Management of Neonatal Surgery

Dallas: Paul J. Samuels, MD Cincinnati Children’s Hospital

Chicago: Shobha Malviya, MD University of Michigan

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Neonatal Surgery

• GI • Diseases common in – Abdominal wall defects preemies • Omphalocele – NEC • Gastroschisis – HiHernia – Congenital defects • TEF • Duodenal atresia • Malrotation/Midgut • Diap hragmat ic HHiernia volvulus • Hirshsprung’s disease • Imperforate Anus and large bow el – Pyloric Stenosis obstruction

• CCAM 2

Intensive Review of Pediatric Anesthesiology Dallas - 2013 Neonatal Surgery

• Closure of CV shunts • Neonatal pulmonary concerns • Temperature hihomeostasis • Glucose homeostasis • Immature renal function • Sensitivity to opioids and inhalational anesthesia

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Neonatal Surgery • Basic concepts: – Airway control – Maintenance of temperature – Fluid/electrolyte resuscitation – Nasogastric decompression – Antibiotic administration – Glucose homeostasis – Identification of associated congenital anomalies

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Pyloric Stenosis The most frequently encountered infant GI obstruction in most general hospitals

A - Normal stomach in an infant 4 weeks of age B - Hypertrophic Pyloric Stenosis

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Pyloric Stenosis

• 2‐6 weeks of age • Results in classic triad: • Non‐bilious, projectile – Hypochloremia vomiting, visible peristalsis – Hypokalemia • M:F=4:1, 1:500 – Metabolic alkalosis • Hypertrophy of muscularis • Renal response to vomiting layer of pylorus resulting in – Initial excretion of bicarb gastric outlet obstruction to maintain pH ° • Dx 1 made by U/S, occas – Eventual excretion of barium swallow acid “paradoxic • Infants exposed to EES? aciduria”

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Pyloric Stenosis

• Further fluid loss may be • Postpone case if HCO3 > associated with prerenal 30 azotemia, hypovolemic shock, and metabolic • Some like to see Cl < acidosis 100 • Surgical intervention is NOT • Cimetidine has been EMERGENT used to rapidly • Tx of hypovolemia and normalize pH metabolic disturbances IS!

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Pyloric Stenosis

• Anesthesia • Performed open or management laparoscopically – High risk for aspiration • Lap pyloric: faster – Gastric suction prior to progression of feeding, induction and quicker discharge – RSI common • Advanced to feeding – Awake extubation within 24 hours • Pyloromyotomy curative

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Neonatal Intestinal Obstruction: Duodenal, Ileal, and Colonic Atresias

• Presum ptiv e ddagiagn ossosis in all infants with bilious emesis, and with or without gastric distention in first 24 hrs of life • Congenital anomalies – Duodenal atresia – Meconium ileus – Annular pancreas – Stenos is /Atres ia – Commonly associated with other anomalies 9

Intensive Review of Pediatric Anesthesiology Dallas - 2013 Duodenal Atresia • Bilious vomiting within 48 hours of birth • “Double‐bubble sign” • No bowel gas beyond ddduodenum • 20‐30% also have Down syndrome • Other anomalies: prematurity, malrotation, CHD, esophlhageal atresia, anorectal anomalies

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Annular Pancreas

• Rare condition in which the ddduodenum is surrounddded by a ring of pancreatic tissue • Complete or partial duodenal obstruction • May be asymptomatic • Associations: Down syndrome, Meckel’s diverticulum, imperfo r ate aausnus

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Meconium Ileus

• Distal small bowel luminal • Diatrizoate meglumine (DM), obtbstruc tion water solblluble contttrast agent, • Almost exclusively found in as an enema, facilitates pts with Cystic Fibrosis, evacuation though only 10‐20% of CF • Surgical: DM, or pts have MI acetylcysteine, injected into • May result in meconium bowel lumen, and contents peritonitis, forming fibro‐ advanced into colon adhesive bands and • May require enterostomy widespread obstruction • Surgical and medical mgt

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis

• 2 week old 28 week infant with abdominal free air, Hg 909.0. K+ 595.9, PLT 88K

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Major source of • Occurs in 10% of infants perinatal M and M < 1500 gms • 90% infants with NEC • Mortality 10‐30%, premature highest in smallest • Primarily disease of infants premature infants, • Approx 1/3 of infants typically < 1500 gms or with NEC require 32 weekssurgical intervention

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Systemic process • Only clear risk factor is primarily related to prematurity, and sepsis that accompanies intensity of disease is intestinal necrosis and inversely correlated increased mucosal with gestational age permeability • Despite it’s frequency, precise etiology is unknown

