Clinical Practice FAQs

Welcome to the Clinical Practice FAQs page, where some common clinical questions are answered by experts from the SOAP Education Committee. See the important note at the bottom of this page.

REMIFENTANIL (April 2022)

Question: Remifentanil infusions are rarely used on the labor floor for labor analgesia in the United States although they are widely utilized in some areas of Europe. What do we need to know about the use of remifentanil infusion for labor analgesia? Should it be offered as a plausible option?

Answer: 

• In many countries, remifentanil is considered a safe, effective, easy-to-use, systemic analgesic with a rapid onset and offset to match the time course of uterine contractions and minimal to no transfer to the fetus.
• Although not the gold standard for labor analgesia, it’s proposed as a reasonable option for those with contraindications to a neuraxial technique.1,2,3
• Currently, remifentanil can be used as an intermittent patient-administered bolus with a lockout interval and with or without a background infusion. Although the peak CNS effect of a bolus dose of remifentanil occurs within 1–3 min after a rapid IV bolus, research is still ongoing to determine the optimal timing and dose of remifentanil to achieve the most effective and safe analgesic outcome during labor.1,2,3
• In order to consider remifentanil PCA as an option, clinicians must carefully examine their infusion pump speed and pressure. In many settings, even with the right pump settings, a suboptimal pump speed could de-couple the administration of the medication from the timing of the contraction, leading to poor outcomes.
• Most studies have reported maternal desaturation requiring oxygen supplementation that is short lived, as well as maternal sedation. Consequently, various studies point to the need for close (one-to-one nursing/midwife) patient supervision, continuous oxygen saturation monitoring, and a dedicated IV cannula for the remifentanil while a parturient is receiving the drug.1,2
• Variable dose regimens have been presented in the literature (e.g., 40-μg bolus with a 2-min lockout etc.), with each including routine oxygen saturation monitoring, oxygen supplementation if needed to treat maternal desaturation, and one-to-one nursing/midwife monitoring using trained personnel.1,2
• Despite some studies quoting adequate analgesia, similar maternal satisfaction scores and a consistent patient safety profile3; the variable dosing and requirement for close monitoring remains a potential drawback to the routine use of remifentanil in the clinical setting here in the United States. More well-designed studies need to be performed to clearly delineate optimal timing of dose administration to match contractions, the rate of bolus delivery, and the lockout interval for optimal and safe analgesic outcome during labor.

   -Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

1. Hinova A, Fernando R. Systemic remifentanil for labor analgesia. Anesth Analg 2009; 109(6): 1925-1929. doi: 10.1213/ANE.0b013e3181c03e0c.
2. Stocki D, Matot I, Einav S, Eventov-Friedman S, Ginosar Y, Weiniger CF. A randomized controlled trial of the efficacy and respiratory effects of patient-controlled intravenous remifentanil analgesia and patient-controlled epidural analgesia in laboring women. Anesth Analg 2014; 118(3): 589-597.
3. Süğür T, Kızılateş E , Kızılateş A , İnanoğlu K , Karslı B. Labor analgesia: comparison of epidural patient-controlled analgesia and intravenous patient-controlled analgesia. Comparative Study 2020; 32(1): 8-18.

HANDLING SUBOPTIMAL RELATIONSHIPS WITH OBSTETRIC OR NURSING STAFF ON L&D (April 2022)

Question: Any suggestions on how anesthesiology providers could handle suboptimal relationships with obstetric or nursing staff on the labor and delivery floor other than avoiding the labor floor entirely?

Answer: There are no studies to address this dilemma encountered by some anesthesiologists. Nonetheless, suggestions from expert opinion and similar data on this issue exist. 

• First, to gain respect from our obstetric colleagues and nurses, anesthesiologists should always behave in a manner worthy of professional respect that minimizes the possibility of being viewed as simple technicians on the labor floor. In other words, the anesthesiologist should be involved in the care of the parturient beyond the placement of the neuraxial block for pain relief (analgesia) or surgical anesthesia during cesarean delivery. The anesthesiologist should utilize teaching moments that arise in real-time to educate our obstetric colleagues and nurses, when necessary, about what we do and our value in the care of healthy and critically ill parturients.
• Suboptimal relationships on the labor floor often stem from poor communication among a multidisciplinary team of providers in a highly dynamic and constantly evolving clinical environment where there is the potential for conflicting goals. Better communication among all team members on the labor floor can be improved with daily patient safety rounds, preoperative huddles, and postoperative debriefing sessions to discuss near-misses or sentinel events.1,2 The anesthesiologist should be actively involved during these sessions with comments, questions, and providing educational content.
• Creating a “Patient Safety” task force which includes obstetric, nursing, and anesthesia personnel to address active safety issues on a rolling basis and institute simulation drills or team training is KEY as these ultimately affect patient outcomes.2,3 The creation of this task force is particularly important in clinical environments where huddles/rounds/debriefing sessions do not exist. Advocating for the development of these communication platforms is critical.
• Obstetric, anesthesia and nursing leaders should be involved in any active projects to improve communication among all teams. This is important for buy-in on all levels.2 Working together to create a formal structure for escalation of care that is adopted by all services (e.g., Level 1,2,3 C-sections, protocols etc.) minimizes the chance for miscommunication.

