Cesarean section is one of the most frequent procedures in obstetrics and, like any major surgery, it is not without risks. When we add anesthesia to the mix (whether regional or general), the equation becomes a bit more complicated: The safety of the mother and baby depends largely on choosing the right anesthetic technique, applying it rigorously, and anticipating complications..
In recent years, numerous studies and clinical guidelines have been published comparing general anesthesia and neuraxial anesthesia (spinal and epidural) in cesarean sections. Thanks to these, we know that Regional anesthesia is usually the preferred option, but general anesthesia still has its place in very specific situations.We will break down, step by step and without unnecessary technicalities, what types of anesthesia exist, what risks they imply for mother and baby, how they are minimized and what role they also play in postpartum mental health.
Types of anesthesia in cesarean section and when to choose each one
In a cesarean section, spinal, epidural, or general anesthesia can be used.And the choice is not arbitrary: it depends on the urgency of the intervention, the mother's condition, the situation of the fetus, and the contraindications of each technique.
Under ideal conditions, and following the recommendations of the main scientific societies, Neuroaxial anesthesia (spinal or epidural block) is the reference techniqueIt allows the mother to be awake, to see her baby being born and to perform early skin-to-skin contact, something we know improves attachment and neonatal adaptation.
General anesthesia, on the other hand, It is reserved for a very small percentage of cesarean sections (approximately 0,5-1%)., almost always emergencies in which there is no real time to administer regional anesthesia or when it is contraindicated or has failed.
Observational studies in large hospitals show that Most cesarean sections under general anesthesia are performed because it is perceived that "there is no time" for spinal or epidural anesthesia., followed by formal contraindications (coagulopathy, uncontrolled hemorrhage, infection, complex prior spinal surgery) and, in a small percentage, patient refusal of the puncture.
From a practical point of view, the anesthesiologist assesses three sets of factors: urgency (how many minutes are actually available), maternal safety (airway, hemodynamics, comorbidities) and fetal well-being (baby's condition, need for immediate discharge)Based on that combination, the safest technique for the mother-baby dyad is chosen.
Differences between neuraxial anesthesia and general anesthesia in cesarean section
When comparing general and regional anesthesia for cesarean section, the results are not black and white: Each technique has advantages and disadvantages, and its impact changes depending on whether we are talking about the mother, the newborn, infectious complications, or even long-term neurodevelopment..
Meta-analyses that have reviewed randomized clinical trials find that, With spinal or epidural anesthesia, the mother experiences more intraoperative nausea and vomiting.probably due to the hypotension induced by the sympathetic blockade. In return, General anesthesia is associated with more blood loss and more chills..
Regarding the newborn, classic studies showed small differences in umbilical cord pH between techniqueswith a slightly lower pH after spinal anesthesia; however, these differences are minimal and, in general, These findings do not result in relevant Apgar changes or the need for resuscitation when the pregnancy is progressing without serious complications..
Where significant differences have been observed is when analyzing large population databases: When comparing general anesthesia to neuraxial blocks, general anesthesia is associated with a higher risk of wound infection, a greater need for neonatal intubation, and more newborns with low Apgar scores at 5 minutes.Part of this is explained by the fact that general anesthesia is used more in truly emergency cesarean sections, with already depressed fetuses, but it is a fact that requires extreme caution.
It has also been seen that Women who have cesarean sections under regional anesthesia usually have somewhat shorter hospital stays., possibly due to better pain control, fewer infections, and a faster functional recovery.
Special cases: preeclampsia, hemorrhage, and high-risk emergencies
There are groups of patients for whom the choice of anesthesia is even more delicate. A clear example is women with preeclampsia, where Blood pressure is elevated, endothelial function is impaired, and the risk of neurological complications, such as stroke, is higher..
Large-scale cohort studies have shown that, In preeclamptic women undergoing cesarean section, general anesthesia is associated with a significantly higher risk of stroke in later years. compared to neuraxial anesthesia. There is no evidence of significant differences between spinal and epidural anesthesia at this point, but there is a clear message: whenever possible and there is no contraindication, Neuroaxial imaging is preferable in preeclampsia..
