Effect of Dural-Puncture Epidural vs Standard Epidural for Epidural Extension on Onset Time of Surgical Anesthesia in Elective Cesarean Delivery: A Randomized Clinical Trial

Importance

Dural-puncture epidural (DPE) and standard epidural are common modes of neuraxial labor analgesia. Little is known about conversion of DPE-initiated labor analgesia to surgical anesthesia for cesarean delivery.

Objective

To determine whether DPE provides a faster onset and better-quality block compared with the standard epidural technique for cesarean delivery.

Design, Setting, and Participants

This double-blind, randomized clinical trial was conducted between April 2019 and October 2022 at a tertiary care university hospital (University of Arkansas for Medical Sciences). Participants included women aged 18 years and older undergoing scheduled cesarean delivery with a singleton pregnancy.

Interventions

Participants were randomized to receive DPE or standard epidural in the labor and delivery room. A T10 sensory block was achieved and maintained using a low concentration of bupivacaine with fentanyl through the epidural catheter until the time of surgery. Epidural extension anesthesia was initiated in the operating room.

Main Outcomes and Measures

The primary outcome was the time taken from chloroprocaine administration to surgical anesthesia (T6 sensory block). The secondary outcome was the quality of epidural anesthesia, as defined by a composite of the following factors: (1) failure to achieve a T10 bilateral block preoperatively in the delivery room, (2) failure to achieve a surgical block at T6 within 15 minutes of chloroprocaine administration, (3) requirement for intraoperative analgesia, (4) repeat neuraxial procedure, and (5) conversion to general anesthesia.

Results

Among 140 women (mean [SD] age, 30.1 [5.2] years), 70 were randomized to the DPE group, and 70 were randomized to the standard epidural group. The DPE group had a faster onset time to surgical anesthesia compared with the standard epidural group (median [IQR], 422 [290-546] seconds vs 655 [437-926] seconds; median [IQR] difference, 233 [104-369] seconds). The composite rates of lower quality anesthesia were 15.7% (11 of 70 women) in the DPE group and 36.3% (24 of 66 women) in the standard epidural group (odds ratio, 0.33; 95% CI, 0.14-0.74; P = .007).

Conclusions and Relevance

Anesthesia initiated following a DPE technique resulted in faster onset and improved block quality during epidural extension compared with initiation with a standard epidural technique. Further studies are needed to confirm these findings in the setting of intrapartum cesarean delivery.

Trial Registration

ClinicalTrials.gov Identifier: NCT03915574.

Optimizing systems to manage postpartum hemorrhage

Systems to optimize the management of postpartum hemorrhage must ensure timely diagnosis, rapid hemodynamic and hemostatic resuscitation, and prompt interventions to control the source of bleeding. None of these objectives can be effectively completed by a single clinician, and the management of postpartum hemorrhage requires a carefully coordinated interprofessional team. This article reviews systems designed to standardize hemorrhage diagnosis and response.

ED 90 of Intrathecal Chloroprocaine With Fentanyl for Prophylactic Cervical Cerclage: A Sequential Allocation Biased-Coin Design

BACKGROUND

Chloroprocaine is a short-acting local anesthetic that has been used for spinal anesthesia in outpatient surgery. There is limited experience with spinal chloroprocaine for prophylactic cervical cerclage placement. We sought to determine the effective dose of intrathecal chloroprocaine for 90% of patients (ED90) undergoing prophylactic cervical cerclage placement. We hypothesized that the ED90 of intrathecal chloroprocaine when combined with 10-ug fentanyl would be between 33 and 54 mg.

METHODS

In this prospective 2-center double-blinded study, we enrolled women undergoing prophylactic cervical cerclage placement under combined spinal-epidural anesthesia. A predetermined dose of intrathecal 3% chloroprocaine with fentanyl 10 ug was administered. The initial dose was 45-mg intrathecal chloroprocaine. Subsequent dose adjustments were determined based on the response of the previous subject using an up-down sequential allocation with a biased-coin design. A dose was considered effective if at least a T12 block was achieved, and there was no requirement for epidural activation or intraoperative analgesic supplementation during the procedure. The primary outcome was the ED90 of intrathecal chloroprocaine with fentanyl 10 ug. Secondary outcomes included duration of surgery, anesthetic side effects, time to resolution of motor and sensory block, time to achieve recovery room discharge criteria, and patient satisfaction with anesthetic care. Isotonic regression was used to estimate the ED90.

