What's New in Neuraxial Labor Analgesia.

PURPOSE OF REVIEW: This article provides an update of recent practice trends in neuraxial labor analgesia. It reviews available evidence regarding management of labor pain in obstetric patients with COVID-19, serious adverse events in obstetric anesthesia to help inform risk/benefit decisions, and increasingly popular neuraxial labor analgesia techniques and adjuvants. State-of-the-art modes of epidural drug delivery are also discussed. RECENT FINDINGS: There has recently been a focus on several considerations specific to obstetric anesthesia, such as anesthetic management of obstetric patients with COVID-19, platelet thresholds for the safe performance of neuraxial analgesia in obstetric patients with thrombocytopenia, and drug delivery modes for initiation and maintenance of neuraxial labor analgesia. SUMMARY: Neuraxial labor analgesia (via standard epidural, dural puncture epidural, and combined spinal epidural techniques) is the most effective therapy to alleviate the pain of childbirth. SARS-CoV-2 infection is not, in and of itself, a contraindication to neuraxial labor analgesia or cesarean delivery anesthesia. Early initiation of neuraxial labor analgesia in patients with COVID-19 is recommended if not otherwise contraindicated, as it may reduce the need for general anesthesia should emergency cesarean delivery become necessary. Consensus regarding platelet thresholds for safe initiation of neuraxial procedures has historically been lacking. Recent studies have concluded that the risk of spinal epidural hematoma formation after neuraxial procedures is likely low at or above an imprecise range of platelet count of 70-75,000 × 106/L. Thrombocytopenia has been reported in obstetric patients with COVID-19, but severe thrombocytopenia precluding initiation of neuraxial anesthesia is extremely rare. High neuraxial blockade has emerged as one of the most common serious complications of neuraxial analgesia and anesthesia in obstetric patients. Growing awareness of factors that contribute to failed conversion of epidural labor analgesia to cesarean delivery anesthesia may help avoid the risks associated with performance of repeat neuraxial techniques and induction of general anesthesia after failed epidural blockade. Dural puncture techniques to alleviate the pain of childbirth continue to become more popular, as do adjuvant drugs to enhance or prolong neuraxial analgesia. Novel techniques for epidural drug delivery have become more widely disseminated.

The Society for Obstetric Anesthesia and Perinatology Interdisciplinary Consensus Statement on Neuraxial Procedures in Obstetric Patients With Thrombocytopenia.

Because up to 12% of obstetric patients meet criteria for the diagnosis of thrombocytopenia in pregnancy, it is not infrequent that the anesthesiologist must decide whether to proceed with a neuraxial procedure in an affected patient. Given the potential morbidity associated with general anesthesia for cesarean delivery, thoughtful consideration of which patients with thrombocytopenia are likely to have an increased risk of spinal epidural hematoma with neuraxial procedures, and when these risks outweigh the relative benefits is important to consider and to inform shared decision making with patients. Because there are substantial risks associated with withholding a neuraxial analgesic/anesthetic procedure in obstetric patients, every effort should be made to perform a bleeding history assessment and determine the thrombocytopenia etiology before admission for delivery. Whereas multiple other professional societies (obstetric, interventional pain, and hematologic) have published guidelines addressing platelet thresholds for safe neuraxial procedures, the US anesthesia professional societies have been silent on this topic. Despite a paucity of high-quality data, there are now meta-analyses that provide better estimations of risks. An interdisciplinary taskforce was convened to unite the relevant professional societies, synthesize the data, and provide a practical decision algorithm to help inform risk-benefit discussions and shared decision making with patients. Through a systematic review and modified Delphi process, the taskforce concluded that the best available evidence indicates the risk of spinal epidural hematoma associated with a platelet count ≥70,000 × 106/L is likely to be very low in obstetric patients with thrombocytopenia secondary to gestational thrombocytopenia, immune thrombocytopenia (ITP), and hypertensive disorders of pregnancy in the absence of other risk factors. Ultimately, the decision of whether to proceed with a neuraxial procedure in an obstetric patient with thrombocytopenia occurs within a clinical context. Potentially relevant factors include, but are not limited to, patient comorbidities, obstetric risk factors, airway examination, available airway equipment, risk of general anesthesia, and patient preference.

