Association between breakthrough labor pain, patient-controlled epidural analgesia use, and numeracy: A pilot observational study.

OBJECTIVE: Labor analgesia can be maintained with a continuous epidural infusion, supplemented by patient-controlled epidural boluses. patient-controlled epidural boluses use and timing require numeric understanding, as patients need to understand when they can administer supplemental boluses, lockout intervals, and total doses. We hypothesized that women with lower numeric literacy have a higher rate of provider-administered supplemental boluses for breakthrough pain because they do not understand the concept behind patient-controlled epidural boluses. DESIGN: Pilot observational study SETTING: Labor and Delivery Suite PARTICIPANTS: Nulliparous, English-speaking patients with singleton, vertex pregnancies admitted for postdates (gestational age ≥ 41 weeks) induction of labor requesting neuraxial labor analgesia. INTERVENTIONS: Combined spinal-epidural labor analgesia was initiated with intrathecal fentanyl and epidural analgesia was maintained using continuous epidural infusion with patient-controlled epidural boluses. MEASUREMENTS AND FINDINGS: Numeric literacy was assessed using the Lipkus 7-item expanded numeracy test. Patients were stratified by whether or not they required supplemental provider-administered analgesia and patient-controlled epidural boluses use patterns were evaluated. A total of 89 patients completed the study. There were no demographic differences between patients who required supplemental analgesia compared with those who did not. Patients that required supplemental analgesia were more likely to request and receive patient-controlled epidural boluses (P<0.001). Hourly bupivacaine requirement was higher in women with breakthrough pain. There were no differences in numeric literacy between the two groups. KEY CONCLUSIONS: Patients who required treatment of breakthrough pain had higher patient-controlled epidural boluses demands-to-delivery ratio. Numeric literacy was not correlated with the need for provider-administered supplemental boluses. IMPLICATIONS FOR PRACTICE: Easy to understand scripts on how to use patient-controlled epidural boluses allows for understanding of patient-controlled epidural boluses use.

Frequency and Risk Factors for Difficult Intubation in Women Undergoing General Anesthesia for Cesarean Delivery: A Multicenter Retrospective Cohort Analysis.

BACKGROUND: Estimates for the incidence of difficult intubation in the obstetric population vary widely, although previous studies reporting rates of difficult intubation in obstetrics are older and limited by smaller samples. The goals of this study were to provide a contemporary estimate of the frequency of difficult and failed intubation in women undergoing general anesthesia for cesarean delivery and to elucidate risk factors for difficult intubation in women undergoing general anesthesia for cesarean delivery. METHODS: This is a multicenter, retrospective cohort study utilizing the Multicenter Perioperative Outcomes Group database. The study population included women aged 15 to 44 yr undergoing general anesthesia for cesarean delivery between 2004 and 2019 at 1 of 45 medical centers. Coprimary outcomes included the frequencies of difficult and failed intubation. Difficult intubation was defined as Cormack-Lehane view of 3 or greater, three or more intubation attempts, rescue fiberoptic intubation, rescue supraglottic airway, or surgical airway. Failed intubation was defined as any attempt at intubation without successful endotracheal tube placement. The rates of difficult and failed intubation were assessed. Several patient demographic, anatomical, and obstetric factors were evaluated for potential associations with difficult intubation. RESULTS: This study identified 14,748 cases of cesarean delivery performed under general anesthesia. There were 295 cases of difficult intubation, with a frequency of 1:49 (95% CI, 1:55 to 1:44; n = 14,531). There were 18 cases of failed intubation, with a frequency of 1:808 (95% CI, 1:1,276 to 1:511; n = 14,537). Factors with the highest point estimates for the odds of difficult intubation included increased body mass index, Mallampati score III or IV, small hyoid-to-mentum distance, limited jaw protrusion, limited mouth opening, and cervical spine limitations. CONCLUSIONS: In this large, multicenter, contemporary study of more than 14,000 general anesthetics for cesarean delivery, an overall risk of difficult intubation of 1:49 and a risk of failed intubation of 1:808 were observed. Most risk factors for difficult intubation were nonobstetric in nature. These data demonstrate that difficult intubation in obstetrics remains an ongoing concern.