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Three stages of NEC – 2: definite (surgical) disease • All of the above, AND (Bell, 1978) radiographic evidence of – 1: suspected (mild) disease pneumatosis or portal • Non‐specific symptoms venous air including vomiting, gastric ’ ’ residuals, A s and B s, – 3: advanced disease guaiac+, nl radiograp hs • Evidence of intestinal necrosis or perforation • Hemodynamic, resp, and hematologic instability

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Modified Bell’s Staging for NEC (Walsh and Kleigman)

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Pathophysiology – Intestinal mucosal injury from – Occurs sporadically and in ischemia caused by clusters diminished mesenteric blood – When in FT infants, typically flow is commonly believed to in first 1‐3 DOL, with hx of contribute to NEC hypoxic or ischemic event – Risk factors include: birth such as perinatal asphyxia, asphyxia, hypotension, RDS, RDS, CHD PDA, recurrent ap,pnea, – When in preemies, tends to presence of UVC or UAC, occur after 2‐3 weeks after systemic infection, early enteral feeds initiated, enteral feeding without sentinel event

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Most commonly occurs • Combination of bowel ischemia in ilio‐colic region, and btbacterem ia undliderlie NEC – Exaggerated inflammatory response though often in the setting of abnormal bacterial discontinuous and colonization, an inadequate patchy in both sm and epithelial barrier, immature intestinal immunity lg intestine – Character ize d by idinadequate • Primary pathology secretion of MUCIN, predisposing to increased permeability and – Coagul opath y bacterial adherence – Ischemic necrosis – Inflammatory 19

Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC) • Preop Mgt • Laboratory findings – Typically preterm, <1000gms – Hyper gly cemia – – Presentation Thrombocytopenia – Coagulopathy • Temp instability – Anemia • A’s and B’s – Hypotension • Poor feeding with gastric – residuals Metabolic acidosis – • Vomiting Pre‐renal azotemia • Malabsorption of feeds • Radiographic findings • Lethargy – Ileus • Hyperglycemia – Pneumatosis Intestinalis • Heme positive stool – Gas in biliary tract • Toxic, with distended and tender – Free air abdomen

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC) Clinical Management • Mild cases: • Absolute indications – GI decompression, – Pneumoperitoneum cessation of feeds, IV – Intestinal gangrene fluids, Abx, Inotropic • Relative indications support – Clinical deterioration • Metabolic acidosis • More severe cases: • Vent failure – Surgical exploration • Oliguria, hypovolemia • Thromobocytopenia – Peritoneal drain • Portal vein gas • Abd wall erythema • Fixed abdominal mass • Persistently dilated bowel loop

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Necrotizing Enterocolitis (NEC)

• Intra‐op management • Post‐op Mgt – Availability of blood products – Mechanical ventilation – IV access and arterial line – Continued CV support – Potent inhal agents poorly tolerated – TPN – NM blockers – Inotropic support • Outcome – Glucose monitoring – Mortality 10‐30% (higher in ELBW) – Temp homeostasis – Short gut syndrome (20‐25%) – Preserve as much bowel as possible – Neurodevelopmental issues (2x incidence in those treated surgically vs medically)

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Perforated NEC

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Abdominal Wall Defects: Gastroschisis and Omphalocele • Two most common congenital abdominal anomalies – Impaired blood flow to herniated organs – Fluid shifts – Infifection rikisk – Associated anomalies • Approx 95% of defects are confirmed with U/S, allowing high‐risk delivery

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele • Herniation of viscera into base of umbilical cord • Typically covered and midline • “Uh‐oh” omphalocele • 50‐75% of infants with omphalocele have other congenital anomalies • 45% have cardiac anomalies • 20‐30% have chromosomal anomalies 25

Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele • Incidence 1:5000 • Male:Female 2:1 • Represents a failure of the gut to return from the yolk sac into the abdomen during the first trimester (occurs earlier than gastroschisis) • Bowel is covered, and is morphologically normal

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele • Central defect • GllGenerally larger than 4 cm in diameter • Always covered by sac, into which umbilicus inserts • Usually contains liver and midgg,ut, sometimes spleen and gonads

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele: Other associated anomalies

• GI tract: malrotation, atresia, stenosis, Meckel’s • Cardiac: 20‐40% VSD, TOF, ASD, ectopia cordis • GU: bladder extrophy, hypoplastic kidney • Craniofacial: cleft lip and palate

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele: Associated syndromes • Beckwith‐Weidemann • Pentalogy of Cantrell – Macroglossia – Upper midline Omphalocele – Hypoglycemia – Anterior CDH – Organomegaly – Sternal clfleft – Ectopia cordis – Intracardiac defects

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphaloceles can be large or small