RESULTS

Forty-seven patients were enrolled into the study. Two patients were excluded (1 protocol violation and 1 failed block). In total, 45 patients completed the study. The estimated ED90 (95% confidence interval) for intrathecal chloroprocaine combined with fentanyl 10 ug was 49.5 mg (45.0-50.1 mg). The median (interquartile range [IQR]) duration of surgery was 15 (10-24) minutes. Resolution of the motor (Bromage 0) and sensory block took a median time of 60 (45-90) minutes and 90 (75-105) minutes, respectively. The median time to achieve recovery room discharge criteria was 150 (139-186) minutes. Satisfaction with anesthetic management was high in all patients. There were no reports of postdural puncture headache or transient neurological symptoms postoperatively.

CONCLUSIONS

The ED90 of intrathecal chloroprocaine combined with fentanyl 10 ug was 49.5 mg. Intrathecal chloroprocaine was associated with rapid block recovery and high patient satisfaction, which makes it well suited for outpatient obstetric procedures.

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.

Factors associated with non-survival from in-hospital maternal cardiac arrest: An analysis of Get With The Guidelines® (GWTG) data

INTRODUCTION

Maternal mortality has risen in the United States during the 21st century. Factors influencing outcome of maternal cardiac arrest (MCA) remain largely unexplored.

OBJECTIVE

We sought to further elucidate the factors affecting maternal death from in-hospital (IH) MCA.

METHODS

Our query of the American Heart Association's GWTG®-Resuscitation voluntary registry from 2000-2017 revealed 561 index cases of IH MCA with complete outcome data. Logistic regression was performed using hospital death as the primary outcome and included variables with a p value = 0.1 or less based upon univariate analysis. Age, race, year of arrest, pre-existing conditions, first documented pulseless rhythm and location of arrest were used in the model. Sensitivity analyses and assessment of variable interaction were also performed to test model stability. Institutional review deemed this research exempt from ethical approval.

RESULTS

Among 561 cases of MCA, 57.2% (321/561) did not survive to hospital discharge. IH death was not associated with maternal age, race and year of event. In the final model, IH death was significantly associated with pre-arrest hypotension/hypoperfusion (OR = 1.80 (95% CI, 1.16-2.79); p = 0.009). The occurrence of MCA outside of the delivery suite (referent group) or operating room was associated with a significantly higher risk of death: ICU/Post-Anesthesia Care Unit (PACU) (OR = 3.32 (95% CI, 2.00-5.52); p < 0.001) and ER/other (OR = 1.89 (95% CI, 1.15-3.11); p = 0.012). While MCA cases with a shockable vs. non-shockable first documented pulseless rhythm had similar outcomes, those with an indeterminate rhythm were less likely to die, (OR = 0.41(95% CI, 0.20-0.84); p = 0.014). In a sensitivity analysis, removal of the indeterminate group did not alter outcomes regarding first documented pulseless rhythm or arrest location. Area under the curve for the final model was 0.715 (95% CI 0.673-0.757).

CONCLUSIONS

Our study identified several novel factors associated with IH death of our MCA cohort. More research is required to further understand the pathophysiologic dynamics affecting outcomes of IH MCA in this unique population.

Obstetric Anesthesia During the COVID-19 Pandemic

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.

Characteristics and outcomes of maternal cardiac arrest: A descriptive analysis of Get with the guidelines data

BACKGROUND

Maternal mortality has risen in the United States in the twenty-first century, yet large cohort data of maternal cardiac arrest (MCA) are limited.

OBJECTIVE

We sought to describe contemporary characteristics and outcomes of in-hospital MCA.

METHODS

We queried the American Heart Association's Get with the Guidelines Resuscitation voluntary registry from 2000 to 2016 to identify cases of maternal cardiac arrest. All index cardiac arrests occurring in women aged 18-50 with a patient illness category designated as obstetric or location of arrest occurring in a delivery suite were included. Institutional review deemed that this research was exempt from ethical approval.

