Cardio/resp/immuno Flashcards by Priyal Nanda

How do you calculate Qp:Qs? (Pulmonary to systemic blood flow?)

Qp/Qs= (Ao sats- MV sats / PV sats- PA sats)

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How do you calculate Qp:Qs? (Pulmonary to systemic blood flow?)

Qp/Qs= (Ao sats- MV sats / PV sats- PA sats)

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What is the formula to calculate PVR?

PVR= (mean PA pressure - LA pressure) / pulmonary blood flow

Normal value= 1-2

Poiselle equation

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How do you calculate fractional shortening?

FS= (end diastolic diameter- end systolic diameter) / end diastolic diameter

Normal value = 30%

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How do you calculate ejection fraction?

EF= (end diastolic volume- end systolic volume)/ end diastolic volume

Normal= 55-60%

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Cardiac anomalies associated with T21?

ASD 
VSD 
AVSD 
PDA 
TOF

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Cardiac anonalies associated with Turners?

Coarctation of Ao
Bicuspid Ao
Aortopathy

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Cardiac anomalies associates with 22q11 deletion?

Interrupted Ao arch
TOF +/- PA,
RAA
Truncus arteriosis

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Cardiac anomalies associated with William’s syndrome?

Supraventricular AS

Peripheral PS

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What is the equation to calculate change in pressure in an echo?

Change in pressure = 4x distal velocity²

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What is the Fick equation to calculate CO?

CO= VO2 / AVDO2
(Vo2 should be 120ml/m2)

AVDo2 = ((PV sats- PA sats) x hb x 1.36)

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What are the 4 different stages of sleep?

N1: Transition to light sleep, easily roused
N2: light sleep (characterised by K complexes and spindles on EEG)
N3- deep sleep, slow wave sleep, difficult to rouse. Regular breathing
REM sleep- dream sleep- decreased tone, rapid eye movemets, partial paralysis, vivid dreams, irregular breathing, increased upper airway resistance and decreased tidal volume

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If required, what medication can be used for parasomnias of night terrors and sleepwalking?

Clonazepam (if extreme)

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What is periodic limb movement disorder, and what is it associated with?

Part of restless leg syndrome
Caused by partial iron deficiency in CNS (systemic stores are normal but hasn’t gone into basal ganglia)
Aim to have ferrtin level >50 to force into basal ganglia

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What are the two awakening neurotransmitters and where are they secreted from?

Orexin
Hypocretin
From the amygdala

Deficiency in hypersomnia disorders

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What is the CFTR protein and where is it found?

CTFR= cystic fibrosis transmembrane conductor regulator- gene that regulates CTFR protein function
–> chloride channel in the apical membrane of exocrine epithelial cells (resp tract, pancreas)

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What is the CFTR protein and where is it found?

CTFR= cystic fibrosis transmembrane conductor regulator- gene that regulates CTFR protein function
–> chloride channel in the apical membrane of exocrine epithelial cells (resp tract, pancreas)

Describe the normal functioning CFTR protein?

What happens in CF?

Chloride transporter- transports Cl outside of the cell (along with Na going inside and H20 following)

In CF:
Chloride transport does not occur so less Cl in extracellular space which means less H20 following which means thick and sticky mucous

Which chromosome is the CFTR gene found in?

Long arm (q) of chromosome 7 
More than 2000 mutations

6 types of CFTR mutations?

Nornal function: protein made in nucleus, processed in ER and transported epithelial surface

Class 1: no protein made in nucleus (most severe form) [G542X, R553X, W1282X
Class 2: protein produced but problem with processing- misfolded; doesn’t reach epithelial surface [del508- most common, N1393K, delI507)
Class 3: protein produced but incorrectly- glycine replaced with aspartic acid- sits on cell surface but doesnt function (G551D)
Class 4: change in structure of protein which resitricts Cl movement through channel [R117H(5T), R334W, R347P
Class 5: reduced amount of CFTR protein [A455E, 2789+5GA]
Class 6: increased turnover of CFTR protein at cell surface- functional but unstable and quickly removed from cell surface

Quick way of remembering:
1- no protein, 2- no transport, 3- no function, 4- less function, 5- less protein, 6- less stable

What is the drug Ivacaftor used for?

Can be used in class 3 mutations (G551D mutations)- CFTR potentiator which improves transport of Cl through the channel by binding directly with the channel ensuring its open

How does the NBST screen for CF?