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis • Typically NOT associated with other congenital anomalies – GI: jejuno‐ileal atresia (10‐ 15%) and stenosis, auto‐ amputation, strangulation and bowel malrotation • Incidence 1:2500 (more common than omphlhaloce le) • Male:Female 1:1 Photo courtesy of Cincinnati Children’s Hospital

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis • Develops later in fetal life, after abd contents have returned to abd cavity • Typically right of umbilicus (l(normal umbilica l iiti)nsertion) • Due to occlusion of right omphalomesenteric artery

Photo courtesyyp of Cincinnati Children’s Hospital 32

Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis • Generally small (<4cm) abd wall def ect • Uncovered, bowel is inflamed, edematous, foreshortened • Midgut herniated through defect • Teratogens: maternal aspirin, pseudoephedrine, acetaminophen, smoking

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis/Omphalocele Pre‐operative Considerations

• Herniated viscus wrapped in sterile dressing • Maintain normothermia • NG in place • Antibiotics • Assess fluid status, as these patients are prone to significant fluid and protein loss (gastro>>omphalo) • Fluid requirements can be significant (>100 to 200 ml/kg) • Rule out other congenital anomalies • Not urgent unless bowel is compromised

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis/Omphalocele Inter‐operative Considerations

• Induction: awake or rapid sequence • Monitors: routine, with possible a‐line, CVP, foley, intra‐gastric or bladder pressures • No nitrous oxide • Watch CVP, airway, and other pressures as closure proceeds; be prepared to re‐open! • Plan on post‐operative ventilation

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Omphalocele/Gastroschisis Surgical treatment • Primary vs. Staged closure – Primary advantages – Primary disadvantages • Preferred for smaller • IVC compression defects • Respiratory compromise • Decreased infection risk • Bowel ischemia • Earlier return of GI fxn • Decreased renal blood • Single anesthetic flow • Wound dehiscence

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Staged closure

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Staged Closure

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Gastroschisis/Omphalocele Post‐op considerations and surgical outcome • Post‐op ventilation due to pulmonary compromise and need for mm relaxation • TPN dddependent • Early complications: NEC, renal insufficiency, PDA, cellu litis/breakdow n of abdominal inc ision • Omphalocele: mortality 10‐30%, usually due to associated congenital anomalies • Gastroschisis: virtually all patients survive

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Malrotation/Midgut Volvulus

• Result from • Malrotation 2x more abnormalities in normal common in boys than bowel rotation that girls occurs during the 10‐ • Other major abdominal 12th week of gestation defects, including • Areas of ischemia and gastroschisis, atresia develop, or omphalocele, and CDH volvulus are also associated with malrotation

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Malrotation/Midgut Volvulus

• Bilious vomiting in newborn period • Recurrent abd pp,ain, FTT, or recurrent vomiting in older children • Dx with upper GI series and/or U/S • Emergent laparotomy

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Malrotation/Midgut Volvulus

• Children with less than • Malrotation is common 30‐40 cm of small (1 in 500) bowel generally develop • May produce sx of short gut syndrome, obstruction in first 8 and TPN dependence weeks of life • May be entirely asymptomatic

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Inguinal Hernia

• The most common indication • Typical presentation bulge in for general surgery in neonates groin or scrotum in boys, • 2% of full‐term, 10% all labial bulge in girls preemies, 35% < 28 wks • Incarceration most common • Peak during 1st month complication, occurs 12% of • Most common in boys (10:1), the time, typically in first year though bilateral hernia more of life common in girls • Post‐op concerns include app,nea, anemia

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Neonatal Colo‐rectal Disease

• Hirshsprung’s disease: lack of • Imperforate anus ganglion cells in intramuscular – plexus results in lack of bowel Associations: caffeine, relaxation and functional bowel tobacco obstruction – Additional genitourinary • Sx vary from bowel obstruction to abnormalities 48% constipation – Tethered cord: 24% • 10‐20% clinically evident at birth – Males: emergent – Delayed passage of meconium, decompression irritibility, distention – Females: usually have recto‐ • AitiAssociations: Down syndrome vagilinal fistu la, w/o bblowel obstruction

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Sacrococcygeal Teratoma • Most common • Arise from tip of coccyx congenital neoplasm • Options include fetal or • 1:40,000 infants post‐natal resection • 95% female • Massive blood loss, • Tumor consists of all hypothermia, three germ layers coaggpy,ulopathy, CV • 50% malignant by 12 instability moosnths of age • Predictors: prematurity, • High alpha‐fetoprotein hydrops, low birth wt, levels poor Apgars 45 Intensive Review of Pediatric Anesthesiology Dallas - 2013 GI Emergencies/Overview

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Esophageal Atresia and Tracheoesophageal Fistula (EA and TEF)

