What is considered the most appropriate choice for anesthetic technique in the setting of cesarean delivery?

Neuraxial anesthesia is the preferred choice of anesthetic in the majority of cesarean deliveries because of the following advantages:

Likely improved safety profile and role in reducing maternal mortality
Limited drug exposure for the neonate
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Maternal consciousness for delivery

However, general anesthesia may be a more appropriate choice than neuraxial anesthesia in some clinical circumstances.

When is general anesthesia considered an appropriate choice for anesthetic technique for cesarean delivery?

General anesthesia may be a more appropriate choice in situations such as:

Emergent (category I) delivery (e.g., fetal bradycardia, uterine rupture, umbilical cord prolapse)
When there are contraindications to neuraxial anesthesia such as coagulopathy or extensive spinal surgery (e.g., severe hemorrhage, placenta abruption with evidence of coagulopathy)
When neuraxial anesthesia fails
When the patient refuses neuraxial anesthesia

Is maternal mortality higher if general anesthesia is employed for cesarean delivery?

This is difficult to directly compare prospectively; most evidence comes from retrospective epidemiologic investigations.
The absolute risk of anesthetic-related maternal mortality is low in the United States for both general and regional anesthesia.
Represented as per million live births between 1997 and 2002, case fatality rates by anesthetic technique were: 6.5 deaths per million general anesthetics and 3.8 deaths per million neuraxial anesthetics, and the risk ratio for using general as compared with neuraxial anesthesia is 1.7 (CI 0.6-4.6, P=0.2).
Selection bias likely influences those rates, in that patients who received general anesthetics were likely higher risk patients. However, many experts feel that much of the substantial reduction in anesthetic-related maternal mortality over the last few decades is attributable to a greater reliance on neuraxial anesthesia.
Over time, the risk of general anesthesia has decreased while that for neuraxial anesthesia has risen. This likely reflects a shift in practice whereby higher risk patients being managed increasingly with neuraxial techniques.

Is it possible that the risk of general anesthesia in a fasted, healthy, non-obese parturient with airway anatomy predictive of an easy intubation is the same as a neuraxial anesthetic for cesarean delivery?

There is limited evidence about anesthetic technique safety in this setting.
It may not be an unreasonable anesthetic plan to proceed with an elective general anesthetic in the low risk patient population if there are other compelling reasons that favor general anesthesia.
The American Society of Anesthesiologists (ASA) practice guidelines do not address this question directly, generally encourage neuraxial anesthesia, and defer to the judgment of the individual practitioner.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

The urgency of most cesarean deliveries is contingent mostly upon fetal status, obstetric conditions, and occasionally maternal co-morbidities.

Emergent: General anesthesia is often the most practical technique for emergent cesarean delivery.

Urgent: Although neuraxial anesthesia is usually possible, and often preferable, in urgent cesarean deliveries, general anesthesia may be used if placement of neuraxial anesthesia is difficult, requires a prolonged period of time to accomplish, or fails.

Elective: General anesthesia is rarely preferable to neuraxial anesthesia for elective cesarean delivery unless a contraindication is present such as coagulopathy or the patient refuses neuraxial anesthesia.

2. Preoperative evaluation

Assessing the likelihood of difficulty or inability to intubate a pregnant woman is one of the most important parts of the preoperative evaluation.

Approximately 2.3 (95% CI 1.7-2.9) per 1000 general anesthetics for cesarean delivery result in failed intubation (1 in 443 cases). Generally, difficult to intubate is defined as the inability to obtain a view of the vocal cords with multiple attempts and alterations in position and direct laryngoscopy equipment.
This incidence may represent a higher relative risk compared with the nonpregnant population and it has been relatively unchanged for 40 years.
Surgical airway procedures are reported to occur at a rate of 3.4 (95% CI 0.7 to 9.9) per 100,000 general anesthetics for cesarean delivery (approximately 1 procedure per 60 failed intubations).
Maternal mortality from failed intubation is reported to be 2.3 (95% CI 0.3 to 8.2) per 100,00 general anesthetics for cesarean delivery and has decreased in recent decades presumably due to better preparation, equipment and skills.
Anatomical considerations more common in pregnancy that may partially explain this increased risk include airway edema, enlarged breasts, and the need for left uterine displacement from the supine position.
Predicting a difficult airway by Mallampati classification may change over the course of labor, presumably due to progressive edema, especially during pushing and Valsalva maneuvers.

