Practice Guidelines for Obstetric Anesthesia: an Updated Report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology










  • What other guidelines are available on this topic?




    • These Practice Guidelines update the “Practice Guidelines for Obstetric Anesthesia: An Updated Report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia,” adopted by the American Society of Anesthesiologists (ASA) in 2006 and published in 2007.



    • Other guidelines on the topic for the anesthetic management of the parturient have been published by the American College of Obstetricians and Gynecologists in 2002 and reaffirmed in 2010 and 2013.




  • Why was this guideline developed?




    • In October 2014, the ASA Committee on Standards and Practice Parameters, in collaboration with the Society for Obstetric Anesthesia and Perinatology, elected to collect new evidence to determine whether recommendations in the existing practice guidelines continue to be supported by current evidence. The resultant guidelines, presented in this issue, incorporate an analysis of current scientific literature and expert consultant survey results.




  • How does this statement differ from existing guidelines?




    • This statement presents new findings from the scientific literature since 2006 and surveys of both expert consultants and randomly selected ASA members.



    • This document represents the first practice guideline to be developed as a collaborative effort between the ASA and a subspecialty society (Society for Obstetric Anesthesia and Perinatology) with content expertise relevant to the recommendations.




  • Why does the statement differ from existing guidelines?




    • The American College of Obstetricians and Gynecologists Practice Bulletin focuses on limited aspects of cesarean anesthesia (e.g., when an anesthesiology consult is appropriate) and of labor analgesia (e.g., parenteral opioids) that an obstetrician would use to counsel their patients.



    • These guidelines also include perianesthetic management of other obstetric procedures and emergencies.



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 the clinical needs and constraints and are not intended to replace local institutional policies. In addition, practice guidelines developed by the American Society of Anesthesiologists (ASA) 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 and practitioner opinion, open-forum commentary, and clinical feasibility data.


This document updates the “Practice Guidelines for Obstetric Anesthesia: An Updated Report by the ASA Task Force on Obstetric Anesthesia,” adopted by ASA in 2006 and published in 2007. b


b Practice guidelines for obstetric anesthesia: An updated report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia. Anesthesiology 2007;106:843-863.



Methodology


Definition of Perioperative Obstetric Anesthesia


For the purposes of these updated guidelines, obstetric anesthesia refers to peripartum anesthetic and analgesic activities performed during labor and vaginal delivery, cesarean delivery, removal of retained placenta, and postpartum tubal ligation.


Purposes of the Guidelines


The purposes of these guidelines are to enhance the quality of anesthetic care for obstetric patients, improve patient safety by reducing the incidence and severity of anesthesia-related complications, and increase patient satisfaction.


Focus


These guidelines focus on the anesthetic management of pregnant patients during labor, nonoperative delivery, operative delivery, and selected aspects of postpartum care and analgesia (i.e., neuraxial opioids for postpartum analgesia after neuraxial anesthesia for cesarean delivery). The intended patient population includes, but is not limited to, intrapartum and postpartum patients with uncomplicated pregnancies or with common obstetric problems. The guidelines do not apply to patients undergoing surgery during pregnancy, gynecological patients, or parturients with chronic medical disease (e.g., severe cardiac, renal, or neurologic disease). In addition, these guidelines do not address (1) postpartum analgesia for vaginal delivery, (2) analgesia after tubal ligation, or (3) postoperative analgesia after general anesthesia (GA) for cesarean delivery.


Application


These guidelines are intended for use by anesthesiologists. They also may serve as a resource for other anesthesia providers and health care professionals who advise or care for patients who will receive anesthetic care during labor, delivery, and the immediate postpartum period.


Task Force Members and Consultants


In 2014, the ASA Committee on Standards and Practice Parameters requested that the updated guidelines published in 2007 be reevaluated. This current update consists of a literature evaluation and the reporting of new survey findings of expert consultants and ASA members. A summary of recommendations is found in Appendix l .


This update was developed by an ASA-appointed Task Force of 11 members, consisting of anesthesiologists in both private and academic practices from various geographic areas of the United States, and consulting methodologists from the ASA Committee on Standards and Practice Parameters. The Task Force developed these updated guidelines by means of a multistep process. First, original published research studies from peer-reviewed journals published subsequent to the previous update were reviewed. Second, a panel of expert consultants was asked to (1) participate in opinion surveys on the effectiveness of various anesthetic management strategies and (2) review and comment on a draft of the update developed by the Task Force. Third, survey opinions about the guideline recommendations were solicited from a random sample of active members of the ASA. Finally, all available information was used to build consensus within the Task Force to finalize the update.


Availability and Strength of Evidence


Preparation of these guidelines followed a rigorous methodologic process. Evidence was obtained from two principal sources: scientific evidence and opinion-based evidence.


Scientific Evidence


Scientific evidence used in the development of these updated guidelines is based on cumulative findings from literature published in peer-reviewed journals. Literature citations are obtained from PubMed and other healthcare databases, direct Internet searches, Task Force members, liaisons with other organizations, and manual searches of references located in reviewed articles.


Findings from the aggregated literature are reported in the text of the guidelines by evidence category, level, and direction. Evidence categories refer specifically to the strength and quality of the research design of the studies. Category A evidence represents results obtained from randomized controlled trials (RCTs), and Category B evidence represents observational results obtained from nonrandomized study designs or RCTs without pertinent comparison groups. When available, Category A evidence is given precedence over Category B evidence for any particular outcome. These evidence categories are further divided into evidence levels. Evidence levels refer specifically to the strength and quality of the summarized study findings (i.e., statistical findings, type of data, and the number of studies reporting/replicating the findings within the evidence categories). In this document, only the highest level of evidence is included in the summary report for each intervention–outcome pair, including a directional designation of benefit, harm, or equivocality for each outcome.