  -Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

 1. McQuaid-Hanson E, Pian-Smith MC. Huddles and Debriefings: Improving communication on labor and delivery. Anesthesiol Clin 2017; 35(1): 59-67
2.Zhang XJ, Song Y, Jiang T, Ding N, Shi TY. Interventions to reduce burnout of physicians and nurses: an overview of systematic reviews and meta-analyses. Medicine (Baltimore) 2020; 99(26): e20992. doi: 10.1097/MD.0000000000020992
3. Schmidt J, Gambashidze N, Manser T, Güß T, Klatthaar M, Neugebauer F, Hammer A. Does interprofessional team-training affect nurses’ and physicians’ perceptions of safety culture and communication practices? Results of a pre-post survey study. BMC Health Serv Res. 2021; 21(1): 341. doi: 10.1186/s12913-021-06137-5.PMID: 33853593

NITROUS OXIDE AS ANALGESIC MODALITY FOR LABOR PAIN (April 2022)

Question: Regarding the use of Nitrous Oxide as an analgesic modality for labor pain, what should we be concerned about? Should this be offered to all patients or a select group of patients? If nitrous oxide is used, what nursing ratio or monitoring modalities are recommended? Do most patients using nitrous oxide eventually request neuraxial pain relief? What of patient satisfaction with nitrous oxide? (Despite knowing the literature, most providers have indicated they want to know the practical experience of others)

Answer:

• Both the literature and the anecdotal experience of several physician providers endorse a low utilization of nitrous oxide and high conversion rate to neuraxial analgesia during labor in the United States.1,2,3 There are mixed reviews about its efficacy although in practices where anesthesiologists are responsible for its administration, most providers attest to an increased workload surrounding its use which outweighs the efficacy and reimbursement obtained. At institutions where this is handled by the obstetrical service and administered by nurses this may not be the case. Nonetheless, data show that nitrous oxide remains a safe and satisfactory analgesic option for labor in selected patients who are motivated.4,5 Nitrous oxide is also utilized by providers in other parts of the world where neuraxial options are not so ubiquitous.
• Concerns surrounding the possibility of “nitrous oxide” pollution” in the labor room also exist. Although this gas only flows when the patient inhales (demand system of the equipment only delivers gas when negative pressure is applied), it is eventually released into the labor room when the patient exhales as nitrous oxide is not metabolized. In some institutions, the nurse monitors the patient to ensure that exhalation is directed into the mask as current delivery systems provide a scavenging system for exhaled nitrous; however, this is not a perfect system.2,3,6 There are no data addressing the implications of nitrous oxide use during the COVID pandemic albeit some practices have discontinued its use due to concerns of aerosolization.
• Nitrous oxide is a greenhouse gas with a long stratospheric half-life. It accounts for about 6-7% of all greenhouse emissions. However, the contribution from medical use of nitrous oxide is less than 1%; hence it is not listed as a significant greenhouse gas source by EPA.3,6
• (https://www.epa.gov/ghgemissions/overview-greenhouse-gases#nitrous-oxide) Care should be taken to track exposure levels in healthcare workers and follow the recommended exposure limit (REL) proposed by NIOSH in the labor room.2,6
• Contraindications to nitrous oxide administration in parturients are similar to those for the general population. Although there is a theoretical risk of elevated homocysteine levels and thrombosis in a patient with a history of homozygous MTHFR when nitrous oxide is used, clear adverse events have not been identified in these select patients.3 In some practices, untreated vitamin B12 deficiency and active thrombosis are considered contraindications to the use of nitrous oxide. Nitrous oxide is also contraindicated in parturients at risk for its accumulation in enclosed spaces (i.e., pneumothorax, small bowel obstruction) and should be avoided when congenital heart defects and/or pulmonary hypertension is present due to a potential increase in pulmonary vascular resistance.2
• Nitrous oxide and neuraxial analgesia cannot be administered simultaneously during labor; nonetheless, most providers do not impose a mandatory wait period between the use of nitrous oxide and the placement of an epidural given the rapid resolution of the effects of nitrous oxide. A detailed informed consent delineating both techniques should be obtained prior to administration. Although a few providers endorse the use of continuous pulse oximetry, most do not require special monitoring to administer nitrous oxide and maintain their usual nursing ratios.
• Despite neuraxial analgesia being a superior analgesic option compared to nitrous oxide, patient satisfaction with nitrous oxide can be quite high, especially for patients who are not candidates for neuraxial analgesia, those who wish to avoid labor epidural analgesia, or those who just want to have some form of control through the availability of multiple analgesic options during labor.2,4,5

  -Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

*EPA (Environmental Protection Agency), NIOSH (National Institute for Occupational Safety and Health), MTHFR (Methylenetetrahydrofolate reductase)
1. Sutton CD, Butwick AJ, Riley ET, Carvalho B. Nitrous oxide for labor analgesia: utilization and predictors of conversion to neuraxial analgesia. J Clin Anesth 2017; 40: 40-45 
2.Broughton K, Clark AG, Ray AP. Nitrous oxide for labor analgesia: what we know to date. Ochsner J. 2020; 20(4): 419-421
3.Vallejo MC, Zakowski MI. Pro-Con Debate: Nitrous oxide for labor analgesia. Biomed Res Int. 2019: 4618798. doi: 10.1155/2019/4618798. eCollection 2019.P
4. Nodine PM, Collins MR, Wood CL, Anderson JL, Orlando BS, McNair BK, Mayer DC, Stein DJ. Nitrous oxide use during labor: satisfaction, adverse effects, and predictors of conversion to neuraxial analgesia. J Midwifery Womens Health 2020; 65(3): 335-341
5. Richardson MG, Lopez BM, Baysinger CL, Shotwell MS, Chestnut DH. Nitrous oxide during labor: maternal satisfaction does not depend exclusively on analgesic effectiveness. Anesth Analg 2017; 124(2): 548-553
6. Morley B, Paulsen W. Nitrous oxide for labor analgesia: is it safe for everyone? 2017 Circulation 122, 210. Volume 32, No. 1
https://www.apsf.org/article/nitrous-oxide-for-labor-analgesia-is-it-safe-for-everyone/ 

PREGNANCY TESTING IN WOMEN OF CHILDBEARING AGE PRIOR TO SURGERY (April 2022)

Question: What is the recommendation on pregnancy testing in women of childbearing age prior to surgery? Is a patient permitted to opt out of testing?

