Brenda A. Bucklin

Practice guidelines for obstetric anesthesia: An updated report by the American Society of Anesthesiologists Task Force on obstetric anesthesia

PRACTICE guidelines are systematically developed recommendations that assist the practitioner and patient in making decisions about health care. These recommendations may be adopted, modified, or rejected according to clinical needs and constraints and are not intended to replace local institutional policies. In addition, practice guidelines are not intended as standards or absolute requirements, and their use cannot guarantee any specific outcome. Practice guidelines are subject to revision as warranted by the evolution of medical knowledge, technology, and practice. They provide basic recommendations that are supported by a synthesis and analysis of the current literature, expert opinion, open forum commentary, and clinical feasibility data. This update includes data published since the “Practice Guidelines for Obstetrical Anesthesia” were adopted by the American Society of Anesthesiologists in 1998; it also includes data and recommendations for a wider range of techniques than was previously addressed.

Obstetric anesthesia workforce survey : Twenty-year update

A dvances and changes in any medical specialty are often defined and detected by surveys. This is particularly true in obstetric anesthesia, especially given the complications arising from medicolegal, financial, maternal, and fetal considerations. Economic pressures, payment variations, decreased numbers of anesthesia providers, patient expectations, and technical aspects have challenged obstetric anesthesia practice. This 2001 obstetric anesthesia workforce survey was performed in conjunction with the Society from Obstetric Anesthesia and Perinatology to estimate and assess current trends and identify potential areas for improvement. A stratified random sample frame of 1300 hospitals was selected. The institutions were stratified based on geographic region and number of births for that year (stratum I, >1500 births; II, 500–1499 births; and III, 100–500 births). Three key labor and delivery personnel were identified at each institution that responded to the initial query. These personnel included from each hospital the chief of anesthesiology, the chief of obstetrics, and the labor and delivery manager. The number of hospitals providing obstetric care decreased from 4163 in 1981 to 3545 in 1992, to 3160 in 2001. A substantial decrease in stratum III facilities occurred between 1992 and 2001 (1603 down to 1081). A total of 378 of the 1300 initially sampled hospitals responded to the request for contact information (29% overall response). In the anesthesiology survey, the response rate was 57% and that for the obstetrics survey was 45%. In the labor and delivery manager survey, the rate of response was 75%. An overall increase in the percent of maternity cases using regional analgesia for labor was noted across all strata. The use of epidural analgesia for labor increased compared with previous surveys; spinal analgesia was used in <10% of cases. Patient-controlled epidural analgesia was used in about 33% of stratum I and II hospitals but in only 18% of stratum III hospitals. For cesarean delivery, use of spinal anesthesia increased and use of epidural anesthesia decreased across all strata. Combined spinal-epidural anesthesia was used in <10% of cesarean deliveries in all strata. Availability of in-house regional analgesia during labor was reported by only 3% of the smallest hospitals. In-house coverage was available in 77% of stratum II hospitals, and only 3% of stratum III hospitals reported that regional analgesia for labor was unavailable. Across all strata in 2001, an anesthesiologist was slightly more often directly involved in the care of patients receiving regional analgesia for labor compared with 1981 and 1992 survey data. In stratum III hospitals, 34% of regional analgesics for labor were administered by independently practicing certified nurse anesthetists, with 14% administered by these personnel under the medical direction of nonanesthesiologist physicians. Pediatricians performed an average of 42% and 48% of neonatal resuscitations during cesarean deliveries in stratum I and II hospitals, respectively. Vaginal birth after cesarean delivery (VBAC) was allowed in 98% and 92% of stratum I and II hospitals, but only 68% of stratum III institutions. Only 25% to 30% of all patients attempted it across all strata. Based on the American College of Obstetricians and Gynecologists practice bulletin on VBAC, 40% of stratum III hospitals no longer perform VBAC, and stratum I and II hospitals reported a reduction in VBAC attempts. Across all strata, at least 60% of VBACs were successful. Most institutions in all strata required anesthesia providers to be in-house during epidural infusion. Between 63% and 94% of hospitals required providers to be in-house when women were attempting VBAC with regional analgesia. Although almost all hospitals allowed ambulation during labor, only about 50% allowed ambulation during epidural or combined spinal-epidural analgesia. Interestingly, only a very small percentage of patients actually ambulated. Across all strata, <10% of hospitals allowed labor floor nurses (LFNs) to reinstitute epidural infusions. LFNs could adjust infusion rates in 28% and 7% of stratum II and I hospitals, respectively. LFNs were allowed to administer epidural boluses in 13% and 3% of stratum II and I hospitals, respectively. Collection rates for professional fees for anesthesia for labor, vaginal and cesarean deliveries, and other surgical procedures steadily decreased from 1981 to 2001. Collection rates for cesarean delivery declined from 76% in 1981 to 70% in 1992 to 66% in 2001. Respective anesthesia collection rates for labor and vaginal delivery were 67%, 68%, and 60%, and for other surgical procedures, 85%, 74%, and 68%. Stratum I hospitals had the largest percentage of health maintenance organization payers, and stratum II and III institutions the largest percentage of Medicaid payers. Percentage payment of actual charges was similar among all groups of payers across all sizes of hospitals. The 2001 survey results indicate that, despite staffing and payment challenges in obstetric anesthesia care, availability of services and anesthesia personnel have improved.

