Neonatal Emergencies Alyssa Brzenski

Overview Tracheoesphageal Fistulas Congenital Diaphragmatic Hernias Omphaloceles and Gastroschisis Necrotizing Enterocolitis Myelomeningocele

TEF

Background TEF/EA associated with 1:2,500-4,000 live births 30% of the neonate are premature Few cases diagnosed prenatally May present after birth with inability to pass an OGT

Background

Co-morbidities

Waterson Classification

Spitz Classification

Pre-repair Bronchoscopy

The Evidence behind the pre-repair Bronch May change the operative management (changed operative approach in 57% with 31% being crucial changes) Bronchoscopy can Define the fistula location Determine unusual characteristics of the fistula(double fistula or trifurcation) Determine presence of tracheobronchitis (surgery contraindicated) Locate the aortic arch Influence anesthetic management

Thorascopic vs. Open Repair Reduces Musculocutaneous sequelae 32% of patients have significant musculocutaeous sequelae 24% with winged scapula 20% asymmetry of chest wall 2/2 atrophic serratus anterior 18% developed thoracic scoliosis Better visualization Reduced Pain Post-operatively

Anesthesia for Thorascopic Rarely need lung isolation as operative lung compressed by CO2 insufflation (5mmHg) Can be associated with mild desaturation requiring 100% O2 or mild hand ventilation. Some centers using HFOV for these repairs to minimize the movement of the operative side (MAP 14-24, Hz=10-14, delta P=20-27, FiO2 adjusted to Sat of 92%) EtCO2 will be falsely low due to compression of the lung and CO2 insufflation.

Patient Position

Anesthetic Considerations Routine ASA monitors +/- A-line Maintence of spontaneous ventilation during induction Classic teaching that paralysis can be given after fistula ligated Balanced anesthetic +/- epidural for post-op pain management May have difficulty with hypercapnia or difficulty ventilating

Fistula Management

Extubate or Not? Must consider pre-op lung disease and other comorbidities Spontaneous ventilation decreases the stress placed on the suture line Risk of injury to the repaired fistula with re-intubation

Congenital Diaphragmatic Hernia

Background 1 in 2,500 births Location of the defect Etiology unknown 80% left sided 20% right sided 1-2% bilateral Etiology unknown 50-70% post-natal survival

Co-morbidities

Co-morbidities Trisomy 13, 18, 21 Goldenhar syndrome Beckwith-Wiedemann syndrome Survival in patients with co-morbidities 15%

Diagnosis Prenatal diagnosis Postnatal diagnosis Ultrasound can detect 50-60% Fetal MRI can further delineate Postnatal diagnosis Respiratory distress Scaphoid abdomen Distended Chest NGT coiled in the chest

Pathophysiology Impaired lung development bilaterally with hypoplastic ipsilateral lung Decreased bronchial branches and alveoli Increased muscularization into the intraacinar alveoli Decreased type II pneumocytes Pulmonary Hypertension and persistent fetal circulation Hypoxemia, Hypercapnea, and Acidosis

Prenatal Management Balloon Tracheal Occlusion

Postnatal Management Not a surgical emergency!!!! Definitive airway control Minimize airway pressures to avoid pneumothorax NGT to decompress the stomach Cardiac Echocardiogram to assess pulmonary HTN

Postnatal Ventilatory Strategy Gentle ventilation- PIP less than 25cm H20 pH> 7.25 paCO2<65 Preductal Sat>90% Rescue Ventilatory Strategies iNO HFOV ECMO

When can we operate? Delay surgery for Physiologic stabilization Improvement in pHTN Hemodynamically stable Minimal vent support Exact criteria is insitution-dependent Surgery can occur on the HFOV or on ECMO

Anesthesia for CDH Repiars Standard ASA monitors and A-line Have adequate access, blood, iNO and inotropes available Minimize peak inspiratory pressures Avoid nitrous oxide Peak airway pressures may increase from increased abdominal pressure following repair DO NOT try to expand the contralateral lung after the repair

Intraoperative Complications Exacerbation of Pulmonary HTN PTX on contralateral lung Hemorrhage Hypothermia

