Anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure for congenital high airway obstruction syndrome (CHAOS)

We report an experience of anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure performed in a fetus with congenital high airway obstruction syndrome (CHAOS) due to laryngeal atresia at 30 weeks' gestation. Anesthesia of the mother was induced with rapid sequence, and maintained with 3.5% sevoflurane in 100% oxygen and fentanyl before delivery. Two minimum alveolar concentration (MAC) sevoflurane provided excellent uterine relaxation without maternal hypotension. After hysterotomy, a sterile pulse oxymeter was placed on the fetus hand for monitoring fetal SpO2 and pulse rate, and a Doppler ultrasound transducer was applied to monitor fetal heart rate. Fentanyl (5 microg x dl(-1)) and pancuronium (0.2 mg x dl(-1)) were injected into the fetal upper arm in addition to transplacental anesthetic agents. The fetal heart rate and SpO2 were stable throughout the fetal manipulations, but the rise in SpO2 after initiating ventilation via tracheostomy was very slow. The uterine tone improved soon after discontinuing sevoflurane and oxytocin infusion was started after delivery. Surfactant administration before first ventilation is recommended in preterm babies undergoing EXIT procedure, and capnometer may be useful to confirm the adequate ventilation before cutting the umbilical cord.     

Four cases of the ex utero intrapartum treatment (EXIT) procedure: anesthetic implications

The ex utero intrapartum treatment (EXIT) procedure is a method of maintaining utero-placental circulation during cesarean section to gain time to secure a potentially obstructed fetal airway. Four cases of the EXIT procedure are described with special reference to the maternal anesthetic technique. Deep volatile anesthesia (approximately 2 MAC) with isoflurane or sevoflurane for a prolonged period of time, in three cases in combination with an intravenous nitroglycerin infusion, was used to ensure a fully relaxed uterus during the procedure. All mothers were maintained hemodynamically stable with preserved utero-placentary perfusion. It was possible to intubate the tracheas of two fetuses, whereas in the other two tracheostomies had to be performed. Fetal gas exchange was not negatively affected during the EXIT procedure as evidenced by normal blood gas values in the umbilical artery at the time of delivery. After reducing the concentration of volatile anesthetic, delivery of the neonate and administration of oxytocin, uterine contractility was promptly re-established and there were no signs of uterine atony in the postoperative period. All four neonates survived the procedure without complications.     

Two cases of congenital airway obstruction managed with ex utero intrapartum treatment procedures: anesthetic implications

An ex utero intrapartum treatment (EXIT) procedure provides sufficient time to gain control of the potentially obstructed fetal upper airway while uterine placental circulation is maintained during cesarean section. We report 2 cases in which fetal congenital upper airway obstruction was managed without complications during EXIT procedures. We also discuss general considerations concerning the obstetric patient and the performance of intramuscular fetal anesthesia. Before the hysterotomy, sevoflurane at 1.5 minimum alveolar concentration was administered to assure sufficient uterine relaxation during EXIT. The 2 parturients remained hemodynamically stable during the procedure and uterine and placental perfusion was adequate. Nasotracheal intubation was possible in 1 fetus after a cervical mass was dissected. In the other, a tracheostomy was created. After the umbilical cord was clamped, the concentration of sevoflurane anesthetic gas was reduced and oxytocin and methylergometrine were administered to induce adequate uterine contractions within a few minutes. Both neonates survived the EXIT procedure with no complications.     

Anesthesia for Ex Utero Intrapartum Treatment (EXIT procedure) in Fetus with Prenatal Diagnosis of Oral and Cervical Malformations: Case Reports