The Society for Obstetric Anesthesia and Perinatology Coronavirus Disease 2019 Registry: An Analysis of Outcomes Among Pregnant Women Delivering During the Initial Severe Acute Respiratory Syndrome Coronavirus-2 Outbreak in the United States.

BACKGROUND: Early reports associating severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection with adverse pregnancy outcomes were biased by including only women with severe disease without controls. The Society for Obstetric Anesthesia and Perinatology (SOAP) coronavirus disease 2019 (COVID-19) registry was created to compare peripartum outcomes and anesthetic utilization in women with and without SARS-CoV-2 infection delivering at institutions with widespread testing. METHODS: Deliveries from 14 US medical centers, from March 19 to May 31, 2020, were included. Peripartum infection was defined as a positive SARS-CoV-2 polymerase chain reaction test within 14 days of delivery. Consecutive SARS-CoV-2-infected patients with randomly selected control patients were sampled (1:2 ratio) with controls delivering during the same day without a positive test. Outcomes were obstetric (eg, delivery mode, hypertensive disorders of pregnancy, and delivery <37 weeks), an adverse neonatal outcome composite measure (primary), and anesthetic utilization (eg, neuraxial labor analgesia and anesthesia). Outcomes were analyzed using generalized estimating equations to account for clustering within centers. Sensitivity analyses compared symptomatic and asymptomatic patients to controls. RESULTS: One thousand four hundred fifty four peripartum women were included: 490 with SARS-CoV-2 infection (176 [35.9%] symptomatic) and 964 were controls. SARS-CoV-2 patients were slightly younger, more likely nonnulliparous, nonwhite, and Hispanic than controls. They were more likely to have diabetes, obesity, or cardiac disease and less likely to have autoimmune disease. After adjustment for confounders, individuals experiencing SARS-CoV-2 infection exhibited an increased risk for delivery <37 weeks of gestation compared to controls, 73 (14.8%) vs 98 (10.2%) (adjusted odds ratio [aOR], 1.47; 95% confidence interval [CI], 1.03-2.09). Effect estimates for other obstetric outcomes and the neonatal composite outcome measure were not meaningfully different between SARS-CoV-2 patients versus controls. In sensitivity analyses, compared to controls, symptomatic SARS-CoV-2 patients exhibited increases in cesarean delivery (aOR, 1.57; 95% CI, 1.09-2.27), postpartum length of stay (aOR, 1.89; 95% CI, 1.18-2.60), and delivery <37 weeks of gestation (aOR, 2.08; 95% CI, 1.29-3.36). These adverse outcomes were not found in asymptomatic women versus controls. SARS-CoV-2 patients (asymptomatic and symptomatic) were less likely to receive neuraxial labor analgesia (aOR, 0.52; 95% CI, 0.35-0.75) and more likely to receive general anesthesia for cesarean delivery (aOR, 3.69; 95% CI, 1.40-9.74) due to maternal respiratory failure. CONCLUSIONS: In this large, multicenter US cohort study of women with and without peripartum SARS-CoV-2 infection, differences in obstetric and neonatal outcomes seem to be mostly driven by symptomatic patients. Lower utilization of neuraxial analgesia in laboring patients with asymptomatic or symptomatic infection compared to patients without infection requires further investigation.

Lumbar neuraxial procedures in thrombocytopenic patients across populations: A systematic review and meta-analysis.