Answer: The ASA, in its statement on routine preoperative laboratory testing, did not recommend any specific test as a requirement for all patients. Testing guidelines should be tailored to each individual institution and according to its influence on select populations.

The ASA’s stand on preoperative pregnancy testing is as follows:

• The practice advisory of the ASA Task Force on Pre-anesthesia Evaluation recommends offering an informed patient the opportunity to choose whether she wants to have a pregnancy test. Testing should not be mandatory.1
• Pregnancy testing may be offered to female sex patients of childbearing age for whom the results would alter the patient's medical management.1
• Best practice should employ shared decision-making between patients and providers. Risks, benefits, and alternatives related to preoperative pregnancy testing should be discussed with the patient (including the potential for false negatives and false positives).1
• Ideally, preanesthetic educational materials should be given to patients to allow for informed decision making. Materials should include information about the accuracy of pregnancy testing and should emphasize that there is currently, insufficient scientific evidence on whether exposure to anesthesia causes unknown harmful effects during early pregnancy.1
• Preoperative pregnancy testing should be addressed as an institutional policy. The general misconception is that preoperative pregnancy testing is an “anesthesia requirement” because of the “anesthesia risk” and should therefore be an “anesthesia service responsibility”. However, currently, no frequently used anesthetic agents have been shown to have any teratogenic effects in humans of any age when used in standard clinical doses, concentrations, and duration.1,2,3
• An institutional policy should address how a discussion of the test results, including implications of a positive test, possible false positive or negative test, alternatives, changes in medical management, counseling etc.will be handled since medicolegal and ethical concerns could arise from the discussion.1,2
  
    -Onyi C. Onuoha, MD. MPH
  University of Houston, Houston, Texas 

 1. American Society of Anesthesiologists, Committee on Quality Management and Departmental Administration. Pregnancy testing prior to anesthesia and surgery. Last amended: October 2021 https://www.asahq.org/standards-and-guidelines/pregnancy-testing-prior-to-anesthesia-and-surgery
2. Jackson SH. Pre-anesthesia pregnancy testing in adults. ASA Monitor November 2018, Vol. 82(11), 24–27.
3. American College of Obstetricians and Gynecologists, Committee on Obstetric Practice. Nonobstetric surgery during pregnancy, Committee Opinion No. 775. 2019 (Reaffirmed 2021).

PREFERRED ANESTHETIC FOR EMERGERNT CESAREAN IN SYMPTOMATIC COVID+ PARTURIENT (April 2022)

Question: What is the preferred anesthetic of choice for an Emergent Cesarean Delivery in a symptomatic COVID+ (fever, shortness of breath) parturient with no laboratory results available and a category 3 fetal tracing?

Answer:

• Although there are currently no appropriately designed studies to address this ongoing question, expert opinion and consensus still favors neuraxial (spinal, combined spinal epidural) over general anesthesia as the preferred anesthetic choice even in symptomatic COVID positive patients when possible.1,2 The utilization of full personal protective equipment is required regardless of anesthetic technique.3
• Care should be taken to review the patient’s anticoagulation status in the setting of a COVID infection prior to neuraxial placement as these patients may be receiving anticoagulant medications.
• Clinical judgment should be utilized in weighing the risks and benefits of the different anesthetic options in the symptomatic COVID parturient with very limited respiratory reserve and the inability to tolerate the supine position or the loss of accessory muscle function, which could occur with a dense level of T4 or higher. In some instances, general anesthesia may be necessary and considered safe.3

1. Diab A Bani Hani et al. Successful anesthetic management in cesarean section for pregnant woman with COVID-19. Am J Case Rep. 2020; 21: e925512. doi: 10.12659/AJCR.925512.
2. Jan M, Bhat WM, Rashid M, Ahad B. Elective cesarean section in obstetric COVID-19 patients under spinal anesthesia: a prospective study. Anesth Essays Res 2020; 14(4): 611-614. Epub 2021 May 21
3. Chen R, Zhang Y, Huang L, Cheng BH, Xia ZY, Meng QT. Safety and efficacy of different anesthetic regimens for parturients with COVID-19 undergoing Cesarean delivery: a case series of 17 patients. Can J Anaesth. 2020 Jun; 67(6): 655-663. doi: 10.1007/s12630-020-01630-7. Epub 2020 Mar 16. 

CONTRAINDICATION FOR NEURAXIAL PROCEDURE IN FEBRILE PATIENT WITH CHORIOMNIONITIS (April 2022)

Question: Is there any contraindication to performing a neuraxial procedure in a febrile patient with a confirmed diagnosis of chorioamnionitis? 

Answer: Despite the theoretical plausibility of “seeding" the epidural or subarachnoid space in the presence of suspected bacteremia, there are no reported cases in the literature of clinically significant infectious complications following the performance of a neuraxial procedure in a parturient with chorioamnionitis even prior to antibiotic administration.1,2

However, given the paucity of adequately powered and well-designed studies in this patient population, there is no evidence-based recommendation or consensus opinion from SOAP. Some would argue that in non-emergent cases, administering antibiotics and waiting for therapeutic concentrations to be achieved in the bloodstream (about an hour) prior to placement would be preferable.3

  -Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

1.Bader AM, Gilbertson L, Kirz L, Datta S. Regional anesthesia in women with chorioamnionitis. Reg Anesth 1992; 17(2): 84-86.
2. Goodman EJ, DeHorta E, Taguiam JM. Safety of spinal and epidural anesthesia in parturients with chorioamnionitis. Reg Anesth 1996; 21(5): 436-441.
3. Osborne L, Synder M, Villecco D, Jacob A, Pyle S, Crum-Cianflone N. Evidence-based anesthesia: fever of unknown origin in parturients and neuraxial anesthesia. AANA J, 2008; 76(3): 221-226 

RE-SITING AN EPIDURAL CATHETER OR THREADING A SPINAL CATHETER (April 2022)

Question:  What is the consensus on re-siting an epidural catheter after a wet tap (postdural puncture) as opposed to threading a spinal catheter in a laboring patient?