Background and objectivesFetus prenatally diagnosed with neck tumors, or with any other disease that obstructs the airways, should not be treated conventionally, as the assistant physician has to face two challenges right after the infant's delivery: the limited time to establish the access to the potentially difficult airways and the lack of anesthesia of the neonate in case of instrumentation of the airways. The ex utero intrapartum treatment, i.e., the EXIT procedure consists of maintaining the fetoplacental circulation during the cesarean section, until the airways of the fetus be secured.Case ReportsFemale patient, 37 years old, G3P2, 38 weeks pregnant, having polyhydramnios and fetus diagnosed with large cervical masses by prenatal ultrasound. A cesarean section was performed using the EXIT procedure to enable safe access to the infant's airways. After hysterotomy, the fetus was intubated by direct laryngoscopy. The neonate was immediately transferred to another operating room, where cervical tumor resection of the neck tumor and tracheostomy were successfully performed. Female patient, 27 years old, G3P1A1, 32 weeks pregnant, whose fetus was prenatally diagnosed with a large oral tumor. As the tumor obstructed the fetus’ airways, a tracheostomy was performed when the fetus underwent EXIT procedure. It was then possible to use direct laryngoscopy for neonate intubation. The fetus underwent tumor resection and was sent to the Neonatal Intensive Care Unit.ConclusionsReports describe the successful use of general anesthesia with isoflurane for cesarean delivery followed by the EXIT procedure in fetus diagnosed with tumors obstructing the airways.     

Management of a prenatally diagnosed huge teratoma arising from the soft palate

Teratomas arising from the oral cavity are relatively rare and can cause life-threatening airway obstruction immediately after birth. We report a case of a huge teratoma arising from the soft palate detected prenatally. To save the patient, a caesarean section and ex utero intrapartum treatment (EXIT) were planned at 29 weeks of gestation. However, during EXIT, the patient's cardiopulmonary status deteriorated due to unstable cord blood flow secondary to uterine contractions. EXIT was abandoned, the patient was delivered and an emergency tracheotomy performed. The tumour was successfully excised 4 hours after tracheotomy. The tumour weighed 1,591 g and was 20 x 22 x 12 cm. The patient, a female, weighed 715 g. Histopathology showed Grade II teratoma. The postoperative course was uneventful and she is now 5 years old with no neurological sequelae. EXIT is indicated in patients who have a high risk for airway obstruction immediately after birth. However, if EXIT must be abandoned, as in this case, urgent tracheotomy is mandatory. Planned prevention of airway obstruction at delivery is indispensable for successful outcome and requires excellent coordination among obstetricians, neonatologists, anaesthesiologists and paediatric surgeons.     

Anesthetic management of the exit (ex utero intrapartum treatment) procedure

The EXIT (ex utero intrapartum treatment) procedure is used to maintain fetal-placental circulation during partial delivery of a fetus with a potentially life-threatening upper airway obstruction. We performed the EXIT procedure on a fetus with a large intra-oral cyst. Sevoflurane was used as the anesthetic because of its rapid titratability. Sevoflurane provided excellent maternal and fetal anesthesia. Modifications to previously described monitoring techniques for the EXIT procedure were also used.     

Anesthetic management for EXIT (ex-utero intrapartum treatment) of a twin gestation: one normal and one with a large epignathus

We experienced cesarean section of a twin gestation of which one was normal and the other had a large epignathus. Anesthesia was induced with rapid administration of propofol and suxamethonium, then her trachea was intubated and operation was started. Anesthesia was maintained with 3% sevoflurane in 100% oxygen. Five minutes from the start of the surgery, the first baby was born with Apgar score of 3/7. One minute later, the head of the second with large epignathus was out of the uterus. But we judged that her trachea was difficult to intubate, but she showed spontaneous respiration. Then we inserted a tracheal tube (ID 2 mm) to her nose for the airway, and she was carried into the infant warmer after amputating the umbilical cord. After the delivery, sevoflurane was discontinued, and propofol, fentanyl and ketamine were started. Cesarean section was finished with total blood loss of 1,900 g including amniotic fluid. In the infant warmer, tracheostomy was performed on the second baby, and the baby was carried to NICU. Thirteen days later, the epignathus was extracted without complication. General anesthesia with inhalational agent is usually chosen for cesarean section with EXIT. For EXIT, uterine relaxation and fetal akinesia are necessary, but deep inhalational anesthesia causes massive bleeding, hypotension and loss of spontaneous respiration of the fetus. Twin gestation with one normal and the other with airway trouble has many problems. We have to consider mother, normal baby and troubled baby during EXIT. We should treat them appropriately with prudence.     

