Joy L. Hawkins

Anesthesia-Related Maternal Mortality in the United States : 1979-2002

OBJECTIVE: To examine 12 years of anesthesia-related maternal deaths from 1991 to 2002 and compare them with data from 1979 to 1990, to estimate trends in anesthesia-related maternal mortality over time, and to compare the risks of general and regional anesthesia during cesarean delivery. METHODS: The authors reviewed anesthesia-related maternal deaths that occurred from 1991 to 2002. Type of anesthesia involved, mode of delivery, and cause of death were determined. Pregnancy-related mortality ratios, defined as pregnancy-related deaths due to anesthesia per million live births were calculated. Case fatality rates were estimated by applying a national estimate of the proportion of regional and general anesthetics to the national cesarean delivery rate. RESULTS: Eighty-six pregnancy-related deaths were associated with complications of anesthesia, or 1.6% of total pregnancy-related deaths. Pregnancy-related mortality ratios for deaths related to anesthesia is 1.2 per million live births for 1991–2002, a decrease of 59% from 1979–1990. Deaths mostly occurred among younger women, but the percentage of deaths among women aged 35–39 years increased substantially. Delivery method could not be determined in 14%, but the remaining 86% were undergoing cesarean delivery. Case-fatality rates for general anesthesia were 16.8 per million in 1991–1996 and 6.5 per million in 1997–2002, and for regional anesthesia were 2.5 and 3.8 per million, respectively. The resulting risk ratio between the two techniques for 1997–2002 was 1.7 (confidence interval 0.6–4.6, P=.2). CONCLUSION: Anesthetic-related maternal mortality decreased nearly 60% when data from 1979–1990 were compared with data from 1991–2002. Although case-fatality rates for general anesthesia are falling, rates for regional anesthesia are rising. LEVEL OF EVIDENCE: II

Epidural analgesia for labor and delivery.

A 30-year-old pregnant woman is undergoing induction of labor and is experiencing severe pain despite intravenous opioid administration. Epidural analgesia is recommended. Epidural analgesia involves the injection of a local anesthetic agent and an opioid analgesic agent into the lumbar epidural space. These agents diffuse across the dura and act on the spinal nerve roots. Rates of cesarean delivery are not increased with epidural analgesia.

Oral intake policies on labor and delivery: a national survey

STUDY OBJECTIVE To examine current policies on oral intake during labor among hospitals throughout the United States. DESIGN AND SETTING Anonymous questionnaire survey distributed to the directors of anesthesia and obstetrics departments of 740 hospitals. Completed surveys were then grouped by number of deliveries performed each year. MEASUREMENTS AND MAIN RESULTS A total of 2,265 surveys were distributed. Of that number, 902 (33% response rate) surveys, representing 740 U.S. hospitals, were returned. Of the surveys returned, 419 surveys were received from obstetricians and 401 surveys were received from anesthesiologists. Oral intake during labor is limited primarily to clear liquids, although hospitals with fewer deliveries allow significantly more oral intake during latent phase than do hospitals with larger services. Allowing nonclear liquids or solid foods is uncommon in either phase of labor, regardless of hospital size. CONCLUSIONS The results give an indication of oral intake policies used by labor and delivery units in the United States, and they may be helpful for obstetric services that are in the process of developing their own policies.

Maternal mortality in the United States: where are we going and how will we get there?

M aternal mortality is considered a basic health indicator that reflects the adequacy of health care (1). Although the maternal mortality rate (MMR) in the United States (US) is approximately 7.5 per 100,000, most studies suggest that the actual number of maternal deaths is larger because of the continuing problem of under reporting (2). Unfortunately, the goal of reducing the MMR to 5 per 100,000 suggested by the Surgeon General in 1980 has not been attained. Maternal mortality has decreased over the last half of the 20th century but preventable cases continue to occur. Thus, despite numerous improvements in health care, poor outcome in the parturient remains a major public health concern that follows us into the 21st century. Although the majority of the approximately 600,000 annual maternal deaths takes place in third-world countries, western Europe and the US are not immune. As we enter the new millennium, we should ask why these deaths continue and what can be done individually and as a profession to decrease the incidence? In this issue, Panchal et al. (3) review 13 yr of maternal mortality in the State of Maryland using a state-maintained database. By analyzing patient demographics and diagnosis and procedure codes for women who died during their admission for childbirth, these authors identified some medical and demographic risks associated with maternal mortality in their state. This is useful information for physicians and hospitals in Maryland and may also provide a model for other states to examine their maternal mortality data and thus help in efforts to develop important preventative intervention strategies. Panchal et al. (3) found a state delivery mortality ratio (maternal deaths per 100,000 live births) of 16.4, with marked year-to-year variability ranging from 5.9 to 29.6. This compares with the Centers for Disease Control and Prevention (CDC) estimate of a national maternal mortality of 7.5. Other risk factors identified for maternal mortality in their study were AfricanAmerican race (odds ratio [OR], 5.4), racial category other than African-American or White (OR, 12.2), Cesarean delivery (OR, 5.3), delivering in a “minor teaching hospital” (OR, 3.1), and being transferred from another hospital (OR, 6.2). As has been reported in other series, the MMR for women aged ,34 yr was 13.9 as compared with 23.9 with advanced maternal age. The five most common diagnoses associated with maternal mortality were preeclampsia/eclampsia, postpartum hemorrhage, pulmonary complications, cerebrovascular event, and embolism. Anesthesiarelated complications, although not on the top of the list, still accounted for more than 5% of the deaths. The Ninth Revision of the International Classification of Diseases (ICD-9), commonly used in similar studies, defined maternal death as “the death of a woman while pregnant or within 42 days of termination of pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes.” Recently, the tenth revision (ICD-10) has revised that definition to include “the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the cause of death.” It was hoped that the introduction of this new definition would allow better classification, especially in cases in which the cause of death in a pregnant patient was uncertain. Unfortunately, multiple definitions increase the confusion and have helped turn this subject into a quagmire. Results from studies using different definitions cannot be compared and incomplete databases provide information that is at best inaccurate and at worst wrong. When evaluating maternal deaths, under-reporting is the rule, rather than the exception, and may reach as much as 75% (4). Even in the UK, which has the best system for collecting this data, it has been suggested that underestimates are approximately 30% (5). Despite the importance of collecting and analyzing data regarding maternal mortality, in the US this data Accepted for publication February 27, 2001. Address correspondence to David J. Birnbach, MD, Department of Anesthesiology, St. Luke’s-Roosevelt Hospital Center, College of Physicians and Surgeons of Columbia University, Hospital Center, 1000 Tenth Avenue, New York, NY 10019.