Abdominal Wall Defects- Omphalocele and Gastroschisis

Background Omphalocele 1 in 4000 live births Gender: Males > females Location: Umbilical Membranous Sac: Present Size of defect: > 4 cm (Giant > 5 cm) Liver involvement: 30-50%

Co-morbidities- Omphalocele 50-75% of patients will have other anomalies Cardiovascular (30-50%)- tetralogy of fallot Gastrointestinal(25%)- Genitourinary (25%)- cloacal extrophy Beckwith-Wiedemann syndrome (10%) Chromosomal abnormalities- Trisomy 13, 18, 21 Multiple anomalies more common in minor omphaloceles

Background- Gastroschisis 1 in 4000 births Genders: Male = Female Location: Right of the umbilicus Membranous Sac: Absent Size of defect: 2-5 cm Liver involvement: Rare

Co-morbidities-- Gastroschisis Low association with other anomalies (10-20%) Gastrointestinal– bowel atresia Genitourinary– cyrptorchidism Chromosomal anomalies: Rare Prematurity common

Prenatal Care All children with omphalocele or gastroschisis should be born at a hospital with a NICU Vaginal or C-Section are both acceptable birth plans

Surgical Closure Omphalocele has a membranous covering– emergent surgery not necessary Unless the membranous covering is ruptured Gastroschisis does not have a membranous covering- Primary Closure vs Staged Closure

Staged Closure– Spring Loaded Silo

Preoperative Considerations Optimize the fluid status– Correct hypoglycemia Maintain euthermia Cover mucosal surfaces with plastic wrap NGT decompression Labs Type and Cross +/- ECHO

Anesthetic Considerations Standard ASA monitors Adequate IV access Avoid nitrous oxide Balanced anesthetic technique– most babies will remain intubated Fluid, fluid, fluid

Abdominal Compartment Syndrome Impaired ventilation Decreased preload and hypotension Lower limb venous congestion Arterial compression Decreased renal perfusion and oliguria Decreased perfusion to the lower extremities and bowels Monitor the peak airway pressures during closure of the fascia!!!!

Necrotizing Entercolitis

Background Occurs in 1-5 of every 1000 live births Most common in premature and ELBW neonates 11.5% of neonates weighing 401-750g will develop High mortality (15-30%)

Term babies Unusual in term neonates First 1-3 days of life Occurs before feedings begin Associations Perinatal asphyxia Congenital Heart Disease Respiratory Distress

Risk Factors Prematurity Enteral Feeds Hyperosmolar formula Bacterial infections Umbilical arterial catheters

Reduced Mesenteric Blood Flow Pathophysiology Reduced Mesenteric Blood Flow Mucosal Ischemia Intestinal Mucosal Injury Reduced blood flow is 2/2 hypotension, PDA

Pathophysiology

What else is affected? Cardiovascular Metabolic Hematologic Renal Hypotension Metabolic Hyperglycemia Metabolic Acidosis Hematologic Thrombocytopenia Coagulopathy Anemia Renal

Treatment Prevention Medical management Peritoneal drain Feed with breast milk Medical management Stop feeds Optimize hemodynamics and treat with antibiotics Peritoneal drain Surgical exploration

Intraoperative Management Standard ASA monitors plus A-line Adequate IV access Narcotic based anesthetic Large volume fluid resuscitation Have pRBC, FFP and Platelets available Glucose source Keep the baby warm

Myelomeningocele

What is Spina Bifida? Back to the basics of embryology… In utero the neural tube is created when the notochord causes its overlying ectoderm to differentiate into the neural plate. This plate then folds along its axis with the two neural crests ultimately fusing to create the neural tube. Failure of this fusion results in a neural tube defect depending on the location of the opening.

Varying Neural Tube Defects Iniencephaly- defect of the cervical vertebra with cervical spina bifida and back bending of the cervical spine

Spina Bifida Spinal Bifida is a neural tube defect with varied neural tissue involvement. SB Occulta has an isolated deficit of the vertebrae. This defect can be ducted by ultrasound. Clinically, a tuff of hair may overlie the defect. Spina bifida with meningocele had vertebral defect with a cystic thecal sac protruding out of the skin. SB with myelomeningocele is a vertebral defect with protrusion of the thecal sac with the spinal cord. Finally SB with myeloschisis is a vertebral defect with exposed neural tissue.

