterial blood gas, if needed) to assess appropriate level of care and monitoring plan for potential deterioration. Early multidisciplinary collaboration should be arranged to determine level of care, fetal monitoring, and delivery plan. Discussion of the risks and benefits for administering steroids for fetal lung maturity, magnesium for neuroprotection, and indomethacin for tocolysis should be addressed, since there is concern those drugs may worsen COVID-19 infection (Table 2) . 9 Avoiding urgent cesarean delivery is essential to reduce the risk for general anesthesia and provider exposure during uncontrolled transfers to the operating room. Therefore, ongoing assessment of both maternal and fetal statuses are key to balance risks of prolonged labor versus cesarean delivery. It is unclear whether uterine decompression improves maternal respiratory status and how the potential benefit balances against the known operative risks in the setting of COVID-19. On the other hand, prolonged maternal hypoxemia may ultimately cause fetal acidemia, leading to a more urgent cesarean delivery. 9 Routine monitoring should include frequent vital signs (tailored to the current clinical status and adjusted as necessary) with the addition of continuous pulse oximetry and strict input and output measurements to assure fluid restriction. Pulse oximetry goal should be an oxygen saturation ≥95%. Early warning criteria systems specific for obstetric patients may aid in early detection and prompt escalation of care. 16 Women requiring supplemental oxygen, who develop increasing oxygen requirements or worsening hypoxia (pulse oximetry [Spo 2 ] < 95%), should have prompt arterial blood gas analysis with frequent clinical reassessment to guide the requirement for escalation of care and mechanical ventilation. Highflow nasal oxygen or noninvasive ventilation may be considered as temporizing measures but are generally discouraged due to the potential for greater aerosolization. In addition, increasing oxygen requirements serve as a marker of disease progression, with increasing risk of atelectasis and pulmonary consolidation. It is recommended to perform early endotracheal intubation in a controlled manner minimizing exposure to health care workers and equipment with airborne precautions in an urgent/emergent situation. 17 One of the frequent complications of patients with COVID-19 is acute respiratory distress syndrome The routine use of oxygen for fetal indications should be suspended

Overall, the use of oxygen for fetal indications is controversial

The use of high-flow nasal cannula or facemask oxygen may be an aerosolizing procedure Nitrous oxide 9 Discuss the relative risks and benefits of nitrous oxide for labor analgesia and consider suspending its use (ARDS). Ventilator management strategies for ARDS involve lung-protective strategies such as low tidal volumes (6 mL/kg using predicted body weight), plateau pressure <30 cm H 2 O, and the combined use of reduced Fio 2 with increases in positive end-expiratory pressure (PEEP) to maintain a Pao 2 of 65-90 mm Hg. 18 Useful ventilator titration techniques using the ARDSnet ventilator protocol can be found in http:// www.ardsnet.org/files/ventilator_protocol_2008-07. pdf.17 Pregnant patients have a physiological decrease in Paco 2 , and it is recommended to maintain a Paco 2 of 28-32 mm Hg with ventilation to augment off-loading of oxygen to the fetus. However, the priority is maintaining oxygenation with low tidal volumes and PEEP, and this strategy may not allow for maintaining the physiologic Paco 2 in pregnancy. Multidisciplinary discussion should determine the fetal monitoring and delivery plan during mechanical ventilation.

Neuraxial labor analgesia remains a mainstay of obstetric care even with concurrent COVID-19 infection. In fact, early epidural placement is desirable to avoid exacerbation of respiratory symptoms with labor pain and to reduce the likelihood of general anesthesia if intrapartum cesarean delivery becomes needed. The benefits of neuraxial analgesia in the setting of COVID-19 pneumonia are 2-fold: (1) for the patient, it will help avoid any exacerbation of respiratory status with intubation and mechanical ventilation and (2) for health care providers, it reduces the risks associated with aerosol exposure and transmission of COVID-19 infection during intubation and extubation, if general anesthesia is provided.

The risk of COVID-19 exposure for the anesthesiologist during neuraxial labor analgesia placement is presumably low, since this is not an aerosol-generating procedure. All health care workers in the room should wear contact (impervious gown and gloves) and droplet (surgical mask and eye protection) precautions. The patient should wear a surgical mask at all times to limit droplet spread, and the number of personnel present during placement of neuraxial labor analgesia should be minimized but with assistance readily available. Several strategies may minimize contamination of equipment and COVID-19 exposure in anesthesiologists, while also minimizing the consumption of PPE (Box 1 and Figure) .