Category A.


Randomized controlled trials report comparative findings between clinical interventions for specified outcomes. Statistically significant ( P < 0.01) outcomes are designated as either beneficial (B) or harmful (H) for the patient; statistically nonsignificant findings are designated as equivocal (E).




  • Level 1: The literature contains a sufficient number of RCTs to conduct meta-analysis, c


    c All meta-analyses are conducted by the ASA methodology group. Meta-analyses from other sources are reviewed but not included as evidence in this document.

    and meta-analytic findings from these aggregated studies are reported as evidence.



  • Level 2: The literature contains multiple RCTs, but the number of RCTs is not sufficient to conduct a viable meta-analysis for the purpose of these updated guidelines. Findings from these RCTs are reported separately as evidence.



  • Level 3: The literature contains a single RCT, and findings are reported as evidence.



Category B.


Observational studies or RCTs without pertinent comparison groups may permit inference of beneficial or harmful relations among clinical interventions and clinical outcomes. Inferred findings are given a directional designation of beneficial (B), harmful (H), or equivocal (E). For studies that report statistical findings, the threshold for significance is a P value of less than 0.01.




  • Level 1: The literature contains observational comparisons (e.g., cohort and case-control research designs) with comparative statistics between clinical interventions for a specified clinical outcome.



  • Level 2: The literature contains noncomparative observational studies with associative statistics (e.g., relative risk, correlation, or sensitivity/specificity).



  • Level 3: The literature contains noncomparative observational studies with descriptive statistics (e.g., frequencies and percentages).



  • Level 4: The literature contains case reports.



Insufficient literature.


The lack of sufficient scientific evidence in the literature may occur when the evidence is either unavailable (i.e., no pertinent studies found) or inadequate. Inadequate literature cannot be used to assess relations among clinical interventions and outcomes because a clear interpretation of findings is not obtained due to methodologic concerns (e.g., confounding of study design or implementation), or the study does not meet the criteria for content as defined in the “Focus” of the guidelines.


Opinion-Based Evidence.


All opinion-based evidence (e.g., survey data, Internet-based comments, letters, and editorials) relevant to each topic was considered in the development of these updated guidelines. However, only the findings obtained from formal surveys are reported in the current update. Identical surveys were distributed to expert consultants and a random sample of ASA members who practice obstetric anesthesia.


Category A: Expert opinion.


Survey responses from Task Force-appointed expert consultants are reported in summary form in the text, with a complete listing of the consultant survey responses reported in Appendix 2 .


Category B: Membership opinion.


Survey responses from active ASA members are reported in summary form in the text, with a complete listing of ASA member survey responses reported in Appendix 2 .


Survey responses from expert and membership sources are recorded using a 5-point scale and summarized based on median values. d


d When an equal number of categorically distinct responses are obtained, the median value is determined by calculating the arithmetic mean of the two middle values. Ties are calculated by a predetermined formula.




  • Strongly Agree: Median score of 5 (at least 50% of the responses are 5)



  • Agree: Median score of 4 (at least 50% of the responses are 4 or 4 and 5)



  • Equivocal: Median score of 3 (at least 50% of the responses are 3, or no other response category or combination of similar categories contain at least 50% of the responses)



  • Disagree: Median score of 2 (at least 50% of responses are 2 or 1 and 2)



  • Strongly Disagree: Median score of 1 (at least 50% of responses are 1)



Category C: Informal opinion.


Open-forum testimony obtained during the development of these guidelines, Internet-based comments, letters, and editorials are all informally evaluated and discussed during the formulation of guideline recommendations. When warranted, the Task Force may add educational information or cautionary notes based on this information.




Guidelines


Perianesthetic Evaluation and Preparation


Perianesthetjc evaluation and preparation topics include (l) a focused history and a physical examination, (2) an intrapartum platelet count, (3) a blood type and screen, and (4) perianesthetic recording of fetal heart rate patterns.


History and Physical Examination


Literature findings.


Although it is a well-accepted clinical practice to review medical records and conduct a physical examination, comparative studies are insufficient to directly evaluate the impact of these practices. Studies with observational findings suggest that certain patient or clinical characteristics (e.g., hypertensive disorders of pregnancy such as preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome, obesity, and diabetes mellitus) may be associated with obstetric complications ( Category B2/B3-H evidence ).


Survey findings.


The consultants and ASA members both strongly agree (l) to conduct a focused history and physical examination before providing anesthesia care and (2) that a communication system should be in place to encourage early and ongoing contact between obstetric providers, anesthesiologists, and other members of the multidisciplinary team.


Intrapartum Platelet Count


Literature findings.


The literature is insufficient to assess whether a routine platelet count can predict anesthesia-related complications in uncomplicated parturients. An observational study reported that platelet count and fibrinogen values are associated with the frequency of postpartum hemorrhage ( Category B2 evidence ). Other observational studies and case reports suggest that a platelet count may be useful for diagnosing hypertensive disorders of pregnancy, such as preeclampsia; hemolysis, elevated liver enzymes, and low platelet count syndrome; and other conditions associated with coagulopathy ( Category B3/B4-B evidence ).


Survey findings.


The consultants and ASA members strongly agree that the anesthesiologist’s decision to order or require a platelet count should be individualized and based on a patient’s history (e.g., preeclampsia with severe features), physical examination, and clinical signs.


Blood Type and Screen


Literature findings.