• Incidence: 1:2500 – 1:4000 live births • Gender: M>F 25:3 • OhOther congenilital dfdefects in 30‐50% ‐ 50‐70% in infants with isolated EA ‐ least common with H‐type fistula 47

Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: VACTERL Association

• Vertebral (15%) Hemivertebrae, scoliosis, rib deformities • Anal (24%) Imperforate anus, cloacal deformities, duodenal or ileal atresia, malrotation • Cardiac (25‐30%) VSD, TOF, PDA, ASD, AV canal, R sided aortic arch • Trachhlheoesophageal EA, TEF • Renal (24%) Renal agenesis or dysplasia, Potter syndrome, horseshoe kidney, polycystic kidneys, urethlhral atresia, ureteral malformations • Limb Radial dysplasia, absent radius, polydactyly, syndactyly, tibial deformities 20‐25% of infants with EA have at least 3 of the VACTERL lesions Other lesions: Trisomy 18, 13 or 21 in 7% cases, prematurity in 12%

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF

Mortality depends on severity of heart disease and birth weight

Survival 1994 2006 B.W. >1500 g, no cardiac anomaly 97% 98% B.W. < 1500 g or major cardiac anomaly 59% 82% B.W. < 1500 g + major cardiac anomaly 22% 50%

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Embryology

• Exact embryogenesis unknown • In a 4‐ to 6‐week‐old embryo, the caudal part of the foregut forms a ventral diverticulum that evolves into the trachea. • Longitudinal TE folds begin to fuse toward the midline and ultimately form the TE septum • Posterior deviation of the TE septum as it is forming results in the occurrence of EA and TEF

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Embryology

• Hedgehog proteins are glycoproteins involved in embryogenesis of the foregut • Of these, only sonic hedgehog proteins (Shh) are expressed in mammalian gut and lung • Mutant Shh have been found in TEF and VACTERL lesions and have been implicated in the pathogenesis of TEF

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Prenatal Diagnosis

Ultrasound Findings: • Polyhydramnios ‐ esophageal obstruction prevents swallowing of amniotic fluid ‐ seen at ≥ 24 wk gestation ‐ increased intrauterine volume may precipitate preterm labor • Absent stomach bubble may be seen at 18 wk • Upper pouch sign ‐ dilated blind ending upper pouch of esophagus • Low sensitivity & specificity, prenatal detection rate of 40‐50% • Prenatal detection should prompt karyotyping and search for other structural anomalies

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Presentation

• In delivery room – inability to pass orogastric tube • Cough, choking and cyanosis during the first feed • Resp distress exacerbated by feeding • Excessive salivation and drooling, regurgitation of feeds • Distended abdomen when TEF present • Scaphoid abdomen ‐ absence of stomach/bowel gas in isolated EA • H‐fistula often presents later with episodes of recurrent pneumonia, aspiration

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Pre‐operative workup

• H&P ‐ extent of resp compromise ‐ significant pgprognostic indicator ? ability to tolerate one‐lung ventilation ‐ hemodynamic stability ‐ limb defects, anorectal anomalies • Echocardiogram to assess cardiac anomalies, aortic arch ‐ anesthetic implications, timing of surgery, positioning and surgical approach • Renal ultrasound to identify renal and other GU anomalies • CBC, electrolytes, type and cross match

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Pre‐operative workup X‐Ray ‐pneumonia, infiltrates, RDS ‐ OG catheter coiled in upper pouch ‐ distended stomach ‐ gasless abdomen in EA without TEF ‐ vertebral anomalies

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Risk Factors

• Co‐existing complex CHD • Low birth weight • Poor pulmonary compliance • Large fistula • Fistula very close to carina • Planned thoracoscopic repair

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Pre‐operative management

• Surgical repair of TEF is urgent • Emergent only if infant requires IPPV such that dilation of stomach is compromising respiration • Protect the lungs from aspiration pneumonia – Avoid feeding – Uppgright pgpositioning of infant to minimize regggurgitation of gastric contents through fistula – Replogle tube for suctioning the upper pouch – Antibiotics to treat pneumonia

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Surgical Management

• Optimal surgical management comprises a 1‐stage repair: ‐ Fistula is ligated ‐ Esophagus is primarily anastomosed ‐ Right thoracotomy, posterolateral extrapleural approach ‐ Left thoracotomy in case of a right aortic arch • Open thoracotomy or thoracoscopy • Rig id or fiberop tic bhbronchoscopy prior to surgilical procedure ‐ Locate fistula, determine if more than one fistula is present ‐ Assess for tracheomalacia ‐ Evaluate correct position of ETT

