Ultrasound-determined landmarks decrease pressure pain at epidural insertion site in immediate post-partum period

BACKGROUND

Women have blamed epidurals for their post-partum back pain for decades. Survey-based studies have shown similar incidence of chronic back pain between women who delivered with epidurals compared to those who did not. However, epidural insertion site pain has yet to be evaluated by a quantitative measure: pressure pain threshold (PPT). Algometer measured PPT has been shown to be accurate and reproducible in acute, chronic, and postoperative pain studies. This study determines the effect of ultrasound-based landmarks on the PPT at the epidural insertion site in the post-partum period.

METHODS

Participants were randomized into either the ultrasound or sham groups. In addition, a non-randomized control group (no epidural) participated. Ultrasound of the lumbar region was used to mark mid intervertebral levels in the US group but not in the sham group. Epidural were placed using the marks in the US group or palpated bony landmarks in the sham group. PPT at each intervertebral space measured before and after the use of epidural.

RESULTS

Epidural placement did significantly decreased PPT in US (68%) and US sham (79%) groups and less in the control group (21%). US group showed decreased PPT only at insertion site whereas US sham group also showed decreased PPT at insertion site and adjacent levels.

CONCLUSIONS

We showed that epidural placed with ultrasound-determined landmarks not only improves the success of epidural placement but also minimizes the number of intervertebral levels with decreased PPT.

Proposed diagnostic criteria for the case definition of amniotic fluid embolism in research studies

Amniotic fluid embolism is a leading cause of maternal mortality in developed countries. Our understanding of risk factors, diagnosis, treatment, and prognosis is hampered by a lack of uniform clinical case definition; neither histologic nor laboratory findings have been identified unique to this condition. Amniotic fluid embolism is often overdiagnosed in critically ill peripartum women, particularly when an element of coagulopathy is involved. Previously proposed case definitions for amniotic fluid embolism are nonspecific, and when viewed through the eyes of individuals with experience in critical care obstetrics, would include women with a number of medical conditions much more common than amniotic fluid embolism. We convened a working group under the auspices of a committee of the Society for Maternal-Fetal Medicine and the Amniotic Fluid Embolism Foundation whose task was to develop uniform diagnostic criteria for the research reporting of amniotic fluid embolism. These criteria rely on the presence of the classic triad of hemodynamic and respiratory compromise accompanied by strictly defined disseminated intravascular coagulopathy. It is anticipated that limiting research reports involving amniotic fluid embolism to women who meet these criteria will enhance the validity of published data and assist in the identification of risk factors, effective treatments, and possibly useful biomarkers for this condition. A registry has been established in conjunction with the Perinatal Research Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development to collect both clinical information and laboratory specimens of women with suspected amniotic fluid embolism in the hopes of identifying unique biomarkers of this condition.

Passive leg raising during pregnancy

OBJECTIVE

To determine if passive leg raising (PLR) significantly increases cardiac output in a cohort of healthy pregnant women during the third trimester.

STUDY DESIGN

Using a noninvasive monitor, baseline hemodynamic measurements for arterial blood pressure, systolic and diastolic blood pressure, heart rate, cardiac output, cardiac index, stroke volume, and systemic vascular resistances were obtained with patients in the semirecumbent position. Measurements were repeated after a 3-minute PLR maneuver in supine, right lateral decubitus, and left lateral decubitus positions.

RESULTS

After 10 minutes of bed rest, the cohort's mean baseline heart rate was 80 ± 12 beats/minute. Baseline stroke volume was 98 ± 14 mL, mean cardiac output was 7.8 ± 1.2 L/min, and mean cardiac index was 4.32 ± 0.63 L/min. The baseline systemic vascular resistance value was 893 ± 160 dynes/sec/cm(5). Baseline mean arterial blood pressure was 84 ± 11 mm Hg. Following a PLR maneuver in the supine position, heart rate decreased significantly. No difference was noted in other measurements. Findings were similar with PLR in the left lateral decubitus. PLR in the right lateral decubitus resulted in significantly decreased heart rate, cardiac output, and cardiac index.

CONCLUSIONS

PLR did not result in cardiac output recruitment in a cohort of healthy pregnant women during the third trimester.

Acute antihypertensive therapy in pregnancy-induced hypertension: is nicardipine the answer?

Hypertensive disorders in pregnancy constitute one of the most frequent medical complications during gestation. Unfortunately, maternal and perinatal mortality remains significant worldwide in this population. Not infrequently, patients with severe preeclampsia will need parenteral agents to achieve rapid blood pressure control to avoid end-organ damage. During the last decades, new antihypertensive medications have become available for management of hypertensive crisis. One of these agents is the calcium channel blocker nicardipine. Nicardipine has been used extensively in different clinical settings including neurosurgery, cardiothoracic surgery, transplant medicine, and internal medicine patients. Minimal data exist in the literature regarding the use of this medicine during pregnancy. The purpose of this article is to review the pharmacological properties of nicardipine, the available literature regarding its use during pregnancy, and potential interactions with other medicines used commonly in preeclampsia, as well as potential side effects directly affecting the peripartum period.