External Validation of Postpartum Hemorrhage Prediction Models Using Electronic Health Record Data.

OBJECTIVE: A recent study leveraging machine learning methods found that postpartum hemorrhage (PPH) can be predicted accurately at the time of labor admission in the U.S. Consortium for Safe Labor (CSL) dataset, with a C-statistic as high as 0.93. These CSL models were developed in older data (2002-2008) and used an estimated blood loss (EBL) of ≥1,000 mL to define PPH. We sought to externally validate these models using a more recent cohort of births where blood loss was measured using quantitative blood loss (QBL) methods. STUDY DESIGN: Using data from 5,261 deliveries between February 1, 2019 and May 11, 2020 at a single tertiary hospital, we mapped our electronic health record (EHR) data to the 55 predictors described in previously published CSL models. PPH was defined as QBL ≥1,000 mL within 24 hours after delivery. Model discrimination and calibration of the four CSL models were measured using our cohort. In a secondary analysis, we fit new models in our study cohort using the same predictors and algorithms as the original CSL models. RESULTS: The original study cohort had a substantially lower rate of PPH, 4.8% (7,279/228,438) versus 25% (1,321/5,261), possibly due to differences in measurement. The CSL models had lower discrimination in our study cohort, with a C-statistic as high as 0.57 (logistic regression). Models refit in our study cohort achieved better discrimination, with a C-statistic as high as 0.64 (random forest). Calibration improved in the refit models as compared with the original models. CONCLUSION: The CSL models' accuracy was lower in a contemporary EHR where PPH is assessed using QBL. As institutions continue to adopt QBL methods, further data are needed to understand the differences between EBL and QBL to enable accurate prediction of PPH. KEY POINTS: · Machine learning methods may help predict PPH.. · EBL models do not generalize when QBL is used.. · Blood loss estimation alters model accuracy..

Difficulty in Advancing Flexible Epidural Catheters When Establishing Labor Analgesia: An Observational Open-Label Randomized Trial.

BACKGROUND: While flexible epidural catheters reduce the risk of paresthesia and intravascular cannulation, they may be more challenging to advance beyond the tip of a Tuohy needle. This may increase placement time, number of attempts, and possibly complications when establishing labor analgesia. This study investigated the ability to advance flexible epidural catheters through different epidural needles from 2 commonly used, commercially available, epidural kits. METHODS: We hypothesized that the multiorifice wire-reinforced polyamide nylon blend epidural catheters will have a higher rate of successful first attempt insertion than the single-end hole wire-reinforced polyurethane catheters for the establishment of labor analgesia. The primary outcome was a difference in proportions of failure to advance the epidural catheter between the 2 epidural kits and was tested by a χ2 test. Two-hundred forty epidural kits were collected (n = 120/group) for 240 laboring patients requesting epidural analgesia in this open-label clinical trial from November 2018 to September 2019. Two-week time intervals were randomized for the exclusive use of 1 of the 2 kits in this study, where all patients received labor analgesia through either the flexible epidural catheter "A" or the flexible epidural catheter "B." Engineering properties of the equipment used were then determined. RESULTS: Flexible epidural catheter "A," the single-end hole wire-reinforced polyurethane catheter, did not advance at the first attempt in 15% (n = 18 of 120) of the parturients compared to 0.8% (n = 1 of 120) of the catheter "B," the multiorifice wire-reinforced polyamide nylon blend epidural catheter (P < .0001). Twenty-five additional epidural needle manipulations were recorded in the laboring patients who received catheter "A," while 1 epidural needle manipulation was recorded in the parturients who received catheter "B" (P < .0001). Bending stiffness of the epidural catheters used from kit "B" was twice the bending stiffness of the catheters used from kit "A" (bending stiffness catheters "A" 0.64 ± 0.04 N·mm2 versus bending stiffness catheters "B" 1.28 ± 0.20 N·mm2, P = .0038), and the angle formed by the needle and the epidural catheter from kit "A" was less acute than the angle formed from kit "B" (kit "A" 14.17 ± 1.72° versus kit "B" 21.83 ± 1.33°, P = .0036), with a mean difference of 7.66° between the 2 kits' angles. CONCLUSIONS: The incidence of an inability to advance single-end hole wire-reinforced polyurethane catheter was higher compared to the use of multiorifice wire-reinforced polyamide nylon blend epidural catheter. Variation of morphological features of epidural needles and catheters may play a critical role in determining the successful establishment of labor epidural analgesia.