Intrathecal opioids versus epidural local anesthetics for labor analgesia: A meta-analysis☆

Background and Objectives Some anesthesiologists contend that intrathecal opioid administration has advantages over conventional epidural techniques during labor. Randomized clinical trials comparing analgesia and obstetric outcome using single-injection intrathecal opioids versus epidural local anesthetics suggest that intrathecal opioids provide comparable analgesia with few serious side effects. This meta-analysis compared the analgesic efficacy, side effects, and obstetric outcome of single-injection intrathecal opioid techniques versus epidural local anesthetics in laboring women. Methods Relevant clinical studies were identified using electronic and manual searches of the literature covering the period from 1989 to 2000. Searches used the following descriptors: intrathecal analgesia, spinal opioids, epidural analgesia, epidural local anesthetics, and analgesia for labor. Data were extracted from 7 randomized clinical trials comparing analgesic measures, incidence of motor block, pruritus, nausea, hypotension, mode of delivery, and/or Apgar scores. Results Combined test results indicated comparable analgesic efficacy 15 to 20 minutes after injection with single-injection intrathecal opioid administration. Intrathecal opioid injections were associated with a greater incidence of pruritus (odds ratio, 14.01; 99% confidence interval, 6.9 to 28.3), but there was no difference in the incidence of nausea or in the method of delivery. Conclusions Published studies suggest that intrathecal opioids provide comparable early labor analgesia when compared with epidural local anesthetics. Intrathecal opioid administration results in a greater incidence of pruritus. The choice of technique does not appear to affect the method of delivery.

Postpartum tubal ligation : Safety, timing, and other implications for anesthesia

A network for transferring packet data in a frame structure, preferably mixed with isochronous data. The frame structure is a continuously repeating structure, with each frame having a number of time slots. Certain ones of the time slots are available for transmitting packet data. The packet data is re-timed, e.g., by using a FIFO to output the data nibble-wise as required by the frame structure. Information about variability in delays at the transmitting end is sent to the receiving end. The receiving end uses the information to eliminate the variability, such as by a variable delay FIFO, thus restoring/recreating the original packet and IFG timing. Preferably, the frame structure is translated to and from a packet structure to permit the present invention to be used with previously available packet circuitry such as a media access controller and a hub repeater circuit.