RESULTS

A total of 462 index events met criteria for MCA, with a mean age of 31 ± 7 years and a racial distribution of: 49.4% White, 35.3% Black and 15.3% Other/Unknown. While 32% had no pre-existing conditions or physiologic disorders, respiratory insufficiency (36.1%) and hypotension/hypoperfusion (33.3%) were the most common antecedent conditions. In most cases, the first documented pulseless rhythm was non-shockable; pulseless electrical activity (50.8%) or asystole (25.6%). Only 11.7% presented with a shockable rhythm; ventricular fibrillation (6.5%) or pulseless ventricular tachycardia (5.2%) while the initial pulseless rhythm was unknown in 11.9% of cases. Return of spontaneous circulation occurred in 73.6% but 68 (14.7%) had more than one arrest. The rate of survival to discharge was 40.7% overall; 37.3% with non-shockable rhythms, 33% with shockable rhythms and 64.3% with unknown presenting rhythms.

CONCLUSIONS

Maternal survival at hospital discharge in this cohort was less than 50%, lower than rates reported in other epidemiological datasets. More research is required in maternal resuscitation science and translational medicine to continue to improve outcomes and understand maternal mortality.

Cardiac arrest during pregnancy: ongoing clinical conundrum

While global maternal mortality has decreased in the last 25 years, the maternal mortality ratio in the United States has actually increased. Maternal mortality is a complex phenomenon involving multifaceted socioeconomic and clinical parameters including inequalities in access to health care, racial and ethnic disparities, maternal comorbidities, and epidemiologic ascertainment bias. Escalating maternal mortality underscores the importance of clinician preparedness to respond to maternal cardiac arrest that may occur in any maternal health care setting. Management of maternal cardiac arrest requires an interdisciplinary team familiar with the physiologic changes of pregnancy and the maternal resuscitation algorithm. Interventions intended to mitigate obstacles such as aortocaval compression, which may undermine the success of resuscitation interventions, must be performed concurrent to standard basic and advanced cardiac life support maneuvers. High-quality chest compressions and oxygenation must be performed along with manual left lateral uterine displacement when the uterine size is ≥20 weeks. While deciphering the etiology of maternal cardiac arrest, diagnoses unique to pregnancy and those of the nonpregnant state should be considered at the same time. If initial basic life support and advanced cardiac life support interventions fail to restore maternal circulation within 4 minutes of cardiac arrest, perimortem delivery is advised provided the uterus is ≥20 weeks' size. Preparations for perimortem delivery are best anticipated by the resuscitation team for the procedure to be executed opportunely. Following delivery, intraabdominal examination may reveal a vascular catastrophe, hematoma, or both. If return of spontaneous circulation has not been achieved, additional interventions may include cardiopulmonary bypass and/or extracorporeal membrane oxygenation. Simulation and team training enhance institution readiness for maternal cardiac arrest. Knowledge gaps are significant in the science of maternal resuscitation. Further research is required to fully optimize: relief of aortocaval compression during the resuscitation process, gestational age and timing of perimortem delivery, and other interventions that deviate from nonpregnant standard resuscitation protocol to achieve successful maternal resuscitation. A robust detailed national and international prospective database was recommended by the International Liaison Committee on Resuscitation in 2015 to facilitate further research unique to cardiac arrest during pregnancy that will produce optimal resuscitation techniques for maternal cardiac arrest.

The Validity of Discharge Billing Codes Reflecting Severe Maternal Morbidity

BACKGROUND

Discharge diagnoses are used to track national trends and patterns of maternal morbidity. There are few data regarding the validity of the International Classification of Diseases (ICD) codes used for this purpose. The goal of our study was to try to better understand the validity of administrative data being used to monitor and assess trends in morbidity.

METHODS

Hospital stay billing records were queried to identify all delivery admissions at the Massachusetts General Hospital for the time period 2001 to 2011 and the University of Michigan Health System for the time period 2005 to 2011. From this, we identified patients with ICD-9-Clinical Modification (CM) diagnosis and procedure codes indicative of severe maternal morbidity. Each patient was classified with 1 of 18 different medical/obstetric categories (conditions or procedures) based on the ICD-9-CM code that was recorded. Within each category, 20 patients from each institution were selected at random, and the corresponding medical charts were reviewed to determine whether the ICD-9-CM code was assigned correctly. The percentage of correct codes for each of 18 preselected clinical categories was calculated yielding a positive predictive value (PPV) and 99% confidence interval (CI).