Sugammadex Administration in Pregnant Women: A Case Series of Maternal and Fetal Outcomes.

Sugammadex, given its high affinity for amino-steroid neuromuscular blockers, offers rapid and reliable neuromuscular blockade reversal, making it a popular reversal agent. This characteristic can be very useful in pregnant women, where incomplete reversal can have poor maternal and fetal outcomes. However, its use antenatally in pregnancy is controversial given concerns for progesterone binding, a hormone that is crucial for maintenance of pregnancy. This case series presents obstetric and fetal outcomes in 25 pregnant women who received sugammadex during the antenatal period, thus highlighting the need for further research into the safety of sugammadex during pregnancy.

Opportunities to Improve the Capacity to Rescue: Intraoperative and Perioperative Tools.

Postoperative complications, which occur in approximately 23% of surgeries, are a major source of patient mortality. Some of these deaths may be preventable. This article explores factors and contexts during the intraoperative period, in the postanesthesia care unit, perioperatively, and after discharge that may represent opportunities to intervene and prevent mortality after a potentially treatable complication. Tools to improve the identification and response to life-threatening complications in these unique care settings are discussed.

User Perceptions of an Electronic Maternal Alerting System.

This survey study evaluates the user experience of an electronic maternal early warning system that generates automated pages. Survey domains included the system's effect on patient care, alarm fatigue, and continued use of the system. The response rate was 47.7% (273 of 572). A majority, 83%, felt that the system should remain in use, and 64.5% felt it improved patient safety. Of those who believed that they had received a page, 51.4% felt that they received pages "too frequently." Although alarm fatigue was not fully evaluated, providers on our unit support the continued use of this automated maternal electronic surveillance system.

Use of a Novel Electronic Maternal Surveillance System and the Maternal Early Warning Criteria to Detect Severe Postpartum Hemorrhage.

BACKGROUND: A leading cause of preventable maternal death is related to delayed response to clinical warning signs. Electronic surveillance systems may improve detection of maternal morbidity with automated notifications. This retrospective observational study evaluates the ability of an automated surveillance system and the Maternal Early Warning Criteria (MEWC) to detect severely morbid postpartum hemorrhage (sPPH) after delivery. METHODS: The electronic health records of adult obstetric patients of any gestational age delivering between April 1, 2017 and December 1, 2018 were queried to identify scheduled or unscheduled vaginal or cesarean deliveries. Deliveries complicated by sPPH were identified and defined by operative management of postpartum hemorrhage, transfusion of ≥4 units of packed red blood cells (pRBCs), ≥2 units of pRBCs and ≥2 units of fresh-frozen plasma, transfusion with >1 dose of furosemide, or transfer to the intensive care unit. The test characteristics of automated pages and the MEWC for identification of sPPH 24 hours after delivery were determined and compared using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) and their 95% confidence intervals (CIs). McNemar test was used to compare these estimates for both early warning systems. RESULTS: The average age at admission was 30.7 years (standard deviation [SD] = 5.1 years), mean gestational age 38 weeks 4 days, and cesarean delivery accounted for 30.0% of deliveries. Of 7853 deliveries, 120 (1.5%) were complicated by sPPH. The sensitivity of automated pages for sPPH within 24 hours of delivery was 60.8% (95% CI, 52.1-69.6), specificity 82.5% (95% CI, 81.7-83.4), PPV 5.1% (95% CI, 4.0-6.3), and NPV 99.3% (95% CI, 99.1-99.5). The test characteristics of the MEWC for sPPH were sensitivity 75.0% (95% CI, 67.3-82.7), specificity 66.3% (95% CI, 65.2-67.3), PPV 3.3% (95% CI, 2.7-4.0), and NPV 99.4% (95% CI, 99.2-99.6). There were 10 sPPH cases identified by automated pages, but not by the MEWC. Six of these cases were identified by a page for anemia, and 4 cases were the result of vital signs detected by the bedside monitor, but not recorded in the patient's medical record by the bedside nurse. Therefore, the combined sensitivity of the 2 systems was 83.3% (95% CI, 75.4-89.5). CONCLUSIONS: The automated system identified 10 of 120 deliveries complicated by sPPH not identified by the MEWC. Using an automated alerting system in combination with a labor and delivery unit's existing nursing-driven early warning system may improve detection of sPPH.