Difficult mask ventilation has not been studied extensively in pregnancy.

Rates from nonpregnant patients provide some perspective; 1.4% to 1.5% of nonpregnant patients can be expected to be difficult to mask ventilate and 0.15% of nonpregnant patients are “impossible” to ventilate.
Pregnant patients may have a higher but undefined incidence of difficult mask ventilation due to airway edema.
Fortunately, in most of these circumstances, ventilation can be reliably obtained with laryngeal mask airways.
The ASA difficult airway algorithm should be used to guide management; however fetal status, which is not addressed in the algorithm, plays an important role in guiding decision making in the setting of cesarean delivery.
The Obstetric Anaesthetists’ Association and Difficult Airway Society in the United Kingdom published guidelines for difficult airway management in the context of cesarean delivery and incorporating unique considerations in pregnancy. The guidelines include a table to assist with the decision to proceed with surgery or wake up the patient in the setting of failed intubation.

What are appropriate NPO times for elective cesarean deliveries?

ASA guidelines for fasting in healthy patients prior to elective cesarean deliveries are based primarily on expert opinion and recommendations include:

Fasting of 6 hours for solids (8 hours for a meal with high fat content).
Allowing moderate amounts of clear liquids up until 2 hours prior to surgery.

Recommendations for laboring parturients include:

Avoiding solid food in labor.
Encouraging moderate intake of clear liquids.
Instituting further restrictions on a case by case basis based on the presence of an anticipated difficult airways, increased risk for operative delivery, or medical conditions that may reduce gastric emptying (e.g., diabetes mellitus, morbid obesity).

Should one wait to initiate a cesarean delivery in a laboring patient who has recently eaten?

There is evidence that labor pain and the administration of systemic opioids decrease gastric emptying as compared with non-laboring patients and this, combined with fetal status considerations, may justify proceeding in performing a non-elective cesarean delivery earlier than the recommended guidelines.
It may be difficult to compare the relative anesthetic risks of aspiration and difficult airway management with specific obstetric/fetal risks. Collaboration decision-making is essential in circumstances when anesthesiologists and obstetricians each possess incomplete knowledge of each other’s specialty. For example, the decision on timing to proceed with cesarean in a non-fasted, non-laboring patient with breech presentation and ruptured membranes may be determined by a higher likelihood of cord prolapse and fetal injury than the risk of sequential failed neuraxial technique, inability to intubate, and occurrence of aspiration.

3. What are the implications of coexisting disease on perioperative care?

Perioperative risk reduction strategies

Pulmonary aspiration of gastric contents during general anesthesia for cesarean delivery is very rare but can be catastrophic. Rates of aspiration during general anesthesia for cesarean delivery have been estimated to be 0.1%, 0.7% with observed regurgitation.
Aspiration during cesarean delivery has evolved from being a leading cause of anesthetic-related maternal mortality several decades ago to a very rare cause today.
Risks associated with aspiration at term pregnancy include gastroesophageal reflux-prone anatomy and physiology, frequent non-fasting status, and predicted intubation difficulty.
Pulmonary aspiration of gastric contents may occur more likely at emergence as compared with induction.
Expert opinion and limited evidence support that morbidity from aspiration is likely reduced if prophylactic strategies, such as premedication with nonparticulate antacids, Histamine-2 receptor antagonists, or metoclopramide are administered, and the use of a rapid sequence induction with cricoid pressure is employed.