The literature is insufficient to determine whether obtaining a blood type and screen is associated with fewer maternal anesthetic complications. In addition, the literature is insufficient to determine whether a blood cross-match is necessary for healthy and uncomplicated parturients.


Survey findings.


The ASA members agree and the consultants strongly agree that (1) a routine blood cross-match is not necessary for healthy and uncomplicated parturients for vaginal or operative delivery and (2) the decision whether to order or require a blood type and screen or cross-match should be based on maternal history, anticipated hemorrhagic complications (e.g., placenta accreta in a patient with placenta previa and previous uterine surgery), and local institutional policies.


Perianesthetic Recording of Fetal Heart Rate Patterns


Literature findings.


Studies with observational findings and case reports indicate that fetal heart rate patterns may change after the administration of neuraxial anesthetics ( Category B3/B4 evidence ).


Survey findings.


The consultants and ASA members strongly agree that fetal heart rate patterns should be monitored by a qualified individual before and after administration of neuraxial analgesia for labor.


Recommendations for Perianesthetic Evaluation and Preparation


History and Physical Examination





  • Conduct a focused history and physical examination before providing anesthesia care.




    • This should include, but is not limited to, a maternal health and anesthetic history, a relevant obstetric history, a baseline blood pressure measurement, and an airway, heart, and lung examination, consistent with the ASA “Practice Advisory for Preanesthesia Evaluation.” e


      e Practice advisory for preanesthesia evaluation: An updated report by the American Society of Anesthesiologists Task Force on Preanesthesia Evaluation. Anesthesiology 2012;116:522-538.




    • When a neuraxial anesthetic is planned, examine the patient’s back.



    • Recognition of significant anesthetic or obstetric risk factors should encourage consultation between the obstetrician and the anesthesiologist.





  • A communication system should be in place to encourage early and ongoing contact between obstetric providers, anesthesiologists, and other members of the multidisciplinary team.



Intrapartum Platelet Count





  • The anesthesiologist’s decision to order or require a platelet count should be individualized and based on a patient’s history (e.g., precclampsia with severe features), physical examination, and clinical signs. f


    f A specific platelet count predictive of neuraxial anesthetic complications has not been determined.




    • A routine platelet count is not necessary in the healthy parturient.




Blood Type and Screen





  • A routine blood cross-match is not necessary for healthy and uncomplicated parturients for vaginal or operative delivery.



  • The decision whether to order or require a blood type and screen or cross-match should be based on maternal history, anticipated hemorrhagic complications (e.g., placenta accreta in a patient with placenta previa and previous uterine surgery), and local institutional policies.



Perianesthetic Recording of Fetal Heart Rate Patterns





  • Fetal heart rate patterns should be monitored by a qualified individual before and after administration of neuraxial analgesia for labor.




    • Continuous electronic recording of fetal heart rate patterns may not be necessary in every clinical setting and may not be possible during placement of a neuraxial catheter. g


      g American College of Obstetricians and Gynecologists: ACOG Practice Bulletin No. 106: Intrapartum fetal heart rate monitoring: Nomenclature, interpretation, and general management principles. Obstet Gynecol 2009;114:192-202.





Aspiration Prevention


Aspiration prevention includes (l) clear liquids, (2) solids, and (3) antacids, H 2 -receptor antagonists, and metoclopramide.


Clear Liquids


Literature findings.


There is insufficient published literature to examine the relation between fasting times for clear liquids and the risk of emesis/reflux or pulmonary aspiration during labor.


Survey findings.


ASA members agree and the consultants strongly agree that (l) oral intake of moderate amounts of clear liquids may be allowed for uncomplicated laboring patients and (2) the uncomplicated patient undergoing elective surgery (e.g., scheduled cesarean delivery or postpartum tubal ligation) may have moderate amounts of clear liquids up to 2 h before induction of anesthesia.


Solids


Literature findings.


A specific fasting time for solids that is predictive of maternal anesthetic complications has not been determined. There is insufficient published literature to address the safety of any particular fasting period for solids in obstetric patients.


Survey findings.


The consultants and ASA members strongly agree that (l) the patient undergoing elective surgery (e.g., scheduled cesarean delivery or postpartum tubal ligation) should undergo a fasting period for solids of 6 to 8 h depending on the type of food ingested (e.g., fat content); (2) laboring patients with additional risk factors for aspiration (e.g., morbid obesity, diabetes mellitus, and difficult airway) or patients at increased risk for operative delivery (e.g., nonreassuring fetal heart rate pattern) may have further restrictions of oral intake, determined on a case-by-case basis; and (3) solid foods should be avoided in laboring patients.


Antacids, H 2 -Receptor Antagonists, and Metoclopramide


Literature findings.


Randomized controlled trials indicate that preoperative nonparticulate antacids (e.g., sodium citrate and sodium bicarbonate) are associated with higher gastric pH values during the peripartum period ( Category A2-B evidence ) and are equivocal regarding gastric volume ( Category A2-E evidence ). Randomized placebo-controlled trials indicate that H 2 -receptor antagonists are associated with higher gastric pH values in obstetric patients ( Category A2-B evidence ) and are equivocal regarding gastric volume ( Category A2-E evidence ). Randomized placebo-controlled trials indicate that metoclopramide is associated with reduced peripartum nausea and vomiting ( Category A2-B evidence ). Literature is not available that examines the relation between reduced gastric acidity and the frequency of pulmonary aspiration, emesis, morbidity, or mortality in obstetric patients who have aspirated gastric contents.


Survey findings.