Sacral anatomical interspace landmark for lumbar puncture in pregnancy: A randomized trial.

OBJECTIVE: To determine whether the sacral anatomical interspace landmark (SAIL) technique is more accurate than the classic intercristal line (ICL) technique in pregnant patients and to assess the percentage of clinical determinations above the third lumbar vertebra. METHODS: In this prospective, randomized, open-label trial, there were 110 singleton pregnant patients with gestational age greater than 37 weeks included. Selection procedure was a convenience sample of pregnant patients who presented for office visits or vaginal or cesarean delivery between March 15 and July 31, 2018, at a single-center obstetric tertiary care university hospital. Both techniques were evaluated by 2 physicians independently assessing each method. Before data collection, we hypothesized that the SAIL technique would be more accurate than the ICL technique in determining the L4-L5 interspace, and that the SAIL technique would produce more estimations below the third lumbar vertebra than the ICL technique. Therefore, the primary outcome was accuracy in identifying the L4-L5 lumbar interspace with SAIL vs ICL. The secondary outcome was difference in clinical assessments above the third lumbar vertebra. Both outcomes were measured via ultrasonography. RESULTS: Patients were 31 ± 5 years of age (mean ± SD) and had body mass index of 31.8 ± 5.7 kg/m2 and gestational age of 38.8 ± 1.1 weeks. A total of 110 patients were analyzed. SAIL correctly identified the L4-L5 interspace 49% of the time vs 8% using ICL (p < 0.0001). Estimations above L3 were 1% for SAIL vs 31% for ICL (p < 0.0001). CONCLUSIONS: Our study shows improved accuracy in identifying intervertebral space using the SAIL technique; this may prevent direct mechanical trauma to the conus medullaris when lumbar punctures are performed in pregnancy. CLINICALTRIALSGOV IDENTIFIER: NCT03433612.

Exploring various polygenic risk scores for skin cancer in the phenomes of the Michigan genomics initiative and the UK Biobank with a visual catalog: PRSWeb.

Polygenic risk scores (PRS) are designed to serve as single summary measures that are easy to construct, condensing information from a large number of genetic variants associated with a disease. They have been used for stratification and prediction of disease risk. The primary focus of this paper is to demonstrate how we can combine PRS and electronic health records data to better understand the shared and unique genetic architecture and etiology of disease subtypes that may be both related and heterogeneous. PRS construction strategies often depend on the purpose of the study, the available data/summary estimates, and the underlying genetic architecture of a disease. We consider several choices for constructing a PRS using data obtained from various publicly-available sources including the UK Biobank and evaluate their abilities to predict not just the primary phenotype but also secondary phenotypes derived from electronic health records (EHR). This study was conducted using data from 30,702 unrelated, genotyped patients of recent European descent from the Michigan Genomics Initiative (MGI), a longitudinal biorepository effort within Michigan Medicine. We examine the three most common skin cancer subtypes in the USA: basal cell carcinoma, cutaneous squamous cell carcinoma, and melanoma. Using these PRS for various skin cancer subtypes, we conduct a phenome-wide association study (PheWAS) within the MGI data to evaluate PRS associations with secondary traits. PheWAS results are then replicated using population-based UK Biobank data and compared across various PRS construction methods. We develop an accompanying visual catalog called PRSweb that provides detailed PheWAS results and allows users to directly compare different PRS construction methods.

Succinylcholine Use and Dantrolene Availability for Malignant Hyperthermia Treatment: Database Analyses and Systematic Review.