Back-up emergency airway equipment should be equivalent to that available for airway management in non-obstetric cases. In addition to laryngoscopes and endotracheal tubes, this should include several of the following: laryngeal mask airways (preferably intubating LMA with gastric port), videolaryngocopy, fiberoptic intubation equipment, a jet ventilating stylet, other supraglottic airway devices, retrograde intubation equipment, and surgical airway access equipment.

b. Cardiovascular system:

N/A

c. Pulmonary:

Term pregnant patients have reduced functional residual capacity (FRC), which has both negative and positive considerations.
Parturients will desaturate more quickly following apnea, but denitrogenation can be achieved more efficiently prior to induction and intubation.
Several techniques using an effective mask seal and 100% oxygen have been advocated with the following time requirements for effectiveness as measured by end tidal (ET) oxygenation:

a) Tidal volume breathing for 180 seconds provides ET oxygen of 90 ± 6%

b) Four deep breaths over 40 seconds provide ET oxygen of 83 ± 6%

c) Eight deep breaths over 80 seconds provide ET oxygen 89% ± 5%.

Deep breathing is more efficient than tidal volume breathing in achieving denitrogenation.
Clinicians must determine how much time should be dedicated to denitrogenation based on fetal status and the likelihood of difficult intubation.

d. Renal-GI:

N/A

e. Neurologic:

N/A

f. Endocrine:

N/A

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)

N/A

4. What are the patient’s medications and how should they be managed in the perioperative period?

Pregnant patients undergoing surgical procedures should receive pharmacologic aspiration prophylaxis, although the ideal regimen is unknown. Non-particulate antacids and H2 blockers are widely used in conjunction with cesarean delivery although there is limited direct evidence of improved outcomes.
Nonparticulate antacids are effective in raising gastric pH without increasing gastric volume.
Histamine-2 receptor blocking agents are effective in raising gastric pH and reducing gastric volume. Their onset time is approximately thirty minutes and there are minimal side effects.
Metoclopramide increases lower esophageal sphincter tone and reduces gastric volume, including in laboring patients and those that have received systemic opioids. Metoclopramide reduces peripartum nausea and vomiting with an onset time of approximately 30 minutes, but is associated with a rare incidence of dystonic reactions, which are less commonly seen with single dose administration.
Proton pump inhibitors reduce gastric pH and may be more effective than H2 blockers, but costs may limit their use.
Mechanical decompression of the stomach with an orogastric tube after induction of general anesthesia and securing the airway may reduce morbidity from aspiration.

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

Concerns about the prevalence of venous thromboembolism in the parturient have led to recommendations for increased use of anticoagulation which may contraindicate neuraxial anesthesia in a greater subset of patients presenting for cesarean delivery.
Venous thromboembolism remains a leading, preventable cause of maternal mortality whereas anesthetic causes have markedly declined in recent decades. It was understood in the development of new thromboprophylactic guidelines in parturients that there is some interdependence of these two risks but thromboembolism represents the greater quantitate risk currently.

i. What should be recommended with regard to continuation of medications taken chronically?

N/A

j. How to modify care for patients with known allergies

N/A

k. Latex allergy – If the patient has a sensitivity to latex (e.g., rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.

N/A

l. Does the patient have any antibiotic allergies – Common antibiotic allergies and alternative antibiotics

N/A

m. Does the patient have a history of allergy to anesthesia?

Malignant hyperthermia (MH)

Avoid all trigger agents such as succinylcholine and inhalational agents.
Follow a proposed general anesthetic plan to include total intravenous anesthesia with propofol ± opioid infusion ± nitrous oxide.
Ensure that an MH cart is available [MH protocol].

5. What laboratory tests should be obtained and has everything been reviewed?

N/A

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

In an emergency, general anesthesia is usually more rapid than spinal anesthesia for cesarean delivery.
However, in some centers, anesthetic conditions for a cesarean delivery can be achieved with a single-shot spinal almost as quickly as with general anesthesia. This may be appropriate in the setting of urgent (Category II) indications for cesarean delivery but less likely for emergent (Category I) indications.
In order to achieve this type of efficiency with neuraxial anesthesia, equipment must be prepositioned, the most skilled proceduralist engaged, and a clear understanding of the goals and time limitations by both anesthesiologists and obstetricians required.
The anesthesiologist and obstetrician must communicate clearly about the fetal status and the amount of time that can be allowed for attempted neuraxial anesthesia.

Are neonatal outcomes worse with general anesthesia as compared with neuraxial anesthesia?