At the opposite extreme, we have the severe obstetric hemorrhages with hypovolemiaIn this context, general anesthesia may be the most reasonable option because It offers more leeway to stabilize hemodynamics, control ventilation, and manage potentially complex and prolonged surgery.However, the decision is individual and must assess, on a case-by-case basis, the patient's actual condition and the time available.
In true emergencies (cord prolapse with severe bradycardia, placental abruption with severe fetal distress, uterine rupture, etc.), The absolute priority is to get the baby out and stabilize the motherIf there is no epidural block already in place that can be reinforced within a few minutes, a rapid induction of general anesthesia is almost always used.
Impact of anesthesia on the newborn: from umbilical cord pH to neurodevelopment
Concern for the baby is central when choosing anesthetic technique. Drugs administered to the mother cross the placenta to a greater or lesser degree and can depress the breathing or tone of the newbornespecially if high or prolonged doses of general anesthetics or opioids are used before clamping the cord.
Comparative studies between general and regional anesthesia have yielded interesting data. In population studies, Newborns delivered by cesarean section under general anesthesia are more likely to require intubation in the delivery room and have a higher frequency of Apgar scores below 7 at 5 minutes.especially when the indication for cesarean section is previous fetal depression.
However, not everything depends on the anesthesia: When the fetus arrives in poor condition (low pH, sustained bradycardia, thick meconium), the margin for maneuver is very limited.Therefore, many authors emphasize that it is difficult to separate in studies the effect of the anesthetic technique from the impact of the fetal pathology itself that necessitated the emergency cesarean section.
Another field that has gained relevance is that of long-term effects. Some cohort analyses that followed thousands of children for years have observed that Infants born by cesarean section with neuraxial anesthesia may have a slightly lower incidence of learning disorders than those born under general anesthesia or through vaginal delivery with certain exposures. Although the results are not conclusive, they align with concerns, stemming from animal studies, about the potential neurotoxic effects of some general anesthetics on developing brains.
The prudent interpretation is that, If there are equally safe alternatives for mother and baby, it is advisable to limit the neonate's exposure to prolonged general anesthesia or high doses of certain agents.In obstetrics, this translates in practice to prioritizing neuraxial therapy whenever possible and carefully adjusting the doses and timing of general medications when they are essential.
General anesthesia in cesarean section: advantages, disadvantages and indications
General anesthesia is not "the enemy," but neither is it a harmless wild card. When done correctly and with the right instructions, it can be the technique that makes the difference between a good and a bad result., both for the mother and the baby.
Among its clearest advantages is speed: Rapid sequence induction allows a surgical plane to be obtained in a matter of minutes.This is critical in situations where every second counts. Furthermore, it offers complete airway and ventilation controlwhich is excellent when the patient is bleeding, has pulmonary edema, a hypertensive crisis, or a complex cardiac pathology.
It also makes it easier to perform combined or more extensive surgeries in the same session (e.g., hysterectomy, repair of bowel injuries, addressing associated abdominal pathology) and allows for easier management of seizures and extreme agitation, such as in uncontrolled eclampsia.
The disadvantages, however, are not insignificant. During pregnancy, the risk of aspiration increases, there are more anatomical changes in the airway, reduced functional residual capacity, and higher oxygen consumption, therefore Difficult intubation and rapid desaturation are very real threats. Also Neonatal depression due to transplacental passage of hypnotics and opioids requires close coordination with the neonatology team.
From an obstetric point of view, Halogenated agents can produce some degree of uterine relaxationThis, in high concentrations, promotes atony and postpartum hemorrhage. All of this means that the indications for general anesthesia must be very well defined and the technique performed with extreme precision.
Drugs used in general anesthesia for cesarean section
When it is decided to use general anesthesia during a cesarean section, The classic sequence is a rapid induction with a hypnotic and relaxant, maintenance with inhalational gases and, sometimes, adjuvants such as opioids or magnesiumalways trying to minimize the impact on the fetus before clamping the cord.
