PBL 1 Flashcards
What is the pathophysiology of neonatal respiratory distress syndrome?
surfactant deficiency so there is increased surface tension and the lungs are more likely to collapse
what is atelectasis?
a complete or partial collapse of the entire lung or area (lobe) of the lung.
what are some causes of surfactant deficiency?
congenital absence where proteins dont produce it being prematurely born having an infection metabolic acidosis hypothermia meconium aspiration
when do babies begin producing surfactant?
between 24-28 weeks in utero
what are some risk factors for NRDS?
premature baby <28 weeks maternal diabetes C-section multiple births asphyxia precipitous delivery maternal history of NRDS in previous infant
at what week in utero should there be enough surfactant produced to keep alveoli from collapsing?
34 weeks
why can maternal diabetes cause NRDS?
Glucose passes across the placenta to the baby causing hyperplasia of pancreatic beta cells causing hyper insulinism and therefore hypoglycaemia -
this disrupts normal surfactant production
why can a C-section cause NRDS?
vaginal birth causes more stress so more cortisol is produced which helps push fluid out the lungs and produce surfactant
what lecithin to sphingomyelin ratio is characteristic of mature foetal lungs?
> 2:1
what is the lecithin - sphingomyelin ratio usually before 28 weeks?
1:1
what are symptoms of respiratory depression
shortness of breath, tachypnoea, audible prominent grunting, intercostal muscle restrictions, nasal flaring, resp failure, cyanosis, crackles due to oedema in lungs, harsh tubular breath sounds, hypotension
what do alveoli look like microscopically in NRDS?
as alveoli collapse, damaged cells (hyaline cells) build up in the lungs and you would be able to see this
how can you prevent NRDS?
avoid unnecessary C-sections before 39th week
antenatal steroid prophylaxis to increase surfactant production before 34 weeks
postnatal surfactant administration
prevention of complications like maternal diabetes
how do we diagnose NRDS?
- a physical examination
- blood tests to measure oxygen sats and check for an infection
- a pulse oximetry test to measure oxygen sats
- a chest X-ray to look for the distinctive cloudy appearance of the lungs in NRDS
what are some complications of NRDS?
death
respiratory alkalosis or acidosis
oxygen toxicity due to free radical damage of lungs, retina and bronchioles
patent ductus arteriousus due to lack of ventilation
necrotising enterocolitis due to intestinal ischaemia
bronchopulmonary dysplasia
developmental disabilities
haemorrhage
interstitial emphysema
pneumothorax
foetal hypoglycaemia can lead to seizures or neuronal damage
how do we treat NRDS?
supportive care for breathing - supplemental oxygen or mechanical ventilation
continuous monitoring for grunting and breathing - if grunting disappeared and cyanosis appears then the syndrome is worsening
artificial surfactant administration
incubator
how many neonates experience some degree of jaundice in the first week of life?
60%
what’s the difference between jaundice and hyperbilirubinaemia
jaundice is the yellowing of skin and sclera
hyperbilirubinemia refers to the total serum bilirubin being >95th percentile for their age
what are the symptoms of hyperbilirubinemia?
yellowing of skin and sclera dark yellow urine pale coloured stool increased sleepiness increased feeding difficulties
what is physiologic jaundice?
Babies typically have high haematocrit and RBCs with shorter lifespans which both increase potential for RBC turnover. they are also slower to metabolise unconjugated bilirubin as they are just starting to upregulate the UGT1A1 enzyme in the developing liver. As baby is learning to feed, excretion of bilirubin in the stool may be decreased
This jaundice often peaks by day 5 and resolved by 1-2 weeks of life
what is breastfeeding failure jaundice?
some babies dont breastfeed well at first which causes dehydration and less urination causing bilirubin to buildup in the body
what is breastmilk jaundice?
when newborns being breastfed get jaundice- it is thought to be due to beta glucoronidase within breast milk that increases enterohepatic circulation. it may also be due to it contaiing factors to help absorb more bilirubin from the intestine or factors that inhibit liver proteins to break down bilirubin
what can cause jaundice from haemolysis?
Rh disease
polycythaemia
or excessive destruction of RBCs
what proportion of preterm babies get jaundice?