Although there are conflicting data in studies comparing cesarean deliveries conducted with general versus neuraxial anesthesia, overall there are no substantive differences in neonatal outcome.
In broad analyses inclusive of nonrandomized trials and urgent cesarean deliveries, general and epidural anesthesia resulted in superior umbilical cord gases as compared with spinal anesthetics, but there were no differences between anesthetic techniques when only non-urgent cesarean deliveries were included in analysis.
Lower Apgar scores are seen with general compared to neuraxial anesthesia at one minute, but no differences are observed at 5 minutes.
There is no difference in the proportion of severely low scores overall between techniques. In two studies evaluating neonatal neurological adaptive scores, there were conflicting results. The smaller study reported better results with neuraxial anesthesia, but the larger study showed no difference between neuraxial and general anesthesia.

a. General anesthesia

Benefits

Speed and reliability of onset
Secured airway in a patient with a high aspiration risk.

Drawbacks

Increased drug exposure for the neonate and maternal unconsciousness for the birth.

a. To minimize neonatal drug exposure, preparations are usually made for immediate delivery following general anesthetic induction.

b. It is not known how urgently an infant should be delivered following the induction of general anesthesia, even in a healthy parturient without any evidence of fetal distress.

c. In subanalyses of neonatal outcomes from cesarean delivery, prolonged induction to delivery intervals have been associated with worsened umbilical cord gases. Thus most institutions try to achieve the shortest induction to delivery interval by having the abdomen antiseptically prepared and the obstetricians scrubbed in and ready for skin incision.

d. Prolonged uterine incision to delivery time was also associated with worsened umbilical cord gases.

e. There are several anesthetic considerations that likely influence neonatal status such as the use of hypnotics and other medications such as opioids that are bolused at induction and readily transmitted to the fetus, then redistributed and metabolized by both the mother and fetus.

f. Muscle relaxants do not readily cross the placenta because of their large molecular size.

g. Volatile anesthetic partial pressures rise over several minutes before peaking in the fetus.

h. Optimal delivery time probably comprises the window after redistribution of most of the hypnotic but prior to accumulation of substantial volatile anesthetic.

i. Since the incision to delivery time is not always predictable, antiseptic preparation of the abdomen and surgical readiness prior to induction are probably judicious.

Other issues: maternal cardiac output and blood pressure strongly influence placental perfusion. Maintaining normal hemodynamic status following the administration of anesthetics may have a more important effect on neonatal status than the presence of anesthetic drugs in the neonatal brain.

Airway concerns

If the parturient cannot be easily intubated, and an LMA has been inserted to aid ventilation, it may be appropriate to use an LMA for the duration of the cesarean delivery.
Laryngeal mask airways do not reliably prevent the aspiration of stomach contents in this population at high risk, but aspiration rates in healthy parturients with LMA’s may not be substantially different than with cuffed endotracheal tubes.
The use of an LMA (or mask ventilation) are important steps in the difficult airway algorithm and should certainly be considered if there is urgency based on fetal status and the airway cannot be secured with an endotracheal tube.
Intubation through the LMA can be accomplished with equipment designed for this contingency, or with improvisation. The decision to proceed to delivery or through an entire case with an LMA alone must be weighed against the fetal status and the risks of further airway manipulation.

b. Monitored anesthesia care:

Not appropriate for cesarean delivery.

6. What is the author’s preferred method of anesthesia technique and why?

Induction for emergent cesarean delivery when neuraxial anesthesia is not possible:

Premedication with non-particulate antacid, H2 blocker and metoclopramide.
Left uterine displacement and denitrogenation with approximately 8 deep breaths.
Administration of lidocaine (1.5 mcg/kg) to blunt the sympathetic response to laryngoscopy. Avoidance of lidocaine if local anesthetic had been administered in a large dose in augmenting epidural anesthesia (alternative: esmolol (0.5-1 mg/kg).
Rapid sequence induction with propofol (2-3 mcg/kg) and succinylcholine (1.5 mg/kg) with application of cricoid pressure.
Maintenance with sevoflurane 2% with nitrous oxide 50% in oxygen 50%.
Decompression of the stomach with a nasogastric tube.
Transition to sevoflurane 0.7% with nitrous oxide 70% in oxygen 30% following delivery with opioid (typically fentanyl or hydromorphone) and midazolam for analgesia and amnesia.
Ondansetron 4 mg for routine post operative nausea prophylaxis.
Nondepolarizing muscle relaxant only if necessary with reversal at emergence.