The consultants and ASA members both agree that before surgical procedures (e.g., cesarean delivery or postpartum tubal ligation), consider the timely administration of nonparticulate antacids, H 2 -rcceptor antagonists, and/or metoclopramide for aspiration prophylaxis.


Recommendations for Aspiration Prevention h

h The Task Force recognizes that in laboring patients the timing of delivery is uncertain; therefore, adherence to a predetermined fasting period before nonelective surgical procedures is not always possible.


Clear Liquids





  • The oral intake of moderate amounts of clear liquids may be allowed for uncomplicated laboring patients.



  • The uncomplicated patient undergoing elective surgery may have clear liquids up to 2 h before induction of anesthesia.




    • Examples of clear liquids include, but are not limited to, water, fruit juices without pulp, carbonated beverages, clear tea, black coffee, and sports drinks.



    • The volume of liquid ingested is less important than the presence of particulate matter in the liquid ingested.




  • Laboring patients with additional risk factors for aspiration (e.g., morbid obesity, diabetes mellitus, and difficult airway) or patients at increased risk for operative delivery (e.g., nonreassuring fetal heart rate pattern) may have further restrictions of oral intake, determined on a case-by-case basis.



Solids





  • Solid foods should be avoided in laboring patients.



  • The patient undergoing elective surgery (e.g., scheduled cesarean delivery or postpartum tubal ligation) should undergo a fasting period for solids of 6 to 8 h depending on the type of food ingested (e.g., fat content). i


    i Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: An updated report by the American Society of Anesthesiologists Task Force on Preoperative Fasting. Anesthesiology 2011;114:495-511.




Antacids, H 2 -Receptor Antagonists, and Metoclopramide





  • Before surgical procedures (e.g., cesarean delivery or postpartum tubal ligation), consider the timely administration of nonparticulate antacids, H 2 -receptor antagonists, and/or metoclopramide for aspiration prophylaxis.



Anesthetic Care for Labor and Vaginal Delivery


Anesthetic care for labor and vaginal delivery includes (l) timing of neuraxial analgesia and outcome of labor, (2) neuraxial analgesia and trial of labor after prior cesarean delivery, and (3) anesthetic/analgesic techniques. Appendix 3 contains an overview of anesthetic care for labor and vaginal delivery. j


j Note that statements in Appendix 3 are intended to provide an overview and are not recommendations.



Timing of Neuraxial Analgesia and Outcome of Labor


Literature findings.


Meta-analyses of RCTs report equivocal findings for spontaneous, instrumented, and cesarean delivery when comparing early administration (i.e., cervical dilations of less than 4 or 5 cm) with late administration (i.e., cervical dilations of greater than 4 or 5 cm) of epidural analgesia ( Category A1-E evidence ). An RCT comparing cervical dilations of less than 2 cm with greater than or equal to 2 cm also reports equivocal findings ( Category A3-E evidence ). Finally, RCTs comparing early versus late combined spinal-epidural (CSE) analgesia administration report equivocal findings for cesarean, instrumented, and spontaneous delivery ( Category A2-E evidence ).


Survey findings.


The consultants and ASA members strongly agree to (1) provide patients in early labor (i.e., less than 5 cm dilation) the option of neuraxial analgesia when this service is available; (2) offer neuraxial analgesia on an individualized basis; and (3) not withhold neuraxial analgesia on the basis of achieving an arbitrary cervical dilation.


Neuraxial Analgesia and Trial of Labor after Prior Cesarean Delivery


Literature findings.


Nonrandomized comparative studies are equivocal regarding mode of delivery, duration of labor, and adverse outcomes when epidural analgesia is used in a trial of labor for previous cesarean delivery patients ( Category B1-E evidence ).


Survey findings.


The consultants and ASA members strongly agree (1) to offer neuraxial techniques to patients attempting vaginal birth after previous cesarean delivery and (2) that for these patients, it is appropriate to consider early placement of a neuraxial catheter that can be used later for labor analgesia or for anesthesia in the event of operative delivery.


Analgesia/anesthetic techniques.


Considerations for analgesic/anesthetic techniques include (l) early insertion of a neuraxial (i.e., spinal or epidural) catheter for complicated parturients, (2) continuous infusion epidural (CIE) analgesia, (3) epidural local anesthetics combined with opioids, (4) higher versus lower concentrations of local anesthetics, (5) single-injection spinal opioids with or without local anesthetics, (6) pencil-point spinal needles, (7) CSE analgesia, and (8) patient-controlled epidural analgesia (PCEA).


Early Insertion of a Neuraxial Catheter for Complicated Parturients


Literature findings.


The literature is insufficient to assess whether, when caring for the complicated parturient, the early insertion of a neuraxial catheter, with immediate or later administration of analgesia, improves maternal or neonatal outcomes.


Survey findings.


The consultants and ASA members strongly agree to consider early insertion of a neuraxial catheter for obstetric (e.g., twin gestation or preeclampsia) or anesthetic indications (e.g., anticipated difficult airway or obesity) to reduce the need for GA if an emergent procedure becomes necessary.


CIE Analgesia


Literature findings.


Randomized controlled trials indicate that CIE local anesthetics are associated with reduced maternal pain and discomfort compared with single-shot IV opioids during labor ( Category A2-B evidence ). The literature is insufficient to evaluate CIE compared with continuous infusion of IV opioids. An RCT reports greater pain relief during labor for CIE when compared with intramuscular opioids ( Category A3-B evidence ), with equivocal findings for duration of labor and mode of delivery ( Category A3-E evidence ). A nonrandomized comparative study reports equivocal findings for duration of labor and mode of delivery when CIE local anesthetics are compared with single-injection spinal opioids ( Category B1-E evidence ).


