Congenital Anomalies Flashcards
Neural tube defects
Congenital anomalies that develop when a portion of the neural tube fails to close as it should during the 5th and 6th weeks of gestation. Prenatal diagnosis is based on specific ultrasound findings and high maternal AFP levels. After birth diagnosis is clinical . Treatment - surgery to close the opening wherever it might be
Can Involve the vertebrae , spinal cord , cranium or brain
Can be open (defect is covered by a membrane and not skin) or closed( covered by skin)
Spina bifida- affects the spine - open NTD
Anencephaly / major portion of brain , skill and scalp is missing - open NTD
Cleft palate/ cleft lip
Present at birth
Cleft lip is when the individuals upper lip doesn’t form completely and has an opening in it usually associated with a cleft palate which is when the palate doesn’t form completely and has an opening in it
These defects can be isolated malformations or as part of a syndrome involving multiple organs including the heart
Prenatal diagnosis - ultrasound - accurate after 13 or 14 weeks of gestation - see fetal lip and palate
After birth - clinical diagnosis
Early management is supportive - aims to help baby eat / done with devices like specially designed bottle nipples , dental appliances , a feeder that can be squeezed to deliver formula and an artificial palate moulded to the individuals own palate
Surgical closure - definitive treatment - cleft palate - 2 stage procedure - first cleft lip , nose and soft palate are repaired at age 3-6 months and then the residual hard palate cleft repaired at 15-18 months
Congenital heart diseases
2 categories based on presence or absence of cyanosis
Acyanotic defects: left to right shunting
- VSD
- ASD
- PDA
- coarctation
Cyanotic defects: right to left shunting
- Tetralogy of fallot
- transposition of the great vessels
- truncus arteriosus
- total anomalous pulmonary venous return
- hypoplastic left heart syndrome
Echocardiography to confirm diagnosis
ECG, chest X-ray , cardiac catheterisation with angiography May be used
CT or MRI if diagnosis is inconclusive
Most heart defects are detected prenatally by standard obstetric ultrasound examination
Optimal gestational age screening for structural fetal cardiac anomalies is 18-22 weeks of gestation
First 2 days of life - pulse oximetry saturation less than 90% in the right hand or either foot requires urgent echo.
If there is a saturation difference greater than 3% between right hand and either foot then repeat hourly and if positive 3 times - echo.
Oesophageal atresia
Interrupted oesophagus
2 sections - upper and lower that do not connect
1 or more fistulas between oesophagus and trachea May also occur
Prenatal diagnosis - rare but suspected if polyhydramnios on ultrasound and an absent or small stomach in 2/3rd trimester
After birth - newborn chokes or vomits most or all of the food they consume
Gastric tube can be inserted in infants nose or mouth , if it cannot pass down into the stomach - diagnosis is confirmed and an x-day is needed to assess the location of the obstruction
Surgery to remove the obstruction and reconnect the 2 segments of the oesophagus, it present any fistulas will also need to be litigated
Congenital diaphragmatic hernia
Absent or abnormal fusion of the pleuroperitoneal folds during formation of the diaphragm which causes the organs in the abdomen to slip into the chest
Herniation commonly occurs on the left side so lung on affected side doesn’t develop and becomes hypoplastic - undeveloped lung
Prenatal diagnosis - ultrasound- small Bowel in chest , stomach absent from abdomen , liver herniated too appearing as dark mass in chest
Post natal - respiratory distress syndrome , barrel shaped chest, scaphoid or boat appearing abdomen, absence of breath sounds on affected side, heart beat displaced to right because of shift in mediastinum
Chest radiography - herniatjon of bowels into hemithorax with little or no visible lung on the affected side , displacement of mediastinum organs like heart on opposite side, compression of healthy lung , small abdomen with no visible bowel
Pre-operative management - correcting oxygenation , BP, acid-base status
