Airway management on placental support (AMPS)--the anaesthetic perspective

EXIT (ex utero intrapartum treatment) surgery for the management of fetal airway obstruction: A systematic review of the literature

PURPOSE

To provide a comprehensive overview of the perinatal and maternal outcomes of fetuses undergoing EXIT surgery for the management of fetal airway obstruction secondary to cervical or oral tumors.

METHODS

A comprehensive search from inception to September 2018 was conducted on databases including MEDLINE, EMBASE, Cochrane Library and LILACS. All studies that reported an EXIT surgery in singleton were considered eligible. A descriptive analysis was performed.

RESULTS

Out of the 250 full-text study reports, 120 articles reporting 235 cases of EXIT surgery were included. EXIT surgery was performed at 35.1 weeks of gestation on average. The most frequent diagnosis was teratoma (46.4%, n = 109/235). There were 13 adverse maternal events, and the most frequent one was postpartum hemorrhage (4.7%, n = 11/235). No maternal death was reported. Fetal and neonatal death occurred in 17% (40/235) of the cases. There were 29 adverse fetal events (12.2%), and the most frequent one was the failure of intubation or tracheostomy (3.4%, n = 8/235).

CONCLUSION

EXIT surgery could be considered for the management of an oral or cervical tumor that's highly suspicious of blocking the fetal airway. This systematic review reports that EXIT surgery poses substantial risks of maternal and fetal adverse events, including neonatal death.

LEVEL OF EVIDENCE

IV case series with no comparison group.

Ex utero intrapartum treatment for giant congenital omphalocele

BACKGROUND

To determine whether ex utero intrapartum treatment (EXIT) is an appropriate approach for managing fetuses antenatally diagnosed with giant congenital omphaloceles.

METHODS

We retrospectively reviewed patients with omphaloceles who underwent either an EXIT procedure or a traditional repair surgery. Basic and clinical parameters including gender, gestational age, birth weight, maternal blood loss, operative times and operative complications were analyzed. During the 6-12-month follow-ups, postoperative complications including bowel obstruction, abdominal infections, postoperative abdominal distension were monitored, and survival rate was analyzed.

RESULTS

A total of seven patients underwent the EXIT procedure and 11 patients underwent the traditional postnatal surgery. We found no differences in maternal age, gestational age at diagnosis, gestational age at delivery and birth weight between the two groups. In the EXIT group, the average operation time for mother was 68.3 ± 17.5 minutes and the average maternal blood loss was 233.0 ± 57.7 mL. The operation time in the EXIT group (22.0 ± 4.5 minutes) was shorter than that in the traditional group (35 ± 8.7 minutes), but the length of hospital stay in the EXIT group (20.5 ± 3.1 days) was longer than that in the traditional group (15.7 ± 2.5 days, P < 0.05). During the follow-up, one patient in the EXIT group had an intestinal obstruction, one developed abdominal compartment syndrome and one died in the traditional group.

CONCLUSIONS

In our experience, EXIT is a safe and effective procedure for the treatment of giant congenital omphaloceles. However, more experience is needed before this procedure can be widely recommended.

Anesthesia for ex utero intrapartum treatment: renewed insight on a rare procedure

The ex utero intrapartum treatment is a rare surgical procedure performed in cases of expected postpartum fetal airway obstruction. The technique lies on a safe establishment of a patent airway during labor in anticipation of a critical respiratory event, without interrupting maternal-fetal circulation. Anesthetic management is substantially different from that regarding standard cesarean delivery and its main goals include uterine relaxation, fetal anesthesia and preservation of placental blood flow. We present the case of an ex utero intrapartum treatment procedure performed on a fetus with a large cervical lymphangioma and prenatal evidence of airway compromise. Modifications to the classic ex utero intrapartum treatment management strategies were successfully adopted and will be discussed in the following report.

The ex utero intrapartum treatment (EXIT) procedure: application of a new therapeutic paradigm

The ex utero intrapartum treatment (EXIT) procedure is a term given to a technique that can transform a potentially fatal neonatal emergency to a controlled intervention with an improved outcome. It has revolutionised the care of prenatally diagnosed congenital malformations in which severe upper airway obstruction is anticipated. An extended period of utero-placental circulation can be utilised to avoid profound cardiopulmonary compromise. Its therapeutic applications have been broadened to include fetuses with congenital diaphragmatic hernia after tracheal plugging, high-risk intrathoracic masses, severe cardiac malformations and conjoined twins. It requires the co-ordination of a highly skilled and experienced multidisciplinary team. The recent enthusiasm for the EXIT procedure needs to be balanced against maternal morbidity. Specific indications and guidelines are likely to be refined as a consequence of ongoing advances in fetal intervention and antenatal imaging.

Paediatric airway management: What is new?