Among hypnotics, thiopental has been the standard for decades, with doses of 3-7 mg/kg. It is known that moderate doses achieve good hypnosis with little depressant effect on the newborn.While very high doses are associated with poorer neonatal adaptation, the current problem is that it is not readily available in many countries, which is why propofol has become the most widely used alternative.
Propofol, in adjusted doses (usually 1,5-2 mg/kg in hemodynamically stable pregnant women), It allows for a rapid and clean induction, but can cause significant hypotension if very generous boluses are administered, especially in hypovolemic or preeclamptic patients.Furthermore, because it has a somewhat slower site-effect equilibrium, the risk of intraoperative awakening must be carefully monitored if it is not adequately accompanied by inhalational anesthetics.
Midazolam, although it has good hypnotic and anxiolytic potency, It easily crosses the placenta and can cause marked neonatal depressionTherefore, it is reserved for specific moments, always knowing that flumazenil exists to reverse its effect on the newborn if necessary.
Ketamine is a very useful tool in cesarean sections with hypotensive or shock mothers, since It better maintains blood pressure and cardiac outputHowever, its sympathomimetic profile makes it undesirable in severe preeclampsia, and its use can complicate the situation if a difficult intubation occurs and the patient needs to be awakened quickly.
As for inhalants, sevoflurane, isoflurane, or desflurane are administered taking care to maintain approximately a minimum alveolar concentration (MAC) of 0,7, which is usually sufficient to ensure adequate hypnosis when accompanied by nitrous oxide or adjuvants and helps to prevent intraoperative awakeningVery high concentrations should be avoided as they increase the likelihood of uterine atony.
Muscle relaxants and airway management in pregnant women
The cornerstone of general anesthesia in cesarean section is airway safety. Pregnant women have a higher risk of regurgitation, an anatomically complicated airway, and rapid desaturation during apnea.Therefore, everything is planned around these three points.
The most classic relaxant in rapid sequence induction is succinylcholine, in doses close to 1 mg/kg, due to its very short latency and relatively rapid recovery. It allows for optimal intubation conditions in about one minute., which helps reduce the time the mother spends apneic.
Rocuronium, in high doses (1-1,2 mg/kg), It is an effective alternative, with an onset profile almost as rapid as that of succinylcholine and the advantage of having a specific antagonist, sugammadex.which can reverse even deep airway blockages in just a few minutes. This is especially valuable in "don't intubate, don't ventilate" scenarios, where buying time is vital.
The decision between one or the other is usually based on Contraindications for succinylcholine (risk of hyperkalemia, history of malignant hyperthermia, certain myopathies, personal or family history of previous complications), the availability and cost of sugammadex, and the team's experience.
Pre-oxygenation before induction is mandatory. The aim is to "fill" the lungs with oxygen to lengthen the time until desaturation in the event of complicated intubation.It can be done with normal breathing for three minutes or with several deep breaths in one minute, depending on the urgency. In pregnant women and people with obesity, it is recommended to perform it in a semi-seated position to increase functional residual capacity and, if necessary, to perform respiratory tests such as the spirometry.
The cricoid pressure maneuver (Sellick maneuver) is still routinely used in many units during rapid induction, although The evidence regarding its actual effectiveness in preventing aspiration is controversial, and some studies have even described more regurgitation when it is applied improperly.In any case, it should be performed by a trained person and withdrawn if it prevents ventilation or significantly hinders the view of the glottis.
Main complications of general anesthesia in cesarean section
General anesthesia in obstetrics carries with it a number of complications that, although infrequent, They can be catastrophic if they are not anticipated and treated quicklyThe three major risk areas are the airway, aspiration, and intraoperative awakening.
Failed intubation is significantly more common in pregnant women than in the general population, with incidences close to 1 in every 250 obstetric general anesthesias. The combination of weight gain, airway edema, large breasts, and cervical anatomical changes makes laryngoscopy difficult., and the reduction in oxygen reserve makes the margin of error very small.
For this reason, every unit should have a clear and trained protocol for managing difficult intubation in obstetricswhich includes the maximum number of attempts allowed, the rapid transition to mask or laryngeal mask ventilation, the presence of alternative devices (video laryngoscopes, light stylets, combitubes) and, ultimately, emergency cricothyrotomy or tracheostomy if the patient cannot be oxygenated.