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Staged Repair • High risk infants unable to tolerate thoracotomy • Gastrostomy ‐ decompress stomach, prevent regurgitation via fistula into lungs ‐ Local or general anesthesia ‐ In large fistula, avoids excessive gastric distent ion and rupture ‐ May permit tidal volume to escape in infants with poor lung compliance ‐ Occlusion of fistula using balloon‐tipped catheter placed via FOB guidance or retrograde via gastrostomy ‐ Emergent ligation of fistula if unable to ventilate • Definitive procedure when infant has stabilized

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Staged Repair

• Long gap atresia (longer than 2.5 cm or 2 ‐ 6 vertebral bodies) • Ligate fistu la, gastrostomy ± esophagostomy to exteriiiorize upper pouch • Nutrition via gastrostomy until definitive surgery • Esophageal anastomosis between 3 and 6 months of age if spontaneous growth of esophagus is adequate • Techniques for lengthening native esophagus include placement of external or internal traction sutures and thoracoscopic elongation of esophagus • ItInterposed non‐esophlhageal tissue is btbest avoide d due to almost 100% incidence of severe reflux and dysmotility

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Anesthetic Management

• Meticulous operating room set up: ‐ Warm room, overhead warmer, forced air warmer ‐ Standard monitoring: EKG, pulse oximetry, end tidal CO2, arterial line, urine output ‐ Precordial stethoscope ‐ ETT without Murphy’ s eye, microcuffed ETT ‐ Fiberoptic bronchoscope ‐ 5% albumin, PRBCs, Blood warmer

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF – Anesthetic Management

• Goal for induction is to establish airway without aspiration or gastric distension ‐ Pre‐oxygenation, continuous suction of upper pouch ‐ Maintain spontaneous ventilation ‐ Avoid PPV to avoid insufflation of stomach via fistula • Awake intubation safest but difficult in a vigorous infant • Inhalation induction with cautious gentle PPV as needed • Ideally, maintain spontaneous ventilation until fistula ligated wihith assidisted ventilat ion if needdded using low airway pressures

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Anesthetic Management • Position ETT below fistula and above carina ‐ RMSB intubation, then withdraw slowly just until bilateral breath sounds heard ‐ Cuffed ETT without Murphy’s eye, bevel facing anteriorly so posterior wall can occlude fistula • Confirmation – FOB or gastrostomy to water seal and observe for gas bubbles • If fistula is too close to or below carina ‐ Selective bronchial intubation and 1‐lung ventilation until fistula ligated ‐ Position ETT above fistula with spontaneous ventilation or gentle assisted ventilation ‐ Occlusion of fistula with balloon‐tipped catheter

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF – Intraoperative Events • Difficulty with ventilation, hypoxemia, hypercarbia ‐ Displacement of ETT into bronchus or fistula, or above the fistula ‐ Displacement of balloon tipped catheter causing tracheal obst ‐ Surgical manipulation causing kinking of trachea ‐ Insufflation of CO2 during thoracoscopic procedure ‐ ETT obstruction: blood clot, secretions ‐ One‐lung ventilation ‐ may need to re‐expand lung intermittently ‐ Gastric distention • Hemodynamic instability, bradycardia ‐ Compression of mediastinal structures ‐ Vagal response: tracheal manipulation and bradycardia

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Postoperative Management

• Early extubation desirable to avoid pressure of ETT on suture line • Rarely accomplished due to: ‐ Degree of pulmonary dysfunction, associated anomalies, prematurity ‐ Tension at esophageal anastomotic site following long‐gap EA repair makes deep sedation, neuromuscular blockade and controlled ventilation preferable ‐ Defective tracheal wall at the site of fistula or tracheomalacia may cause airway collapse • Distance btw lip and site of esophageal repair measured, to avoid suctioning too deep • Avoid extension of neck to minimize tension on anastomosis • Postoperative pain management ‐ IV opioid infusions or epidural analgesia via catheter inserted in caudal space and threaded cephalad

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 EA and TEF: Outcomes • Early complications ‐ Anastomotic leaks in 15% of cases, managed expectantly or by surgical exploration depending on extent of leak ‐ Esophageal strictures in 30‐40%, may require serial dilations • Long‐term complications ‐ GERD in 40‐70%, more common in long‐gap EA, prolonged gastrostomy feeds, non‐esophageal tissue interposition ‐ GERD associated with recurrent aspiration and pulmonary disease ‐ Esophageal dysmotility, feeding aversion, dysphagia, growth failure ‐ Tracheomalacia ‐ common but clinically significant in only 10% of cases ‐ Abnormal cilia and goblet cells in tracheal epithelium – frequent URIs ‐ Open thoracotomy –higher incidence of musculoskeletal defects such as winged scapula

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Congenital Diapgphragmatic Hernia ()(CDH)