Airway management plays a pivotal role in Paediatric Anaesthesia. Over the last two decades many improvements in this area have helped us to overcome this final frontier. From an era where intubation with a conventional laryngoscope or blind nasal intubation was the only tool for airway management, we have come a long way. Today supraglottic airway devices have pride of place in the Operating Room and are becoming important airway devices used in routine procedures. Direct and indirect fibreoptic laryngoscopes and transtracheal devices help us overcome difficult and previously impossible airway situations. These developments mean that we need to update our knowledge on these devices. Also much of our basic understanding of the physiology and anatomy of the paediatric airway has changed. This article attempts to shed light on some of the most important advances/opinions in paediatric airway management like, cuffed endotracheal tubes, supraglottic airway devices, video laryngoscopes, rapid sequence intubation, the newly proposed algorithm for difficult airway management and the role of Ex Utero Intrapartum Treatment (EXIT) procedure in the management of the neonatal airway.

In Vitro Effects of Propofol on Gravid Human Myometrium

The aim of this study was to evaluate the direct effect of propofol (di-isopropyl phenol) on the contractile properties of gravid human uterine muscle.

Six specimens of uterine muscle were obtained from term parturients undergoing elective lower segment caesarean section. Small strips (1 × 2 x 12 mm) of muscle were prepared and suspended in an organ bath containing oxygenated Kreb's solution at 36.5°C. Following preparation, spontaneous regular contractions developed at a rate of one contraction every six to 10 minutes. Force of contraction was recorded continuously using an isometric tension transducer. Following baseline measurements, propofol was introduced into the bath at concentrations corresponding to 2 /μg/ml, 5 /μg/ml and 8 /μg/ml. The specimens were also exposed to intralipid in concentrations equivalent to that found in the 8 μ/ml solution of propofol to determine whether this additive influenced uterine contractility. Contractility (defined as area under the tension/time curve) was decreased to 89 ± 6.5% of control at 2 μg/ml 53±4.3% at 5 μ/ml and 45 ± 4.1% at 8 μg/ml. This decrease in contractility was statistically significant at concentrations >2 μg/ml. Intralipid did not significantly affect uterine contractility. The results of this study show that propofol decreases isolated human uterine muscle contractility in a dose-dependent manner.

Airway management during an EXIT procedure for a fetus with dysgnathia complex

Nonsyndromal dysgnathia is a rare disorder with a probable genetic basis characterized by a hypoplastic or absent mandible (agnathia), microstomia, microglossia, and ear anomalies secondary to a defect in the ventral portion of the first branchial arch caused by defective neural crest migration or proliferation. Dysgnathic newborn infants often suffer fatal respiratory failure from airway obstruction. Nineteen children with isolated dysgnathia complex are described in the literature--six were stillborn, eight died shortly after birth, and only five survived infancy. All survivors required tracheostomy to maintain an airway. It is difficult to intubate the trachea of these children and early airway management planning is important. We report a neonate who presented with a prenatal ultrasound diagnosis of severe micrognathia, polyhydramnios and a family history of severe micrognathia. Airway management was achieved with fiberoptic intubation through a laryngeal mask airway (LMA) during an ex utero intrapartum treatment procedure. Fiberoptic intubation was hampered by copious amounts of amniotic fluid. This child and her sibling are the first two siblings with isolated dysgnathia complex to have survived infancy and provide further support for a genetic basis to this condition.

The pediatric airway

Good airway management technique is an essential skill for physicians in most specialties. This article begins with a review of basic airway anatomy and the physiology of the uninstrumented airway. This subject is of particular importance given the increasing use of procedural sedation and the increased recognition of sleep-disordered breathing in infants and children. A discussion of the various artificial airways and their advantages and disadvantages follows. The difficult airway is an important contributor to both patient morbidity and mortality. It is important to have a planned management approach available for the anticipated and, more importantly, the unanticipated difficult airway. The recommendations of the American Society of Anesthesiologists Taskforce on the Management of the Difficult Airway have good application for this important problem. The fetus with the prenatal diagnosis of a lesion that predicts a difficult airway presents a particular challenge. The utilization of an ex-utero intrapartum treatment method is presented as an important approach for the delivery and airway management of these infants. This section closes with a discussion of the prehospital airway management of the pediatric patient.

Ex utero intrapartum surgery (EXIT): indications and anaesthetic management

The ex utero intrapartum treatment (EXIT) procedure is a technique for safely managing airway obstruction at birth, in which placental support is maintained until the airway is evaluated and secured. In addition to the usual considerations of anaesthesia in obstetrics there are special considerations relating to the EXIT procedure: maintaining fetoplacental circulation by profound uterine relaxation and achieving fetal anaesthesia for airway manipulations. This chapter focuses on the key issues involved in managing this procedure: the indications, preoperative concerns, organization of a multidisciplinary team, problems of maternal and fetal anaesthesia, maintenance of the uterine relaxation and control of fetal airway.