What induction agent is most appropriate for general anesthesia for cesarean delivery?

Choice of induction agent is made based on availability, desired hemodynamic goals and perceptions of maternal and neonatal risks. There are virtually no controlled trials on the use of induction agents in parturients. Assessment of maternal and neonatal safety must be inferred from animal trials and population data. The US Food and Drug Administration is phasing out its use of a lettered pregnancy drug categorization in favor of narrative descriptions of risk.

Propofol(formerly FDA Pregnancy Category B): In doses of 2-3 mg/kg it is associated with more maternal hypotension and greater neonatal depression when compared to sodium thiopental. Its time to redistribution is rapid, this may result in lighter anesthesia between induction and delivery, and could be a risk factor for awareness. The lipid base serves as a bacterial growth medium and thus it has a shorter shelf life if drawn up as an emergency agent.
Ketamine (formerly US FDA Pregnancy Category C) is an NDMA antagonist which serves as an appropriate alternative induction agent in circumstances of existing hypotension, hypovolemia, or if resultant hypotension may be more consequential. It has limited neonatal depression at standard doses of 1-1.5 mg/kg and may decrease postoperative pain and opioid requirements. It may increase maternal heart rate and blood pressure. Other side effects may include maternal hallucinations and increased nausea and vomiting.
Etomidate (formerly US FDA Pregnancy Category C) may be an appropriate induction agent in circumstances where hemodynamic stability is desired. Limited neonatal depression has been reported at doses of 0.2-0.3 mg/kg, but maternal side effects associated with single dose administration include increased nausea and vomiting, lowered seizure thresholds, and involuntary motor movement. Immunosuppression has been observed even with single dose administration in non-obstetric patients but the impact of this phenomenon in pregnancy is unknown.
Dexmedetomidine (formerly US FDA Pregnancy Category C) is an alpha-2 agonist and may be an appropriate induction agent in circumstances where hemodynamic stability is desired. There are limited data on its use in pregnancy. Limited neonatal depression has been reported at doses of 0.2-0.3 mg/kg.
Sodium thiopental is no longer available in the U.S. market, but has the longest history of use for cesarean delivery. It is formerly US FDA Pregnancy Category C with a long-standing safety record in pregnancy with limited neonatal depression at standard doses of 4-5 mg/kg. Its time to redistribution overlaps with volatile anesthetic equilibration intervals, theoretically reducing the risk of awareness. It is stable in a suspended preparation.

Should opioid be used as part of the induction of a general anesthetic for cesarean delivery?

All opioids are transmitted to the fetus and represent some risk for neonatal depression.
Opioids confer the maternal benefit of blunting the hemodynamic response to laryngoscopy, reducing hypnotic requirements and establishing the foundation for postpartum analgesia.
Alternatives to blunt the hemodynamic response to laryngoscopy (in severe preeclampsia for example) include dexmedetomidine, beta blockers and sodium channel blockers such as lidocaine.
Clinical judgment must be exercised as to how much priority should be placed on maternal hemodynamic control versus need for neonatal resuscitation.
Despite some theoretical pharmacokinetic advantages of remifentanil in cesarean deliveries, it has not been shown to be superior to small doses of longer acting opioids such as fentanyl. Remifentanil boluses of 1 mcg/kg, when combined with a hypnotic induction, effectively blunt the hemodynamic response to laryngoscopy, and its rapid onset and short duration closely match the clinical goals. Although Apgar scores are not different between neonates exposed to remifentanil versus placebo, approximately 10% of those who receive 1 mcg/kg remifentanil required naloxone for respiratory depression in one study.

Should succinylcholine dose be altered at term pregnancy?