Surgical repair - closure of the defect and reduction of the viscera into the abdominal cavity
Gastroschisis
Abdominal wall defect through which the bowel and sometimes other abdominal organs slips outside the abdomen
Prenatal diagnosis - AFP maternal serum , ultrasound by 12wks gestation
Post natal - exteriorisation of bowels thru midline defect and absence of covering membrane
Treatment: covering the bowels with sterile saline dressings and wrapping them with a plastic wrap is mandatory
Fluids and broad spectrum antibiotics - gentamicin - prevent infection
Insert an orogastric tube to decompress the stomach and provide resp support if required
Surgery - to close the defect
Omphalocele
Midline abdominal wall defect through which the abdominal contents eviscerate- occurs at the base of the umbilical cord wit cord and umbilical vessels Inserting at apex of omphalocele sac
However these are covered by a membrane of amnion and peritoneum and Wharton’s jelly between those 2
Prenatal - ultrasound by 1st trimester - imp to know if liver containing or non liver containing sac - as non liver containing omphalocele is associated with fetal aneuploidy - when individuals have an abnormal no of chromosomes
Post natal - clinical finding of an anterior midline abdominal mass with a covering membrane at site of cord insertion
Management begins with supportive care - sterile wrapping of bowel to preserve heat and minimise fluid loss
Insertion of an orogastric tube to decompress the stomach and intubation if needed
Surgery then required to repair the defect
Biliary atresia
Progressive fibro-obliterative disease of the extra hepatic biliary tree that leads to biliary obstruction and neonatal jaundice
Prenatal - ultrasound - absent or abnormal gallbladder in 2nd trimester or presence or triangular cord sign
Post natal - jaundice anywhere from birth upto 8 weeks of age - dark urine , enlarged liver and splenomegaly
Lab tests - bilirubin levels(incr) , aminotransferrases ( mildly incr), GGT(incr)
Abdominal ultrasound - exclude other causes of Cholestasis such as a choledochal cyst - gallbladder - absent or irregular in shape , absence of CBD, gallbladder contractility, triangular cord sign
Hepatobiliary scintigraphy- tracer passes - if not excreted in bowel - this is suspected and can exclude this if it is excreted into bowel from liver
Liver biopsy
Intraoperative cholangiogram- contrast doesn’t fill biliary tree or reach the intestine - diagnosis confirmed
Treatment - hepatoportoenterostomy- kasai procedure - loop of bowel created and anastomosed to liver to restore bile flow from liver to proximal small bowel following excision of the biliary remnant
Bladder exstrophy
Failure of midline closure from umbilicus to the perineum so the bladder pokes outside the belly and instead of normal round shape - bladder is flat and open suprapubically and urine drips from open bladder rather than thru the urethra
Ultrasound prenatally - absent bladder filling , lower abdominal mass that incr in size , small genitalia for gestational age
May be confirmed by MRI if ultrasound inconclusive
Post natal - diagnosis made clinically
Exposed bladder is irrigated and a non adherent film is placed to prevent contamination , reconstructive surgery follows soon after that , goals are to provide enough urine storage , create outer sex organs that look and function acceptably , establish bladder control and preserve kidney function
Ventricular septal defect
Most common paediatric heart defects
Small defect - minimal left to right shunting across the ventricles - asymptomatic and no incr in pulmonary vascular resistance
Larger defects- can be heard on auscultation - loud harsh or blowing holosystolic murmur - over lower left sternal border - parasternal heave and a displaced apex beat
Can lead to Pulmonary hypertension
Maybe- Palpable thrill
Mid diastolic low pitched rumble at apex may be heard - incr blood flow across mitral valve
Left heart failure may develop - oedema , as it’s and liver enlargement
Transthoracic echo - estimating size as position of VSD
Doppler echo- magnitude of the shunt
Chest X-ray (cardiomegaly, incr pulmonary vasculature pressure), ECG( left ventricle hypertrophy)