• Extrusion of abdominal viscera into thoracic cavity via dfdefect in the diaphragm • Occurs at 7‐10 wk gestation as diaphragm completes its formation • Incidence 1:2000 ‐ 1:5000 live births • Significant cardiovascular, pulmonary, and GI sequelae

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Anatomy • Herniation occurs through the postero‐lateral foramen of Bochdalek in 90% of cases, 75% of which occur on the left • RiiRemaining 10% ildinclude foramen of Morgagni defects, paraesophageal hernias and eventrations • Bilateral hernias <1% are associated with high mortality

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Embryology

• Embryogenesis of CDH remains unclear, several theories exist • Delayed fusion of various components of the developgping diapg,phragm, specifically the pleuroperitoneal canals beyond 9‐10 wk gestation • Return of midgut from umbilical cord to abdominal cavity prior to fusion of all components of diapgphragm • Genetic or environmental triggers disrupt differentiation of mesenchymal cells during formation of the diaphragm and other somatic structures • Which came first – Diaphragmatic defect or lung hypoplasia? ‐ Teratogenic effects of nitrofen in rat models of CDH ‐ Retinoid receptor hypothesis – Vitamin A adm decreased incidence of CDH and attenuated of lung hypoplasia in the nitrofen CDH rat model ‐ Human study ‐ vitamin A markers were reduced in infants with CDH

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Pathogenesis

Herniation of viscera During branching of bronchi and PAs

Interference with lung development

Decreased bronchiolar branching Loss of lung mass Over‐muscularization of pulmonary arterial tree Dysfunctional surfactant system

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Survival • SilSurvival idimproved from 40‐60% in 1980s to 70‐ 80% in 1990s • Improved survival largely credited to strategy of delaying surgery for neonatal stabilization, use of techniques such as ventilation with low tidal volumes and permissive hypercapnea to avoid barotrauma, ECMO • Survival and long term sequelae in survivors are inversely proportional to severity of pulm hypoplasia and pulm HTN • Mort alit y figures dis tor te d by number of stillbirths and pregnancy terminations

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH – Associated Conditions

• 50‐60% are isolated i.e. CDH + its consequences ‐ pulm hypoplasia, malrotation and cardiac dextroposition • Congenital heart disease in 11% of cases ‐ VSD, ASD, aortic arch obst, single ventricle, TOF, other • NlNeural tbtube ddfefec ts ‐ anencephlhaly, encephlhaloce le, hdhydrocep hlhalus myelomeningocele • Other midline defects ‐ esophageal atresia, omphalocele, cleft palate, hypospadias • Chromosomal anomalies ‐ trisomies 18, 13, and 21, others • Syndromes ‐ Apert, Beckwith Wiedemann, CHARGE, Goldenhar, Cornelia‐ De Lange, Pentalogy of Cantrell, other rare syndromes

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Prenatal Diagnosis • Level 2 ultrasound by experienced sonographer • Left CDH: heterogeneous mass in L chest, R mediastinal shift, fluid filled stomach, bowel peristalsis or fluid filled bowel in chest, liver • Rig ht CDH : liver, gall bla dder, bblowel in R chhtest, L mediasti na l shift • Prognostic indicators: Lung to head ratio (LHR) and herniated liver ‐ C.S. area of contralateral lung : Head circumference ‐ LHR > 1.4 associated with 100% survival and < 0.8 with 100% mortality ‐ Herniated liver is associated with 50% mortality • Amniocentesis and karyotyping to identify chromosomal anomalies • Fetal echocardiography to identify congenital cardiac anomalies • Ultrafast MRI using rapid HASTE technique to demonstrate liver herniation • PtlPrenatal diagnos is of CDH shldhould prompt ddlielivery at tttiertiary care center equipped to provide specialized services for the neonate

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Clinical Presentation

• Respiratory distress, cyanosis • Barrel shaped chest, scaphoid abdomen • Auscultation: ‐ absent breath sounds, ‐ heart sounds displaced to the right ‐ bowel sounds heard in the chest • X‐Ray ‐ bowel loops in left chest ‐ heart displaced to right ‐ n/g tube in stomach within chest cavity ‐ displaced course of UVC

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Fetal Interventions

• Rationale : To prevent or reverse pulm hypoplasia and restore adequate lung growth

• Open approach with patch repair of defect abandoned due to no survival advantage in clinical trials

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH ‐ Fetal Interventions • Fetal Endoscopic Tracheal Occlusion (FETO) ‐ prenatal TO prevents the normal egress of lung fluid during lung development causing increased transpulmonic pressure and large fluid‐filled lungs ‐ FETO reddduced pulm hlihypoplasia, but also reddduced type II pneumocytes and hence surfactant secretion ‐ removal of the TO before delivery mitigates this unwanted effect ‐ preliminary data from an ongoing European study are promising ‐ additional studies needed to confirm the advantage of FETO vs. expectant management in terms of survival and long term morbidity