The standard intubating dose of 1-1.5 mg/kg is recommended in parturients.
Plasma pseudocholinesterase levels are reduced by approximately 25-30% at term pregnancy, although this reduction of succinylcholine metabolism is probably not clinically relevant due to the increased volume of distribution at term.
Significantly reduced levels of pseudocholinesterase are very rare, and the morbidity would be presumably limited to minutes to, at most, several hours of extended endotracheal intubation.
If succinylcholine is contraindicated, rocuronium is a reasonable alternative for intubating pregnant patients, providing intubating conditions almost as quickly as succinylcholine. In combination with an induction agent, 0.6 mg/kg provides intubating conditions at 80-100 seconds, while 1.2 mg/kg allows intubation in 60 seconds. The duration of action, particularly with the higher dose, may be prolonged and may require postoperative intubation if surgical duration is short.
The availability of selective relaxant binding agents such as sugammedex have the potential to improve the safety and logistics of using long acting relaxants in cesarean delivery.

What should be used for anesthetic maintenance during a cesarean delivery?

MAC for volatile anesthetics in the setting of term pregnancy has been reported to be reduced by approximately 25-40%. Elevated progesterone concentrations have been implicated, but a strong linear correlation with progesterone levels has not been consistently reported.
Importantly, under-dosing of volatile anesthetic during cesarean delivery has been implicated as a leading cause of the high prevalence of awareness.
However volatile anesthetics also have a dose dependent relaxant effect on uterine smooth muscle, but this effect is not typically significant below 1 MAC.
The best strategy for minimizing both neonatal depression and maternal awareness may be immediate and generous administration of volatile anesthetic in the period between induction and delivery, administration of opioids concurrent with a reduction in volatile anesthetic after delivery, and reliance on nitrous oxide 50-70% throughout the case to reduce the volatile anesthetic requirements.

Should benzodiazepines be routinely administered to reduce the risk of awareness during cesarean delivery?

Awareness occurs most frequently in the interval between redistribution of the induction agent and achievement of adequate brain levels of volatile anesthetic, and in the setting of uterine atony or hypotension where volatile anesthetic has been intentionally limited.
Benzodiazepines are effective anterograde amnestics, but have not been shown to be effective for inducing retrograde amnesia in the setting of suspected awareness, so in most settings where a concern for awareness exists, benzodiazepines are routinely administered prophylactically. Pre-induction administration of benzodiazepines is not believed to be a commonly employed strategy with concerns that it may compound respiratory depression risk in the neonate.
A small dose of benzodiazepine immediately post delivery may be effective in reducing the incidence of awareness but it has not been extensively studied.

Should muscle relaxant dosing be altered in the setting of magnesium administration for preeclampsia?

Most cesarean deliveries can be managed effectively with succinylcholine dosed for intubation and no further relaxants administered.
Magnesium sulfate does not alter the metabolism of succinylcholine, but non-depolarizing relaxants have been reported to have prolonged action in the setting of intravenous magnesium sulfate therapy.
A precise relationship between dose, magnesium level and duration of paralysis has not been established, nor have effective dosing strategies been developed for this setting.
This phenomenon does not preclude the use of non-depolarizing neuromuscular blockers when magnesium sulfate has been administered, but caution is warranted if extubation is planned at the end of the case.

What is the impact of general anesthetic medications on subsequent breastfeeding?

Many medications used for general anesthesia can be found expressed in breast milk with theoretical concerns for neonatal safety.
Factors that affect include molecular size, lipid solubility, protein binding, pKa and maternal serum levels of the drug.
Assays of some induction agents and opioids suggest that levels of anesthetic drugs in breast milk are typically limited and, when combined with low oral bioavailability of these drugs in neonates, the risks are deemed minimal.
Exceptions include the opioids meperidine and hydromorphone in which some discretion is advised due to longer half-lives in breast milk.
Current recommendation is that breastfeeding can be initiated immediately following general anesthesia with cautions only in the setting of meperidine and hydromorphone use.
Additional information can be found for individual substances at the National Institutes of Health website LactMed.

What prophylactic antibiotics should be administered?

