Paediatric core conditions- 3 Flashcards
Haemorrhagic disease of the newborn
- Newborn babies are relatively deficient in vitamin K. This may result in impaired production of clotting factors which in turn can lead to haemorrhagic disease of the newborn (HDN). Bleeding may range from minor brushing to intracranial haemorrhages
- Breast-fed babies are particularly at risk as breast milk is a poor source of vitamin K. Maternal use of antiepileptics also increases the risk
- Because of this all newborns in the UK are offered vitamin K, either intramuscularly or oral
Haemolytic disease of the newborn
An immune condition which develops after a rhesus negative mother becomes sensitised to the rhesus positive cells of her baby whilst in utero. Sensitisation events are when foetal blood cross the placenta into the maternal circulation and are indication for anti-D prophylaxis.
Examples of Haemolytic disease of the newborn
- Antepartum haemorrhage
- Placental abruption
- Abdominal trauma
- External cephalic version
- Invasive uterine procedures such as amniocentesis and chorionic villus sampling
- Rhesus positive blood transfusion to a rhesus negative woman
- Intrauterine death, miscarriage or termination
- Ectopic pregnancy
- Delivery (normal, instrumental or caesarean section)
Features of haemolytic disease of the newborn
- Hydrops foetalis appearing as foetal oedema in at least two compartments (for example pericardial effusion, pleural effusion, ascites), seen on antenatal ultrasound
- Yellow coloured amniotic fluid due to excess bilirubin
- Jaundice and kernicterus in the neonate
- Foetal anaemia causing skin pallor
- Hepatomegaly or splenomegaly
- Severe oedema if hydrops foetalis was present in utero
Tests for haemolytic disease of the newborn
- all babies born to Rh -ve mother should have cord blood taken at delivery for FBC, blood group & direct Coombs test
- Coombs test: direct antiglobulin, will demonstrate antibodies on RBCs of baby
- Kleihauer test: add acid to maternal blood, fetal cells are resistant
Haemolytic disease of the newborn: Affected fetus
- oedematous (hydrops fetalis, as liver devoted to RBC production albumin falls)
- jaundice, anaemia, hepatosplenomegaly
- heart failure
- kernicterus
- treatment: transfusions, UV phototherapy
Fractures: NAI
- Fractures, single or multiple, in children without a medical condition predisposing them to fragile bones, should be investigated for NAI.
- Fractures of different ages, especially where there is no documentation of caregivers seeking medical attention, are highly suspicious of NAI.
- Metaphyseal corner fractures – reported as almost pathognomonic of NAI.
- Evidence of occult rib fractures is also a common finding in infants/children who have been grabbed by the chest and squeezed/shaken.
- Spiral fractures are a result of twisting forces so cannot be caused by simple falling, and are highly suspicious of NAI
Growth plates (epiphyseal plates)
They are the area at the ends of long bones that allow the bones to grow in length. They are made of hyaline cartilage and sit between the epiphysis and the metaphysis. Once the epiphysis and the metaphysis fuse during the teenage years, the growth plates become the epiphyseal lines.
Fractures in children
- Children have more cancellous bone, which is the spongy, highly vascular bone in the centre of long bones whereas adults have more cortical bone
- More likely to have greenstick fracture where one side of the bone breaks whilst the other side stays intact and buckle fracture
Salter-Harris classification
Growth plate fractures are graded using the Salter-Harris classification. The higher the Salter-Harris grade, the more likely the fracture is to disturb growth.
SALTR mnemonic:
* Type 1: Straight across
* Type 2: Above
* Type 3: BeLow
* Type 4: Through
* Type 5: CRush
Fractures: Pain management
Codeine and tramadol are not used in children as there is unpredictability in their metabolism, so the effects vary too greatly to make them safe and effective options. Aspirin is contraindicated in children under 16 due to the risk of Reye’s syndrome (except in certain circumstances such as Kawasaki disease).
- Step 1: Paracetamol or ibuprofen
- Step 2: Morphine
Hypoxic ischaemic encephalopathy
The term for brain damage resulting from ante or perinatal hypoxia
Pathophysiology:
* The lack of oxygen in the foetal circulation results in poor supply of oxygen to the brain.
* This ischaemia results in irreversible brain damage, both from primary neuronal death (immediate) and secondary reperfusion injury (delayed).
* Causes= Pre-partum (i.e. placental abruption), during delivery (i.e. cord compression), post partum (i.e. prolonged respiratory arrest)
Presentation and diagnosis of Hypoxic ischaemic encephalopathy
Presentation= depends on the degree of neurological damage, ranging from mild (irritability) to severe (hypotonia, poor response, prolonged seizures).
Diagnosis= investigation of HIE is with ECG monitoring and multiple MRI brain scans
Hypoxic ischaemic encephalopathy: Management
- Includes respiratory support, anticonvulsant therapy, careful fluid balance and electrolyte monitoring, and potentially the use of inotropes.
- Cooling the baby to induce mild hypothermia can also prevent further damage by secondary reperfusion injury. The only intervention known to reduce neuronal damage caused by perinatal hypoxia
- Prognosis= depends on degree of neurological damage which can be assessed with an MRI scan. Severe cases are strongly associated with chronic neurological disability (i.e. cerebral palsy). Fatal in 1/3 of cases
HIE: prognosis
An estimated 10% - 60% of infants with HIE die during the neonatal period, and an estimated 25% of those who survive suffer from long-term neurological impairment including epilepsy, mental retardation or cerebral palsy.
HIE: pathophysiology
- Primary neuronal death occurs at the time of severe ischaemic insult.
- Secondary neuronal death (resulting in irreversible failure of mitochondrial function) occurs after a period of at least six hours post ischaemic insult= can be stopped by therapeutic cooling
HIE: therapeutic cooling
- Must be initiated within 6 hours of birth for a period of 72 hours
- EEG is useful in determining eligibility
- 33 to 34 degrees for whole body cooling, 34 to 35 degrees for selective head cooling
- Following cooling rewarming should be carried out slowly (0.5°C every 1 to 2 hours) over a period of 6-12 hours.
- Shouldn’t be done with severe head trauma/intracranial bleeding or if the child has severe congenital/genetic abnormalities
- Whole-body cooling- placing the infant on a cooling blanket or mattress circulated with coolant fluid.
- Selective head cooling- circulating cold water in a cap fitted around the head.
Indications to stop hypothermia and rewarm the infant include
- Hypotension (unresponsive to inotropes)
- Persistent pulmonary hypertension with associated hypoxemia (despite treatment)
- Clinically significant coagulopathy (despite treatment)
Idiopathic thrombocytopenic purpura
Immune (or idiopathic) thrombocytopenic purpura (ITP) is an immune-mediated reduction in the platelet count. Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex. It is an example of a type II hypersensitivity reaction. ITP in children is typically more acute than in adults and may follow an infection or vaccination.
Features: Bruising, Petechial or purpuric rash. Bleeding is less common an normally presents as epistaxis or gingival bleeding
Idiopathic thrombocytopenic purpura: Investigations
- Full blood count- should demonstrate an isolated thrombocytopenia
- Blood film
- Blood marrow examination is only required if there are atypical features i.e. lymph node enlargement/splenomegaly, high/low white cells. Failure to resolve/respond to treatment