Answer:  The decision to place an intrathecal catheter (ITC) or re-site the epidural catheter after an accidental dural puncture (ADP) should be a risk-benefit clinical judgment, depending on these factors:

1. The efficacy of ITCs – Both the placement of an ITC and re-attempting to place an epidural catheter, have been shown to be effective, viable options for labor analgesia after an ADP. However, according to a 6-year retrospective cohort review of 235 parturients who had an ADP during epidural placement, ITCs were associated with a higher rate of failed analgesia.1 Frequent monitoring of an ITC during labor is critical as these catheters can easily get dislodged.
2. The difficulty of placement – For a very difficult epidural placement where the risk of an additional ADP and the failure to intubate is high (e.g., morbidly obese parturient), placing an ITC rather than re-attempting to place an epidural catheter might be the better choice.2
3. The side effect profile – According to a retrospective review of 218 patients over a 10-year period, there was no difference in the incidence of postdural puncture headache between the re-sited epidural group and the spinal catheter group.3 However, the use of an ITC can lead to an increased risk of motor block, high spinal anesthesia, hypotension requiring vasopressors, drug error, respiratory depression, and fetal bradycardia. It is imperative to adhere to strict aseptic technique, meticulous labeling, cautious administration of medications and good communication with the patient and other staff. Hence, every institution considering the use of ITCs for labor analgesia should establish a protocol which accounts for the optimal epidural dosing via ITC and adequately trains staff on dosing, precautions, and possible complications.4

 -Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

1. Jagannathan DK, Arriaga AF, Elterman KG, Kodali BS, Robinson JN, Tsen LC, Palanisamy A. Effect of neuraxial technique after inadvertent dural puncture on obstetric outcomes and anesthetic complications. Int J Obstet Anesth. 2016 Feb; 25:23-9. doi: 10.1016/j.ijoa.2015.09.002. Epub 2015 Sep 18.
2. Soens MA, Birnbach DJ, Ranasinghe JS, van Zundert A. Obstetric anesthesia for the obese patient: an ounce of prevention is worth more than a pound of treatment. Acta Anaesthesiol Scand. 2008 Jan; 52(1):6-19. doi: 10. 111/j. 1399-6576.2007.01483.x
3. Bolden N, Gebre E. Accidental dural puncture management: 10-year experience at an academic tertiary care center. Reg Anesth Pain Med. 2016 Mar-Apr;41(2):169-74. doi: 10.1097/AAP.0000000000000339.
4. Orbach-Zinger S, Jadon A, Lucas DN, Sia AT, Tsen LC, Van de Velde M, Heesen M. Intrathecal catheter use after accidental dural puncture in obstetric patients: literature review and clinical management recommendations. Anaesthesia 2021; 76(8): 1111-1121. doi: 10.1111/anae.15390. Epub 2021 Jan 21.

POSTPARTUM NEUROPRAXIAS (June 2020)

Question: This lady's foot is still numb after the epidural came out yesterday. What should I do?

Answers:

1. Am I going to have a numb foot forever? 
An epidural is a type of pain control you can choose to have when you are in labor. It is done by a doctor specialized in this type of procedure. Complications such as permanent neurologic damages are VERY rare.

2. What is going on? 
The reasons for your numb foot are not necessarily a negative effect of your epidural but often it is just a “left-over” from your epidural and will disappear before you leave the hospital. The longer you had the epidural for during labor, the longer it can take for the numb foot to disappear.

3. What else can it be if not a "left-over?" 
True neurologic complications happen regardless of the use of epidural during labor. They are often related to a “suffering” of the nerve due to:

• Big baby
• Abnormal presentation of the baby during delivery/labor
• Prolonged pushing
• Prolonged position with legs flexed
• Use of special instruments to deliver the baby

4. Which nerves can be affected and how? 
Your numb foot might be due to a damage of different types of nerves you have in your legs:

• Lumbosacral trunk: it happens often if you have had a large baby or a prolonged labor with difficult presentation of the baby
• Sciatic nerve: it happens when you have had a prolonged pushing period with your legs hyper-flexed for a long time
• Common peroneal nerve: happens with prolonged squatting during labor and prolonged flexion of the knees during delivery
• Femoral nerve injury: happens with prolonged pushing in extreme flexion

5. Do I need a follow-up? 
Most of the time the symptoms will go away on their own but it can take up to a few weeks to do so. You should follow-up with your obstetrician and seek attention if the symptoms worsen or do not go away/improve after a few weeks

-Barbara Orlando, MD
Mount Sinai Hospital

PREOPERATIVE ANESTHESIA EVALUATION (June 2020) 

Question: What pregnant patients should have a preoperative anesthesia consultation prior to admission for delivery? Note: Conditions are NOT necessarily contraindications to neuraxial analgesia/anesthesia

Answer: Pregnant patients with the following conditions should ideally undergo evaluation by an anesthesiologist by 32 weeks gestation, or earlier if premature delivery is anticipated:

1. Hematologic:
1. Thrombocytopenia- (platelet count < 100,000 x 106/L) with known diagnosis
2. Thrombocytopenia- (platelet count < 100,000 x 106/L) with unknown diagnosis should be referred to hematology expert prior to 32 weeks, and then to anesthesiologist
3. Thromboprophylaxis/Anticoagulation therapy
4. Known factor deficiency or Platelet Disorder
5. Sickle Cell Disease
2. Cardiac:
1. Valvular disease with moderate-severe degree of functional impairment
2. History of chest pain without negative cardiac work-up
3. Arrythmias (specifically SVT, atrial fibrillation, VT)
4. Pacemakers/ICDs
5. Cardiomyopathy or IHSS
6. Complex congenital cardiac defects (excluding simple ASD or VSD repair as an infant)
7. Pulmonary Hypertension (moderate-severe)
8. History of Coronary Artery Disease or Myocardial Infarction
3. Neurologic:
1. Spinal Anatomic Aberrations: such as: prior surgery (excluding simple disc-related); moderate to severe scoliosis (corrected or uncorrected); spinal cord injury; spina bifida (other than asymptomatic, incidental finding on imaging; hardware (eg, spina cord stimulators, VL shunts); severe low back pain
2. Neuromuscular disease: (eg multiple sclerosis with significant functional compromise), myasthenia gravis, Guillian-Barre
3. Intracranial lesion: e.g. tumor, vascular lesion, hemorrhage (excluding incidental finding with no anatomic consequence, or pituitary microadenoma)
4. Arnold Chiari malformation
5. Patients with Previous Cerebral Ischemia or Stroke – especially with residual deficits
4. Pulmonary/Airway:
1. Asthma/Reactive Airway Disease- symptomatic despite medical therapy
2. Airway Compromise (eg., tracheal stenosis, history of neck radiation or jaw surgery, restricted mouth opening, severe tooth decay)
3. Other Pulmonary disease (eg, cystic fibrosis, prior lung surgery, restrictive lung disease)
5. Patients with solid organ dysfunction or transplant – Liver Cirrhosis, End-Stage Renal Disease
6. Rheumatology – patients with severe systemic autoimmune diseases (e.g. Systemic Lupus Erythematous)
7. Morbid Obesity (each institution may determine their threshold for preoperative evaluation)
8. Local Anesthetic or Opioid Allergy
9. Opioid Use Disorder (if possible, even if on stable opioid replacement therapy)
10. History of anesthetic issues or complications in patient or first-degree relative family members (e.g. Malignant Hyperthermia; history of difficult airway)
11. Refusal of Blood products (e.g. Jehovah’s Witness)
12. Patient with suspected abnormal placentation – (accreta, increta, percreta)
13. Request for non-standard accommodations during admission; general educational questions or concerns about obstetric anesthesia care.

NEURAXIAL ANESTHESIA – COAGULOPATHY (June 2020) 

Question: Neuraxial Anesthesia in Parturients with Thrombocytopenia: How Low Can You Go?

Answer: Thrombocytopenia is commonly encountered in the obstetric population, with ~2% of parturients demonstrating platelet counts less than 100,000/mm3.1,2 Given the theoretical risk of epidural hematoma, thrombocytopenia is considered a relative contraindication to neuraxial anesthesia. Several studies have attempted to delineate the platelet count at which it is “safe” to attempt a neuraxial technique. Recent evidence suggests the risk of epidural hematoma is extremely low in parturients with platelet counts > 70,000/mm3.1-3 The risk of epidural hematoma with platelet counts < 70,000/mm3 remains poorly defined.

The etiology of thrombocytopenia and considerations for platelet function should be considered when making a decision for neuraxial anesthesia. The use of platelet function analysis (PFA), thromboelastography, or thromboelastometry to guide a decision for neuraxial analgesia and anesthesia placement is controversial.

–Emily Baird, MD
Oregon Health Sciences University

References:
1. Lee LO, Bateman BT, Kheterpal S, et al. Risk of epidural hematoma after neuraxial technique in thrombocytopenic parturients. Anesthesiology 2017; 126: 1053-63.
2. Levy N, Goren O, Cattan A, et al. Neuraxial block for delivery among women with low platelet counts: a retrospective analysis. Int J Obstet Anesth 2018; 35: 4-9.
3. Goodier CG, Lu JT, Hebbar L, Segal BS, Goetz L. Neuraxial anesthesia in parturients with thrombocytopenia: a multisite retrospective cohort study. Anesth Analg 2015; 121: 988-91.

GESTATIONAL THROBOCYTOPENIA
Question: This lady has gestational thrombocytopenia. Can we do an epidural?

Answer: Gestational thrombocytopenia is a benign condition diagnosed by exclusion in parturients with platelet counts lower than 150K, and usually does not fall below 80K. Platelet function is not affected on these patients. Multiples retrospective studies have found minimal risk for epidural hematoma after neuraxial procedures on patients with platelet counts between 70 and 100K (Incidence < 0.2%). Below that number, a specific platelet count predictive of neuraxial complications has yet to be determined. If other conditions have been ruled out and the platelet count is above 70K, neuraxial placement is probably safe. More data is needed for lower counts.

–Maria Cristina Gutierrez, MD
University of California Davis Medical Center

References:
1. Ciobanu AM, Colibaba S, Cimpoca B, Peltecu G, Panaitescu AM. Thrombocytopenia in Pregnancy. Maedica (Buchar). 2016 Mar;11(1):55-60.
2. Levy N, Goren O, Cattan A, Weiniger CF, Matot I. Neuraxial block for delivery among women with low platelet counts: a retrospective analysis. Int J Obstet Anesth. 2018 Aug;35:4-9.
3. L. Apfelbaum, J.L. Hawkins, M. Agarkar, et al. 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. Anesthesiology, 124 (2016), pp. 270-300

NEURAXIAL ANESTHESIA – TECHNIQUES (June 2020)

Question: Which is best: Loss of Resistance to AIR or SALINE?

Answer: Loss of resistance to air versus saline for epidural placement remains controversial and incites polarizing opinions despite a lack of randomized clinical trials to support the superiority of one technique over another. Saline supporters report a lower risk for accidental dural puncture, difficulty threading the epidural catheter, nerve root compression, incomplete analgesia, venous air embolism, or pneumocephalus and headache. Ultimately, a retrospective study evaluating the effectiveness of loss of resistance to air or saline for identification of the epidural space found that clinicians should practice their preferred technique, whether air or saline, as this practice will result in fewer attempts, paresthesias, and accidental dural punctures.