RESULTS

The overall number of correctly assigned ICD-9-CM codes, or PPV, was 218 of 255 (86%; CI, 79%-90%) and 154 of 188 (82%; CI, 74%-88%) at Massachusetts General Hospital and University of Michigan Health System, respectively (combined PPV, 372/443 [84%; CI, 79-88%]). Codes within 4 categories (Hysterectomy, Pulmonary edema, Disorders of fluid, electrolyte and acid-base balance, and Sepsis) had a 99% lower confidence limit ≥75%. Codes within 8 additional categories demonstrated a 99% lower confidence limit between 74% and 50% (Acute respiratory distress, Ventilation, Other complications of obstetric surgery, Disorders of coagulation, Cardiomonitoring, Acute renal failure, Thromboembolism, and Shock). Codes within 6 clinical categories demonstrated a 99% lower confidence limit <50% (Puerperal cerebrovascular disorders, Conversion of cardiac rhythm, Acute heart failure [includes arrest and fibrillation], Eclampsia, Neurotrauma, and Severe anesthesia complications).

CONCLUSIONS

ICD-9-CM codes capturing severe maternal morbidity during delivery hospitalization demonstrate a range of PPVs. The PPV was high when objective supportive evidence, such as laboratory values or procedure documentation supported the ICD-9-CM code. The PPV was low when greater judgment, interpretation, and synthesis of the clinical data (signs and symptoms) was required to support a code, such as with the category Severe anesthesia complications. As a result, these codes should be used for administrative research with more caution compared with codes primarily defined by objective data.

Evaluation of a simulation-based curriculum for implementing a new clinical protocol

OBJECTIVE

To evaluate the implementation of a new clinical protocol utilizing on-unit simulation for team training.

METHODS

A prospective observational study was performed at the obstetrics unit of Von Voightlander Women's Hospital, Michigan, USA, between October 1, 2012 to April 30, 2013. All members of the labor and delivery team were eligible for participation. Traditional education methods and in-situ multi-disciplinary simulations were used to educate labor and delivery staff. Following each simulation, participants responded to a survey regarding their experience. To evaluate the effect of the interventions, paging content was analyzed for mandated elements and adherence to operating room entry-time tracking was examined.

RESULTS

In total, 51 unique individuals participated in 12 simulations during a 6-month period. Simulation was perceived as a valuable activity and paging content improved. Following the intervention, the inclusion of a goal time for reaching the operation room increased from 7% to 61% of pages and the proportion of patients entering to operating room within 10 minutes of the stated goal increased from 67% to 85%.

CONCLUSION

The training program was well received, and the accuracy of the communication and the goal set for reaching the operating room improved.

Cardiac Arrest in Pregnancy

This is the first scientific statement from the American Heart Association on maternal resuscitation. This document will provide readers with up-to-date and comprehensive information, guidelines, and recommendations for all aspects of maternal resuscitation. Maternal resuscitation is an acute event that involves many subspecialties and allied health providers; this document will be relevant to all healthcare providers who are involved in resuscitation and specifically maternal resuscitation.

Performance of racial and ethnic minority-serving hospitals on delivery-related indicators

OBJECTIVE

We sought to explore how racial/ethnic minority-serving hospitals perform on 15 delivery-related indicators, and examine whether indicators vary by race/ethnicity within the same type of hospitals.

STUDY DESIGN

We used 2008 through 2011 linked State Inpatient Database and American Hospital Association data from 7 states, and designated hospitals with >50% of deliveries to non-Hispanic white, non-Hispanic black, and Hispanic women as white-, black-, and Hispanic-serving, respectively. We calculated indicator rates per 1000 deliveries by hospital type and, separately, for non-Hispanic white, non-Hispanic black, and Hispanic women within each hospital type. We fitted multivariate Poisson regression models to examine associations between delivery-related indicators and patient and hospital characteristics by hospital type.