A parturient who is symptomatic PUI, or COVID-19 positive, should have a complete blood count before neuraxial analgesia placement. Early studies from China suggested that thrombocytopenia may be associated with COVID-19 infection; in a cohort of 1099 patients, 36.2% had thrombocytopenia (<150,000 × 10 6 /L). 19 A meta-analysis of 1779 patients with COVID-19 infection observed that platelet counts are lower in patients with more severe disease. 20 Though less common, a platelet count <100,000 × 10 6 /L can occur; 3 studies of 243 patients reported a total of 6.6% patients with that level of thrombocytopenia. [21] [22] [23] We suggest a platelet count on admission without the need to check serial counts before needle placement unless there is a major change in clinical symptoms. It is generally safe to perform neuraxial procedures at platelet counts of 70,000 × 10 6 /L or above, 24 and, given the rare risk of spinal/epidural hematoma and the much higher risk of respiratory compromise with general anesthesia, neuraxial procedures at even lower platelet counts should be considered.

While theoretically possible, the risk of epidural or subarachnoid space seeding with viremic blood, causing encephalitis or meningitis, is exceedingly rare. At the time of this writing, there are 77 pregnant women reported in the literature who received uneventful neuraxial procedures for cesarean or vaginal delivery (4 combined spinal-epidural, 27 epidural, 46 spinal procedures; Table 3 ). 6 tray-the required equipment (epidural kit) and drugs should be prepared and brought into the room in a bag before the procedure. 5. Have the most experienced anesthesiologist perform the procedure to ensure adequate placement and reduce the risk of accidental dural puncture that may require an epidural blood patch. 6. Increase the dosing of neuraxial medications for labor analgesia (eg, increasing the bupivacaine concentration from 0.0625% to 0.1%) or changing the setting of the programmed epidural intermittent bolus (eg, increasing the volume from 5 to 8 mL, or decreasing the interval from every 45 to 30 minutes) or adding neuraxial adjuvants (eg, epidural clonidine) to minimize intrapartum breakthrough pain requiring epidural top-up. 7. Round on parturients with video or phone calls into the patient's room for hourly assessments of general status and effects of neuraxial analgesia. spinal-epidural, epidural procedures all are acceptable, and no technique confers more risk that the other based on the literature available. None of the patients experienced neurologic sequelae. Current recommendations on the use of nitrous oxide (Entonox) for labor analgesia suggest "there is insufficient information about the cleaning, filtering, and potential aerosolization of nitrous oxide in the setting of COVID-19." Individual Labor and Delivery Units should consider suspending use. 9 Additionally, the practice of high-flow oxygen for fetal distress does not improve fetal outcomes and should be suspended due to the risk of aerosolization. 9 ANESTHESIA FOR CESAREAN DELIVERY In reports from China, most women with a diagnosis of COVID-19 infection underwent a cesarean delivery. 25 In the absence of universal testing and rapid availability of results, COVID-19 status may not necessarily be known at the time of cesarean delivery. The baseline failure rate for conversion of labor epidural analgesia to cesarean delivery anesthesia is 5%. 30 Urgent intrapartum cesarean delivery represents an important risk factor for failed conversion from intrapartum neuraxial labor analgesia to cesarean delivery anesthesia-therefore, ongoing communication with the obstetricians is crucial to allow safe transfer to the operating room, and adequate time for initiation of surgical block to avoid general anesthesia. 30 To minimize the risk of exposure during urgent endotracheal intubation, airborne protection (N95 respirator mask) is recommended for all providers in the operating room unless the patient is known to be COVID-19 negative.

A publication from Wuhan, China, describing outcomes in 17 COVID-19-positive women undergoing cesarean delivery, concluded that "excessive hypotension" occurred in 12 of 14 cases with epidural anesthesia in comparison with the 3 women who had received general anesthesia; however, information about the blood pressure trends and description of the use of vasopressors is not reported. 26 A larger case series of 49 patients receiving spinal anesthesia (45 for cesarean delivery and 4 for orthopedic procedures) was well tolerated with stable blood pressure. 29 In our early experience, maternal hypotension during cesarean delivery with epidural or spinal anesthesia has not been noted, most likely because prevention of hypotension with phenylephrine is part of our routine clinical practice. Along with antihypotensive medication, antiemetic medication should also be administered. However, we recommend using an alternative to dexamethasone in a PUI or patient with known COVID-19 infection given the risk of worsening clinical severity. 14 Specific considerations for medication use in PUI or COVID-19-positive patients during labor, delivery, and the postpartum period are described in Table 2 . 

