La Caesarean section with general anesthesia It has become an increasingly less common technique, but it remains essential in certain emergency situations or when regional anesthesia is contraindicated. Many women hear about its risks without anyone properly explaining what they are, when it is used, and what implications it has for their health and that of their baby.
Understanding the safety of general anesthesia During a cesarean section, it helps to reduce fears, clarify expectations, and allow for more active participation in decision-making. Today, we have ample scientific evidence regarding its advantages, disadvantages, effects on the newborn, potential maternal complications—including postpartum mental health—and how anesthesiologists use it to minimize risks.
When is general anesthesia used in a cesarean section?
The main international guides They agree: whenever possible, neuraxial anesthesia (spinal or epidural) compared to the general procedure in cesarean section. The main reason is to reduce the risk of respiratory complications, aspiration of gastric contents, and problems in airway management, which are more frequent in pregnant women.
Even so, between 0,5 and 1% of cesarean sections They are still performed under general anesthesia. Most of these procedures correspond to urgent or emergency cesarean sections, in which there is not enough time to perform a safe regional technique or it is contraindicated.
Studies of large series of patients Studies show that when general anesthesia has been required during cesarean sections, the primary indication has been the need to terminate the pregnancy immediately due to maternal or fetal risk. In these situations, speed is paramount: the priority is to deliver the baby and stabilize the mother, rather than being able to calmly prepare for spinal anesthesia.
Among the most frequent reasons for choosing general anesthesia They highlight the perception that there is no time for a regional block, the presence of formal contraindications for neuraxial anesthesia (coagulopathies, significant hemorrhages, infections at the puncture site, certain neurological pathologies, etc.) and, to a lesser extent, the patient's explicit rejection of fears during childbirth or the failure of a previously initiated regional anesthesia.
In a very small percentage of cases General anesthesia is used after insufficient or failed spinal or epidural anesthesia. If adequate blockade is not achieved with supplemental local anesthetic or opioids and surgery must continue, the procedure is converted to a cesarean section under general anesthesia with endotracheal intubation to ensure analgesia and airway control.
Advantages and disadvantages of general anesthesia in cesarean section
General anesthesia is not "bad" by definitionHowever, it is a technique with very marked pros and cons that should be understood. When properly indicated and performed with strict protocols, it can be a key tool for saving lives in obstetrics.
Among its main advantages There is the speed with which the anesthetic plane is established, something crucial in serious emergencies. Furthermore, it offers a low failure rate Regarding intraoperative analgesia, it allows complete control of breathing through intubation and mechanical ventilation, facilitates hemodynamic management in critical situations, and allows for combined interventions (e.g., cesarean section and another simultaneous surgery).
Another key advantage is the rapid control of seizures In cases such as eclampsia, general anesthesia allows stabilization of the central nervous system, protection of the airway, and coordinated action with the obstetric and intensive care team.
On the downsideThe most feared is the difficulty of intubation: pregnant women have a higher risk of difficult airway due to anatomical changes (tissue edema, increased breast size, less mobile neck, higher body mass index) and reduced functional lung capacity, which accelerates oxygen desaturation.
There is also the risk of aspiration of gastric contents During induction or extubation, since all pregnant women are considered to have a "full stomach" from the second trimester until at least 24 hours postpartum. Excessive uterine relaxation due to halogenated agents (with increased bleeding), respiratory or neurological depression in the newborn due to transplacental passage of drugs, and a possible delay in delivery may also occur. skin to skin contact and the establishment of breastfeeding.
Comparison with regional anesthesia: mortality, morbidity, and baby
The literature of the last decades This has significantly nuanced the traditional view that general anesthesia for cesarean sections is "much more dangerous" than regional anesthesia. Thanks to improvements in techniques, medications, and monitoring, maternal mortality associated with general anesthesia has been reduced to levels very similar to those of regional anesthesia when cases are managed correctly.
Some population studies They indicate that the risk of maternal death from anesthetic-related causes in cesarean sections with general anesthesia is similar to that of neuraxial anesthesia, with figures around 1,7 per 100.000 procedures and wide confidence intervals. However, it should be noted that general anesthesia is used precisely in the most serious situations, so the underlying clinical context is different.
In terms of morbidityRegional anesthesia is generally associated with less blood loss, a lower incidence of surgical site infection, less immediate postoperative pain, and shorter hospital stays. A large study demonstrated a significantly higher risk of surgical site infection with general anesthesia, with an odds ratio close to 3,7 compared to neuraxial anesthesia.