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Pre‐surgical Management • Goals of initial management ‐ avoid surgery in an infant with cardiorespiratory instability ‐ medical management used to improve preductal SpO2 to >90%, correct metabolic acidosis, reduce R‐L shunting and increase pulm perfusion using gentle ventilation to prevent lung injury • Delivery room – avoid bag‐mask ventilation to minimize overdistention of non compliant lung and distension of stomach and intestines in the chest • Early intubation of trachea and decompression of stomach • Low PIP and PEEP, Vt 5‐10 ml/kg, permissive hypercapnea (PaCO2 60‐65 mm Hg), HFOV as primary vs. rescue therapy per institutional preference • Vasopressors, blood transfusion and volume resuscitation to maintain hemodynamic stability and intravascular volume

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH :Pre‐surgical Management

• Measures used to treat persistent pulmonary hypertension: ‐ Inhaled nitric oxide ‐ a free radical with short half life, selective pulmonary vasodilator, no clear benefit has been demonstrated in infants with CDH ‐ iNO has been used effectively in some infants as a rescue agent when ECMO is unavailable ‐ High Frequency Oscillatory ventilation (HFOV) ‐ reserved for infants with persistent hypoxia and hypercarbia on conventional ventilation, some centers use it primarily ‐ HFOV delivers rapid low tidal volumes and has been pppurported to improve oxygenation while avoiding volutrauma

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Extra Corporeal Membrane Oxygenation (ECMO) • ECMO has been used extensively to stabilize infants with CDH before, during and after surgery • Preoperatively it is used to support the patient until the PVR drops or the reactive component of PH resolves • Indications for ECMO include: ‐ Inability to maintain SpO2 > 85% or PaO2 > 30 ‐ PIP > 28 or Mean Airway Pressure > 15 cm H2O ‐ Hypotension unresponsive to fluids and inotropes ‐ Inadequate O2 delivery, metabolic acidosis • Infants with lethal chromosomal anomalies and severe IVH are excluded • Interpretation of survival benefit is difficult since infants with more severe disease require ECMO

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Surgical Management • Surgical repair ‐ approach via abdominal incision, thoracotomy or thoracoscopy • Infants with severe pulm dysfunction may not tolerate 1‐lung ventilation making it difficult to use MIS. • Infants with large defects may not tolerate primary closure of the abdomen once the hernia is reduced –may require a patch closure, silastic pouch or chimney prosthesis • In such cases, lower extremity venous access is best avoided due to IVC compression after reduction of hernia

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Anesthetic Management • Ventilation strategy: Use of low PIP, adequate PEEP, small tidal volumes to maintain oxygenation, avoid atelectasis and volutrauma, avoid acidosis • Sudden deterioration of ventilation or hemodynamic status: ‐ r/o PH, pneumothorax of the contralateral lung ‐ iNO 20 ppm may be initiated if PH is suspected • MtilMeticulous attenti on to temp maiitntenance ‐ hypothermia increases PVR, R‐L shunting and O2 consumption causing tissue hypoxia and acidosis ‐ Acidosis leads to pulm vasoconstriction and decrease in SpO2 • N2O should be avoided to maintain higher FiO2 and avoid distension of bowel loops in chest • Anesthetic agents selected on the basis of cardiopulmonary status • High dose narcotic technique, opioid infusions continued postop

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CDH: Outcomes

• Long term pulm complications: ‐ chronic lung disease from ventilator associated injury ‐ 25% of survivors have obstructive lung disease ‐ need for bronchodilators, inhaled steroids, tracheostomy • GI complications: ‐ oral aversion, GERD in 45‐90% • Neurocognitive disorders including motor and language deficits especially in those who required ECMO • Chest wall dfdeform iiities and scolios is

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Congenital Lobar Emphysema (CLE)

• CLE is an abnormally emphysematous lobe of the lung that communicates with a bronchus • Prevalence of 1 in 20,000 to 1 in 30,000 • Most commonly affects left upper lobe, then right middle and upper lblobes • Causes of obstruction include deficiency of bronchial cartilage resulting in airway collapse during expp,iration, aberrant blood vessels, bronchial cysts and bronchial stenosis • Hyperinflation and progressive air trapping of the affected lblobe lldead to compression of the remaiiining lung tissue, mediastinal shift and impaired venous return