Survey findings.


The consultants and ASA members strongly agree that (1) continuous epidural infusion may be used for effective analgesia for labor and delivery, and (2) when a continuous epidural infusion of local anesthetic is selected, an opioid may be added.


Analgesic Concentrations


Literature findings.


Meta-analyses of RCTs report improved analgesic quality when comparing epidural local anesthetics combined with opioids versus equal concentrations of epidural local anesthetics without opioids ( Category A1-B evidence ). Findings were equivocal for frequency of spontaneous delivery, hypotension, pruritus, and 1-min Apgar scores ( Category A1-E evidence ).


Randomized controlled trials are equivocal for analgesic efficacy and duration of labor when continuous epidural infusion of low concentrations of local anesthetics with opioids are compared with higher concentrations of local anesthetics without opioids for maintenance of analgesia ( Category A2-E evidence ). Meta-analyses of RCTs are also equivocal regarding spontaneous delivery and neonatal Apgar scores when continuous epidural infusion of low concentrations of local anesthetics with opioids are compared with higher concentrations of local anesthetics without opioids ( Category A1-E evidence ). A lower frequency of motor block was found for lower concentrations of local anesthetics ( Category A1-B evidence ). , k


k The Task Force notes that the addition of an opioid to a local anesthetic infusion allows an even lower concentration of local anesthetic for providing equally effective analgesia.

The literature is insufficient to determine the effects of epidural local anesthetics with opioids on other maternal outcomes (e.g., hypotension, nausea, pruritus, respiratory depression, and urinary retention).


Survey findings.


The consultants and ASA members strongly agree to use dilute concentrations of local anesthetics with opioids to produce as little motor block as possible.


Single-Injection Spinal Opioids with or without Local Anesthetics


Literature findings.


An RCT reports a longer duration of analgesia when a spinal opioid is compared with an IV opioid ( Category A1-B evidence ). Nonrandomized comparisons are equivocal for duration of labor, mode of delivery, and other adverse outcomes such as nausea, vomiting, headache, and pruritus ( Category B1-E evidence ). The literature is not sufficient to compare single-injection spinal opioids with local anesthetics versus single-injection spinal opioids without local anesthetics.


Survey findings.


The consultants and ASA members agree that single-injection spinal opioids with or without local anesthetics may be used to provide effective, although time-limited, analgesia for labor when spontaneous vaginal delivery is anticipated. The ASA members agree and the consultants strongly agree that a local anesthetic may be added to a spinal opioid to increase duration and improve quality of analgesia.


Pencil-Point Spinal Needles


Literature findings.


Meta-analysis of RCTs indicate that the use of pencil-point spinal needles reduces the frequency of postdural puncture headache when compared with cutting-bevel spinal needles ( Category A1-B evidence ).


Survey findings.


The consultants and ASA members strongly agree to use pencil-point spinal needles instead of cutting-bevel spinal needles to minimize the risk of postdural puncture headache.


CSE Analgesia


Literature findings.


Meta-analyses of RCTs report improved analgesia and a faster onset time ( Category A2-B evidence ) when CSE local anesthetics with opioids are compared with epidural local anesthetics with opioids, with equivocal findings for maternal satisfaction with analgesia, mode of delivery, hypotension, pruritus, and 1-min Apgar scores ( Category A1-E evidence ). Meta-analysis of RCTs report an increased frequency of motor block with CSE ( Category A1-H evidence ).


Survey findings.


The consultants and ASA members strongly agree that (1) if labor is expected to last longer than the analgesic effects of the spinal drugs chosen, or if there is a good possibility of operative delivery, then consider a catheter technique instead of a single-injection technique and (2) CSE techniques may be used to provide effective and rapid onset of analgesia for labor.


Patient-Controlled Epidural Analgesia


Literature findings.


Meta-analysis of RCTs report reduced analgesic consumption ( Category A1-B evidence ) when PCEA is compared with CIE. Meta-analysis of RCTs report equivocal findings for duration of labor, mode of delivery, motor block, and 1- and 5-min Apgar scores when PCEA is compared with CIE ( Category A1-E evidence ). Meta-analysis of RCTs indicate greater analgesic efficacy for PCEA with a background infusion compared with PCEA without a background infusion ( Category A1-B evidence ) and is equivocal regarding mode of delivery and frequency of motor block ( Category A1-E evidence ).


Survey findings.


The consultants and ASA members strongly agree that (l) PCEA may be used to provide an effective and flexible approach for the maintenance of labor analgesia and (2) the use of PCEA may be preferable to fixed-rate CIE for providing fewer anesthetic interventions and reducing dosages of local anesthetics. The consultants and ASA members agree that PCEA may be used with or without a background infusion.


Recommendations for Anesthetic Care for Labor and Vaginal Delivery


Timing of Neuraxial Analgesia and Outcome of Labor





  • Provide patients in early labor (i.e., less than 5 cm dilation) the option of neuraxial analgesia when this service is available.



  • Offer neuraxial analgesia on an individualized basis regardless of cervical dilation.




    • Reassure patients that the use of neuraxial analgesia does not increase the incidence of cesarean delivery.




Neuraxial Analgesia and Trial of Labor after Prior Cesarean Delivery





  • Offer neuraxial techniques to patients attempting vaginal birth after previous cesarean delivery.



  • For these patients, consider early placement of a neuraxial catheter that can be used later for labor analgesia or for anesthesia in the event of operative delivery.



Analgesia/Anesthetic Techniques


Early insertion of a neuraxial catheter for complicated parturients





  • Consider early insertion of a neuraxial catheter for obstetric (e.g., twin gestation or preeclampsia) or anesthetic indications (e.g., anticipated difficult airway or obesity) to reduce the need for GA if an emergent procedure becomes necessary.