-Jennifer Hofer, MD
University of Chicago

References:
1. Van de Velde, M. Identification of the epidural space: Stop using the loss of resistance to air technique!. Acta Anaesth Belg 2006; 57:51-4.
2. Segal S, Arendt KW. A retrospective effectiveness study of loss of resistance to air or saline for identification of the epidural space. Anesth Analg 2010; 110:558-63.

LABOR AND DELIVERY (June 2020) 

Question: What should NPO restrictions be for labor and delivery?

Answer: Unfortunately, there are no definitive data to suggest optimal fasting times during labor. However, the American Society of Anesthesiologists (ASA) Task Force on Obstetric Anesthesia, in concert with SOAP, has issued recommendations regarding nil per os (NPO) restrictions for parturients. These guidelines recommend allowing “moderate” amounts of clear liquids for women in labor; solid foods should be avoided. It may be prudent to consider further dietary restrictions during labor for women with risk factors for aspiration or for operative delivery. Patients undergoing elective cesarean delivery should be subject to standard NPO guidelines, avoiding clear liquids two hours prior to induction of anesthesia and solid foods 6-8 hours prior.

-Sharon Reale, MD
Brigham and Women’s Hospital, Boston, MA

References:
1. 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. Anesthesiology 2016;124:270-300.
2. Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures: An Updated Report by the American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Anesthesiology 2017;126:376-93.

CESAREAN DELIVERY (June 2020) 

Question: Should we run the oxytocin “wide open” during a cesarean delivery?

Answer: While oxytocin is the most frequently used uterotonic agent in cesarean deliveries, large doses can lead to cardiovascular compromise or even collapse. Several safe dosing strategies for postpartum oxytocin infusion or administration exist. Tsen and colleagues have posited a “rule of threes” algorithm for administration of oxytocin that involves a 3 units intravenous loading dose, followed by additional 3 units rescue doses at 3 minute intervals for 3 total doses as needed; these initial loading doses should be followed by a maintenance infusion of oxytocin. This algorithm was validated in a randomized control trial that showed adequate uterine tone with lower doses of oxytocin in the rule of threes group vs. the standard group that received “wide open” oxytocin infusions; there were no differences in uterine tone or blood loss.

-Sharon Reale, MD
Brigham and Women’s Hospital, Boston, MA

References:
1. Tsen LC, Balki M. Oxytocin protocols during cesarean delivery: time to acknowledge the risk/benefit ratio? Int J Obstet Anesth 2010;19:243-5.
2. Kovacheva VP, Soens MA, Tsen LC. A Randomized, Double-blinded Trial of a “Rule of Threes” Algorithm versus Continuous Infusion of Oxytocin during Elective Cesarean Delivery. Anesthesiology 2015;123:92-100.

For More Information: 
1. Rule of threes algorithm

LEFT UTERINE DISPLACEMENT OR TILT ON CESAREAN DEVLIERIES

Question: Do we need to do left uterine displacement or tilt on all cesarean deliveries?

Answer: Current recommendations for left uterine displacement (LUD) in cesarean delivery include maintenance of the LUD until delivery of the fetus ^[1,2]. This basic principle is based on previous findings that the supine position increases aortocaval compression, maternal hypotension and fetal compromise ^[3]. In the supine position, the inferior vena cava is completely obstructed; however, most women experience limited hemodynamic change and are asymptomatic ^[4]. Clinically significant hemodynamic effects, also called “supine hypotensive syndrome,” is estimated to occur in 8 to 10% of women at term gestation ^[5].

A few modern studies have countered the standard recommendation for LUD in elective cesarean delivery. Lee, et al. ^[6] found that maternal supine position during elective cesarean delivery with spinal anesthesia in healthy term women does not impair neonatal acid-base status compared to a 15-degree left tilt. During the study, maternal systolic blood pressure was maintained with a co-load of fluid and phenylephrine infusion. However, these findings were limited to healthy pregnant women and should not be generalized to emergency situations or non-reassuring fetal status. The care team should also be aware that phenylephrine requirements were greater in those who were supine versus those with a 15-degree tilt.

- Michael H Wilhelm, DNP, CRNA, APRN
University of Connecticut/John Dempsey Hospital

References:
1. NICE, NIfHaCE: Clinical guidelines and updates: Caesarean section. Available at: https://www.nice.org.uk/guidance/cg132/chapter/1-guidance. Accessed November 16, 2018.
2. 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. Anesthesiology 2016; 124:270–300.
3. Higuchi, H, Takagi, S, Zhang, K, Furui, I, Ozaki, M : Effect of lateral tilt angle on the volume of the abdominal aorta and inferior vena cava in pregnant and nonpregnant women determined by magnetic resonance imaging. Anesthesiology 2015; 122:286–93.
4. Howard, BK, Goodson, JH, Mengert, WF : Supine hypotensive syndrome in late pregnancy. Obstet Gynecol 1953; 1:371–7.
5. Kinsella, SM, Lohmann, G : Supine hypotensive syndrome. Obstet Gynecol 1994; 83:774–88.
6. Lee AJ, et al. : Left Lateral Table Tilt for Elective Cesarean Delivery under Spinal Anesthesia Has No Effect on Neonatal Acid-Base Status: A Randomized Controlled Trial. Anesthesiology 2017; 127(2):241-249.

SPINAL ANESTHESIA ON PATIENT WITH PLACENTA PREVIA FOR CESAREAN SECTION

Question: Can I do spinal anesthesia for this patient with placenta previa for a cesarean section?

