neonatology Flashcards
You are asked to attend a preterm delivery. The neonate is born at 36 weeks gestation via emergency Caesarean section. The neonate has difficulty initiating breathing and requires resuscitation. They are dyspnoeic and tachypnoeic at a rate of 85 breaths/min. On auscultation of the chest, there is reduced breath sounds bilaterally. Heart sounds are displaced medially. The abdominal wall appears concave.
What is the most likely diagnosis?
Congenital diaphragmatic hernia
presents with <strong>scaphoid abdomen</strong>, due to herniation of the abdominal contents into the cleft
Congenital diaphragmatic hernia can present with dyspnoea and tachypnoea at birth. The auscultation findings are due to <u>pulmonary hypoplasia and compression of the lun</u>g due to the presence of abdominal contents in the thoracic cavity. Prompt treatment and respiratory support are required.
what is a congenital diaphragmatic hernia (CDH)?
herniation of abdominal viscera into the chest cavity due to incomplete formation of the diaphragm
=> results in pulmonary hypoplasia and hypertension which causes respiratory distress shortly after birth
occurs in around 1 in 2,000 newborns.
Only around 50% of newborns with CDH survive despite modern medical intervention.
A baby boy born 6 hours ago has an APGAR score of 10. He is not cyanosed, has a pulse of 140, cries on stimulation, his arms and legs resist extension and he has a good cry, He appears jaundiced.
What is the most appropriate action and why?
Measure and record the serum bilirubin level urgently (within 2 hours) in all babies with suspected or obvious jaundice in the first 24 hours of life since this is likely to be pathological rather than physiological jaundice.
what are causes of jaundice in the first 24 hours?
Jaundice in the first 24 hrs is always pathological
- rhesus haemolytic disease
- ABO haemolytic disease
- hereditary spherocytosis
- glucose-6-phosphodehydrogenase
when does physiological jaundice occur?
Jaundice in the neonate from the c. 2-14 days is common (up to 40%) and usually physiological. It is more commonly seen in breastfed babies
what do you do if there are still signs of jaundice after 14 days?
a prolonged jaundice screen
- ***conjugated and unconjugated bilirubin: the most important test as a <strong>raised conjugated bilirubin could indicate biliary atresia </strong>which requires urgent surgical intervention
- direct antiglobulin test (Coombs’ test)
- TFTs
- FBC and blood film
- urine for MC&S and reducing sugars
- U&Es and LFTs
what are the causes of prolonged jaundice?
- biliary atresia
- hypothyroidism
- galactosaemia
- urinary tract infection
- breast milk jaundice
- congenital infections e.g. CMV, toxoplasmosis
what is biliary atresia?
a paediatric condition involving either obliteration/discontinuity within the extrahepatic biliary system –> obstruction in the flow of bile.
This results in a neonatal presentation of <strong>cholestasis</strong> in the first few weeks of life.
The pathogenesis of biliary atresia is unclear, however, infectious agents, congenital malformations and retained toxins within the bile are all contributing factors.
how do pts with biliary atresia present?
Patients typically present in the first few weeks of life with:
- Jaundice extending beyond the physiological two weeks
- Dark urine and pale stools
- Appetite and growth disturbance, however, may be normal in some cases
Signs:
- Jaundice
- Hepatomegaly with splenomegaly
- Abnormal growth
- Cardiac murmurs if associated cardiac abnormalities present
what are the ix done for biliary atresia?
- Serum bilirubin including differentiation into conjugated and total bilirubin: Total bilirubin may be normal, whereas conjugated bilirubin is abnormally high
- Liver function tests (LFTs) including serum bile acids and aminotransferases are usually raised but cannot differentiate between biliary atresia and other causes of neonatal cholestasis
- Serum alpha 1-antitrypsin: Deficiency may be a cause of neonatal cholestasis
- Sweat chloride test: Cystic fibrosis often involves the biliary tract
- Ultrasound of the biliary tree and liver: May show distension and tract abnormalities
- Percutaneous liver biopsy with intraoperative cholangioscopy
what is the mx for biliary atresia?
Surgical intervention (definitive treatment): dissection of the abnormalities into distinct ducts and anastomosis creation
Medical intervention
- antibiotic coverage
- bile acid enhancers following surgery
what are the complications of biliary atresia?
- Unsuccessful anastomosis formation
- Progressive liver disease
- Cirrhosis with eventual hepatocellular carcinoma
what is the Px for biliary atresia?
- good if surgery is successful
- In cases where surgery fails, liver transplantation may be required in the first two years of life
Henry is a premature baby (29 weeks) who was born 2 weeks ago. Over the past week, he has been passing bloody stools, has abdominal distension and has not been feeding well. Physical examination reveals an increased abdominal girth with reduced bowel sounds. Abdominal X-ray shows dilated asymmetrical bowel loops and bowel wall oedema.
What is the likely diagnosis?
necrotising enterocolitis
one of the leading causes of death among premature infants
what are the sx of NEC?
Initial symptoms can include feeding intolerance, abdominal distension and bloody stools, which can quickly progress to abdominal discolouration, perforation and peritonitis.
what is used for Dx of NEC and what do they show?
Abdominal x-rays can show:
- dilated bowel loops (often asymmetrical in distribution)
- bowel wall oedema
- pneumatosis intestinalis (intramural gas)
- portal venous gas
- pneumoperitoneum resulting from perforation
- air both inside and outside of the bowel wall (Rigler sign)
- air outlining the falciform ligament (football sign)
what are the components of the APGAR score ued to assess the health of the newborn baby?
pulse, respiratory effort, colour, muscle tone, reflex irritability
A score of 0-3 is very low score, between 4-6 is moderate low and between 7 - 10 means the baby is in a good state
Microcephaly may be defined as an occipital-frontal circumference < 2nd centile
what are some causes of microcephaly?
- normal variation e.g. small child with small head
- familial e.g. parents with small head
- congenital infection
- perinatal brain injury e.g. hypoxic ischaemic encephalopathy
- fetal alcohol syndrome
- syndromes: Patau
- craniosynostosis
how are gastroschisis and exomphalos similar?
they are both examples of congenital visceral malformations.
how are gastroschisis and exomphalos different?
Gastroschisis describes a congenital defect in the anterior abdominal wall just lateral to the umbilical cord.
In exomphalos (also known as an omphalocoele) the abdominal contents protrude through the anterior abdominal wall but are covered in an amniotic sac formed by amniotic membrane and peritoneum.
how is gastrochisis managed?
- vaginal delivery may be attempted
- newborns should go to theatre as soon as possible after delivery, e.g. within 4 hours
how is exomphalos (omphalocoele) managed?
- caesarean section is indicated to reduce the risk of sac rupture
- a staged repair may be undertaken as primary closure may be difficult due to lack of space/high intra-abdominal pressure
- if this occurs the sacs is allowed to granulate and epithelialise over the coming weeks/months
- this forms a ‘shell’
- as the infant grows a point will be reached when the sac contents can fit within the abdominal cavity. At this point the shell will be removed and the abdomen closed
how often is an APGAR score assessed?
APGAR scores, including appearance/colour, should be assessed at 1 min, then reassessed at 5 and 10 minutes.
In first 10 minutes of life, suboptimal SpO2 readings can be expected from a healthy neonate. Transient cyanosis is very common initially after birth. It does not require any further management as it usually self-resolves.
how can you recognise central cyanosis clinically?
when concentration of reduced haemoglobin in the blood exceeds 5g/dl