INTRODUCTION: There is currently no consensus regarding the minimum threshold platelet count to ensure safe neuraxial procedures. Numerous reports describe the safe performance of lumbar punctures in severely thrombocytopenic patients but reports of neuraxial anesthetic procedures in thrombocytopenic patients are limited. To date, the focus on specific populations in contemporary reviews has failed to include any actual hematoma cases. This systematic review aggregates reported lumbar neuraxial procedures from diverse thrombocytopenic populations to best elucidate the risk of spinal epidural hematoma. METHODS: MEDLINE, Embase, Cochrane, CINAHL databases were searched for articles about thrombocytopenic patients (<100,000 × 106/L) who received a lumbar neuraxial procedure (lumbar puncture; spinal, epidural, or combined spinal-epidural analgesia/anesthesia; epidural catheter removal), whether spinal epidural hematoma occurred. RESULTS: Of 4167 articles reviewed, 131 met inclusion criteria. 7476 lumbar neuraxial procedures were performed without and 33 procedures with spinal epidural hematoma. Within the platelet count ranges of 1-25,000 × 106/L, 26-50,000 × 106/L, 51-75,000 × 106/L, and 76-99,000 × 106/L there were 14, 6, 9, and 4 spinal epidural hematomas, respectively. An infection point and narrow confidence intervals were observed near 75,000 × 106/L or above, reflecting a low probability of spinal epidural hematoma in this sample. Of the 19 spinal epidural hematoma cases for which the onset of symptoms was reported, 18 (95%) were symptomatic within 48 h of the procedure. CONCLUSIONS: Spinal epidural hematoma in thrombocytopenic patients is rare. In this sample of patients, an inflection point and narrow confidence intervals are observed near a platelet count of 75,000 × 106/L or above, reflecting an estimated low spinal epidural hematoma event rate with more certainty given a larger sample size and inclusion of spinal epidural hematoma cases. Thrombocytopenic patients should be monitored, particularly in the first 48 h, and educated about symptoms concerning for spinal epidural hematoma.

Complement factor B activation in patients with preeclampsia.

Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. Bb, the active fragment of complement factor B (fB), has been reported to be a predictor of preeclampsia. However, conflicting results have been found by some investigators. We hypothesized that the disagreement in findings may be due to the racial/ethnic differences among various study groups, and that fB activation is significant in women of an ethnic minority with preeclampsia. We investigated the maternal and fetal levels of Bb (the activated fB fragment) in pregnant women of an ethnic minority with or without preeclampsia. We enrolled 291 pregnant women (96% of an ethnic minority, including 78% African-American). Thirteen percent of these were diagnosed with preeclampsia. Maternal venous blood was collected from all participants together with fetal umbilical cord blood samples from 154 deliveries in the 291 women. The results were analyzed using the Mann-Whitney U test and multivariate analyses. Maternal Bb levels were significantly higher in the preeclamptic group than in the nonpreeclamptic group. Levels of Bb in fetal cord blood were similar in both groups. Subgroup analyses of African-American patients' results confirmed the study hypothesis that there would be a significant increase in Bb in the maternal blood of the preeclamptic group and no increase in Bb in the fetal cord blood of this group. These results suggest that a maternal immune response through complement fB might play a role in the development of preeclampsia, particularly in African-American patients.

Epidural catheter design: history, innovations, and clinical implications.

Epidural catheters have evolved during the past several decades, as clinicians and manufacturers have sought to influence the quality of analgesia and anesthesia and reduce the incidence of catheter-related complications. This evolution has allowed a transformation from single-shot to continuous-infusion techniques and resulted in easier passage into the epidural space, more extensive medication distribution, and ultimately, improved patient satisfaction. Particular catheter features, including the materials used, tip design, and orifice number and arrangement, have been associated with specific outcomes and provide direction for future development.

Anesthesia drugs in the obstetric and gynecologic practice.

The obstetrician-gynecologist is often solely responsible for analgesia/sedation and regional blocks during office-based and outpatient procedures. The American Society of Anesthesiologists guidelines for the provision of analgesia/sedation for nonanesthesiologists provide helpful recommendations to maximize patient safety during office-based and outpatient procedures. This article provides a review of the fundamentals of sedation/analgesia, monitored anesthesia care, and local anesthetics.