Answer: For scheduled, non-urgent cesarean delivery without profound vaginal bleeding and with a reassuring fetal status, a single shot spinal or other neuraxial anesthetic can be safely performed. If the patient had a bleeding episode recently, the patient should be adequately volume resuscitated prior to performing the neuraxial; clinical judgment should be used to determine if preoperative coagulation testing is needed to determine the safety of neuraxial anesthesia. If there is suspicion of a placenta accreta spectrum in a patient with previa (e.g. placenta previa in current pregnancy with known prior low-transverse cesarean scar), then excessive bleeding should be anticipated, and appropriate preparations made. In such cases, an epidural or a combined spinal-epidural may be performed to allow extension of surgical time, with selective conversion to general anesthetic if massive hemorrhage is encountered. Placenta previa in the absence of other risk factors is not a contraindication for neuraxial anesthesia for cesarean delivery.

-Sonal Zambare, MD
Baylor College of Medicine, Houston, TX

References:
1. Markley JC, Farber MK, Perlman NC, Carusi DA; Neuraxial anesthesia during Cesarean delivery for placenta previa with suspected morbidly adherent placenta: A Retrospective Analysis; Anesthesia and analgesia; VOL.:127, ISSUE: 4; 930-938
2. Berrin Günaydın, Mertihan Kurdoğlu, İsmail Güler, et al; Management of Neuraxial Anaesthesia for Emergent Caesarean Section for Placenta Previa; Turkish journal of anaesthesiology and reanimation; 2016; 44: 40-3

FAILED CONVERSION OF EPIDURAL CATHETER FOR INTRAPARTUM CESAREAN DELIVERY

Question: Failed conversion of epidural catheter for surgical anesthesia for intrapartum cesarean delivery: Should I do a spinal?

Answer: The two major risks of placing a spinal after a failed epidural analgesia conversion to anesthesia, are 1) spinal failure due to presence of fluid in the epidural space that can be mistaken for CSF, and 2) the development of a high neuraxial block (HNB). 27% of HNB occur after a spinal technique following a failed epidural. Presence of fluid in the epidural space decreases the intrathecal (IT) volume therefore causing cephalad distribution of the local anesthetic. To minimize that risk, one approach can be to decrease the IT dose of local anesthetic and/or associate it with a catheter-based technique (epidural or CSE), to extend the duration of anesthesia if needed.

–Maria Cristina Gutierrez, MD
University of California Davis Medical Center

References:
1. D’Angelo R, Smiley RM, Riley ET, Segal S. Serious Complications Related to Obstetric Anesthesia: The Serious Complication Repository Project of the Society for Obstetric Anesthesia and Perinatology. Anesthesiology 2014;120(6):1505-1512.
2. Ginosar Y, Mirikatani E, Drover DR, Cohen SE, Riley ET. ED50and ED95of Intrathecal Hyperbaric Bupivacaine Coadministered with Opioids for Cesarean Delivery. Anesthesiology 2004;100(3):676-682.
3. Higuchi H, Takagi S, Onuki E, Fujita N, Ozaki M. Distribution of Epidural Saline Upon Injection and the Epidural Volume Effect in Pregnant Women. Anesthesiology 2011;114(5):1155-1161.

EXTERNAL CEPHALIC VERSION (June 2020) 

Question: What should we (anesthesia) do for external cephalic versions (ECV)?

Answer: External cephalic version (ECV) is encouraged by ACOG as a method to reposition the breech fetus to a vertex presentation before the onset of labor with the hope of avoiding a Cesarean delivery and facilitate a vaginal one. There is evidence¹ that neuraxial (spinal, combined spinal-epidural (CSE), and epidural) analgesia and/or anesthesia improves the success rate of the ECV. While there are numerous studies demonstrating this effect, optimal dosing has not been fully established. A recent randomized study by Chalifoux² et al. did not show any increased success with intrathecal bupivacaine doses greater than 2.5mg as part of a CSE with intrathecal fentanyl 15mcg. Carvalho and Bateman³ suggest, however, that the optimal dose for a given patient may depend on the clinical plan. If the plan is discharge to home after ECV, then lower dose bupivacaine may be best. If the plan is delivery immediately after ECV (either Cesarean or induction depending on the ECV outcome), then larger dose (7.5mg or 10mg) bupivacaine may be best.

— Stephanie Goodman, MD
Columbia University Medical Center

References:
1. Magro-Malosso ER, Saccone G, Di Tommaso M, Mele M, Berghella V: Neuraxial analgesia to increase the success rate of external cephalic version: A systematic review of meta-analysis of randomized controlled trials. Am J Obstet Gynecol 2016; 215: 276-86.
2. Chalifoux LA, Bauchat JR, Higgins N, Toledo P, Peralta FM, Farrer J, Gerber SE, McCarthy RJ, Sullivan JT: Effect of intrathecal bupivacaine dose on the success of external cephalix version for breech presentation: A prospective, randomized, blinded clinical trial. Anesthesiology 2017; 127; 625-32.
3. Carvalho B, Bateman BT: Not too little, not too much: Finding the goldilocks zone for spinal anesthesia to facilitate external cephalic version. Anesthesiology 2017; 127; 596-8.

For more information:
1. Please listen to Dr. Carolyn Weiniger’s excellent podcast on ECV. 

POSTOPERATIVE ANALGESIA (June 2020) 

Question: What’s a TAP block? Should everyone get it?

Answer: The transversus abdominis plane (TAP) block is a regional technique providing sensory blockade of the abdominal wall. Analgesia is achieved by targeting anterior rami of spinal nerves that travel between the internal oblique and transversus abdominis muscles. Several variations exist. ¹

TAP blocks may be most beneficial when intrathecal morphine is contraindicated or solely inadequate. As part of an opioid-sparing, multimodal analgesic regimen, TAP blocks may be performed at any point during the perioperative period. ^2,3 The technique is considered low risk and with few complications. Unable to block visceral pain, TAP blocks cannot provide intra-abdominal surgical anesthesia alone.