The use of either cefazolin alone before surgical incision or an extended-spectrum regimen after cord clamp is associated with a reduction in post-cesarean maternal surgical site infection.
Substantial reductions in endometritis RR 0.54 (95% CI 0.45-0.72) and wound infection RR 0.59 (95% CI 0.36-0.79) without adverse neonatal effects have been reported when antibiotics are administered prior to incision which has shifted practice to pre-incision antibiotic administration for cesarean delivery.

a. Neurologic:

N/A

b. If the patient is intubated, are there any special criteria for extubation?

Pregnant patients are at an increased risk for aspiration, although the absolute risk is low. The patient should be awake and alert enough to manage her airway prior to extubation.

c. Postoperative management

What analgesic modalities can be implemented for post-cesarean pain?

Opioids
Non-steroidal anti-inflammatory drugs (NSAIDs)
Acetaminophen
Transversus abdominus plane blockade
Epidural analgesia

What level bed acuity is appropriate?

A standard floor bed most commonly
Less than 5% of obstetric patients require intensive care surveillance, most commonly for hemorrhage and complications of preeclampsia

What are common postoperative complications, and ways to prevent and treat them?

Thromboembolism

Thromboembolism is a leading cause of maternal mortality. Prophylaxis should include either anticoagulation or pneumatic sequential compression stockings until the patient is ambulatory. The National Council on Patient Safety has recently released a safety bundle with recommendations for reducing the incidence of postpartum venous thromboembolic events.

Surgical Site infection

Prophylactic antibiotics administered prior to incision have been shown to significantly reduce endometritis and wound infections without altering neonatal outcomes.

Awareness during anesthesia

Approximately one in 250-500 parturients who receive a general anesthetic may experience awareness.
The incidence of awareness during general anesthesia for cesarean delivery has been reported to be slightly higher than that for non-pregnant patients although the confidence intervals for these two groups overlap in some studies; 0.2-0.4% during cesarean versus 0.1-0.2% in the general surgical population.
The highest risk has been associated with the following intraoperative periods: between induction and incision (likely when redistribution of hypnotic occurs prior to achieving adequate volatile anesthetic levels) and immediately postpartum when under-dosing of volatile anesthetic may occur while managing uterine atony or hypotension.
Brain function (or depth of anesthesia) monitoring represents a theoretical strategy to reduce this concerning complication, however, clinical trials in non-pregnant patients have not demonstrated a benefit of using brain function monitoring to reduce awareness.

a.) In favor of its use, depth of anesthesia monitoring may promote greater vigilance during at-risk periods for awareness, it is non-invasive, and individual costs are nominal.

b.) Against its use, evidence for effectiveness has not been demonstrated even in high risk populations, there is limited information specifically in pregnancy, values that correspond to general anesthesia in the pregnant patient have not been clearly established, there are logistical issues related to placing these monitors and obtaining values in the short interval between induction and delivery in emergent cases, and their use may not be cost-effective overall.

How should patients be monitored in the PACU following general anesthesia?

With improvements in intraoperative airway management, a greater proportion of anesthetic-related maternal mortality may now be occurring in the postpartum period.
Obesity and black race have been identified as independent risk factors for consequential postpartum respiratory depression.
The development of post-general anesthetic respiratory depression is certainly multifactorial and monitoring strategies and technologies, adequacy of PACU nurse staffing and training may be areas for improvement.
The ASA Practice Guidelines for obstetric anesthesia promote the same standards of care for postpartum monitoring as established for non-pregnant postsurgical care.

What’s the Evidence?

PRACTICE GUIDELINES

Apfelbaum, JL, Hawkins, JL, Bucklin, BA. “Practice guidelines for obstetric anesthesia: An updated report by the American Society of Anesthesiology task force on obstetric anesthesia and the Society of Obstetric Anesthesiology and Perinatology”. Anesthesiology. vol. 124. 2016. pp. 270-300.

Mushambi, MC, Kinsella, SM, Popat, M. “Obstetric Anaesthetists’ Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics”. Anaesthesia. vol. 70. 2015. pp. 1286-1306.

AIRWAY MANAGEMENT

Boutonnet, M, Faitot, V, Katz, A, Salomon, L, Keita, H. “Mallampati class changes during pregnancy, labour, and after delivery: can these be predicted”. Br J Anaesth. vol. 104. 2010. pp. 67-70.

