ANESTHESIA FOR FETAL SURGERY - PRINCIPLES AND CONSIDERATIONS: A CONCISE REVIEW

Fetal surgery, an integral part of fetal therapy has undergone evolution since is conception, which was possible due to continuous refinements in surgical as well as anesthetic techniques The fetal surgery can be done in various stages of the gestation for corrective treatment. Time tested criteria have been laid down for patient selection which help improve the outcome of the whole exercise. The anesthesia concerns and considerations are unique as are the ethical issues involved in this treatment modality involving two patients with contrasting physiological needs. This article reviews salient aspects of fetal physiology in detail. Anesthesia for the fetal interventions is curated as per the invasive nature of surgical interventions. The type of fetal interventions are classified as minimally invasive procedures, Open mid gestation procedures and Ex-utero intrapartum treatment (EXIT) procedures. Preoperative evaluation is dictated by extent of gestation, and invasiveness of the surgical procedure apart from medical status of mother and fetus. This review also tries to enumerate number of clinically useful pharmacological agents in fetal anesthesia including essential tocolytic agents, in addition to management of common fetal complications with a separate section on fetal bradycardia

Anestesia para cirugía fetal: Consideraciones anestésicas y alcances terapéuticos / Implications and anesthetic considerations for fetal surgery

Fetal surgery is a field that has experienced great progress in recent decades. Advances in prenatal imaging techniques have allowed treatment of in-utero fetal pathologies during the prenatal period, so that it is currently possible to intervene in the natural history of certain alterations in the development of the fetus, avoiding sequelae in the newborn and in its subsequent development in extrauterine life. The perioperative management of fetal surgery requires a multidisciplinary team, constituting a challenge for the anesthesiologist to maintain the homeostasis of the mother and the fetus. The understanding of the maternal-fetal physiology together with an adequate management of the anesthetic techniques constitute the cornerstone for the success of the surgery.

La cirugía fetal es un campo que ha experimentado gran progreso en las últimas décadas. El avance en las técnicas de diagnóstico prenatal por imágenes ha permitido tratamiento de patologías fetales in utero durante el período prenatal, de modo que actualmente es posible modificar la historia natural de determinadas alteraciones en el desarrollo del feto evitando secuelas en el recién nacido y en su posterior desarrollo en la vida extrauterina. El manejo perioperatorio de la cirugía fetal precisa de un equipo multidisciplinario, constituyendo un desafío para el anestesiólogo mantener la homeostasis de la madre y el feto. El entendimiento de la fisiología materno-fetal junto con un adecuado manejo de las técnicas anestésicas constituyen un factor fundamental para el éxito de la cirugía.

A Case of Fetal Anesthesia with Fentanyl for Thoracentesis of Fetal Pleural Effusion / 대한산부인과학회지

Fentanyl is an opiate-like, pain-killing drug. It was found in the 1950s and prescribed from the 1960s. Fentanyl shows its effect by acting on opiate-like receptors. This case was a case of a 24-year-old primiparous woman who was referred from local clinic due to fetal pleural effusion in the left lung on antenatal ultrasonographic examination at 32 weeks of gestational age. The amount of pleural effusion increased and fetal heart deviated to the right side. We injected fentanyl 2 microgram intramuscularly into the fetal left thigh under ultrasound-guide for fetal anesthesia at 34 weeks of gestational age. After 5 minutes, we inserted 22 gage spinal needle to the left pleural cavity and aspirated 50 mL pleural fluid under ultrasound-guided. After aspiration, follow-up was performed oat one week interval and there was no more pleural fluid until delivery. At gestational age 41 weeks, the fetus was delivered vaginally as a 3.2 kg, healthy male baby. This is a case of fentanyl injection to fetus as a fetal anesthesia during thoracentesis for fetal pleural effusion at gestational age 34 weeks, we think that fentanyl is useful drug for fetal anesthesia.

Anesthesia for fetal procedures and surgery

Many of the anesthetic considerations for fetal procedures and surgery are identical to those for nonobstetric surgery during pregnancy, including concern for maternal safety, avoidance of both teratogenic drugs and fetal asphyxia, and the prevention of preterm labor and delivery. Anesthesia is required for the mother and quite often the fetus to perform many fetal procedures. Fetal procedures and surgery can be divided into subgroups according to their anesthetic requirements. For example: procedures that only require a needle insertion into the uterus but not into the fetus, such as intrauterine infusions; laser surgical photocoagulation of the communicating placental circulation for twin-twin transfusion syndrome (TTTS) and radio-frequency umbilical cord ablation for managing twin reversed arterial perfusion (TRAP), which are not really fetal procedures, rather they are placental or cord procedures; surgical procedures performed directly on the fetus; and the EX-utero Intrapartum Treatment (EXIT) procedure. Anesthetic considerations also depend on other factors, such as the location of the placenta. Unlike maternal surgery, for fetal procedures, the fetus is not an innocent bystander for whom the least anesthetic interference is used. Instead, the fetus can be the primary patient and may benefit from anesthesia, with close monitoring of the anesthetic effects to ensure well-being. Fetal asphyxia, hypoxia, or distress can be most effectively recognized, predicted, and avoided by fetal monitoring. Monitoring is also crucial for assessing the fetal response to corrective maneuvers.