–Kristin Brennan, MD
Penn State Health System

References:
1. Ng SC, Habib AS, Sodha A et al. High-dose versus low-dose local anaesthetic for transversus abdominis plane block post-caesarean delivery analgesia: a meta-analysis. Br J Anaesth 2018: 120(2): 252-263.
2. Mcdonnell JG, Curley G, Carney J, et al. The analgesic efficacy of transversus abdominis plane block after caesarean delivery: a randomized controlled trial. Anesth Analg 2008;106:186 – 191.
3. Jadon A, Jain P, Chakraborty S et al. Role of ultrasound guided transversus abdominis plane block as a component of multimodal analgesic regimen for lower segment caesarean section: a randomized double blind clinical study. BMC Anesthesiol 2018; 18; 53.

For more information:
1. Abdallah FW, Halpern SH, Margarido CB. Transversus abdominis plane block for postoperative analgesia after caesarean delivery performed under spinal anesthesia? A systematic review and meta-analysis. Br J Anaesth 2012; 109(5): 679 – 87.
2. Blanco R, Ansari T, Girgis E. Quadratus lumborum block for postoperative pain after caesarean section. Eur J Anesthesiol 2015; 32:812 – 818.
3. Young MJ, Gorlin AW, Modest VE and Quraishi SA. Clinical implications of the transversus abdominis plane block in adults. Anesthesiol Res Pract 2012; 2012: 1-11.

ACCIDENTAL DURAL PUNCTURE AND POSTDURAL PUNCTURE HEADACHE (June 2020) 

Question: I got a “wet tap.” Should I do a prophylactic epidural blood patch?

Answer: Since epidural blood patch (EBP) is the gold standard therapy for post-dural puncture headache (PDPH), it has been postulated that administering autologous blood prior to epidural catheter removal after known or suspected dural puncture could prevent PDPH altogether. In 2004, a randomized trial found that prophylactic EBP did not significantly reduce the incidence of PDPH, maximum pain scores, onset time, or days spent unable to perform childcare compared to sham EBP. However, prophylactic EBP did decrease the duration of PDPH symptoms.¹ In 2014 another study showed a reduction of PDPH in patients who received prophylactic EBP, yet it is unclear if randomization and mode of delivery affected these results. As EBP is not without risks, the most severe of which includes arachnoiditis, prophylactic EBP administration is not recommended. Conservative management (hydration, caffeine, migraine medications) and therapeutic EBP should be the mainstays of therapy.

- Thomas R. Gruffi, MD
Mount Sinai West Hospital

References:
1. Scavone BM, Wong CA, Sullivan JT, Yaghmour E, Sherwani SS, McCarthy RJ, Efficacy of a prophylactic epidural blood patch in preventing post dural puncture headache in partuients after inadvertent dural puncture. Anesthesiology 2004;101:1422-7.
2. Stein MH, Cohen S, Mohiuddin MA, Dombrovskiy V, Lowenwirt I. Prophylactic vs therapeutic blood patch for obstetric patients with accidental dural punctue – a randomized controlled trial. Anaesthesia 2014;69:320-6
3. Agerson AN, Scavone BM. Prophylactic epidural blood patch after unintentional dural puncture for the prevention of post-dural puncture headache in parturients. Anesthesia and Analgesia 2012;115:133-6.

WET TAP AND INTRATHECAL CATHETER

Question: I got a “wet tap.” Should I place an intrathecal catheter?

Answer: The decision to place an intrathecal catheter (ITC) or to re-site the epidural catheter after an accidental dural puncture (ADP) should be a risk-benefit clinical judgment, depending on these factors:

1. The efficacy of ITCs – According to a 6-year retrospective cohort review of 235 parturients who had an ADP during epidural placement, ITC were associated with a higher rate of failed analgesia¹.
2. The difficulty of placement – For a very difficult epidural placement where the risk of an additional ADP and the failure to intubate is high (e.g. morbidly obese parturient), placing an ITC over resiting might be the better choice³. However, frequent checks for functionality is critical.^1,3
3. The side effect profile – According to a retrospective review of 218 patients over a 10-year period, there was no difference in the incidence of postdural puncture headache between the resited epidural group and the spinal catheter group.²

-Onyi C. Onuoha, MD. MPH
University of Houston, Houston, Texas 

References:
1. Jagannathan DK, Arriaga AF, Elterman KG, Kodali BS, Robinson JN, Tsen LC, Palanisamy A.
Effect of neuraxial technique after inadvertent dural puncture on obstetric outcomes and anesthetic complications. Int J Obstet Anesth. 2016 Feb; 25:23-9. doi: 10.1016/j.ijoa.2015.09.002. Epub 2015 Sep 18.
2. Bolden N, Gebre E. Accidental dural puncture management: 10-year experience at an academic tertiary care center. Reg Anesth Pain Med. 2016 Mar-Apr;41(2):169-74. doi: 10.1097/AAP.0000000000000339.
3. Soens MA, Birnbach DJ, Ranasinghe JS, van Zundert A. Obstetric anesthesia for the obese patient: an ounce of prevention is worth more than a pound of treatment. Acta Anaesthesiol Scand. 2008 Jan; 52(1):6-19. doi: 10. 111/j. 1399-6576.2007.01483.x.

The educational materials presented here are the individual authors' opinions and not medical advice, are not intended to set out a legal standard of care, and do not replace medical care or the judgment of the responsible medical professional in light of all the circumstances presented by an individual patient. The materials are not intended to ensure a successful patient outcome in every situation and are not a guarantee of any specific outcome. Materials are subject to periodic revision as additional data becomes available. The opinions, beliefs and viewpoints expressed by the authors do not necessarily reflect the opinions, beliefs and viewpoints of SOAP or any of its members, employees or agents.