Report of a case: the anesthetic management for fetal tracheal intubation with intact uteroplacental circulation during cesarean section

We experienced a case of cesarean section in a patient with a fetus having a prenatally diagnosed huge cervical mass, which could cause airway obstruction immediately after delivery. The fetal cervical mass was confirmed at 19 gestational weeks, and amniocentesis was performed at 33 weeks. At 35 weeks, MRI showed the large mass that could disturb the airway patency after birth, and elective cesarean section was scheduled at 37 weeks. In the anesthetic management, anesthesia was maintained with isoflurane in oxygen, and ritodorine and nitroglycerin were used for obtaining uterine relaxation and keeping uteroplacental circulation. Fetal head was exposed from the uterine incision site and tracheal intubation was successfully performed. After confirming the neonatal oxygenation under manual ventilation, the baby was delivered. After delivery, the mass was diagnosed as cystic hygroma and he was maintained under mechanical ventilation in NICU. Five months later subtotal excision of the cervical cystic hygroma and tracheostomy were performed.     

Multimodal general anesthesia approach for Ex Utero Intrapartum Therapy (EXIT) procedures: two case reports

High-dose volatile anesthesia is the most common method of achieving uterine relaxation for Ex Utero Intrapartum Therapy (EXIT) procedures. Other methods employ nitroglycerin for additional uterine relaxation with or without remifentanil for additional fetal analgesia. We report a combination approach including one minimum alveolar concentration of volatile anesthetic plus nitroglycerin and remifentanil infusions, to provide timely uterine relaxation under general anesthesia for both mother and fetus, during two EXIT procedures.     

Obstetric hemorrhage during an exit procedure for severe fetal airway obstruction

Purpose

To report a case of massive obstetric hemorrhage occurring during Cesarean delivery for an ex utero intrapartum treatment (EXIT) procedure. Methods to optimize the anesthetic, obstetric, and perinatal management are discussed.

Clinical features

A healthy parturient underwent an urgent EXIT procedure at 32 weeks gestation for a giant fetal neck mass. During the intraoperative period, severe intraoperative hemorrhage occurred from the site of the uterine incision. No evidence of placental bleeding, premature placental separation, or inadequate uterine relaxation was observed during the perioperative period. Placement of a uterine stapling device was unsuccessful in achieving adequate surgical hemostasis. Initial attempts with laryngoscopy and rigid bronchoscopy to secure the fetal airway on placental support were unsuccessful, and early termination of placental support was deemed necessary due to the severity of maternal blood loss. After full delivery of the neonate and termination of placental support, neonatal ventilation with bag-mask ventilation was achieved and successful endotracheal intubation occurred during repeat bronchoscopy.

Conclusions

The risk of obstetric hemorrhage due to uterine relaxation and inadequate surgical hemostasis in patients undergoing EXIT procedures is poorly reported. To reduce adverse maternal and neonatal outcomes, the premature termination of placental support during EXIT procedures may be required in the setting of severe obstetric hemorrhage.     

The use of potent inhalational agents for the ex- utero intrapartum treatment (exit) procedures: what concentrations?

The anesthetic management of a parturient undergoing ex-utero intrapartum treatment (EXIT) procedures for airway control of a newborn with a potentially life-threatening difficult airway is complex and often challenging. We herein report on the successful anesthetic management of the EXIT procedure in a 30-year-old primigravida carrying a fetus with large cervical lymphangioma. General anesthesia was maintained with sevoflurane 2%, combined with continuous infusion of nitroglycerine (TNG). Although the use of high concentrations of potent inhalational agents (to keep the uterus fully relaxed) is currently recommended we believe that the use of low concentrations of potent inhalational anesthetics with continuous infusion of TNG may be a safer anesthetic strategy for these operations.     

Case series: Combined spinal epidural anesthesia for Cesarean delivery andex utero intrapartum treatment procedure

PURPOSE: To report the use of regional anesthesia and iv nitroglycerin to provide anesthesia and uterine relaxation for three Cesarean deliveries (CD) involving ex utero intrapartum treatment (EXIT) of potentially life-threatening airway obstruction in the newborn. CLINICAL FEATURES: Case 1--a 36-yr-old woman at 38 weeks' gestation was scheduled for an elective CD for fetal skeletal dysplasia and micrognathia. Case 2--a 34-yr-old woman at 35 weeks gestation had a fetal ultrasound revealing fixed neck flexion and micrognathia consistent with fetal arthrogryposis. Case 3--a 27-yr-old woman presented at 38 weeks gestation for CD for severe fetal micrognathia, with mandibular growth below the fifth percentile. For each case, a combined spinal epidural anesthetic was performed with 0.75% bupivacaine, fentanyl and morphine intrathecally followed by placement of a multiorifice epidural catheter. Prior to uterine incision patients received a loading dose followed by an iv infusion of nitroglycerin. Uterine relaxation was sufficient in all cases for delivery of the fetus, and allowed for evaluation by direct laryngoscopy and intubation while maintaining fetal-placental circulation. The surgical procedures were completed without incident. CONCLUSIONS: Anesthesia and uterine relaxation for CD and EXIT procedures can be safely provided with regional anesthesia and iv nitroglycerin.     