    • In these cases, the insertion of a neuraxial catheter may precede the onset of labor or a patient’s request for labor analgesia.




CIE analgesia





  • Continuous epidural infusion may be used for effective analgesia for labor and delivery.



  • 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 the motor block.



Analgesic concentrations





  • Use dilute concentrations of local anesthetics with opioids to produce as little motor block as possible.



Single-injection spinal opioids with or without local anesthetics





  • Single-injection spinal opioids with or without local anesthetics may be used to provide effective, although time-limited, analgesia for labor when spontaneous vaginal delivery is anticipated.



  • If labor duration is anticipated to be longer than the analgesic effects of the spinal drugs chosen, or if there is a reasonable possibility of operative delivery, then consider a catheter technique instead of a single-injection technique.



  • A local anesthetic may be added to a spinal opioid to increase duration and improve quality of analgesia.



Pencil-point spinal needles





  • Use pencil-point spinal needles instead of cutting-bevel spinal needles to minimize the risk of postdural puncture headache.



CSE analgesia





  • If labor duration is anticipated to be longer than the analgesic effects of the spinal drugs chosen, or if there is a reasonable possibility of operative delivery, then consider a catheter technique instead of a single-injection technique.



  • CSE techniques may be used to provide effective and rapid onset of analgesia for labor.



Patient-controlled epidural analgesia





  • Patient-controlled epidural analgesia may be used to provide an effective and flexible approach for the maintenance of labor analgesia.



  • The use of PCEA may be preferable to fixed-rate CIE for administering reduced dosages of local anesthetics.



  • PCEA may be used with or without a background infusion.



Removal of Retained Placenta


Techniques for removal of retained placenta include (l) anesthetic techniques for removal of retained placenta and (2) nitroglycerin for uterine relocation.


Anesthetic Techniques


Literature findings.


The literature is insufficient to assess whether a particular anesthetic technique is more effective than another for removal of retained placenta.


Survey findings.


The consultants and ASA members strongly agree (l) that the hemodynamic status should be assessed before administering neuraxial anesthesia and (2) if an epidural catheter is in place and the patient is hemodynamically stable, consider providing epidural anesthesia. The consultants and ASA members agree to consider aspiration prophylaxis. The consultants and ASA members strongly agree that (1) titration of sedation/analgesia should be performed carefully due to the potential risks of respiratory depression and pulmonary aspiration during the immediate postpartum period and (2) in cases involving major maternal hemorrhage with hemodynamic instability, GA with an endotracheal tube may be considered in preference to neuraxial anesthesia.


Nitroglycerin for Uterine Relaxation


Literature findings.


Randomized controlled trials comparing IV or sublingual nitroglycerin with placebo for the purpose of uterine relaxation report inconsistent findings for the successful removal of retained placenta ( Category A2-E evidence ). Observational studies and case reports indicate successful uterine relaxation and successful placental removal after IV or sublingual nitroglycerin administration ( Category B3/B4 evidence ).


Survey findings.


The ASA members agree and the consultants strongly agree that nitroglycerin may be used as an alternative to terbutaline sulfate or general endotracheal anesthesia with halogenated agents for uterine relaxation during removal of retained placental tissue.


Recommendations for Removal of Retained Placenta


Anesthetic Techniques for Removal of Retained Placenta





  • In general, there is no preferred anesthetic technique for removal of retained placenta.




    • If an epidural catheter is in place and the patient is hemodynamically stable, consider providing epidural anesthesia.




  • Assess hemodynamic status before administering neuraxial anesthesia.



  • Consider aspiration prophylaxis.



  • Titrate sedation/analgesia carefully due to the potential risks of respiratory depression and pulmonary aspiration during the immediate postpartum period.



  • In cases involving major maternal hemorrhage with hemodynamic instability, GA with an endotracheal tube may be considered in preference to neuraxial anesthesia.



Nitroglycerin for Uterine Relaxation





  • Nitroglycerin may be used as an alternative to terbutaline sulfate or general endotracheal anesthesia with halogenated agents for uterine relaxation during removal of retained placental tissue.




    • Initiating treatment with incremental doses of IV or sublingual (i.e., tablet or metered dose spray) nitroglycerin may be done to sufficiently relax the uterus.




Anesthetic Care for Cesarean Delivery


Anesthetic care for cesarean delivery consists of (1) equipment, facilities, and support personnel; (2) general, epidural, spinal, or CSE anesthesia; (3) IV fluid preloading or coloading; (4) ephedrine or phenylephrine; and (5) neuraxial opioids for postoperative analgesia after neuraxial anesthesia.


Equipment, Facilities, and Support Personnel


Literature findings.


The literature is insufficient to evaluate the benefit of providing equipment, facilities, and support personnel in the labor and delivery operating suite comparable to that available in the main operating suite.


Survey findings.


The consultants and ASA members strongly agree that (l) equipment, facilities, and support personnel available in the labor and delivery operating suite should be comparable to those available in the main operating suite; (2) resources for the treatment of potential complications (e.g., failed intubation, inadequate anesthesia, hypotension, respiratory depression, local anesthetic systemic toxicity, pruritus, and vomiting) should also be available in the labor and delivery operating suite; and (3) appropriate equipment and personnel should be available to care for obstetric patients recovering from major neuraxial or GA.


General, Epidural, Spinal, or CSE Anesthesia


Literature findings.