Elevated levels of Immune Reactive Trypsin (IRT) - increased in blood when pancreas isn’t working properly

If level is high then go for 3 gene measurement testing
If this is then positive then child is either a carrier or has CF
Needs clinical assessment with sweat test

What is the cutoff for diagnosis for CF in the sweat chloride test?

Anything above 60mmol/L =CF

Need a good sample of 75-100mg sweat

What is ABPA?

Allergic Broncho Pulmonary Aspergillos

caused by aspergillus fumigatus (most common fungal infection in CF)
Hypersensitivity reaction (type 1 and 3) - increased wheeze chest pain fever and malaise.
thick sputum with brown or black bronchial casts

Dx:

high serum IgE
positive aspergillus IgG and IGE (RAST)
eosinophilia
CXR- pulmonary infiltrates

Treatment of ABPA?

1. PO steroids: pred 2. IV steroids: pulse methylpred (if non adherent or severe) 3 . PO antifungal (itraconozole)- acidity helps absorption so stop PPIs etc, also need to monitor LFTs

What does the drug Orkambi do?

Combo of lumacaftor and tezacaftor New drug Improves protein folding and trafficking to cell surface to increase the CFTR channel (used in delta 508 class 2 mutation CF)

Whats the difference betwern central apnoea and obstructive sleep apnoea on PSG?

Central apnoea: drop is nasal flow associated with desat, with NO effort of breathing in thorax or abdomen Obstructive apnoea: drop in nasal flow corresponding with a desat, with ongoing effort of breathing wiith thorax/ abdo

``` What is the most common consequence of OSA in children? A. Decrements in memory and attention B. Excessive daytime tiredness C. Failure to thrive D. Pulmonary hypertension ```

A- decrements in memory and attention

What area of the brain is affected in OSA? | What other condition is affected in this area?

Prefrontal cortex Also affected in ADHD Affects executive function - impulsiveness, attention/concentration - poor academic performance - can also cause HTN, elevated lipids, insulin resistance If severe can cause FTT and cor pulmonale

What is congenital central hypoventilation syndrome (aka Ondine's curse) and what gene is affected?

Rare hyperventilation disorder worse in sleep Absent or near absent response to hypercarbia and hypoxia Markedly decreased tidal volume when aslewp Caused by PHOX-2B mutation Also implicated in Hirschprung's disease, neuroblastoma and iris problems

You are reviewing an 11mo infant with congenital central hypoventilation syndrome. You notice the infant has dartimg eye movements and difficulty sitting straight, falls to the side. Also missing her mouth when drinking from bottle. Next best Ix? A. Urine catecholamines B. Overnight sats monitoring C. MRI brain D. Nothing

A- urine catecholamines | Infant has opsoclonus myoclonus suggestive of neuroblastoma

What interleukin is associated with eosinophils?

IL-5

What is the defect in chronic granulomatous disease (CGD)? What test can you use?

No NADPH oxidative burst Test using nitro blue tetrazolium (NBT)- activated neutrophils are tested for their ability to phagocytose and reduce NBT- if reduced it will produce dark blue crystals. If unactivated it wont

What do basophils release? What is their receptor?

Basophils release histamine and heparin | Receptor is Fc epsilon receptor

What do mast cells release? What three things are they stimulated by?

Mast cells release granules and hormonal mediators (tryptase, histamine, serotonin, heparin etc) They are stimulated by: 1. Direct injury- physical/chemical (opioids, ETOH, abx, macrophage derived cytokines e.g. IL8 2. IgE - cell receptors for IgE- cross link and activate 3. Activated complement- C5a and C3a (common pathway)

``` What hormone/ mediator is NOT released by mast cells? A. Interleukin B. Interferon C. Serotonin D. Heparin E. Histamin ```

Interferon- is NOT produced by mast cells

Which lymphocytes are associated with IL- 2?

T cells B Cells NK cells (IL-2)

What is the role of CD4 T helper 1 cells?

Th1 cells- act intracellularly, antigens presenter by macrophages (IL2 and interferon gamma)

What is the role for CD4 Th2 cells?

Respond to extracellular pathogens, antigens presented via dendritic cells (IL4, IL5, IL6, IL10, IL13). They help B cells secrete Abs High is atopics (IL-4 amplifies IgE)

What cells are MHC 1 and MHC 2 molecules present on?

MHC1- all nucleated cells in the body except RBC. Activate CD8 t cells MHC2- only on antigen presenting cells. Present foreign antigens. Activate CD4 t cells