Current understanding is that there is little evidence for vertical transmission in women who develop COVID-19 pneumonia in late pregnancy. 2, [31] [32] [33] [34] [35] However, cases of possible in utero infection seem to be emerging including a recent report of a neonate born to a COVID-19 infected mother. This suggests in utero infection during the 23 days between maternal infection and delivery 23 days later and supported by elevated immunoglobulin M (IgM) antibodies, which are not transferred to the fetus via the placenta. [36] [37] [38] [39] Serological testing of virus-specific IgG and IgM antibodies may alternatively be used if RT-PCR testing is not available or if RT-PCR seems to be yielding a false-negative result. 40 

Postpartum considerations for parturients with COVID-19 infection include adequate management of usual postpartum issues (postpartum hemorrhage, pain, hemodynamic status) as well as judicious fluid management, surveillance for respiratory decompensation, and early involvement of subspecialty care as needed. Appropriate isolation of mother and child on the postpartum unit is also recommended. 41

In the setting of postpartum hemorrhage due to uterine atony, carboprost tromethamine (Hemabate) followed by endotracheal intubation was reported to have precipitated immediate and prolonged bronchospasm in a patient who was subsequently found to be COVID-19 positive. 6, 42 Oxytocin and methylergonovine as a second-line choice may be preferred, due to the potential for bronchospasm with carboprost tromethamine (Hemabate), and aerosolization of viral particles during bronchospasm management.

It has been posited that nonsteroidal anti-inflammatory drugs (NSAIDs) for management of symptoms suggestive of COVID-19 infection may worsen the clinical course of COVID-19 patients; however, this remains controversial and robust data are lacking. At this point, for women who are asymptomatic or mildly symptomatic with pain not well controlled with acetaminophen, NSAIDs can continue to be used, as the alternative of opioids likely poses more clinical risks. 9

There are no reported cases of accidental dural puncture resulting in postdural puncture headache (PDPH) in a patient with a COVID-19 infection, and consequently, no available guidance. Similar to usual care, conservative measures should be initially provided.

Usual contraindications to the performance of an epidural blood patch (eg, fever, thrombocytopenia, or other coagulation issues) should apply in a COVID-19 patient. Mitigating the risk of a serious neurologic complications with untreated PDPH 43 versus that of viral seeding in the epidural space with an epidural blood patch will require a case-by-case approach. Postponing the epidural blood patch is recommended in women who are actively ill. Individual assessment of the benefits and risks should be assessed and shared decision-making should be engaged with the patient before proceeding.

Because a nasal sphenopalatine ganglion (SPG) block is likely an aerosol-generating procedure due to the injection/insertion directly into the nasal cavity, it should be avoided to minimize the risk of transmission to health care workers.

Key points emerging in the past weeks from the literature and our experience in Labor and Delivery Units in the United States are that pregnant women may be asymptomatic on admission in labor, and that symptoms of COVID-19 infection may initially be missed or obscured if chorioamnionitis is suspected during labor. Although most women with COVID-19 infection will not present with pneumonia and respiratory decompensation during labor, escalation of care and advanced critical care resources may become necessary in the postpartum period.

In fact, most of the considerations surrounding management of the parturient with suspicion of or known COVID-19 infection include not only best strategies to ensure safe care for the parturient but also those to prevent health care worker exposure to SARS-CoV-2 and contracting COVID-19.

Anesthesiologists are deemed at significant risk of viral exposure during endotracheal intubations of COVID-19-infected patients, and all strategies should be applied to avoid general anesthesia in women who are either untested or known to be COVID-19 positive.

Early neuraxial labor analgesia is strongly recommended to ensure availability of neuraxial anesthesia in the event of an intrapartum cesarean delivery, and spinal anesthesia should be provided if needed. If deemed necessary and unavoidable, provision of general anesthesia should follow general recommendations for intubation and extubation in the setting of COVID-19-infected patients.

The changes in workflow that result from the need to ensure adequate PPE (contact/droplet protection for nonaerosolizing procedures such as [eg, epidural placement] or airborne protection for cesarean deliveries due to the possible conversion to general anesthesia) are considerable and require thorough planning and preparedness.

Close communication around COVID-19 status of all patients admitted to the Labor and Delivery Unit is essential, and anticipation of emergencies is of the essence. Overall, providing the best clinical care for pregnant and postpartum women with COVID-19 infection also must take into account strategies to prevent health care worker exposure to SARS-CoV-2 and contracting COVID-19. E

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