Nonobstetric Surgery During Pregnancy
| Anesthetic relevance |
Medium |
|---|---|
| Anesthetic management |
Nonobstetric anesthesia and surgery in pregnant women involves managing surgical procedures and anesthesia administration with specific considerations for both maternal and fetal safety. A complete discussion with patient, surgeon and obstetrician about timing, urgency and intraoperative monitoring is important. |
| Specialty |
Anesthesiology, Obstetric Anesthesiology |
| Signs and symptoms |
{{{signs_symptoms}}} |
| Diagnosis |
{{{diagnosis}}} |
| Treatment |
{{{treatment}}} |
| Article quality | |
| Editor rating | |
| User likes | 0 |
Nonobstetric anesthesia and surgery in pregnant women involves managing surgical procedures and anesthesia administration with specific considerations for both maternal and fetal safety. It's crucial due to the complexity of balancing the health needs of the pregnant patient with minimizing potential risks to the developing fetus. This topic underscores the importance of specialized medical care and interdisciplinary collaboration to ensure optimal outcomes for both mother and child during nonobstetric surgical interventions.
Surgical Considerations
Timing of Surgery
Emergency surgery, which is urgently needed, should be performed irrespective of the trimester of pregnancy.
Nonurgent surgeries, such as cholecystectomy for recurrent biliary obstruction without infection, are typically scheduled during the second trimester whenever feasible.
According to societal guidelines, elective surgeries that are not urgent should generally be postponed until after delivery.
Rationale
It's advisable to limit fetal exposure to surgery and medications during the first trimester of pregnancy, particularly during organogenesis, due to the inconclusive certainty surrounding the safety of many drugs in pregnancy. Additionally, caution is warranted because common adverse outcomes in the first trimester, such as miscarriage, vaginal bleeding, or fetal structural anomalies, could mistakenly be attributed to surgery and anesthesia without clear alternative causes.
Anesthetic implications
Preoperative optimization
Pregnant patients needing surgery should undergo preoperative evaluation akin to nonpregnant patients. This involves documenting medical and obstetric history comprehensively, alongside a detailed airway assessment during physical examination. Additional laboratory tests should be conducted based on the patient's medical conditions and the planned surgery; however, uncomplicated pregnancies typically do not necessitate extra preoperative testing.
Intraoperative management
Fetal Monitoring
One purpose of fetal monitoring is to identify concerning changes in the fetal heart rate (FHR) that may be influenced by reversible maternal factors not detectable through maternal monitoring alone. Even slight decreases in maternal blood pressure, oxygen levels, or uteroplacental blood flow can potentially affect fetal well-being. Interventions may include administering intravenous fluids, increasing oxygen levels, administering medications to raise maternal blood pressure, or adjusting maternal positioning. However, interpreting FHR patterns can be challenging during general anesthesia, as there is typically a decrease in beat-to-beat variability. Moreover, not all nonobstetric surgeries can be paused to facilitate emergency cesarean delivery, thus the exact benefit to the fetus remains uncertain.
When to perform
The decision to perform intra-operative monitoring should be a group decision between the Patient, Attending Surgeon, Anesthesiologist, and Obstetrician. It should be based on factors such as gestational age, type of surgery, and available resources. It should be recognized that in certain situations: specific surgeries, anesthetics or medications may need to be given that can have negative effects on the FHR, but the ability to stop, pause of reverse the effects may not be possible to facilitate an emergency cesarean delivery.
Society Guidelines recommend continuous monitoring of FHR in all viable fetuses (greater than 23 to 24 weeks of gestation) throughout surgery. The can be done via electronic FHR monitor or Doppler ultrasound. This is not always technically feasible due to positioning, type of surgery and location. At a minimum the FHR should be monitored preoperatively an post operatively for a period of time regardless of the gestational age. It should be recognized continuous FHR monitoring has not been shown conclusively to improve fetal outcome in women under general anesthesia.
If the decision is made to perform Intraoperative, qualified personnel are required to be available to monitor and interpret the FHR throughout the surgery. This must be an obstetrician or clinician experienced in reading and evaluation FHR strips and under almost no circumstances should be the Anesthesiologist directing the patients anesthetic. If continuous monitoring is performed after 23 to 24 weeks gestation, Appropriate resources should be immediately available, including and obstetrician or clinician capable of performing an emergency C-Section.
Medications
General Anesthetics
All general anesthetic drugs cross the placenta and may result in minimal or absent FHR variability
A systematic review of four studies including 155 pregnant women undergoing nonobstetric surgery reported minimal or absent FHR variability in most tracings and a decrease in FHR baseline of 10 to 25 beats per minute for women under general anesthesia
Additional criteria are necessary to identify non-reassuring fetal heart rate (FHR) patterns, such as persistent tachycardia without maternal fever, recurrent or prolonged FHR decelerations, repeated late decelerations, or a sinusoidal pattern. Before determining that an FHR tracing warrants emergency delivery, potential drug-induced causes should be ruled out. For instance, opioids and magnesium sulfate can reduce heart rate variability, butorphanol may produce a sinusoidal pattern, and beta blockers and atropine can elevate the FHR. The presence of moderate variability and/or FHR accelerations effectively rules out metabolic acidemia.
Antibiotics
Whether antibiotic prophylaxis is required depends on the particular procedure being performed.
Safe antibiotic options for pregnant women include cephalosporins, penicillins, erythromycin (excluding estolate), azithromycin, and clindamycin due to their favorable safety profiles. Aminoglycosides are generally safe but pose risks of fetal and maternal ototoxicity and nephrotoxicity.
Thromboprophylaxis
The hypercoagulable state of pregnancy increases the risk of a thromboembolic event in the postsurgical period
Pneumatic compression devices should be used or considered for all surgeries
Tailor the decision to administer pharmacological prophylaxis according to the anticipated scope and duration of the procedure, as well as the patient's risk factors for venous thrombosis, including factors related to pregnancy (such as thrombophilia, prolonged immobilization, previous venous thrombosis, malignancy, diabetes mellitus, varicose veins, paralysis, maternal age, or obesity).
Glucocorticoid administration
Administration of a course of antenatal glucocorticoids 24 to 48 hours prior to surgery for patients between 24 and 34 weeks of gestation can reduce perinatal morbidity/mortality if preterm birth occurs.
The decision to give glucocorticoids, and potentially delay surgery for 24 to 48 hours, must balance the urgency of the surgery with the obstetrician's estimate of the risk of preterm birth because of the underlying disease or the planned procedure.
Postoperative management
Maternal monitoring
Similar to any postoperative monitoring, close monitoring of the airway and respiratory system is essential during the recovery from anesthesia, as significant anesthetic complications can arise during emergence or shortly after surgery. See other specific Post Anesthesia General Adult Recovery texts
Fetal assessment
The FHR should be monitored in the recovery room, intermittently for previable fetuses, and continuously for the viable fetus. Uterine activity should also be monitored in cases in which the fetus is viable, as contractions are most likely to occur proximate to the procedure and as any tocolytic effect of general anesthetics wears off
Left Uterine Displacement
Left lateral position or uterine displacement should be maintained until the patient is fully awake, alert, and able to adjust her own position.
Postoperative pain control
A multimodal analgesia should be used for postoperative pain control for all patients. This should include nonpharmacologic methods of pain control, acetaminophen, regional anesthesia techniques, and local anesthetic infiltration. Opioids should be used on an as-needed basis.
Nonsteroidal anti-inflammatory drugs (NSAIDs) should not be used routinely during pregnancy (particularly in the early first and late third trimesters) because of potential fetal effects.