RESULTS

White-serving hospitals offer obstetric care to an older and wealthier population than black- or Hispanic-serving hospitals. Rates of the most prevalent indicators examined (complicated vaginal delivery, complicated cesarean delivery, obstetric trauma) were lowest in Hispanic-serving hospitals. Generally, indicator rates were similar in Hispanic- and white-serving hospitals. Black-serving hospitals performed worse than other hospitals on 12 of 15 indicators. Indicator rates varied greatly by race/ethnicity in white- and Hispanic-serving hospitals, with non-Hispanic blacks having 1.19-3.27 and 1.15-2.68 times higher rates than non-Hispanic whites, respectively, for 11 of 15 indicators. Conversely, there were few indicator rate differences by race/ethnicity in black-serving hospitals, suggesting an overall lower performance of these hospitals compared to white- and Hispanic-serving hospitals.

CONCLUSION

We found considerable differences in delivery-related indicators by hospital type and patients' race/ethnicity. Obstetric care quality measures are needed to track racial/ethnic disparities at the facility and population levels.

The use of postpartum hemorrhage protocols in United States academic obstetric anesthesia units

BACKGROUND

Postpartum hemorrhage (PPH) is the leading cause of severe maternal morbidity, cardiac arrest, and death during the hospitalization for childbirth. Protocol-driven care has been associated with improved outcomes in many settings; the National Partnership for Maternal Safety now recommends that PPH protocols be implemented in every labor and delivery unit in the United States. In this study, we sought to identify the level of PPH protocol availability in academic United States obstetric units. We hypothesized that the majority (>80%) of academic obstetric anesthesia units would have a PPH protocol in place.

METHODS

A survey was developed by an expert panel. Domains included hospital characteristics, availability of PPH protocol or plans to develop such a protocol, and protocol components included in the upcoming National Partnership for Maternal Safety obstetric hemorrhage safety bundle initiative. The electronic survey was emailed to the 104 directors of United States academic obstetric anesthesia units. Responses were stratified by PPH protocol availability as appropriate. Univariate statistics were used to characterize survey responses and the probability distribution for PPH protocol availability was estimated using the binomial distribution.

RESULTS

The survey response rate was 58%. The percentage of responding units with a PPH protocol was lower than hypothesized (P = 0.03); there was a PPH protocol in 67% of responding units (N = 40, 95% confidence interval [CI]: 53%-78%). The median annual delivery volume for responding units with PPH protocol was 3900 vs 2300 for units without PPH protocol (P = 0.002), with no difference in cesarean delivery rate (P = 0.73) or observed PPH rate (P = 0.69). There was no difference in annual delivery volume between responding and nonresponding hospitals (P = 0.06), suggesting that academic centers with delivery volume >3200 births per year are more likely than smaller volume hospitals to have a PPH protocol in place (odds ratio 3.16 (95% CI: 1.01-9.90). Adjusting for delivery volume among nonresponding hospitals, we estimate that 67% (95% CI: 55%-77%) of all academic obstetric anesthesia units had a PPH protocol in place at the time of this survey. Institutional processes for escalation do not correlate with the presence of a PPH protocol. There was a massive transfusion protocol in 95% of units with a PPH protocol and in 90% of units without (95% CI of difference: -7% to 7%). A PPH code team or rapid response team was available in 57% of responding institutions, with no difference between units with or without a PPH protocol [mean difference 4%, 95% CI (-24% to 32%)].

CONCLUSIONS

Despite increasing emphasis on national quality improvement in patient safety, there are no PPH protocols in at least 20% of U.S. academic obstetric anesthesia units. Delivery volume is the most important variable predicting the presence of a PPH protocol. National efforts to ensure universal presence of a PPH protocol in all academic centers will achieve the greatest impact by focusing on small-volume facilities. Future work is needed to evaluate and facilitate PPH implementation in nonacademic obstetric units.

Development of a comorbidity index for use in obstetric patients

OBJECTIVE

To develop and validate a maternal comorbidity index to predict severe maternal morbidity, defined as the occurrence of acute maternal end-organ injury, or mortality.