Anesthetic management for cesarean section in a patient with hydrops foetalis

In cases of hydrops foetalis, respiratory management is frequently required after delivery. We experienced 7 anesthetic managements for cesarean section in patients with hydrops foetalis. Spinal anesthesia was performed in 3 patients, because the transition of local anesthesia through the placenta was little. On the other hand, general anesthesia was performed in 4 patients because of babies requiring endotracheal intubation or fetal anesthesia immediately after a delivery. Before surgery, we discussed perioperative and anesthetic management among pediatricians, pediatric surgeons, and obstetricians in a conference. Since the anesthetic drugs used for the cesarean section have great influences on the fetus, the choice of anesthesia should be performed based on fetal conditions.     

O desafio multidisciplinar da anestesia para procedimento intraparto extra‐uterino: relato de caso

The Ex‐ Utero Intrapartum Treatment (EXIT) is a surgical procedure performed in cases of expected postpartum fetal airway obstruction, allowing the establishment of patent airway while maintaining placental circulation. Anesthesia for EXIT procedure has several specific features such as adequate uterine relaxation, maintenance of maternal blood pressure fetal anesthesia and fetal airway establishment. The anesthesiologist should be aware of these particularities in order to contribute to a favorable outcome. This is a case report of an EXIT procedure performed on a fetus with a cervical lymphangioma with prenatal evidence of partial obstruction of the trachea and risk of post‐delivery airway compromise.     

An ex utero intrapartum treatment procedure in a patient with a family history of malignant hyperthermia

In the EXIT (ex utero intrapartum treatment) procedure, after uterine incision, uterine relaxation is maintained to prevent placental separation and the fetus is supported via the placenta until the airway is successfully established. The traditional method to maintain uterine relaxation is with the use of high-dose potent inhaled anesthetics during general anesthesia. A patient with a family history of malignant hyperthermia required an EXIT procedure. The history of malignant hyperthermia precluded the use of potent inhaled anesthetics and an alternate plan using propofol and remifentanil infusions for anesthesia and nitroglycerin 16 μg/kg/min for uterine relaxation allowed for good surgical conditions. The presence of malignant hyperthermia required an alternate plan and close collaboration in order to ensure good patient outcome.     

Verifying correct endotracheal intubation by measurement of end-tidal carbon dioxide during an ex utero intrapartum treatment procedure

The ex utero intrapartum treatment (EXIT) procedure provides time to secure the airway of the fetus while utero-placental circulation supplies the fetus with oxygen. We report the anesthetic management of a fetus with a large neck mass during an EXIT procedure in which the confirmation of correct endotracheal intubation was hampered by parts of the mass, blood, and other fluids. The use of a standard end-tidal carbon dioxide probe provided a reliable signal and proved the endotracheal position of the tube while utero-placental circulation was still intact.     

Ex utero intrapartum treatment in the management of giant cervical teratomas

PurposeThe purpose of this study is to present the outcome and technical details of the Ex Utero Intrapartum Treatment (EXIT) procedure performed in the management of the fetus with a giant cervical teratoma.MethodsA retrospective review of the medical records of patients undergoing the EXIT procedure between September 1995 and September 2010 was performed.ResultsEighty-seven EXIT procedures were performed. In 20% of cases (17/87), the indication was giant cervical teratoma. There were 10 females and 7 males. Polyhydramnios was present in 82%. Median gestational age at EXIT was 35 weeks (range, 30-39 weeks). Median birth weight was 2.5 kg (range, 1.7-3.7 kg). Access to the airway under placental support was established in all cases via direct laryngoscopy/bronchoscopy in 8 patients (47%) and via surgical exploration (tracheostomy or retrograde intubation) in 9 patients (53%). The mortality rate under placental support was zero. Seven patients had the tumors resected immediately after the EXIT, 6 patients had the resection later, and 4 patients died before resection. The neonatal mortality rate was 23% (4/17 patients). Patients who died had severe pulmonary hypoplasia that resulted from the upward traction by the giant cervical mass on the airway and compression of the lungs against the thoracic apex.ConclusionsWe conclude that the EXIT procedure continues to be the optimal delivery strategy for patients with prenatally diagnosed giant cervical teratomas and potential airway obstruction at birth. A thorough evaluation of the prenatal images and an experienced multidisciplinary team are key factors for an effective approach to the obstructed fetal airway.     