Randomized controlled trials report higher Apgar scores at 1 and 5 min for epidural anesthesia when compared with GA ( Category A2-B evidence ) and equivocal findings for umbilical artery pH values ( Category A2-E evidence ). When spinal anesthesia is compared with GA, RCTs report equivocal findings for 1- and 5-min Apgar scores and umbilical artery pH values ( Category A1-E evidence ). RCTs also are equivocal regarding total time in the operating room when epidural or spinal anesthesia is compared with GA ( Category A2-E evidence ).


When spinal anesthesia is compared with epidural anesthesia, RCTs are equivocal regarding induction-to-delivery times, hypotension, umbilical pH values, and Apgar scores ( Category A2-E evidence ).


When CSE is compared with epidural anesthesia, RCTs report equivocal findings for the frequency of hypo­tension and for 1-min Apgar scores ( Category A2-E evidence ). RCTs report equivocal findings for delivery times, time in the operating room, hypotension, and l- and 5-min Apgar scores when CSE is compared with spinal anesthesia ( Category A2-E evidence ).


Survey findings.


The consultants and ASA members strongly agree that (1) the decision to use a particular anesthetic technique for cesarean delivery should be individualized, based on anesthetic, obstetric, or fetal risk factors (e.g., elective versus emergency), the preferences of the patient, and the judgment of the anesthesiologist; (2) uterine displacement (usually left displacement) should be maintained until delivery regardless of the anesthetic technique used; (3) consider selecting neuraxial techniques in preference to GA for most cesarean deliveries; (4) if spinal anesthesia is chosen, use pencil-point spinal needles instead of cutting-bevel spinal needles; (5) for urgent cesarean delivery, an indwelling epidural catheter may be used as an alternative to initiation of spinal anesthesia; and (6) GA may be the most appropriate choice in some circumstances (e.g., profound fetal bradycardia, ruptured uterus, severe hemorrhage, severe placental abruption, umbilical cord prolapse, and preterm footling breech).


IV Fluid Preloading or Coloading


Literature findings.


Randomized controlled trial findings are inconsistent regarding the frequency of maternal hypotension when IV fluid preloading or coloading for spinal anesthesia is compared with no fluids ( Category A2-E evidence ). Meta-analyses of RCTs are equivocal for maternal hypotension when IV fluid preloading is compared with coloading ( Category A2-E evidence ).


Survey findings.


The consultants and ASA members agree that IV fluid preloading may be used to reduce the frequency of maternal hypotension after spinal anesthesia for cesarean delivery. The ASA members agree and the consultants strongly agree that, although fluid preloading reduces the frequency of maternal hypotension, it does not delay the initiation of spinal anesthesia in order to administer a fixed volume of IV fluid.


Ephedrine or Phenylephrine


Literature findings.


Meta-analysis of double-blind placebo-controlled RCTs report reduced maternal hypotension during anesthesia for cesarean delivery when IV ephedrine is administered compared with placebo ( Category A1-B evidence ). RCTs are equivocal for hypotension when intramuscular ephedrine is compared with placebo ( Category A2-E evidence ). RCTs comparing phenylephrine with placebo report a lower frequency of hypotension when higher dosages of phenylephrine are administered ( Category A2-B evidence ) and equivocal findings when lower dosages are administered ( Category A2-E evidence ). Meta-analysis of double-blind RCTs report lower frequencies of patients with hypotension when infusions of phenylephrine are compared with ephedrine ( Category A1-B evidence ) ; higher umbilical artery pH values are reported for phenylephrine when compared with ephedrine ( Category A1-H evidence ).


Survey findings.


The consultants and ASA members strongly agree that IV ephedrine and phenylephrine both may be used for treating hypotension during neuraxial anesthesia.


Neuraxial Opioids for Postoperative Analgesia


Literature findings.


Randomized controlled trials comparing epidural opioids with intermittent injections of IV or intramuscular opioids report improved postoperative analgesia for epidural opioids after cesarean delivery ( Category A2-B evidence ) ; meta-analysis of RCTs reports equivocal findings for nausea, vomiting, and pruritus ( Category A1-E evidence ). RCTs report improved postoperative analgesia when PCEA is compared with IV patient-controlled analgesia ( Category A2-B evidence ) with equivocal findings for nausea, vomiting, pruritus, and sedation ( Category A2-E evidence ).


Survey findings.


The consultants and ASA members strongly agree that for postoperative analgesia after neuraxial anesthesia for cesarean delivery, selecting neuraxial opioids rather than intermittent injections of parenteral opioids should be considered.


Recommendations for Anesthetic Care for Cesarean Delivery


Equipment, Facilities, and Support Personnel





  • Equipment, facilities, and support personnel available in the labor and delivery operating suite should be comparable to those available in the main operating suite.



  • Resources for the treatment of potential complications (e.g., failed intubation, inadequate analgesia/anesthesia, hypotension, respiratory depression, local anesthetic systemic toxicity, pruritus, and vomiting) should also be available in the labor and delivery operating suite.



  • Appropriate equipment and personnel should be available to care for obstetric patients recovering from neuraxial or GA.



General, Epidural, Spinal, or CSE Anesthesia





  • The decision to use a particular anesthetic technique for cesarean delivery should be individualized, based on anesthetic, obstetric, or fetal risk factors (e.g., elective versus emergency), the preferences of the patient, and the judgment of the anesthesiologist.




    • Uterine displacement (usually left displacement) should be maintained until delivery regardless of the anesthetic technique used.




  • Consider selecting neuraxial techniques in preference to GA for most cesarean deliveries.



  • If spinal anesthesia is chosen, use pencil-point spinal needles instead of cutting-bevel spinal needles.