Maternal morbidity and mortality: anesthetic causes

devastating to all involved; after all, only in the obstetric patient can mortality be 200%! Although infant mortality has declined steadily due to increased survival of preterm infants and prevention of SIDS, maternal mortality has remained approximately 7.5 maternal deaths per 100,000 live births over the last 15 years.1 The reason for the lack of improvement is unclear. More than half of maternal deaths are preventable hemorrhage, pregnancy-induced hypertension (PIH), infection, and ectopic pregnancy account for 59%. Anesthetic causes have fallen to a “respectable” #6 on the list of causes for maternal mortality in the United States. The causes of pregnancy-related deaths are:2

Excess in moderation: general anesthesia for cesarean delivery.

This editorial comments upon a national survey on current anesthesia practices for cesarean deliveries in the Czech Republic, abstracted above by Stourac et al. One of the main findings of the survey was that general anesthesia was administered in 44.4% of cesarean deliveries. Although the authors of the report indicated that this high rate of usage could be an indicator of lower quality health care, the author of this editorial questions whether this percentage is a reliable indicator, as there is no current evidence-based method to determine a preferable rate for general anesthesia in this context. The ideal rate for general anesthesia for cesarean delivery is unknown. There are several reasons why anesthesiologists might find general anesthesia less desirable for cesarean deliveries, including the interference with maternal-infant bonding, lack of immediate skin-to-skin contact, increased blood loss compared with regional anesthesia, inferior pain management following surgery, and an increased risk of thrombotic complications. However, there are also many situations in which general anesthesia would be preferable when immediate delivery is paramount, such as umbilical cord prolapse, significant placental abruption, prolonged fetal bradycardia in the absence of labor neuraxial analgesia, and maternal cardiac disease. A major reason that general anesthesia is avoided is that it is associated with a higher rate of complications during airway management. In the 1970s and 1980s, data indicated that general anesthesia resulted in a higher mortality rate. However, general anesthesia has become safer in recent years in wealthier countries thanks to the introduction of supraglottic airway devices, video laryngoscopes, adoption of difficult airway algorithms, and multidisciplinary simulations and team training to improve response to airway crises. Instead of focusing on the overall rate of general anesthesia, an alternative quality indicator might be the documentation of preanesthetic airway examinations in the Czech Republic. In 64% of elective cases in the survey where general anesthesia was used, patients refused neuraxial anesthesia. In another 9% of elective cases, the neuraxial anesthesia failed. The high rates of patient refusal and neuraxial failure might be more important outcomes on which to focus quality improvement. Proactive antepartum education to help patients understand why neuraxial anesthesia might be preferable might lower the rate of patient refusal. Ongoing education could also help anesthesiologists decrease the failure rate of neuraxial anesthesia. To improve patient outcomes in the Czech Republic, the author of this editorial recommends developing evidencebased guidelines for obstetric practice, requiring preoperative airway evaluations, documenting Mallampati scores, administering antibiotic prophylaxis before skin incision, reversing the effects of nondepolarizing muscle relaxants, and using pencil-point needles for spinal anesthesia.

