lung resistances Part 3: NRDs Flashcards
neonatal respiratory distress syndrome
what causes NRDS?
Caused by deficiency of surfactant
what is cyanosis in NRDS?
tissues (usually skin) will be discoloured because of lack of oxygen to the tissues
what is tachypnea in NRDS
increased breathing rate, upwards of 60 breaths per minute
what does nasal flaring do in NRDS
reduces airflow resistance in nostrils
what do chest retractions suggest in NRDS
suggest increased muscular work and soft tissue in the tip of your abdomen are collapsing
why does grunting occur in NRDS?
because of expiratory distress and respiratory failure, grunting will help airways open.
what is the mortality rate of NRDs in infants less than 1 kg
50%
what is the relationship incidence and severity and gestational age
- incidence and severity of NRDs is inversely proportional to gestational age
symptoms of NRDs
what are 6 symptoms of NRDs
Think:
- T
- G
- N
- I
- C
- R
- tachypnea (greater than 60 breaths per minute)
- grunting
- nasal flaring
- intercostal recession
- cyanosis
- reduced entry of air volume
causes and contributer factors of NRDs
what are 6 causes/contributing factors of NRDs
##
Think:
- genes
- males
- diabetes
- head injury
- aspiration of blood
- sedation
6 causes/contributing factors of NRDS are:
- genetic disorders like abnormalities in proteins B and C in transport proteins ABC transporter 3 [ABCA3]
- being male causes higher risk of NRDs
- maternal diabetes as excess insulin suppresses surfactant production
- fetal head injury during birth
- aspiration of blood or amniotic fluid
- excessive sedation of mother during birth
pathogenesis of NRDs
what is the physiological cause of NRDs?
starts with immature and damaged type II pneumocytes due to risk factor/specific cause
outline the 5 steps involving how low surfactant levels leads to lung tissue changing into fibrin hyaline membrane
- low surfactant
- lung collapse
- leads to hypoxia
- causes pulmonary vasoconstriction and alveolar epithelial damage
- produces fibrous exudate that causes free radicals to change structure of lung tissue into fibrin hyaline membrane
what are 4 features of fibrin hyaline lung membranes when lung tissue changes in NRDs
##
Think:
- fibrin cell debris and other cells involved
- alveoli
- layers and free radicals
- congestion
4 features of fibrin hyaline lung membranes when lung tissue changes in NRDS are:
- the laying down of fibrin, cell debris, erythroctyles, neutrophils & macrophages
- collapsed alveoli
- waxy layers of hyaline due to free radicals
- bleeding and vascular congestion
how do fibrin hyaline lung membranes appear histologically
- glass
consequences of NRDs
what are 6 physiological consequences of NRDs
- inflammation
- atelecrasis
- hyaline membrane
- epithelial necrosis
- decreases fluid abosrption and lung oedema
- haemorrhage