Small VSDs do not require treatment as they can close spontaneously during first year of life and even if they don’t - they don’t cause problems if they are asymptomatic
Large - surgical or percutaneous closure of VSD
Severe pulmonary hypertension - closure of VSD not recommended - instead give pulmonary vasodilators- bosentan or slidenafil
Atrial septal defects
Any portion of atria
Less than 0.5 - small
Greater than 2cm / large
Mid systolic pulmonary flow or ejection murmur with widened split 2nd heart sound in all resp phases
May develop heart failure over time
Harrison groves - atrial enlargement - transverse depressions along 6/7th costal cartilages
Transthoracic echo - initial diagnostic in children
Transoesophageal echo - in adults
Chest X-ray and ECG
Small ASDs close spontaneously in 1st year of life
Those greater than 1cm often require surgical or percutaneous closure
Patent ductus arteriosus
Ductus arteriosus stays open after birth ( connection between aorta and pulmonary artery in the foetus)
Continuous machine like murmur heard in 2nd left intercostal space
Systolic thrill - 2nd left ICS radiating to left clavicle down left sternal border
Over time - congestive heart failure , impaired growth , bounding peripheral arterial pulses , wide pulse pressure
Echo - diagnostic
Doppler - systolic and diastolic retrograde turbulent flow in pulmonary artery.
Chest X-ray and ECg
Haemodynamically stable- Indomethacin, ibuprofen, acetaminophen IV
If haemodynamically sig - ligated surgically or occluded percutaneously
Coaractation of aorta
Narrowing of the aorta commonly occurring below the origin of the left subclavian artery at the origin of the ductus arteriosus
Short systolic murmur heard along the left sternal border at 3rd and 4th intercostal spaces
Systolic ejection click - if bicuspid aortic valve
Classic sign - disparity in pulsation and BP between arms and legs - higher in arms than legs
Femoral radial delay
Cyanosis , tachypnea and signs of heart failure may develop over time
Echo - diagnostic
Chest X-ray and ECG
Mild cases - prostaglandin E1 infusion open the ductus arteriosus and relax it’s tissue of coaractation segment
Treatment thru surgery removing coarctation segment and direct anastomosis or normal aorta and transcatheter technique using balloon and stent angioplasty
Tetralogy of fallot
Pulmonary stenosis
Man-alignment of VSD
Dextro position of aorta that it overrides the ventricular septum
Right ventricular hypertrophy
Systolic murmur - loud , harsh , crescendo-decrescendo / most intense at left sternal border and preceded by a click - louder as severity of pulmonary stenosis increases
Cyanosis May occur later in 1st year of life -
Left anterior hemithorax bulge due to right ventricular hypertrophy and signs of heart failure
Older children - not undergone surgery - dusky blue skin , gray sclerae with engorged blood vessels and marked clubbing of fingers and toes
Dyspnea on mild exertion like playing
Children do the squatting position for relief of dyspnea caused by physical effort
2D echo - diagnostic
Chest X-ray
ECG
Pre ductal and post ductal pulse oximetry should be ordered if suspicious or congenital cardiac malformation
Treatment of those with severe right ventricular outflow obstruction presenting with severe hypoxmia and cyanosis - prostaglandin to maintain ductal patency and pulmonary flow before surgical repair
Definitive treatment - complete surgical repair - closure of VSD and relief of right ventricular outflow tract obstruction
Paraoxysmal hypercyanotic spells / hypoxic or blue spells
In tetralogy of fallot only
During first two years of life
Hyperpneic and restless , cyanosis increases and gasping respirations ensue and syncope May follow
Spells occur after crying or in the morning and can progress to unconsciousness and occasionally to convulsions or hemiparesis
Management:
Knee chest positioning to incr systemic vascular resistance
Oxygen therapy - improve pulmonary vasodilation and systemic vasoconstriction
IV fluid bolus to incr ventricle filling and pulmonary flow
Morphine
IV beta blockers to help improve right ventricle outflow obstruction by relaxing the muscle
IV phenylephrine to incr systemic afterload