Regarding immediate neonatal outcomesHowever, the picture is more nuanced. Meta-analyses comparing umbilical cord pH in cesarean sections with general versus spinal or epidural anesthesia have shown very small differences, likely irrelevant from a clinical standpoint. Nevertheless, large cohort studies have observed that general anesthesia increases the risk of the newborn requiring advanced resuscitation or intubation, as well as the likelihood of having a 5-minute Apgar score below 7.
These differences seem to be becoming more pronounced In emergency cesarean sections due to suspected fetal distress, the baby's condition before surgery is already worse. Therefore, it is difficult to separate what part of the poor neonatal outcome is due to the anesthetic technique and what part to the underlying pathology that necessitated the emergency cesarean.
Long-term impact on child development
Beyond Apgar and cord pHThe potential impact of general anesthesia on children's neurodevelopment is a concern. Multi-year follow-up studies of children born by cesarean section under different anesthetic techniques have explored the association with learning disorders.
In a large cohort No clear differences were found between children born vaginally with regional anesthesia and those born by cesarean section with general anesthesia regarding the incidence of learning disorders. However, infants born by cesarean section with neuraxial anesthesia appeared to have a slightly lower rate of these problems, which has led to hypotheses about the possible neurotoxic effect of some general anesthetics on the immature nervous system.
Expert panels in pediatric anesthesia They have warned that early exposure to certain general anesthetic drugs, especially during the neonatal period, could produce changes in brain synaptic density with still uncertain consequences. To date, there is no conclusive evidence of severe cognitive impairment after a single obstetric exposure, but the debate continues, and there is a push to use the lowest effective dose and reduce the duration of exposure.
In clinical practiceThis translates into precisely adjusting the doses of inhaled hypnotics and anesthetics, ensuring rapid but careful inductions, limiting the use of certain drugs with greater depressant potential on the neonate before clamping the umbilical cord, and considering non-pharmacological alternatives such as alternative therapies where applicable.
General anesthesia and postpartum mental health
In recent years the focus has been placed in an aspect that was traditionally overlooked: the mental health of the mother after a cesarean section under general anesthesia. A recent study of a large cohort of more than 34.000 women found that those who received general anesthesia during their cesarean section had increased risk of postpartum depression with need for hospitalization, as well as a higher probability of having suicidal or self-harming thoughts.
The hypothesis that the researchers are working with The problem is that general anesthesia prevents immediate skin-to-skin contact and delays the start of breastfeeding, two emotionally powerful moments associated with stronger bonding and maternal well-being. Furthermore, many women experience general anesthesia as "missing out" on the birth, which can be a source of frustration, guilt, and feeling of loss of control.
This is in addition to other factorsThe urgency of the procedure, the fear of serious complications, the slower and more painful recovery, and the potential lack of prior information. The result is a cocktail of emotional vulnerability that can trigger or exacerbate pre-existing mental health problems.
Therefore, the authors of these works They recommend that, when a woman has undergone general anesthesia during a cesarean section, postpartum depression screenings, psychological support, assistance in starting breastfeeding, and spaces for her to reconstruct her birth story with the healthcare team be proactively offered.
Special populations: preeclampsia and serious emergencies
Women with preeclampsia They constitute a high-risk group in which the choice of anesthesia type is especially important. Population studies have shown that, in this context, general anesthesia is associated with a increased risk of stroke in the years following cesarean section compared with neuroaxial.
Although the exact cause is not fully understoodIt is suspected that large fluctuations in blood pressure during induction, intubation, and extubation under general anesthesia could contribute to triggering vascular events in brains already compromised by hypertension and endothelial dysfunction characteristic of preeclampsia.
Conversely, in situations of massive hemorrhage In cases of severe hypovolemia, general anesthesia is usually the most hemodynamically stable option, as it avoids the abrupt sympathetic blockade of spinal anesthesia and allows for finer control of blood pressure, intravascular volume, and oxygenation.
In summary, in severe obstetric conditions The choice of anesthetic technique is not a matter of preference but rather a balance of individual risk and benefit, taking into account maternal pathology, fetal status, urgency of the cesarean section, and the team's experience. General anesthesia remains essential in many of these scenarios.
Drugs used in general anesthesia for cesarean section
The pharmacological objective in cesarean section It is delicate: adequately sedating and anesthetizing the mother, controlling the response to surgical stress and maintaining hemodynamic stability, while minimizing the passage of drugs to the fetus and the risk of neonatal depression.