Pregnancy does not alter the threshold for lidocaine-induced seizures in the rat

Although altered effects of various anesthetics have been demonstrated during pregnancy, published studies have incompletely defined potential pregnancy-induced changes in the central nervous system toxicity of lidocaine. Accordingly, the seizure threshold for lidocaine was measured in three groups of mechanically ventilated rats breathing 70% N2O-30% O2: male (n = 21), nonpregnant female (n = 19), and pregnant female (n = 23). Lidocaine was administered intravenously at a constant rate of 2.3 mg.kg-1.min-1 while the electroencephalogram was monitored continuously. Total doses of lidocaine and the durations of lidocaine infusion necessary to induce seizure activity were similar among groups. Plasma lidocaine concentrations at the onset of electroencephalographic seizure activity were also similar among groups (male = 10.7 +/- 5.5, nonpregnant female = 12.1 +/- 4.9, pregnant female = 10.8 +/- 4.1 micrograms/mL). In a subset of each group, brain lidocaine concentrations at the onset of seizure activity were also measured, and again no differences among groups were observed (male = 17.4 +/- 6.3, nonpregnant female = 16.8 +/- 4.5, pregnant female = 16.7 +/- 4.2 micrograms/100 g wet wt). The authors conclude that there are no pregnancy-specific alterations in either plasma or brain concentration thresholds for central nervous system toxicity of lidocaine in rats.

Obstetric Anesthesia: The 1982 American College of Obstetricians and Gynecologists Standards and the Role of Robert E. Johnstone, M.D.

To the Editor:—In their recent obstetric anesthesia workforce survey, Bucklin et al. observed that anesthesiologists provided regional analgesia for labor more often in 2001 than in 1992 or 1981. Obstetricians provided correspondingly less, with the main decrease occurring between 1981 and 1992. In 1981, obstetricians provided 26, 31, and 46% of regional analgesia in the three sizes of institutions surveyed, whereas in 1992, they provided 0, 5, and 3%. Similarly obstetricians administered 3, 4, and 9% of anesthetics for cesarean deliveries in 1981 but none in 1992. Hawkins et al. and Lagasse and Santos previously noted these dramatic decreases between 1981 and 1992, relating them in part to concerns about medicolegal liability by obstetricians. The source of these liability concerns was the publication in 1982 of revised professional standards by the American College of Obstetricians and Gynecologists (ACOG). For the first time, ACOG discouraged the concurrent provision of both an anesthetic and a procedure by an obstetrician, a previously common occurrence, and required the inclusion of anesthesia departments in privileging practitioners for obstetric anesthesia. The fifth edition of the Standards for Obstetric-Gynecologic Services, published in 1982, states,

Gerard W. Ostheimer “what’s New in Obstetric Anesthesia” Lecture

IF physicians would read 2 articles per day of the 6 million medical articles published annually, in 1 yr, they would fall 82 centuries behind. Since 1975, the “What’s New in Obstetric Anesthesia” Lecture has been an integral part of the Society for Obstetric Anesthesia and Perinatology Annual Meeting. The Society for Obstetric Anesthesia and Perinatology was founded in 1968 to provide a forum for discussion of problems unique to the peripartum period. The society is comprised of anesthesiologists, obstetricians, pediatricians, and basic scientists who share an interest in the care of pregnant patients and newborns. After the death of Gerard W. Ostheimer, M.D., in 1995, the lecture was renamed the “Ostheimer What’s New in Obstetric Anesthesia Lecture” to celebrate the life and important contributions to regional and obstetric anesthesia of Dr. Ostheimer, former Professor of Anesthesiology at Brigham and Women’s Hospital (Boston, Massachusetts). Each year, the lecture provides a critical appraisal of the literature from the previous year with contributions from obstetric anesthesia, obstetrics, and neonatology. Nine hundred ninety references were selected and included in the 2005 36th Annual Meeting program syllabus. Although the lecture syllabus was not intended to be exhaustive, it represented less than 10% of the references published in those areas during 2004. This article focuses on four specific areas relevant to anesthesiologists who practice obstetric anesthesia: cardiac disease during pregnancy, preeclampsia, morbidity and mortality in pregnant patients, and risk management in obstetric anesthesia. These topics were selected for their clinical relevance as well as to provide the most novel and recent information about obstetrics and obstetric anesthesia complications.