Can we keep our mothers happy and our babies safe

Not every woman will require or request analgesia for her labour, and if she does, many pharmacologic and nonpharmacologic techniques are available for her. Neuraxial techniques, such as epidural, spinal, or combined spinalepidural, are the most effective forms of intrapartum pain relief and are used by the majority of labouring women in the United States and Canada. As the American Society of Anesthesiologists (ASA) and the American Congress of Obstetricians and Gynecologists note: ‘‘Of the various pharmacologic methods used for pain relief during labour and delivery, neuraxial anesthetic techniques (epidural, spinal, and combined spinal-epidural) are the most flexible, effective, and least depressing to the central nervous system, allowing for an alert participating woman and an alert neonate.’’ In this issue of the Journal, a metaanalysis by Wang et al. helps anesthesiologists clarify the safety profile of spinal or epidural opioids when used to optimize neuraxial techniques for labour analgesia. Their high-quality analysis of 21 trials with 2,859 participants shows that the addition of spinal or epidural opioids does not affect Apgar scores at one and five minutes, Neurological and Adaptive Capacity Scores (NACS) at two and 24 hr, or umbilical cord arterial or venous pH when they are used as adjuncts for neuraxial labour analgesia. The addition of opioids to spinal or epidural local anesthetics offers considerable benefit to the parturient in labour. The quality of the block is improved through their agonist activity on spinal mu receptors, and motor block is reduced because a lower concentration of local anesthetic is thus required to achieve a similar analgesic effect. The ASA practice guidelines for obstetric anesthesia support the use of neuraxial opioids stating: ‘‘The literature supports the induction of analgesia using epidural local anesthetics combined with opioids compared with equal concentrations of epidural local anesthetics without opioids for improved quality and longer duration of analgesia.’’ The guidelines go on to say: ‘‘Meta-analysis of the literature determined that low concentrations of epidural local anesthetics with opioids compared with higher concentrations of epidural local anesthetics without opioids are associated with reduced motor block.’’ The ASA recommendations for maintenance of epidural analgesia in labour state: ‘‘When a continuous epidural infusion of local anesthetic is selected, an opioid may be added to reduce the concentration of local anesthetic, improve the quality of analgesia, and minimize motor block. Adequate analgesia for uncomplicated labour and delivery should be administered with the secondary goal of producing as little motor block as possible by using dilute concentrations of local anesthetics with opioids.’’ In addition to improved quality of analgesia and reduced motor block, there may be another benefit from adding opioids to epidural medications, namely, a lower incidence of both local anesthetic systemic toxicity and high spinals due to unrecognized intravascular or intrathecal catheter placement. By adding opioids, the local anesthetic concentration can be reduced by roughly half, thus reducing the total milligram dose as well. Maternal risks associated with spinal or epidural opioids are minor and rare except for pruritus (Table). Although nausea is a concern with opioid use, there is little or no evidence that use of neuraxial opioids (as opposed to systemic opioids) increases the incidence of nausea or vomiting over baseline in labouring women. A randomized double-blinded study J. L. Hawkins, MD (&) Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO, USA e-mail: Joy.Hawkins@ucdenver.edu

Aplastic anemia during pregnancy: A review of obstetric and anesthetic considerations

Aplastic anemia is a hematologic condition occasionally presenting during pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management is challenging, and treatment requires a coordinated effort by an interdisciplinary team, in order to provide safe care to these patients. In this review, we describe the current state of the literature as it applies to the complexity of aplastic anemia in pregnancy, focusing on pathophysiologic aspects of the disease in pregnancy, as well as relevant obstetric and anesthetic considerations necessary to treat this challenging problem. A multidisciplinary-team approach to the management of aplastic anemia in pregnancy is necessary to coordinate prenatal care, optimize maternofetal outcomes, and plan peripartum interventions. Conservative transfusion management is critical to prevent alloimmunization. Although a safe threshold-platelet count for neuraxial anesthesia has not been established, selection of anesthetic technique must be evaluated on a case-to-case basis.

Aplastic anemia in two consecutive pregnancies: obstetric and anesthetic management

Aplastic anemia is a serious condition occasionally coexisting with pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management are particularly challenging, and treatment requires knowledge of pathophysiologic mechanisms in order to provide safe care to this group of patients. We describe the successful obstetric management and labor analgesia of a patient with a diagnosis of aplastic anemia in two consecutive pregnancies.

150 years in pursuit of optimal pain relief during labour.

Pharmacological relief of pain during childbirth has been both praised and vilified by the public and by physicians. When Simpson first described anaesthetising a woman for childbirth in 1847, strong criticism followed from the medical community and the public. Was it safe? Was it wise to intervene in a natural process? Would it affect the course of labour or the neonate? Simpson contended that pain is without physiological value and only degrades and destroys those who experience it (Caton The history of obstetric anesthesia, in Chestnut’s Obstetric Anesthesia. Amsterdam: Elsevier 2014:3–12). By 1860, public opinion changed and women began requesting pain relief from their obstetricians. Pain during childbirth lost its theological connotation and became a biological process to be studied scientifically. Technology was developed that allowed administration of parenteral medications, and ‘twilight sleep’, a popular combination of morphine analgesia and scopolamine for amnesia, was introduced in 1902. Reports of newborn depression soon followed, suggesting placental transmission of the anaesthetic agents. These concerns led to studies of placental structure and appropriate maternal dosing.