Classically, thiopental Thiopental has been the standard hypnotic for rapid induction in obstetrics, at doses of 3 to 7 mg/kg. At doses below 4 mg/kg, the risk of neonatal depression is low, but above 7 mg/kg, the likelihood of neonatal asphyxia increases. The problem today is that thiopental is difficult to obtain in many centers, and propofol is more frequently used.
Propofol is a widely used drugHowever, it requires caution in pregnant women: it tends to produce dose-dependent hypotension and has a slightly longer time to reach its full effect, which can increase the risk of intraoperative consciousness if not properly adjusted. Comparative studies show that high doses of propofol or the use of midazolam for induction are associated with worse Apgar scores in newborns compared to thiopental.
Therefore, many experts recommend Moderate doses of propofol (around 1,5–2 mg/kg) are used during cesarean section, especially in hemodynamically fragile patients. Midazolam, despite its usefulness in other surgeries, has a significant transplacental passage rate (around 66%) and can cause neonatal depression, generally being reserved for postpartum use if necessary.
Ketamine can be very useful In pregnant women with shock or marked hypotension, it is used because it maintains blood pressure and cardiac output. However, in preeclampsia, it can worsen hypertension and tachycardia, and makes it difficult to awaken if a serious airway problem arises; therefore, its use should be individualized.
Anesthetic maintenance and prevention of intraoperative awakening
Following induction and intubationThe maintenance of general anesthesia in cesarean section is usually done with a combination of inhaled anesthetics (sevoflurane, isoflurane) in an oxygen mixture and, depending on the case, nitrous oxide, along with muscle relaxants and analgesics adjusted to the time of delivery.
The goal is to achieve a minimum alveolar concentration The concentration of halogenated ionization close to 0,7 is sufficient to maintain hypnosis without causing excessive uterine relaxation that could increase bleeding. Bispectral index (BIS) monitoring helps maintain the patient at an appropriate level of hypnosis (values below 60), reducing the risk of conscious awakening.
El labor prior to the cesarean section It appears to slightly reduce sevoflurane requirements, possibly due to the release of endorphins and other endogenous substances with analgesic and sedative effects. This necessitates dynamic adjustment of inhaled gas concentrations based on clinical response and BIS readings.
Magnesium sulfateCommonly used in preeclampsia, it reduces the requirements for propofol and halogenated agents, improves hemodynamic stability, and attenuates the response to nociceptive stimuli. However, its use as an adjunct in all healthy pregnant women is not recommended due to the risk of overdose and side effects; it is primarily reserved for patients with severe hypertension.
Regarding opioidsDrugs such as remifentanil allow for very effective control of the hypertensive response to laryngoscopy and intubation, especially in preeclamptic infants. However, its high transplacental passage is associated with neonatal respiratory depression that often requires resuscitation. Therefore, many teams use it only in highly selected contexts and always after notifying the neonatologist.
Muscle relaxants and advanced airway management
The traditional relaxant of choice In rapid sequence induction of pregnant women, succinylcholine is the drug of choice, due to its very rapid onset of action and short duration, which allows for the recovery of spontaneous ventilation relatively quickly if a "do not ventilate, do not intubate" scenario occurs.
Alternatively, rocuronium at high doses (1-1,2 mg/kg) provides similar intubation conditions in approximately 60 seconds. Its major advantage today is that it can be reversed almost immediately with sugammadex, which opens a way out in serious airway problems, at the cost of higher economic expense.
Difficult airway management guidelines In obstetrics, they insist on always prioritizing oxygenation over intubation at all costs. In the event of a failed intubation, multiple attempts should be avoided; a second attempt is recommended after improving the patient's position, and if this is unsuccessful, proceed to face mask ventilation, relaxing cricoid pressure if necessary.
Second generation laryngeal masks (Supreme, ProSeal) have proven to be a very effective and safe tool in elective cesarean sections and as a lifesaver in difficult intubation, allowing ventilation with a good seal and placement of a gastric tube to reduce the risk of distension and aspiration.
If all of this fails to oxygenate the patientIn such cases, emergency techniques such as percutaneous cricothyrotomy and, ultimately, emergency tracheostomy should be used. Well-trained protocols and clinical simulation help ensure that these rare scenarios are managed quickly and in a coordinated manner.