METHODS

Data were derived from the Medicaid Analytic eXtract for the years 2000-2007. The primary outcome was defined as the occurrence of maternal end-organ injury or death during the delivery hospitalization through 30 days postpartum. The data set was randomly divided into a two-thirds development cohort and a one-third validation cohort. Using the development cohort, a logistic regression model predicting the primary outcome was created using a stepwise selection algorithm that included 24-candidate comorbid conditions and maternal age. Each of the conditions included in the final model was assigned a weight based on its beta coefficient, and these were used to calculate a maternal comorbidity index.

RESULTS

The cohort included 854,823 completed pregnancies, of which 9,901 (1.2%) were complicated by the primary study outcome. The derived score included 20 maternal conditions and maternal age. For each point increase in the score, the odds ratio for the primary outcome was 1.37 (95% confidence interval [CI] 1.35-1.39). The c-statistic for this model was 0.657 (95% CI 0.647-0.666). The derived score performed significantly better than available comorbidity indices in predicting maternal morbidity and mortality.

CONCLUSION

This new maternal comorbidity index provides a simple measure for summarizing the burden of maternal illness for use in the conduct of epidemiologic, health services, and comparative effectiveness research.

LEVEL OF EVIDENCE

II.

Epidemiology of obstetric-related ICU admissions in Maryland: 1999-2008*

OBJECTIVE

To define the prevalence, indications, and temporal trends in obstetric-related ICU admissions.

DESIGN

Descriptive analysis of utilization patterns.

SETTING

All hospitals within the state of Maryland.

PATIENTS

All antepartum, delivery, and postpartum patients who were hospitalized between 1999 and 2008.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We identified 2,927 ICU admissions from 765,598 admissions for antepartum, delivery, or postpartum conditions using appropriate International Classification of Diseases, 9th Revision, Clinical Modification codes. The overall rate of ICU utilization was 419.1 per 100,000 deliveries, with rates of 162.5, 202.6, and 54.0 per 100,000 deliveries for the antepartum, delivery, and postpartum periods, respectively. The leading diagnoses associated with ICU admission were pregnancy-related hypertensive disease (present in 29.9% of admissions), hemorrhage (18.8%), cardiomyopathy or other cardiac disease (18.3%), genitourinary infection (11.5%), complications from ectopic pregnancies and abortions (10.3%), nongenitourinary infection (10.1%), sepsis (7.1%), cerebrovascular disease (5.8%), and pulmonary embolism (3.7%). We assessed for changes in the most common diagnoses in the ICU population over time and found rising rates of sepsis (10.1 per 100,000 deliveries to 16.6 per 100,000 deliveries, p = 0.003) and trauma (9.2 per 100,000 deliveries to 13.6 per 100,000 deliveries, p = 0.026) with decreasing rates of anesthetic complications (11.3 per 100,000 to 4.7 per 100,000, p = 0.006). The overall frequency of obstetric-related ICU admission and the rates for other indications remained relatively stable.

CONCLUSIONS

Between 1999 and 2008, 419.1 per 100,000 deliveries in Maryland were complicated by ICU admission. Hospitals providing obstetric services should plan for appropriate critical care management and/or transfer of women with severe morbidities during pregnancy.

Peripartum management of dual antiplatelet therapy and neuraxial labor analgesia after bare metal stent insertion for acute myocardial infarction

A 31-year-old woman at 32 weeks' gestation presented with an ST segment elevation myocardial infarction with subsequent bare metal stent placement. A multidisciplinary team coordinated the delivery plan, including anticoagulation and delivery mode. Because the patient was at high risk for stent thrombosis, clopidogrel was discontinued after 4 weeks and bridged with eptifibatide for 7 days. Eptifibatide was stopped for induction of labor. Twelve hours after eptifibatide was discontinued, hemostatic function was assessed with thromboelastography before initiating neuraxial analgesia. A successful operative vaginal delivery was performed, followed by an uncomplicated recovery. Clopidogrel was resumed 24 hours postpartum.

The risk and outcomes of epidural hematomas after perioperative and obstetric epidural catheterization: a report from the Multicenter Perioperative Outcomes Group Research Consortium

BACKGROUND

In this study, we sought to determine the frequency and outcomes of epidural hematomas after epidural catheterization.

METHODS

Eleven centers participating in the Multicenter Perioperative Outcomes Group used electronic anesthesia information systems and quality assurance databases to identify patients who had epidural catheters inserted for either obstetrical or surgical indications. From this cohort, patients undergoing laminectomy for the evacuation of hematoma within 6 weeks of epidural placement were identified.