  • For urgent cesarean delivery, an indwelling epidural catheter may be used as an alternative to initiation of spinal or GA.



  • GA may be the most appropriate choice in some circumstances (e.g., profound fetal bradycardia, ruptured uterus, severe hemorrhage, and severe placental abruption).



IV Fluid Preloading or Coloading





  • IV fluid preloading or coloading may be used to reduce the frequency of maternal hypotension after spinal anesthesia for cesarean delivery.



  • Do not delay the initiation of spinal anesthesia in order to administer a fixed volume of IV fluid.



Ephedrine or Phenylephrine





  • Either IV ephedrine or phenylephrine may be used for treating hypotension during neuraxial anesthesia.



  • In the absence of maternal bradycardia, consider selecting phenylephrine because of improved fetal acid-base status in uncomplicated pregnancies.



Neuraxial Opioids for Postoperative Analgesia





  • For postoperative analgesia after neuraxial anesthesia for cesarean delivery, consider selecting neuraxial opioids rather than intermittent injections of parenteral opioids.



Postpartum Tubal Ligation


Literature findings.


The literature is insufficient to evaluate the benefits of neuraxial anesthesia compared with GA for postpartum tubal ligation. In addition, the literature is insufficient to evaluate the impact of the timing of a postpartum tubal ligation on maternal outcome.


Survey findings.


The consultants and ASA members strongly agree (l) that before postpartum tubal ligation, the patient should have no oral intake of solid foods within 6 to 8 h of the surgery, depending on the type of food ingested (e.g., fat content), and (2) that both the timing of the procedure and the decision to use a particular anesthetic technique (i.e., neuraxial versus general) should be individualized based on anesthetic risk factors, obstetric risk factors (e.g., blood loss), and patient preferences. The ASA members agree and the consultants strongly agree to consider selecting neuraxial techniques in preference to GA for most postpartum tubal ligations.


Recommendations for Postpartum Tubal Ligation





  • Before a postpartum tubal ligation, the patient should have no oral intake of solid foods within 6 to 8 h of the surgery, depending on the type of food ingested (e.g., fat content). i



  • Consider aspiration prophylaxis.



  • Both the timing of the procedure and the decision to use a particular anesthetic technique (i.e., neuraxial versus general) should be individualized, based on anesthetic and obstetric risk factors (e.g., blood loss), and patient preferences.



  • Consider selecting neuraxial techniques in preference to GA for most postpartum tubal ligations.




    • Be aware that gastric emptying will be delayed in patients who have received opioids during labor.



    • Be aware that an epidural catheter placed for labor may be more likely to fail with longer postdelivery time intervals.



    • If a postpartum tubal ligation is to be performed before the patient is discharged from the hospital, do not attempt the procedure at a time when it might compromise other aspects of patient care on the labor and delivery unit. l


      l The American College of Obstetricians and Gynecologists (ACOG) has indicated that postpartum tubal ligation “should be considered an urgent surgical procedure given the consequences of a missed procedure and the limited time frame in which it may be performed.” ACOG Committee Opinion No. 530: Access to postpartum sterilization. Obstet Gynecol 2012;120:212-215.


      m 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2010;122(18 suppl 3):S640-933.





Management of Obstetric and Anesthetic Emergencies


Management of obstetric and anesthetic emergencies consists of (1) resources for management of hemorrhagic emergencies, (2) equipment for management of airway emergencies, and (3) cardiopulmonary resuscitation.


Resources for Management of Hemorrhagic Emergencies


Studies with observational findings and case reports suggest that the availability of resources for hemorrhagic emergencies may be associated with reduced maternal complications ( Category B3/B4-B evidence ).


Survey findings.


The consultants and ASA members strongly agree that institutions providing obstetric care should have resources available to manage hemorrhagic emergencies.


Equipment for Management of Airway Emergencies


Case reports suggest that the availability of equipment for the management of airway emergencies may be associated with reduced maternal, fetal, and neonatal complications ( Category B4-B evidence ).


Survey findings.


The consultants and ASA members strongly agree that labor and delivery units should have personnel and equipment readily available to manage airway emergencies consistent with the ASA Practice Guidelines for Management of the Difficult Airway, to include a pulse oximeter and carbon dioxide detector.


Cardiopulmonary Resuscitation


Literature findings.


The literature is insufficient to evaluate the efficacy of cardiopulmonary resuscitation in the obstetric patient during labor and delivery. In cases of cardiac arrest, the American Heart Association has stated that 4 to 5 min is the maximum time rescuers will have to determine whether the arrest can be reversed by Basic Life Support and Advanced Cardiac Life Support interventions. m Delivery of the fetus may improve cardiopulmonary resuscitation of the mother by relieving aortocaval compression. The American Heart Association further notes that the best survival rate for infants more than 24 to 25 weeks in gestation occurs when the delivery of the infant occurs no more than 5 min after the mother’s heart stops beating.


Survey findings.


The consultants and ASA members strongly agree that (1) basic and advanced life-support equipment should be immediately available in the operative area of labor and delivery units, and (2) if cardiac arrest occurs during labor and delivery, to initiate standard resuscitative measures with accommodations for pregnancy such as left uterine displacement and preparing for delivery of the fetus.


Recommendations for Management of Obstetric and Anesthetic Emergencies


Resources for Management of Hemorrhagic Emergencies



Jun 12, 2019 | Posted by in ANESTHESIA | Comments Off on Practice Guidelines for Obstetric Anesthesia: an Updated Report by the American Society of Anesthesiologists Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology

Full access? Get Clinical Tree

Get Clinical Tree app for offline access