Kinsella, SM, Winton, AL, Mushambi, MC. “Failed tracheal intubation during obstetric general anaesthesia: a literature review.”. Int J Obstet Anesth. vol. 24. 2015. pp. 356-374.

Paranjothy, S, Griffiths, JD, Broughton, HK. “Interventions at caesarean section for reducing the risk of aspiration pneumonitis (Review)”. Cochrane Database of Systematic Reviews. vol. 2. 2014. pp. CD004943

Han, TH, Brimacombe, J, Lee, EJ, Yang, HS. “The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases”. Can J Anaesth. vol. 48. 2001. pp. 1117-21.

Chiron, B, Laffon, M, Ferrandiere, M. “Standard preoxygenation technique versus two rapid techniques in pregnant patients”. Int J Obstet Anesth. vol. 13. 2004. pp. 11-4.

Yoo, KY, Kang, DH, Jeong, H. “A dose–response study of remifentanil for attenuation of the hypertensive response to laryngoscopy and tracheal intubation in severely preeclamptic women undergoing caesarean delivery under general anaesthesia”. Int J Obstet Anesth. vol. 22. 2013. pp. 10-18.

Stourac, P, Adamus, M, Seidlova, D. “Low-dose or high-dose rocuronium reversed with neostigmine or sugammadex for cesarean delivery anesthesia: a randomized controlled non-inferiority trial of time to tracheal intubation and extubation”. Anesth Analg. vol. 122. 2016. pp. 1536-45.

MATERNAL MORTALITY

Hawkins, JL, Chang, J, Palmer, SK. “Anesthesia-related maternal mortality in the United States: 1979-2002”. Obstet Gynecol. vol. 117. 2011. pp. 69-74.

Mhyre, JM, Riesner, MN, Polley, LS, Naughton, NN. “A series of anesthesia-related maternal deaths in Michigan, 1985-2003”. Anesthesiology. vol. 106. 2007. pp. 1096-104.

VOLATILE ANESTHETICS

Lee, J, Lee, J, Ko, S. “The relationship between serum progesterone concentration and anesthetic and analgesic requirements: A prospective observational study of parturients undergoing cesarean delivery”. Anesth Analg. vol. 119. 2014. pp. 901-5.

AWARENESS

Cook, T. M. “The 5 National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent, and medicolegal issues”. Anaesthesia. vol. 69. 2014. pp. 1102-1116.

Robbins, K, Lyons, G. “Intraoperative awareness during general anesthesia for cesarean delivery”. Anesth Analg. vol. 109. 2009. pp. 886-90.

Zand, F, Hadavi, SMR. “Survey on the adequacy of depth of anaesthesia with bispectral index and isolated forearm technique in elective Caesarean section under general anaesthesia with sevoflurane”. Brit J Anaesth. vol. 112. 2014. pp. 871-8.

FETAL EFFECTS

Afolabi, BB, Lesi, FEA. “Regional versus general anesthesia for cesarean delivery”. Cochrane Database Systematic Review. 2012. pp. CD004350

“Food and Drug Administration. Content and format labeling for human prescription drugs and biologicial products; requirements for pregnancy and lactation labeling”. 2014.

COMPLICATIONS

D’Angelo, R, Smiley, RM, Riley, ET. “Serious complications related to obstetric anesthesia. The serious complication repository project of the society for obstetric anesthesia and perinatology”. Anesthesiology. vol. 120. 2014. pp. 1505-12.

BREASTFEEDING

Cobb, B, Liu, R, Valentine, E, Onuoha, O. “Breastfeeding after Anesthesia: A review for anesthesia providers regarding the transfer of medications into breast milk”. Transl Periop Pain Med. vol. 1. 2015. pp. 1-7.

INFECTION

Mackeen, AD, Packard, RE, Orta, E, Borghella, V, Baxter, JK. “Timing of intravenous prophylactic antibiotics for preventing postpartum infectious morbidity in women undergoing cesarean delivery”. Cochrane Database Systematic Review. 2014. pp. CD009516

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