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CLE: Clinical Presentation

• Most present between birth and 6 months of age with tachypnea, respiratory distress, and cyanosis • May present emergently with acute deterioration if rapid ppgrogressive accumulation of gas in affected lobe • Milder forms may present insidiously with poor feeding, FTT and recurrent pneumonia • P/E ‐ wheezing caused by airway compression ‐ decreased breath sounds, hyper‐resonance to percussion over involved lobe ‐ Displaced cardiac impulse

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CLE – Diagnosis • Chest X‐Ray ‐ hyperinflation of affected lobe ‐ presence of bronchovascular markings ‐ flattening of diaphragm ‐ atelectasis of other lobes ‐ herniation of affected lobe across midline • CT Scan ‐ hyperex panded lung ‐ mediastinal shift ‐ compression of surrounding lung tissue and/or opposite lung

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CLE: Surgical Management

• May present with ventilatory and cardiac compromise as a surgical emergency to relieve the expanding lobe • Palliative procedures such as CT placement, needle aspiration of trapped air or vigorous mechanical ventilation are associated with higher mortality than open procedures • In emergent situations, cardiopulmonary stability is of primary concern Emphysematous lobe bulging • In non acute situations, cardiac evaluation through thoracotomy incision to r/o co‐existent congenital cardiac anomalies seen in 15% of cases

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CLE: Anesthetic Management

• Standard monitors, arterial line if time permits • Increased air trapping in crying struggling infant or with PPV • Smooth inhalation induction with sevoflurane and oxygen, spontaneous ventilation until chest is open, low inflating pressures if PPV is needdded

• Avoid N2O because it may expand the emphysematous area • One lung ventilation is ideal if time permits • At end of procedure 2‐lung ventilation to check for gas leaks at resection site • Extubate at end if possible to reduce incidence of gas leaks

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Congenital Cystic Adenomatoid Malformat ion (()CCAM)

• Congenital pulmonary airway malformation (CPAM) • CCAMs are hamartomatous lesions comprised of cystic and adenomatous elements arising from tracheal, bronchial, bronchiolar, or alveolar tissue • Large CCAMs compress normal lung tissue and compromise alveolar growth • CCAMs do not participate in gas exchange • May communicate with the tracheobronchial tree • Venous drainage and arterial supply usually from the pulm circulation but may connect with systemic circulation • May be associated with hydrops due to cardiac or vena cava obstuction

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CCAM: Clinical Presentation • Most commonly diagnosed on fetal U/S • Some regress over the course of gestation • PtiPresenting signs ildinclude tachypnea, respiratory distress with grunting, retractions and cyanosis • Most are asymptomatic and may Fetal MRI demonstrating be resected electively in the a large CCAM neonatal period

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 CCAM –Fetal Intervention • Fetal interventions are indicated for large lesions compromising normal lung development • Interventions include: ‐ One time or serial needle aspiration of large cysts ‐ Open procedure ‐ delivery of fetal hemi‐thorax and UE through hysterotomy, pulmonary lobectomy and return of fetus to the uterus for further growth and development ‐ Ex‐Utero Intra‐partum Treatment (EXIT) ‐ for lesions in late gestation causing distress or those expected to interfere with neonatal resuscitation ‐ Fetal thoracotomy and pulmonary lobectomy before clamping the umbilical cord

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Broncho‐pulmonary Sequestration (BPS)

• Non functional mass of lung tissue without bronchial connection, usually found in the lower lobes • Blood supply from anomalous systemic arteries • Most present before 2 yr. of age with cough, pneumonia, FTT • Diagnosis by CT scan • MRI for mapping vascular supply and drainage before resection • Anesthetic Management

‐ Avoid N2O ‐ PPV ok since no connection with bronchus ‐ One lung ventilation may be helpful

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 Amniotic Band Sequence (ABS)

• ABS is a variable spectrum of congenital anomalies that occur in association with amniotic bands • Pathogenesis of ABS is not exactly known • One theory is that early amniotic rupture causes loose strands of amnion to adhere to and entangle the embryo resulting in mechanical or vascular disruption of developing structures • May also occur due to disruption of fetal blood flow • A genetic basis for the malformation has also been implicated

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Intensive Review of Pediatric Anesthesiology Dallas - 2013 ABS – Clinical Manifestations

• Limb ‐ constriction rings, amputation, syndactyly, clubfoot, hand deformities • Body wall defects – abdominal or thoracic contents may herniate through a body wall defect into the amniotic cavity • Visceral defects – lung hypoplasia • Craniofacial – encephalocele, exencephaly, anencephaly, clefts • Other – scoliosis, spinal defects, ambiguous genitalia • Infants may present for surgery to correct any of the above defects • Anesthetic management individualized on basis of procedure and co‐existing defects

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Intensive Review of Pediatric Anesthesiology Dallas - 2013