RESULTS

Seven of 62,450 patients undergoing perioperative epidural catheterizations developed hematoma requiring surgical evacuation. The event rate was 11.2 × 10(-5) (95% confidence interval [CI], 4.5 × 10(-5) to 23.1 × 10(-5)). Four of the 7 had anticoagulation/antiplatelet therapy that deviated from American Society of Regional Anesthesia guidelines. None of 79,837 obstetric patients with epidural catheterizations developed hematoma (upper limit of the 95% CI, 4.6 × 10(-5)). The hematoma rate in obstetric epidural catheterizations was significantly lower than in perioperative epidural catheterizations (P = 0.003).

CONCLUSIONS

In this series, the 95% CI for the frequency of epidural hematoma requiring laminectomy after epidural catheter placement for perioperative anesthesia/analgesia was 1 event per 22,189 placements to 1 event per 4330 placements. Risk was significantly lower in obstetric epidurals.

Peripartum hysterectomy in the United States: nationwide 14 year experience

OBJECTIVE

The objective of the study was to examine the trends in the rate of peripartum hysterectomy and the contribution of changes in maternal characteristics to these trends.

STUDY DESIGN

This was a cross-sectional study of peripartum hysterectomy identified from hospitalizations for delivery recorded in the 1994-2007 Nationwide Inpatient Sample.

RESULTS

The overall rate of peripartum hysterectomy increased by 15% during the study period. The rate of hysterectomy for abnormal placentation increased by 1.2-fold; adjustment for previous cesarean delivery explained nearly all of this increase. The rate of hysterectomy for uterine atony following repeat cesarean delivery increased nearly 4-fold, following primary cesarean delivery approximately 2.5-fold, and following vaginal delivery about 1.5-fold. This fast growing trend in peripartum hysterectomy secondary to uterine atony was also largely explained by increasing rates of primary and repeat cesareans.

CONCLUSION

Rates of peripartum hysterectomy increased substantially in the United States from 1994 to 2007; much of this increase was due to rising rates of cesarean delivery.

What's new in obstetric anesthesia?

The current article covers some of the major themes that emerged in 2009 in the fields of obstetric anesthesiology, obstetrics, and perinatology, with a special emphasis on the implications for the obstetric anesthesiologist.

Delayed time to defibrillation after intraoperative and periprocedural cardiac arrest

BACKGROUND

Delay in defibrillation (more than 2 min) is associated with worse survival in patients with a cardiac arrest because of ventricular fibrillation or pulseless ventricular tachycardia in intensive care units and inpatient wards.

METHODS

We tested the relationship between delayed defibrillation and survival from intraoperative or periprocedural cardiac arrest, adjusting for baseline patient characteristics. The analysis was based on data from 865 patients who had intraoperative or periprocedural cardiac arrest caused by ventricular fibrillation or pulseless ventricular tachycardia in 259 hospitals participating in the National Registry of Cardiopulmonary Resuscitation.

RESULTS

The median time to defibrillation was less than 1 min (interquartile range, <1 to 1 min). Delays in defibrillation occurred in 119 patients (13.8%). Characteristics associated with delayed defibrillation included pulseless ventricular tachycardia and noncardiac admitting diagnosis. The association between delayed defibrillation and survival to hospital discharge differed for periprocedural and intraoperative cardiac arrests (P value for interaction = 0.003). For patients arresting outside the operating room, delayed defibrillation was associated with a lower probability of surviving to hospital discharge (31.6% vs. 62.1%, adjusted odds ratio 0.49; 95% CI 0.27, 0.88; P = 0.018). In contrast, delayed defibrillation was not associated with survival for cardiac arrests in the operating room (46.8% vs. 39.6%, adjusted odds ratio 1.23, 95% CI 0.70, 2.19, P = 0.47).

CONCLUSIONS

Delays in defibrillation occurred in one of seven cardiac arrests in the intraoperative and periprocedural arenas. Although delayed defibrillation was associated with lower rates of survival after cardiac arrests in periprocedural areas, there was no association with survival for cardiac arrests in the operating room.

