Lawrence C. Tsen

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.

Alternative medicine use in presurgical patients.

Background A dramatic increase in the use of complementary and alternative medicines has been observed. The use of such remedies in the presurgical population has implications for the anesthesiologist because of the potential for drug interactions, side effects, and medical liability. This study was undertaken to quantify the use of herbal remedies and vitamins in the presurgical population of a large tertiary care center. Methods A one-page questionnaire was distributed to all patients presenting for evaluation in the preoperative clinic over an 11-week period. Patients answered questions regarding use of prescription and nonprescription medications, herbal remedies, and vitamins. Results Twenty-two percent of presurgical patients reported the use of herbal remedies, and 51% used vitamins. Women and patients aged 40–60 yr were more likely to use herbal medicines. Over-the-counter medication use was strongly associated with herbal preparation use. The most commonly used compounds, from highest to lowest, included echinacea, gingko biloba, St. John’s wort, garlic, and ginseng. Conclusions Alternative medicine use is common in the preoperative period.

Is combined spinal-epidural analgesia associated with more rapid cervical dilation in nulliparous patients when compared with conventional epidural analgesia?

BACKGROUND The combined spinal-epidural technique provides rapid onset of labor analgesia and, anecdotally, is associated with labors of shorter duration. Epidural analgesia, by contrast, has been suggested to prolong labor modestly. It is unclear, however, whether more rapid cervical dilation in patients who receive combined spinal-epidural analgesia is a physiologic effect of the technique or an artifact of patient selection. The authors hypothesized that anesthetic technique may influence the rate of cervical dilation, and we compared the effects of combined spinalepidural with those of epidural analgesia on the rate of cervical dilation. METHODS One hundred healthy nulliparous parturients in spontaneous labor with singleton, vertex, full-term fetuses were enrolled in a double-blinded manner when their cervical dilation was less than 5 cm. The patients were randomly assigned to receive analgesia via a standardized combined spinal-epidural (n = 50) or epidural (n = 50) technique. Data were collected on cervical dilation, pain, sensory level, and motor blockade. RESULTS When regional analgesia was induced in comparable groups at a mean of 3 cm cervical dilation, the mean initial cervical dilation rates were significantly faster in the combined spinal-epidural group (mean values, 2.1 +/- 2.1 cm/h vs. 1 +/- 1 cm/h; P = 0.0008). Five parturients in the combined spinal-epidural group had a very rapid (> 5 cm/h) rate of mean initial cervical dilation, compared with none of the women in the epidural group. Overall mean cervical dilation rates in patients who achieved full cervical dilation were 2.3 +/- 2.6 cm/h and 1.3 +/- 0.71 cm/h (P = 0.0154) in the combined spinal-epidural and epidural groups, respectively. CONCLUSIONS In healthy nulliparous parturients in early labor, combined spinal-epidural analgesia is associated with more rapid cervical dilation compared with epidural analgesia. Further study is needed to elicit the cause and overall effect of this difference.

Patient satisfaction with preoperative assessment in a preoperative assessment testing clinic.

Preoperative Assessment Testing Clinics (PATCs) coordinate preoperative surgical, anesthesia, nursing, and laboratory care. Although such clinics have been noted to lead to efficiencies in perioperative care, patient experience and satisfaction with PATCs has not been evaluated. We distributed a one-page questionnaire consisting of satisfaction with clinical and nonclinical providers to patients presenting to our PATC over three different time periods. Eighteen different questions had five Likert scale options that ranged from excellent (5) to poor (1). We achieved a 71.4% collection rate. The average for the subscale that indicated overall satisfaction was 4.48 ± 0.67 and the average for the total instrument was 4.46 ± 0.55. Although the highest scores were given for subscales describing the anesthesia, nurse, and lab, only the anesthesia subscale improved with time (P = 0.007). The subscale that involved information and communication had the highest correlation with the overall satisfaction subscale (r = 0.76; P < 0.0001). The satisfaction with the total duration of the clinic visit (3.71 ± 1.26) was significantly less (P < 0.0001) than the satisfaction to the other items. The authors conclude that the practitioner and functional aspects of the preoperative visit have a significant impact on patient satisfaction, with information and communication versus the total amount of time spent being the most positive and negative components, respectively.

Value of Preoperative Clinic Visits in Identifying Issues with Potential Impact on Operating Room Efficiency

Background:Preoperative clinics have been shown to decrease operating room delays and cancellations. One mechanism for this positive economic impact is that medical issues are appropriately identified and necessary information is obtained, so that knowledge of the patients’ status is complete before the day of surgery. In this study, the authors describe the identification and management of medical issues in the preoperative clinic. Methods:All patients coming to the Preoperative Clinic during a 3-month period from November 1, 2003, through January 31, 2004, at the Brigham and Women’s Hospital, Boston, Massachusetts, were studied. Data were collected as to the type of issue, information needed to resolve the issue, time to retrieve the information, cancellation and delay rates, and the effect on management. Results:A total of 5,083 patients were seen in the preoperative clinic over the three-month period. A total of 647 patients had a total of 680 medical issues requiring further information or management. Of these issues, 565 were thought to require further information regarding known medical problems, and 115 were new medical problems first identified in the clinic. Most of the new problems required that a new test or consultation be done, whereas most of the old problems required retrieval of information existing from outside medical centers. New problems had a far greater probability of delay (10.7%) or cancellation (6.8%) than old problems (0.6% and 1.8%, respectively). Conclusions:The preoperative evaluation can identify and resolve a number of medical issues that can impact efficient operating room resource use.

Clinical effects and maternal and fetal plasma concentrations of 0.5% epidural levobupivacaine versus bupivacaine for cesarean delivery.