Influence of the Type of Anesthesia Provider on Costs of Labor Analgesia to the Texas Medicaid Program

Background

The Texas Medicaid Program (Medicaid) defines billable time for labor analgesia as face-to-face time; therefore, anesthesia providers determine billed time. The authors' goal was to determine the influence of anesthesia providers on labor analgesia costs billed to Medicaid.

Methods

Under the Freedom of Information Act, Medicaid provided data on claims paid for 6 months in 2001 for labor analgesia administered during the course of a vaginal delivery. Claims were either time based (codes 00946 or 00955) or a flat fee (codes 26311 or 26319). Using modifiers, the authors grouped time-based claims as either anesthesiologist group or certified registered nurse anesthetist (CRNA) group. The cost to Medicaid was based on the 2001 fee schedule. The conversion factor was 18.21 USD per American Society of Anesthesiologists unit. The flat-fee reimbursement was 152.50 USD. CRNA services were paid at 85% of the fee schedule. Average time per time claim, percent of providers with more than 4 h of billed time, and cost per claim were determined for each group. Providers with more than 120 claims (> 20 claims/month) were considered high-volume.

Results

The database included 21,378 claims (anesthesiologist group: 12,698 claims from 219 providers; CRNA group: 8,680 claims from 117 providers). For time-based claims, the average time per case was significantly higher in the CRNA group (146 min) than in the anesthesiologist group (105 min). The CRNA group cost to Medicaid (225.11 USD) was 19% more per claim than the anesthesiologist group (189.26 USD). The difference in cost per claim was greater among high-volume providers--213.10 USD for the CRNA group versus 168.76 USD for the anesthesiologist group. If a flat-fee program were instituted using the average cost per claim for all groups (203.81 USD), the Texas Medicaid program would save more than 500,000 USD annually.

Conclusions

The costs of labor analgesia billed to Texas Medicaid were 19% to 26% less per patient when provided by anesthesiologists than by CRNAs, despite lower per-unit reimbursement of CRNAs.

Mechanisms and management of an incomplete epidural block for cesarean section

Epidural blockade is an important option for anesthesia in parturients undergoing abdominal delivery. Despite the multiple benefits of this method, there is at least one significant downside--a relatively high occurrence of unsatisfactory anesthesia that requires intervention. Depending on the presumed mechanism of epidural block failure and other clinically relevant factors (e.g., timing of diagnosis, urgency of the procedure, and so forth), certain effective measures are recommended to successfully manage this demanding situation. In general, it is important to make every effort to make the pre-existing epidural effective or replace it with another regional technique, because overall, regional anesthesia is associated with significantly lower maternal mortality. It is important to identify a dysfunctional epidural block preoperatively before a maximum volume of local anesthetic has been administered. If catheter manipulation does not produce substantial improvement, and there is no time constraint, it is safe and reasonable to replace the epidural catheter. However, risks associated with excessive volume of local anesthetic should be kept in mind. Additional epidural injections or a second catheter placement might be considered under special circumstances. Single-shot spinal anesthesia after a failed epidural may provide fast onset and reliable surgical anesthesia. Available data, although limited and contradictory, suggest the possibility of unpredictably high or total spinal anesthesia. Many authors, however, believe that appropriate precautions and modifications in technique make this a safe alternative. These modifications include limiting the amount of epidural local anesthetic administered when diagnosing a nonfunctioning epidural and decreasing the dose of intrathecal local anesthetic by 20% to 30%. If there is no documented block when the spinal is inserted, and more than 30 minutes have passed from the last epidural dose, it is probably safe to use a normal dose of local anesthetic. Continuous spinal anesthesia with a macro catheter might be a dependable alternative, particularly if large amounts of local anesthetic have already been used or the patient's airway is a cause for concern. Although there are no reports of combined spinal epidural anesthesia being used in this context, it would appear to be an attractive alternative. It allows the anesthesiologist to give smaller doses intrathecally, while still offering the flexibility of augmenting the block if needed. When inadequate epidural block becomes apparent during surgery there are limited alternatives. Depending on the origin and the pattern of inadequate anesthesia, options may include psychological support, supplementation with a variety of inhalational and intravenous agents, and local anesthetic infiltration. Induction of general anesthesia is typically left as a backup option, but must be strongly considered if the patient continues to have pain/discomfort.

Embolism during pregnancy: thrombus, air, and amniotic fluid

Pulmonary embolism is the primary cause of acute respiratory decompensation during pregnancy. Regardless of the nature of the embolism, a high index of suspicion, early diagnosis, and aggressive resuscitation need to be instituted to achieve a successful maternal and fetal outcome. Several clinical characteristics will assist practitioners to distinguish among the different forms of embolism and to institute specific measures of treatment.