Bispectral index values at sevoflurane concentrations of 1% and 1.5% in lower segment cesarean delivery

Inadequate hypnosis in the absence of opioid analgesia may account for the increased incidence of awareness in cesarean delivery. An end-tidal concentration of 0.5 MAC isoflurane in 50% nitrous oxide (N(2)O) during cesarean delivery resulted in bispectral index (BIS) values >60, the threshold below which consciousness is unlikely. Our aim was to determine the BIS values achieved with the equivalent end-tidal concentration of sevoflurane and to determine if a larger concentration would consistently maintain BIS values <60. Twenty ASA physical status I-II parturients were randomized to receive an end-tidal concentration of either 1% sevoflurane or 1.5% sevoflurane delivered in 50% N(2)O throughout surgery. Thiopental 4 mg/kg was used for anesthetic induction. Morphine 0.1-0.15 mg/kg was administered only after delivery. Mean BIS values in the period between skin incision and neonatal delivery were 61 (95% confidence interval, 57-64) in the 1% sevoflurane group, versus 42 (95% confidence interval, 37-47) in the 1.5% sevoflurane group. BIS values were significantly different between groups at skin incision, uterine incision, delivery, and 10 min after delivery, but not thereafter. Indices of maternal and neonatal outcome were similar between groups. IMPLICATIONS: Bispectral index (BIS) values <60 are consistent with a high probability of unconsciousness. An end-tidal concentration of 1.5% sevoflurane maintained BIS values <60 during cesarean delivery, whereas 1% did not. Adverse effects were not seen with the use of larger concentrations of sevoflurane.     

Remifentanil-nitroglycerin combination as an anesthetic support for ex utero intrapartum treatment (EXIT) procedure

A 21 year old healthy parturient was diagnosed as having a fetus with micrognathia. She was scheduled for an ex-utero intrapartum treatment (EXIT) procedure. General anesthesia consisted of remifentanil, nitrous oxide, and midazolam. Intravenous nitroglycerin was used for uterine relaxation. This technique offered hemodynamic stability and provided uterine relaxation that may be rapidly terminated. For the fetus, it provided excellent transplacental anesthesia. Supplemental direct fetal anesthesia is recommended to prevent the rapid decline of analgesia/anesthesia that occurs after placental separation.     

Desflurane Enhances Reactivity during the Use of the Laryngeal Mask Airway

Background: Desflurane and sevoflurane have markedly different pungencies. The tested hypothesis was that patients breathing equivalent concentrations of desflurane or sevoflurane through a laryngeal mask airway (LMA) would have similar responses.

Methods: After institutional review board approval and informed consent were obtained, 60 patients were enrolled and given intravenous midazolam (14 [mu]g/kg) and fentanyl (1 [mu]g/kg) 5 min before induction of anesthesia. The LMA was inserted at loss of consciousness after 2 mg/kg propofol. When spontaneous breathing returned, a randomly assigned volatile anesthetic was started at an inspired concentration of either 1.8% sevoflurane or 6% desflurane at a fresh gas flow of 6 l/min in air:oxygen (50:50). After 5 min, a controlled movement of the LMA took place. Three minutes later, the inspiratory anesthetic concentration was changed to either 3.6% sevoflurane or 12% desflurane for 3 min. A blinded observer recorded movements and airway events during the start of anesthetic, LMA movement, deepening of the anesthetic, and emergence before LMA removal.

Results: There were no differences at anesthetic start and LMA movement. Desflurane titration to 12% increased heart rate, increased mean arterial blood pressure, and initiated frequent coughing (53% vs. 0% sevoflurane) and body movements (47% vs. 0% sevoflurane). During emergence, there was a twofold greater incidence of coughing and a fivefold increase in breath holding in the desflurane group.