BACKGROUND: Although dantrolene effectively treats malignant hyperthermia (MH), discrepant recommendations exist concerning dantrolene availability. Whereas Malignant Hyperthermia Association of the United States guidelines state dantrolene must be available within 10 min of the decision to treat MH wherever volatile anesthetics or succinylcholine are administered, a Society for Ambulatory Anesthesia protocol permits Class B ambulatory facilities to stock succinylcholine for airway rescue without dantrolene. The authors investigated (1) succinylcholine use rates, including for airway rescue, in anesthetizing/sedating locations; (2) whether succinylcholine without volatile anesthetics triggers MH warranting dantrolene; and (3) the relationship between dantrolene administration and MH morbidity/mortality. METHODS: The authors performed focused analyses of the Multicenter Perioperative Outcomes Group (2005 through 2016), North American MH Registry (2013 through 2016), and Anesthesia Closed Claims Project (1970 through 2014) databases, as well as a systematic literature review (1987 through 2017). The authors used difficult mask ventilation (grades III and IV) as a surrogate for airway rescue. MH experts judged dantrolene treatment. For MH morbidity/mortality analyses, the authors included U.S. and Canadian cases that were fulminant or scored 20 or higher on the clinical grading scale and in which volatile anesthetics or succinylcholine were given. RESULTS: Among 6,368,356 queried outcomes cases, 246,904 (3.9%) received succinylcholine without volatile agents. Succinylcholine was used in 46% (n = 710) of grade IV mask ventilation cases (median dose, 100 mg, 1.2 mg/kg). Succinylcholine without volatile anesthetics triggered 24 MH cases, 13 requiring dantrolene. Among 310 anesthetic-triggered MH cases, morbidity was 20 to 37%. Treatment delay increased complications every 10 min, reaching 100% with a 50-min delay. Overall mortality was 1 to 10%; 15 U.S. patients died, including 4 after anesthetics in freestanding facilities. CONCLUSIONS: Providers use succinylcholine commonly, including during difficult mask ventilation. Succinylcholine administered without volatile anesthetics may trigger MH events requiring dantrolene. Delayed dantrolene treatment increases the likelihood of MH complications. The data reported herein support stocking dantrolene wherever succinylcholine or volatile anesthetics may be used.

Use of a novel electronic maternal surveillance system to generate automated alerts on the labor and delivery unit.

BACKGROUND: Maternal early warning systems reduce maternal morbidity. We developed an electronic maternal surveillance system capable of visually summarizing the labor and delivery census and identifying changes in clinical status. Automatic page alerts to clinical providers, using an algorithm developed at our institution, were incorporated in an effort to improve early detection of maternal morbidity. We report the frequency of pages generated by the system. To our knowledge, this is the first time such a system has been used in peripartum care. METHODS: Alert criteria were developed after review of maternal early warning systems, including the Maternal Early Warning Criteria (MEWC). Careful consideration was given to the frequency of pages generated by the surveillance system. MEWC notification criteria were liberalized and a paging algorithm was created that triggered paging alerts to first responders (nurses) and then managing services due to the assumption that paging all clinicians for each vital sign triggering MEWC would generate an inordinate number of pages. For preliminary analysis, to determine the effect of our automated paging algorithm on alerting frequency, the paging frequency of this system was compared to the frequency of vital signs meeting the Maternal Early Warning Criteria (MEWC). This retrospective analysis was limited to a sample of 34 patient rooms uniquely capable of storing every vital sign reported by the bedside monitor. RESULTS: Over a 91-day period, from April 1 to July 1, 2017, surveillance was conducted from 64 monitored beds, and the obstetrics service received one automated page every 2.3 h. The most common triggers for alerts were for hypertension and tachycardia. For the subset of 34 patient rooms uniquely capable of real-time recording, one vital sign met the MEWC every 9.6 to 10.3 min. Anecdotally, the system was well-received. CONCLUSIONS: This novel electronic maternal surveillance system is designed to reduce cognitive bias and improve timely clinical recognition of maternal deterioration. The automated paging algorithm developed for this software dramatically reduces paging frequency compared to paging for isolated vital sign abnormalities alone. Long-term, prospective studies will be required to determine its impact on patient outcomes.

Risk of Epidural Hematoma after Neuraxial Techniques in Thrombocytopenic Parturients: A Report from the Multicenter Perioperative Outcomes Group.

