Symposium (Additional Bits And Bobs)

Question 1

What transitions need to occur to the lungs at birth

Answer 1

Clear fetal lung fluid
Aerate them
Establish a regular pattern of breathing
Match perfusion and ventilation

Question 2

How is fetal lung fluid cleared from the lungs

Answer 2

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

Question 3

How can we aid in the neonatal respiratory transition at birth

Answer 3

PEEP to keep the fetal lung fluid out of their lungs and maintain aeration

Question 4

What happens to pulmonary circulation at birth compared to in utero

Answer 4

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

Question 5

Why does the foramen ovale close

Answer 5

Reduced R side pressure (pulmonary resistance decreases) and increased volumes of blood being returned to the left side (therefore increasing L side pressure)

Question 6

Why does the ductus arteriosus close

Answer 6

Increased O2 content of blood + reduced prostoglandins lead to smooth muscle contraction

Question 7

Which way does blood flow through the ductus arteriosus and why

Answer 7

Pulmonary artery to aorta

Pulmonary artery pressures are high due to pulmonary system being high resistance

Question 8

Why does blood stop flowing through the umbilical artery

Answer 8

Such high pressures due to physical clamping + Wharton’s jelly constricting + constriction due to increased arterial O2 content and reduced prostoglandins

Question 9

What causes Wharton’s jelly in the umbilical cord to contract

Answer 9

Temperature drop

Question 10

Why does blood stop flowing through the ductus venosus

Answer 10

Cord clamping and Wharton’s jelly constriction leads to the placenta and umbilical vein being extremely high resistance therefore blood just stops flowing

Question 11

Umbilical artery and vein… how many of each and which way is blood flowing

Answer 11

2 arteries carrying blood away from fetus

1 vein carrying blood to fetus

Question 12

What is pseudo PEA

Answer 12

Organised electrical activity + no pulse + cardiac motion of POCUS

Question 13

How can pseudo PEA be diagnosed

Answer 13

POCUS
Presence of a blood pressure if patient has arterial line
Raised ETCO2

Question 14

Why is CPR in pseudo PEA harmful?

Answer 14

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

Question 15

What is refractory cardiac arrest

Answer 15

Found mixed definitions so not sure?
Requires >10 minutes of CPR or >3 defibrillation attempts
>30 minutes of resuscitation efforts

Question 16

Summarise the sub 30 trial

Answer 16

Attempt to establish whether a team can commence ECMO flow within 30 minutes of patient collapse

Question 17

What is Ustein style

Answer 17

Set of guidelines for uniform reporting of cardiac arrest

Question 18

what is SUDI (sudden unexpected death in infancy)

Answer 18

Sudden and unexpected death of a baby when there is no apparent cause of death

Question 19

What is SIDS (sudden infant death syndrome)

Answer 19

Term reserved when death still remains unexplained after extensive investigation

Question 20

In SUDI, where are petechial haemorrhages found

Answer 20

Thymus and lungs

Question 21

What is the triple risk model (SIDS)

Answer 21

Vulnerable infant (genetics, premature)
Critical point in development (4-6 months)
External stressor (nicotine, infection, unsafe sleeping)

Question 22

How does the arousal mechanism alter in babies that die of SIDS

Answer 22

On startling babies should wake from sleep and instantly gasp. There is then irregular breathing pattern and HR changes. This doesn’t happen

Question 23

What is thought to be the cause of abnormal arousal mechanisms in babies that die of SIDS

Answer 23

Genetic alterations to calcium channels in the pre-botzinger complex stopping them from gasping
Abnormality in serotonin also preventing the gasp and HR changes

Question 24

Why is prone sleeping bad for babies

Answer 24

Fall into a deeper sleep with higher threshold for arousal
Sink in allowing them to rebreathe leading to hypercarbia
Splinting of the diaphragm

Question 25

What is the CONI scheme

Answer 25

Care of next infant

Increased surveillance of a child born to parents who lost a baby to SIDS

Question 26

What is obesity hypoventilation syndrome

Answer 26

BMI >30 + decrease O2 in sleep + daytime increased CO2

Due to a failure to breathe rapidly or deeply enough

Question 27

What are the physiological results of obesity hypoventilation syndrome

Answer 27

Kidney compensates by increasing bicarb
Increased erythropoietin
Hypoxic pulmonary vasoconstriction leads to R heart strain and HF

Question 28

What are some problems faced when resuscitating obese people

Answer 28

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

Question 29

Describe how dobutamine is neuroprotective post ROSC

Answer 29

It is a +ve inotrope (potentially via B1 receptors but unknown) and therefore increases cerebral perfusion

Question 30

What does acidosis do the force of myocardial contraction and how

Answer 30

H+ ions displace Ca binding therefore decreasing force of contraction

Question 31

Describe some methods postulated to improve neurological outcome in an arrest patient

Answer 31

head up CPR
ventricular assist devices
vitamin C

Question 32

State some causes of SCD in athletes

Answer 32

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)

Question 33

Compare commotio cordis and contusion cordis

Answer 33

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.