Symposium (Additional Bits And Bobs) Flashcards
What transitions need to occur to the lungs at birth
Clear fetal lung fluid
Aerate them
Establish a regular pattern of breathing
Match perfusion and ventilation
How is fetal lung fluid cleared from the lungs
Mechanically pushed out via contractions and passage through the birth canal
Absorbed - mechanism poorly understood but thought to involve Na channels and the catecholamine surge that occurs at labor
Crying - created a positive intrathoracic pressure to force fluid into the pulmonary capillaries
How can we aid in the neonatal respiratory transition at birth
PEEP to keep the fetal lung fluid out of their lungs and maintain aeration
What happens to pulmonary circulation at birth compared to in utero
In utero it is high resistance (hypoxic pulmonary vasoconstriction)
On air entering the lungs there is vasodilation leading to reduced resistance
This leads to reduced pressures in the RA and RV
Why does the foramen ovale close
Reduced R side pressure (pulmonary resistance decreases) and increased volumes of blood being returned to the left side (therefore increasing L side pressure)
Why does the ductus arteriosus close
Increased O2 content of blood + reduced prostoglandins lead to smooth muscle contraction
Which way does blood flow through the ductus arteriosus and why
Pulmonary artery to aorta
Pulmonary artery pressures are high due to pulmonary system being high resistance
Why does blood stop flowing through the umbilical artery
Such high pressures due to physical clamping + Wharton’s jelly constricting + constriction due to increased arterial O2 content and reduced prostoglandins
What causes Wharton’s jelly in the umbilical cord to contract
Temperature drop
Why does blood stop flowing through the ductus venosus
Cord clamping and Wharton’s jelly constriction leads to the placenta and umbilical vein being extremely high resistance therefore blood just stops flowing
Umbilical artery and vein… how many of each and which way is blood flowing
2 arteries carrying blood away from fetus
1 vein carrying blood to fetus
What is pseudo PEA
Organised electrical activity + no pulse + cardiac motion of POCUS
How can pseudo PEA be diagnosed
POCUS
Presence of a blood pressure if patient has arterial line
Raised ETCO2
Why is CPR in pseudo PEA harmful?
If it’s not synchronised you could be compressing the chest whilst the heart is in diastole and trying to fill then decompressing when it is contracting but has no blood to eject as it hasn’t been allowed to fill
What is refractory cardiac arrest
Found mixed definitions so not sure?
Requires >10 minutes of CPR or >3 defibrillation attempts
>30 minutes of resuscitation efforts
Summarise the sub 30 trial
Attempt to establish whether a team can commence ECMO flow within 30 minutes of patient collapse
What is Ustein style
Set of guidelines for uniform reporting of cardiac arrest
what is SUDI (sudden unexpected death in infancy)
Sudden and unexpected death of a baby when there is no apparent cause of death
What is SIDS (sudden infant death syndrome)
Term reserved when death still remains unexplained after extensive investigation
In SUDI, where are petechial haemorrhages found
Thymus and lungs
What is the triple risk model (SIDS)
Vulnerable infant (genetics, premature) Critical point in development (4-6 months) External stressor (nicotine, infection, unsafe sleeping)
How does the arousal mechanism alter in babies that die of SIDS
On startling babies should wake from sleep and instantly gasp. There is then irregular breathing pattern and HR changes. This doesn’t happen
What is thought to be the cause of abnormal arousal mechanisms in babies that die of SIDS
Genetic alterations to calcium channels in the pre-botzinger complex stopping them from gasping
Abnormality in serotonin also preventing the gasp and HR changes
Why is prone sleeping bad for babies
Fall into a deeper sleep with higher threshold for arousal
Sink in allowing them to rebreathe leading to hypercarbia
Splinting of the diaphragm
What is the CONI scheme
Care of next infant
Increased surveillance of a child born to parents who lost a baby to SIDS
What is obesity hypoventilation syndrome
BMI >30 + decrease O2 in sleep + daytime increased CO2
Due to a failure to breathe rapidly or deeply enough
What are the physiological results of obesity hypoventilation syndrome
Kidney compensates by increasing bicarb
Increased erythropoietin
Hypoxic pulmonary vasoconstriction leads to R heart strain and HF
What are some problems faced when resuscitating obese people
Sats probe less reliable on fat fingers
Only 2 bariatric ambulances in london
Mechanical CPR devices not appropriate
Increased rescuer fatigue from chest compressions
IGels can leak so often need to intubate
Transthoracic echo not reliable
Harder to gain vascular access
Describe how dobutamine is neuroprotective post ROSC
It is a +ve inotrope (potentially via B1 receptors but unknown) and therefore increases cerebral perfusion
What does acidosis do the force of myocardial contraction and how
H+ ions displace Ca binding therefore decreasing force of contraction
Describe some methods postulated to improve neurological outcome in an arrest patient
head up CPR
ventricular assist devices
vitamin C
State some causes of SCD in athletes
commotio cordis
contusion cordis
various genetic cardiac things (see Ed and Dans flashcards)
hyponatraemia
DMAA (amphetamine found in supplements)
anomalous coronary artery origin (L&R both arise from same sinus)
Compare commotio cordis and contusion cordis
commotio - blow to chest in 4th ICS between S & T waves of ECG disrupts that cardiac rhythm. It is an electrical problem with no structural damage
contusion - physical bruising of the heart often seen in RTCs due to the seatbelt.