Basics of MMC 3.4:10,000 births Related to low folate levels, anticonvulsants (carbamazepine, valproic acid) Previous child with same partner is a risk factor NTD are the second most common congenital disorder behind congenital heart disease. Myelomeningocele is the most common neural tube defect making up 85% of all NTD. This defect has been associated with low folate levels. As such the current recommendation is that any female of childbearing age who may become pregnant should take Folic Acid supplement(0.4mg). This single intervention has decreased the rate of occurrence to 3.4:10000 live births, down from 2:1,000 live births. Women taking anticonvulsants such as carbamazepine and valproic acid face higher rates, as high as 1-2% of these women will deliver a baby with a NTD.

Co-morbidities Sensory motor deficits Bowel and Bladder Incontinence Arnold Chiari Type II Caudal displacement of cerebellar vermis, fourth ventricle, and lower brainstem Hydrocephalus Cognitive delay Lower risk if no VP Shunt needed Neurologic deficits reflect the location of the defect. Sensory motor deficit is related to the level of the lesion. This can lead to drastic differences in the ability of a child to walk vs remain wheelchair bound(50% of patients). Bowel and bladder incontinence can be a problem as well, 40-85% have bladder control while 50-85% have bowel control. It is thought that these defects are a result of a 2 hit hypothesis, an open neurotube (hit #1) is then exposed to the amniotic fluid (hit#2) which can worsen prognosis as motor function can be lost throughout the prenatal period. *Note- Arnold Chiari I—caudal displacement of the cerebellar tonsils Arnold Chiari II- caudal displacement of the cerebellar vermis, fourth ventricle, lower brainstem

Co-morbidities MMC is associated with Arnold-Chiari Type II lesions(caudal displacement of the cerebellar vermis, fourth ventricle, and lower brainstem below the foramen magnum). This is thought to develop as CSF leaves the thecal sac there is downward displacement of the hindbrain. Hydrocephalus can then develop which may require VP Shunt placement. In addition cranial nerves can be affects, thus vocal cord paralysis with stridor and respiratory distress, apnea, abnormal swallowing and pulmonary aspiration. This may require a trach and g-tube. Also, CO2 and O2 responsiveness may be decreased.

Latex Allergies All patients with MMC are labeled as latex allergic High rates due to recurrent procedures including urinary catheterization Cross reaction to avocados, banana, passion fruit, kiwi, tomato All Children with MMC are labeled as Latex allergic. Now that we label these patients the rates of true latex allergy am much lower. It is thought that the rates of latex patients with MMC is due to their high rates of recurrent procedures such as urinary catheterization. FYI… If someone has a latex allergy the protein in some of the great fruits may be similar enough to cause anaphylaxis. Thus, latex individuals should also avoid avocados, banana, passion fruit, kiwi and banana.

Management of Myelomeningocele Study Very few of the fetal interventions that are currently undertaken have prospective studies documenting their superiority. However, with MMC we do have a prospective study that suggests it may improve outcomes, notably that there is a decreased rate of death or VP Shunt within the first year. In addition, the motor function in the children treated with prenatal repairs is significantly better than those treated postnatally. Finally, there was a significant regression in the amount of hindbrain herniation.

Post-natal MMC Repair Infants repaired early after birth Must be cautious to not injury the neural tissue during moving or intubation Routine ASA monitors Prone position for repair May or may not receive VP Shunt at the same time Typically remain intubated as infant should not lie supine for the first day

VP Shunts have Complications Ventricular Shunts in the Neonatal Period are not a benign procedure. Depending on the size of the neonate the surgeon may not be able to place the shunt in the peritoneal cavity and may instead place in the subgael region only to revise at a later time. In addition, shunt revisions are more common in kids and even more common in neonates as they grow and are more likely to develop infections.