80%
what is bilirubin-induced neuralgic dysfunction?
when unconjugated bilirubin levels go >25mg/dL
this is when kernicteru occurs due to bilirubin crossing the blood brain barrier and binding to tissue
what is kernicterus?
a type of brain damage that can result from high levels of bilirubin in a baby’s blood.
what can kernicterus cause?
athetoid cerebral palsy and hearing loss
sometimes vision and teeth problems and intellectual disabilities
how do we manage foetal jaundice?
frequent feeding
phototherapy - UV light converts unconjugated bilirubin to bilirubin photo products
what is an exchange transfer and when might it be needed?
when the baby’s blood is removed using a catheter and replaced with blood from a matching donor
only used in severe hyperbilirubinemia
which organism are the msot frequent causes of neonatal infections?
group B streptococcus and Escherichia Coli
what are the TORCHS infections?
toxoplasmosis others (varicella zoster and parvovirus B19) rubella cytomegalovirus herpes syphilis
what are the signs and symptoms of neonatal infections?
lethargy stiff limbs grunting unusual skin changes CPF >3 seconds high/low temp movement only when stimulated cyanosis severe chest undraping
what are some risk factors for neonatal infections?
premature babies
maternal infections in blod, urinary tract or birth canal, mother has a high temperature during labour, mother had a previous baby with an infection from birth, if the membranes have been broken for >18 hours before birth
what are 8 common neonatal infections?
sepsis bacterial meningitis pertussis myocarditis endocarditis infant botulism acute gastro-enteritis enterovirus
what are early onset and late onset neonatal infections?
early onset is in the first 72 hours of life and late onset is after this
how can bacterial sepsis be treated?
empirical antibiotics - gentamicin or benzylpenicillin
what are some common causes of bacterial meningitis in neonates?
E.coli, group B strep, listeria monocytogenes
what is the treatment for neonatal bacterial meningitis?
empirical antibiotics, beta lactase, macrolides or ahminoglycosides
why might dexamethasone be given to a neonate before antibiotics in bacterial meningitis?
to reduce the inflammation and prevent harm to the brain
what causes pertussis?
bordatella pertussis
how is pertussis transmitted?
coughing/sneezing
what are the 3 stages of pertussis?
catarrhal stage - person is highly contagious
paroxysmal stage - 2-8 weeks of a worsening cough
convalescent stage - weeks to months of a subsiding cough
how long is the pertussis incubation period?
1-2 weeks
what is myocarditis?
inflammation and infection of the myocardium
what is the msot common agent to cause myocarditis?
enteroviruses e.g. adenovirus
what is endocarditis?
infection and inflammation of endocardium (heart valves) which can cause thrombus formation
what agent most typically causes endocarditis?
bacteria- strep and staph species
what is infant botulism?
the ingestion of clostridium botulinum - the botulism toxin causes neuromuscular junction dysfunction = poor muscle control and muscular movement
what are signs and symptoms of infant botulism?
diminished muscle activity, poor feeding, lethargy, constipation, respiratory failure, little eye movement
is infant botulism more common in bottle fed or breast fed babies?
breast fed
what is acute gastroenteritis defined by?
increased stool frequency and or vomiting caused by viruses and sometimes bacteria
what are the signs and symptoms of acute gastroenteritis?
myalgia, abdo crampps, diarrhoea, headache fever, vomiting for 1-2 weeks
what are common viruses that cause gastroenteritis?
rotavirus, norovirus or adenovirus
what are common bacteria that cause gastroenteritis?
shigella, salmonella, E.coli
what are some associations that have been made with antibiotic use in neonates?
attenuation of height and weight in boys during the first 6 years of their lives
higher BMI in boys and girls in the first 6 years of their lives
differences in gut microbiome for first 2 years of life (dysbiosis) making them susceptible to several diseases and infections
what are the 2 most common bacteria used on neonates? how often are they given?
amoxycillin- given every 12 hours
gentamicin- given every 24 hours
which antibitoics are msot likely to be ototoxic?
ahminoglycosides
outline how aminoglycosides are ototoxic?
they generate free radicals within the inner ear causing permanent damage to sensory cells and neurones, resulting in permanent hearing loss.
what are risk factors for aminoglycosides causing deafness?
high doses
potentiating medications e.g. loop diuretics
genetic susceptibility - mitochondrial mutations (shown to be ototoxic even when amino glycoside levels are in the normal range)
what are adverse events?
incidents in which harm resulted to a person recieveig health care
what is a near miss?
a situation in which events arising during clinical care fail to develop further whether or not as a result of compensating action, thus preventing injury to a patient
what are never events?
serious incidents that are entirely preventable because guidance or safety recommendations provide strong systemic barriers which are available at a national level and should have been implemented by all healthcare providers
what can increase the risk of an error occuring?
unfamiliarity with a task inexperience shortage of time inadequate checking poor procedures
what should you do when a medical error occurs?
report is on the incident reporting system
assess its seriousness
analyse why it occurred and prevent it from happening again by putting in place actions to reduce tis of repeat
how should you act with the patient when a medical error occurs?
its important to be open and honest with the patient and apologise
what is the duty of candour?
being open and honest with a patient/family when things have gone wrong and apologise