A systematic review of randomized controlled trials that evaluate strategies to avoid epidural vein cannulation during obstetric epidural catheter placement

BACKGROUND

In this systematic review, we evaluated the evidence for seven strategies which have been proposed to minimize the incidence of epidural vein cannulation during lumbar epidural catheter placement in pregnant women.

METHODS

Multiple databases were searched to identify prospective, randomized, controlled trials between December 1966 and October 2007 that evaluated methods to avoid epidural vein cannulation after lumbar epidural catheter placement in pregnant women. Published trials were evaluated using a quality assessment tool, and results were combined to evaluate efficacy to prevent epidural vein cannulation.

RESULTS

Of 90 trials screened, 30 trials were included (n = 12,738 subjects). Five strategies reduce the risk of epidural vein cannulation: the lateral as opposed to sitting position (six trials, mean (sd) quality score = 35% [11%], odds ratio (OR) 0.53 [95% confidence interval (CI) 0.32-0.86]), fluid administered through the epidural needle before catheter insertion (8 trials, quality score 48% [18%], OR 0.49 [95% CI 0.25-0.97]), single rather than multiorifice catheter (5 trials, quality score 30% [6%], OR 0.64 [95% CI 0.45-0.91]), a wire-embedded polyurethane compared with polyamide epidural catheter (1 trial, 31%, plus 4 unscored abstracts, OR 0.14 [95% CI 0.06-0.30]) and catheter insertion depth < or =6 cm (2 trials, 47% [11%], OR 0.27 [95% CI 0.10-0.74]). The paramedian as opposed to midline needle approach and smaller epidural needle or catheter gauges do not reduce the risk of epidural vein cannulation.

CONCLUSION

The risk of intravascular placement of a lumbar epidural catheter in pregnancy may be reduced with the lateral patient position, fluid predistension, a single orifice catheter, a wire-embedded polyurethane epidural catheter and limiting the depth of catheter insertion to 6 cm or less. In general, low manuscript quality weakens the strength of these conclusions.

Internal carotid artery dissection: an unusual cause of postpartum headache

We report a case of postpartum headache caused by internal carotid artery dissection in a 36-year-old woman following uneventful epidural analgesia for spontaneous labor and vaginal delivery. Cervicocerebral arterial dissection requires rapid diagnosis and anticoagulation to prevent thrombus formation and to avoid secondary cerebral thromboembolism. Fortunately, our patient suffered ischemic symptoms, but no permanent neurologic deficit. Anesthesiologists should consider carotid artery dissection in the differential diagnosis of postpartum headache.

Survey of obstetric providers’ views on the anesthetic risks of maternal obesity

BACKGROUND

Maternal obesity is increasing in prevalence and associated with numerous complications. Surveys document that obstetricians recognize the obstetric and perinatal health risks of maternal obesity. To determine if they recognize the anesthetic risks and discuss them antenatally with obese patients, we surveyed all obstetric providers at a university-affiliated obstetric unit.

METHODS

The survey listed complications of obesity and pregnancy sampled from the literature, including eight anesthetic complications, ten prenatal obstetric complications, ten intrapartum or postpartum obstetric complications, five medical complications and five neonatal complications. Respondents reported if and when they routinely discuss each. Reported routine discussion rates were averaged across respondents and complication categories. We postulated that anesthetic aspects would be discussed less frequently than others.

RESULTS

Thirty-six of the 55 obstetric providers responded (65.5%). On average, anesthetic complications were discussed during prenatal care 13.5% of the time, less often than prenatal obstetric complications (48.5%, Wilcoxon signed rank test, P<0.0001), intrapartum or postpartum obstetric complications (40.0%, Wilcoxon signed rank test, P<0.0001) and medical complications (35.0%, Wilcoxon signed rank test, P=0.0001). The survey failed to demonstrate a statistically significant difference in the rate of discussion between anesthetic and neonatal complications (13.5% vs. 22.2%, Wilcoxon signed rank test, P=0.05). Twenty-four respondents reported that they did not routinely discuss any of the listed anesthetic complications with their obese patients in the prenatal period.

CONCLUSIONS

This preliminary study suggests that antenatal education about the anesthetic implications of obesity may not be part of routine prenatal care for obese pregnant women.