BACKGROUND Bupivacaine exists as a mixture of two enantiomers, levobupivacaine and dexbupivacaine. Data suggest that levobupivacaine has equal local anesthetic potency, with reduced potential for central nervous system and cardiovascular toxicity. The present study compares the efficacy of 0.5% levobupivacaine with 0.5% bupivacaine for epidural anesthesia in parturients undergoing elective cesarean delivery. METHODS Sixty healthy obstetric patients undergoing elective cesarean delivery with epidural anesthesia completed the study. Patients were randomized to receive 30 ml of either 0.5% levobupivacaine or 0.5% bupivacaine in a double-blind fashion. The efficacy endpoint measures included onset, offset, and quality of anesthesia. Neonatal blood gas analyses, Apgar score determinations, and neurobehavioral examinations were performed. Venous samples for pharmacokinetic studies and serial electrocardiograms were obtained in 10 patients in each group. RESULTS Levels of sensory block, motor block, muscle relaxation, and overall quality of anesthesia did not differ between groups. The frequency of hypotension was 84.4% in the levobupivacaine group and 100% for the bupivacaine group (P < or = 0.053). No significant difference in observed maximum concentration of drug after dosing or area under the plasma drug concentration versus time curve were seen. The maximum concentrations were 1.017 and 1.053 microg/ml, and the areas were 4.082 and 3.765 h(microg/ml) for the levobupivacaine and bupivacaine groups, respectively. Umbilical vein-to-maternal vein ratios were 0.303 for the levobupivacaine group and 0.254 for the bupivacaine group. CONCLUSIONS The use of epidural 0.5% levobupivacaine for cesarean delivery results in equally efficacious anesthesia compared with 0.5% bupivacaine. Pharmacokinetic parameters were similar in the two groups.

Herbal medicine use in parturients

Alternative medicine use has increased dramatically over the last decade. Recently a 22% incidence of herbal medicine use in presurgical patients was reported. Of concern is the potential for these medications to cause adverse drug-herb interactions or other effects such as bleeding complications. We sought to determine the prevalence and pattern of use of herbal remedies in parturients. A one-page questionnaire examining the use of all prescription and nonprescription medications, including herbal remedies, was sent to parturients expected to deliver within 20 wk who had preregistered with the hospital’s admissions office. Sixty-one percent of the parturients responded to the survey, with 7.1% of parturients reporting the use of herbal remedies. Only 14.6% of users considered them to be medications. Parturients in the 41–50 yr age bracket (5.6% of parturients) were the most likely to use herbal remedies (17.1% rate of use in this age group). Many parturients who took herbal remedies (46%) did so on the recommendation of their health care provider.

General anesthesia for cesarean section at a tertiary care hospital 1990–1995: indications and implications

Complications of general anesthesia for cesarean section remain the leading cause of anesthesia-related maternal mortality. General anesthesia, however, is becoming less popular for obstetric anesthesia, and thus fewer cesarean sections are conducted using this technique. As the number of general anesthesia cases decrease, the number of difficult intubations witnessed and managed by residents decreases. In addition, patients who undergo general anesthesia may have co-morbidities which, while not contraindicating regional anesthesia, may increase the risk of providing anesthesia. We reviewed the medical records of 6 calendar years (1990-1995) at our busy tertiary center, to determine patient demographics, indications for cesarean section, indications for general anesthesia, time of day, and complications related to airway management. From 1990 through 1995, cesarean sections under general anesthesia decreased from 7.2% to 3.6% (P=0.0001), however, they were performed on parturients with more maternal diseases (17.2% to 35.8%; P=0.0034). Although the incidence of difficult intubations in those years ranged from 16.3% to 1.3%, only one failed intubation with resultant maternal mortality occurred. Few residency programs offer instruction on the difficult airway in the parturient population. Organized airway management programs specifically for the obstetric population may assist efforts to decrease the morbidity and mortality associated with the provision of general anesthesia for cesarean section.

Cardiac Arrest during Hospitalization for Delivery in the United States, 1998–2011

Background:The objective of this analysis was to evaluate the frequency, distribution of potential etiologies, and survival rates of maternal cardiopulmonary arrest during the hospitalization for delivery in the United States. Methods:By using data from the Nationwide Inpatient Sample during the years 1998 through 2011, the authors obtained weighted estimates of the number of U.S. hospitalizations for delivery complicated by maternal cardiac arrest. Clinical and demographic risk factors, potential etiologies, and outcomes were identified and compared in women with and without cardiac arrest. The authors tested for temporal trends in the occurrence and survival associated with maternal arrest. Results:Cardiac arrest complicated 1 in 12,000 or 8.5 per 100,000 hospitalizations for delivery (99% CI, 7.7 to 9.3 per 100,000). The most common potential etiologies of arrest included hemorrhage, heart failure, amniotic fluid embolism, and sepsis. Among patients with cardiac arrest, 58.9% of patients (99% CI, 54.8 to 63.0%) survived to hospital discharge. Conclusions:Approximately 1 in 12,000 hospitalizations for delivery is complicated by cardiac arrest, most frequently due to hemorrhage, heart failure, amniotic fluid embolism, or sepsis. Survival depends on the underlying etiology of arrest.

The Society for Obstetric Anesthesia and Perinatology Consensus Statement on the Management of Cardiac Arrest in Pregnancy

This consensus statement was commissioned in 2012 by the Board of Directors of the Society for Obstetric Anesthesia and Perinatology to improve maternal resuscitation by providing health care providers critical information (including point-of-care checklists) and operational strategies relevant to maternal cardiac arrest. The recommendations in this statement were designed to address the challenges of an actual event by emphasizing health care provider education, behavioral/communication strategies, latent systems errors, and periodic testing of performance. This statement also expands on, interprets, and discusses controversial aspects of material covered in the American Heart Association 2010 guidelines.