Respiratory Distress Syndrome Flashcards
Who is at risk of HMD?
Preterm infantsInfants of diabetic mothers
What is the pathophysiology of HMD?
Surfactant deficiency –> increased surface tension causes progressive atelectasis and increased effort of breathing
What inhibits surfactant production?
Hypoxia, hypothermia and acidosis
What is the natural history of HMD?
Respiratory distress soon after birth –> progressively worsens in next 72 hours –> improves after then as baby starts producing surfactant Usually resolves within one week
What are the typical clinical features of HMD?
Preterm infantInactivePoor tone- frog positionOedematous
What are the CXR features of HMD?
Under expanded lungsBilateral diffuse reticular-granular ‘ground-glass’ infiltrates Air-bronchograms
What are the 6 complications of HMD?
Respiratory failureChronic lung disease2ry bacterial pneumoniaPDA–> cardiac failurePeri- and intraventricular haemorrhage Pneumothorax
How to prevent HMD?
Avoid preterm labour and elective C/S before 39/40BMZ if
What are the 5 parameters in managing HMD?
Relieve hypoxiaClose monitoringTemperature controlNutritionCorrect acidosis
How is hypoxia relieved in HMD?
Respiratory support given- NPO2–> CPAP –> IPPV–> HFOVOxygen therapy - monitored sats (88-92), FiO2, paO2 (7-10kPa)Surfactant replacement therapy (in&out)
How is temperature controlled in HMD and what is the aim?
Incubator temperature between 31-34*CAim to maintain neutral thermal environment as to minimize oxygen requirement
What parameters and monitored?
BP (inotropes given if needed)Hb (blood transfusion if needed)Heart rateTemperatureGlucoseSaturations
What is the nutrition plan for an infant with HMD?
IV fluids, electrolytes and energy requirements ASAPMilk feeds via nasogastric tube if infant tolerates themTotal parenteral nutrition (TPN) if unable to tolerate feeds
How is acidosis in HMD corrected if respiratory in origin?
If respiratory acidosis, it is caused by increased paCO2, therefore corrects by improving ventilation.Mild respiratory acidosis is usually tolerate and ventilation not needed.
How is acidosis in HMD treated if metabolic in origin?
If metabolic acidosis, then should improve with adequate ventilation and hydration.
What is believed tap cause TTN?
Delayed clearing of fetal lung fluid into the pulmonary capillaries and lymphatics after delivery –> interferes with gas exchange and increased the work of breathing
Who is at risk of TTN?
Term infants born by elective C/S Can affect prems and NVDs
What is the natural history of TTN?
Respiratory distress within 1-2 hours of birth –> Improves within 24-48 hours, but tachypnoea can last for a few days
What are the clinical features of TTN?
Hyper inflated chestRespiratory support may be needed but O2 usually not >40%IPPV not usually needed
What are the CXR findings in TTN?
Normal lung volume but increased vascular markings Prominent hilar streakingFluid in lung fissures
How do you manage an infant with TTN?
Monitor closelyRespiratory support as neededSupportive measures as needed, but usually systemically well
Who is at risk of meconium aspiration?
Term or post-term infants who become stressed in utero
What increases the risk of meconium aspiration?
Infant that is wasted or UGA
When is the meconium aspirated?
Either at delivery or during gasping in utero when stressed
What are the two clinical sequelae following meconium aspiration and how do they arise?
Chemical irritation –> pneumonitisParticulate matter blocks bronchi and bronchioles –> areas of emphysema and atelectasis
What are the 6 complications of meconium aspiration?
Respiratory failurePneumomediastinum or pneumothoraxHIEPPHN2ry bacterial infectionChronic lung disease
What are the clues pointing toward meconium aspiration?
Meconium staining of the placenta and cord, skin and nails
What are the CXR features of meconium aspiration?
Hyper inflated chestPatchy areas of collapse and overdistensionSigns of complications such as PTX
When do you suction an infant?
When there is evidence of meconium staining, and the infant when delivered is not vivacious or breathing.
If an infant is meconium stained, and cries well after deliver, do you suction the infant?
No
An infant born after signs of fetal distress is delivered floppy and not breathing, what is the immediate management?
Resus the infant. If meconium evident, suction the mouth then the nose, and then dry the infant to stimulate respiration. Continue with resus algorithm if no response.
How is suction performed?
Large bore catheter used, 8/10FInserted to 5cm for 5 secondsSuction pressure
What can occur if infant is suctioned too vigorously?
Vagal bradycardia LaryngospasmDelayed onset of breathing
How do you manage an infant with meconium aspiration?
Suction if indicatedProvide respiratory support as neededGastric lavage - 2% sodium bicarbonate to prevent gastritisGeneral supportive measuresSurfactant may be beneficialMonitor closely Antibiotics if needed
What are the ideal saturation a for a baby with meconium aspiration and why?
> 95%. You want to prevent the infant developing PPHN and there are fewer risks of O2 toxicity in term infants.
Why can surfactant be beneficial in an infant with meconium aspiration?
Condition can lead to secondary surfactant deficiency due to the hypoxia
Which infants are at risk for developing pneumonia?
PROM >18 hoursPPROMPTLChorioamnionitisMaternal untreated chronic infection, such as syphilis
What are the signs of chorioamnionitis?
Maternal pyrexiaFoul smelling liquorFetal tachycardiaUterine tendernessLeucocytosis
How do you differentiate between nocosomial pneumonia and pneumonia contracted from the mother?
An infant who contracts pneumonia from the mother develops signs in the first 72 hours, where as a nocosomial pneumonia develops after 72 hours
What is the pathogenesis of a maternal,y acquired pneumonia?
The infant is exposed to organisms in utero or during passage through the birth canal
What are the most likely causes of a congenital pneumonia?
E. ColiGroup B streptococcus Chronic infections suchas syphilis, rubella, CMV.
What are the most likely causes of nocosomial pneumonia?
Staph aureusKlebsiellaPseudomonas
How would an infant with pneumonia clinically present?
Apnoeic spellsRespiratory distressSepticaemia
How does septicaemia present in a neonate?
LethargyPoor tonePoor handling Poor perfusionAbdominal distention (septic ileus) Vomiting
What are the complications of pneumonia in the neonate?
SepticaemiaRespiratory failureChronic lung disease
What is the management plan for an infant with pneumonia?
Septic screenAntibioticsGeneral supportive measuresRespiratory support
What does a septic screen involve?
Blood cultureFull blood count with differentialCRP
How would you use antibiotics to treat a neonate with pneumonia?
Start with empiric broad spectrum antibiotics, then use more specific antibiotic once organism organism identified, using rx that is specific to local resistance patterns
What are the CXR findings in an infant with pneumonia?
Similar to HMD, especially if GBSPatchy distribution of consolidation and infiltratesAir-bronchograms
Signs needed to diagnose RDS
Two or more of: Tachypnoea >60 Central cyanosis (room air) Grunting Sternocostal recession
Respiratory causes of RDS
- HMD
- TTN
- MAS
- pneumonia
- Chronic lung disease
- Pneumothorax
- Lung hypoplasia
Non-respiratory causes of RDS
Hypothermia Metabolic acidosis Anaemia Polycythemia PDA Heart disease Diaphragmatic hernia
Causes on pneumothorax in neonate
MAS
HMD
Vigorous resuscitation after birth