Aspiration of gastric contents (Mendelson's syndrome) is another feared complication. Pregnant women should always be considered at risk. as a patient with a “full stomach” from the second trimester until 24 hours after deliveryProphylaxis with non-particulate antacids, H2 antagonists, or proton pump inhibitors helps to increase gastric pH, and gastric emptying can be improved with prokinetics, although evidence on direct reduction of clinical aspirations is limited.
Intraoperative awareness is especially relevant in cesarean sections under general anesthesia. Since the dosage of hypnotics and inhalational agents is typically limited before delivery to avoid depressing the baby, The line between “little anesthesia” and “remembering the surgery” is narrowingAlthough the current incidence is much lower than in past decades, it is still higher than in other surgeries.
The use of anesthetic depth monitors such as the bispectral index (BIS), careful drug selection, and the addition of adjuvants such as nitrous oxide or magnesium sulfate can help reduce this risk, always keeping in mind maternal hemodynamic stability and fetal safety.
Regional anesthesia (epidural and spinal) in cesarean section
Compared to general anesthesia, Neuroaxial blocks (epidural and spinal) have been gaining ground to become the preferred option for most cesarean sections., both scheduled and many urgent.
In a planned cesarean section, spinal anesthesia alone is the most common: A small dose of local anesthetic, and sometimes an intrathecal opioid, is injected with a very fine needle.producing a rapid sensory and motor blockade of the legs and abdomen. The mother remains awake, without pain, but with a sensation of pressure and traction during the surgery.
If a woman already has an epidural catheter in place for labor pain relief and a cesarean section becomes necessary, This epidural can be reinforced with more concentrated doses of local anesthetic to achieve a sufficient level of blockade for surgery in about 10-15 minutesIf the urgency is extreme and cannot wait, general anesthesia will be considered.
The great advantage of these techniques is that They avoid manipulation of the airway, reduce the risk of aspiration, and are usually associated with less bleeding and better postoperative pain control.Furthermore, they make it easier for the mother to see her baby being born, to have skin-to-skin contact and to breastfeed very soon, with clear emotional and neonatal adaptation benefits.
The most common adverse effects are maternal hypotension, tremor, and nausea, which are usually well managed with vasopressors, fluids, and antiemetic medication. There are, of course, rare but serious complications (epidural hematoma, neurological injury, infection), which is why There are clear absolute contraindications such as uncorrectable coagulopathy, severe uncontrolled bleeding, or infection at the puncture site..
Postpartum mental health and type of anesthesia in cesarean section
In recent years, more attention has been paid to an aspect that was previously overlooked: How does anesthesia during a cesarean section affect the mother's mental health after childbirth?It's not just about pain or intraoperative memories, but also about postpartum depression, anxiety, and suicidal thoughts.
Recent studies in large populations of women undergoing cesarean section have found an association between the use of general anesthesia and an increased risk of postpartum depression requiring hospitalizationas well as suicidal ideation, compared to cesarean sections performed under regional anesthesia.
The hypothesis is multifactorial. On the one hand, General anesthesia prevents immediate skin-to-skin contact and often delays the start of breastfeeding.These are factors we know promote bonding and lessen the emotional impact of childbirth. On the other hand, many cesarean sections under general anesthesia are indicated in emergency situations, cases of fetal distress, or births that fall far short of the mother's expectations—all of which carry a high level of trauma.
These findings do not mean that general anesthesia “causes” postpartum depression on its own, but they do suggest that Women who have undergone a cesarean section under general anesthesia should be considered a risk group and benefit from more active screening, psychological follow-up, and specific postpartum support..
In parallel, they reinforce the idea that When there is a margin of safe choice, regional anesthesia provides a more favorable environment from both a physical and emotional point of view.by allowing the mother to participate in the moment of birth and maintain a more intact sense of control and continuity with the baby.
Everything we know today fits into a single idea: Anesthesia during a cesarean section is not an isolated technical detail, but a central component of the safety and well-being of both mother and baby, from the delivery room to long-term physical and mental recovery..