BACKGROUND: Thrombocytopenia has been considered a relative or even absolute contraindication to neuraxial techniques due to the risk of epidural hematoma. There is limited literature to estimate the risk of epidural hematoma in thrombocytopenic parturients. The authors reviewed a large perioperative database and performed a systematic review to further define the risk of epidural hematoma requiring surgical decompression in this population. METHODS: The authors performed a retrospective cohort study using the Multicenter Perioperative Outcomes Group database to identify thrombocytopenic parturients who received a neuraxial technique and to estimate the risk of epidural hematoma. Patients were stratified by platelet count, and those requiring surgical decompression were identified. A systematic review was performed, and risk estimates were combined with those from the existing literature. RESULTS: A total of 573 parturients with a platelet count less than 100,000 mm who received a neuraxial technique across 14 institutions were identified in the Multicenter Perioperative Outcomes Group database, and a total of 1,524 parturients were identified after combining the data from the systematic review. No cases of epidural hematoma requiring surgical decompression were observed. The upper bound of the 95% CI for the risk of epidural hematoma for a platelet count of 0 to 49,000 mm is 11%, for 50,000 to 69,000 mm is 3%, and for 70,000 to 100,000 mm is 0.2%. CONCLUSIONS: The number of thrombocytopenic parturients in the literature who received neuraxial techniques without complication has been significantly increased. The risk of epidural hematoma associated with neuraxial techniques in parturients at a platelet count less than 70,000 mm remains poorly defined due to limited observations.

Current applications of big data in obstetric anesthesiology.

PURPOSE OF REVIEW: The narrative review aims to highlight several recently published 'big data' studies pertinent to the field of obstetric anesthesiology. RECENT FINDINGS: Big data has been used to study rare outcomes, to identify trends within the healthcare system, to identify variations in practice patterns, and to highlight potential inequalities in obstetric anesthesia care. Big data studies have helped define the risk of rare complications of obstetric anesthesia, such as the risk of neuraxial hematoma in thrombocytopenic parturients. Also, large national databases have been used to better understand trends in anesthesia-related adverse events during cesarean delivery as well as outline potential racial/ethnic disparities in obstetric anesthesia care. Finally, real-time analysis of patient data across a number of disparate health information systems through the use of sophisticated clinical decision support and surveillance systems is one promising application of big data technology on the labor and delivery unit. SUMMARY: 'Big data' research has important implications for obstetric anesthesia care and warrants continued study. Real-time electronic surveillance is a potentially useful application of big data technology on the labor and delivery unit.

An in vitro evaluation of the pressure generated during programmed intermittent epidural bolus injection at varying infusion delivery speeds.

STUDY OBJECTIVE: Programmed intermittent bolus injection of epidural anesthetic solution results in decreased anesthetic consumption and better patient satisfaction compared with continuous infusion, presumably by better spread of the anesthetic solution in the epidural space. It is not known whether the delivery speed of the bolus injection influences analgesia outcomes. The objective of this in vitro study was to determine the pressure generated by a programmed intermittent bolus pump at 4 infusion delivery speeds through open-ended, single-orifice and closed-end, multiorifice epidural catheters. DESIGN: In vitro observational study. SETTING: Not applicable. PATIENTS: Not applicable. INTERVENTIONS: A CADD-Solis Pain Management System v3.0 with Programmed Intermittent Bolus Model 2110 was connected via a 3-way adapter to an epidural catheter and a digital pressure transducer. Pressures generated by delivery speeds of 100, 175, 300, and 400 mL/h of saline solution were tested with 4 epidural catheters (2 single orifice and 2 multiorifice). These runs were replicated on 5 pumps. Analysis of variance was used to compare the mean peak pressures of each delivery speed within each catheter group (single orifice and multiorifice). MAIN RESULTS: Thirty runs at each delivery speed were performed with each type of catheter for a total of 240 experimental runs. Peak pressure increased with increasing delivery speeds in both catheter groups (P<.001). Peak pressures were higher with the multiorifice catheter compared with the single-orifice catheter at all delivery speeds (P<.001, for all). CONCLUSION: Using a pump designed for programmed intermittent infusion boluses, the delivery speed of saline solution through epidural catheters was directly related to the peak pressures. Future work should evaluate whether differences in the delivery speed of anesthetic solution into the epidural space correlate with differences in the duration and quality of analgesia during programmed intermittent epidural bolus delivery.