Preoxygenation, Sellick position and maneuver
Before rapid sequence inductionPreoxygenation is mandatory in pregnant women to increase the safe breathing time before desaturation occurs in case of intubation difficulties. It can be performed with normal breathing for 3 minutes using 100% oxygen, or with eight deep breaths in 1 minute when time is limited.
In pregnant women and obese patientsIt has been shown that the semi-recumbent position (around 30 degrees) improves functional residual lung capacity and prolongs apnea tolerance time compared to the supine position. Therefore, many teams perform preoxygenation and, if possible, induction in a slightly upright position.
Sellick's maneuver Pressure on the cricoid cartilage has been used for decades to try to prevent regurgitation and aspiration of gastric contents during induction. However, recent observational studies have questioned its effectiveness and even associated it with an apparent increase in regurgitation episodes during induction.
Despite the controversy, most guides They continue to recommend cricoid pressure for rapid sequence induction in pregnant women, always applied by trained personnel and released if it hinders ventilation or intubation. It is also known to compress primarily the postcricoid hypopharynx rather than the esophagus itself.
In addition to these measuresMany countries have incorporated as standard practice the pre-administration of non-particulate antacids, H2 antagonists, or proton pump inhibitors to raise gastric pH and reduce the severity of potential aspiration pneumonitis. Although evidence on their direct impact on the incidence of aspiration is limited, these interventions are considered low-risk and potentially high-benefit.
Intraoperative awakening and maternal safety
The “awareness” or recollection of the surgery During general anesthesia, it is a rare but particularly traumatic complication. In the general population, it is estimated at between 0,1 and 0,2%, but in cesarean sections under general anesthesia, the historical incidence was very high and, although it has been drastically reduced today, it is still higher than in other types of surgery.
The causes are multifactorial: rapid sequence inductions with short administration times of hypnotics, restriction of the use of halogenated or opioid drugs before birth to protect the fetus, and physiological changes of pregnancy that alter the pharmacokinetics of drugs.
The use of anesthetic depth monitoring (BIS) and the rigorous application of minimum effective dose protocols have reduced the incidence of conscious awakening after cesarean section to around 0,26%, that is, one hundred times lower than in previous studies. Even so, any patient who reports memories should be listened to, the event documented, and offered psychological support if needed.
To minimize this riskAnesthesiologists carefully plan the combination and timing of administration of hypnotics, inhalants, and analgesics, increase gas concentrations once the cord is clamped, and use adjuvants such as magnesium when appropriate, always maintaining maternal hemodynamic stability.
Practical overview: how general anesthesia is arranged for a cesarean section
In the actual practice of many hospitalsGeneral anesthesia for cesarean section is reserved for specific cases. When time allows, the woman is informed, her medical history is reviewed, her airway is carefully assessed (Mallampati score, mouth opening, cervical mobility, thyromental distance), and it is verified that all the necessary equipment for a difficult airway is available.
In emergency cesarean sectionsThe typical sequence includes intensive preoxygenation, supine positioning with a slight tilt to the left to avoid aortocaval compression, rapid administration of a hypnotic (propofol or thiopental if available) and a muscle relaxant (succinylcholine or rocuronium at rapid intubation doses) with cricoid pressure maintained until the tube cuff is inflated.
The start of surgery is authorized only After verifying tracheal intubation by auscultation and capnography, the halogenated agents and ventilation are adjusted to maintain a maternal pCO2 close to 30-33 mmHg, avoiding both excessive hyperventilation and hypercapnia, which could affect uteroplacental flow.
After birth and clamping of the cordThe necessary opioids are administered to ensure good pain control (fentanyl, morphine, remifentanil according to local protocol), and hypotension, hypovolemia, or uterine relaxation are corrected with fluids, vasopressors, and oxytocics. At the end of the procedure, the neuromuscular blockade is reversed, and awake extubation is planned, with the patient conscious and with restored protective reflexes.
This entire process requires teamwork. among anesthesiologists, obstetricians, midwives, pediatricians and nursing staff, as well as continuing education, simulation of crisis scenarios and analysis of complex cases to improve protocols and reinforce the safety of the mother-baby dyad.
Looking at the body of evidence and clinical experienceGeneral anesthesia in cesarean section is not an enemy to be avoided at all costs, but a powerful tool that, when used with sound judgment, training and adequate resources, allows us to face the most critical obstetric situations while maintaining very high levels of safety for mother and newborn.