Respiratory

Question 1

List conditions associated with dextrocardia

Answer 1

• Congenital absence of spleen
• Primary ciliary dyskinesia (Kartagener’s syndrome- 50%)
• Scimitar syndrome
• Dextrocardia with situs inversus

Question 2

What are the differences between intra and extralobar types of pulmonary sequestration?

Answer 2

Intralobar:

• contained within same pleura as rest of lung
• often presents later after Ix for repeat infections
• Venous drainage: (usually) pulmonary veins
• generally lower lobe

Extralobar:

• Has its own pleura
• Often presents earlier, or is asymptomatic
• Associations: CDE, colonic duplication, pulmonary hyoplasia
• 10% sub-diaphragmatic
• generally found left lower lobe

Question 3

Describe 1) definition 2) causes and 2) treatment of methaemoglobinaemia

Answer 3

1) The state of excessive methaemoglobin in the blood
methaemoglobin is an altered state of Hb where ferrous ions (Fe2+) of haem are oxidised to the ferric state (Fe3+) and rendered unable to bind O2. Normal level is < 1.5%

2) Acquired- Drugs (benzocaine, sulfonamides, dapsone, chloroquine) ; exposure to nitrites
Congenital- cytochrome b5 reductase deficiency,
haemoglobin M disease, NADH methaemoglobinaemia, G6PD

3) Treat if symptomatic with Methylene blue- if G6PD deficiency, ascorbic acid.

Question 4

Describe CXR changes seen with CLE. How do you differentiate from pneumothorax on CXR?

Answer 4

CLE- hyperlucent area. Usually anterior. Causes mediastinal shift. In contrast to pneumothorax, has linear markings across lung.

Question 5

What are indications for tracheostomy in Duchenne’s Muscular dystrophy?

Answer 5

• Patient and clinician preference- recommend the long-term use of noninvasive ventilation up to and including 24 hours daily in eligible patients
• Inability of patient to use noninvasive ventilation successfully
• Inability of the local medical infrastructure to support noninvasive ventilation
• Three failures to achieve extubation during critical illness despite optimum use of noninvasive ventilation and mechanically assisted cough
• The failure of noninvasive methods of cough assistance to prevent aspiration of secretions into the lung and drops in oxygen saturation below 95 percent or baseline, necessitating frequent direct tracheal suctioning via tracheostomy

Question 6

Describe relationship between changes in pCO2 and HCO3 on VBG

Answer 6

With every change of 10mmHg of pCO2, HCO3 changes by 1

Question 7

What are factors that cause a left shift on the oxygen-haemoglobin dissociation curve?

Answer 7

• Decrease in temp
• Increase in pH
• Decrease in CO2
• Fetal Hb
• Carbon monoxide
• Decrease 2,3 DPG

Question 8

Describe the difference between Type 1 and Type 2 Respiratory Failure

Answer 8

Type 1: normal or decreased pCO2. Cause: VQ mismatch, right to left shunt. Cause is issue with oxygenation
Type 2: high pCO2. Cause: CVA, drugs, trauma, GBS, myasthenia gravis. Cause is issue with ventilation
Mixed: Type 1–> Type 2 due to fatigue/worsening condition

Question 9

Describe the difference between Bipap and Cpap

Answer 9

Bipap- PIP and PEEP. Ventilation problem to remove Co2

Cpap- PEEP only. Oxygentation problem.

Question 10

What is the 1) most common type of mucopolysaccharidosis and 2) inheritance pattern?

Answer 10

1) San Filippo (MPS III)

2) All are autosomnal recessive aside from Hunter (MPS II- X linked recessive

Question 11

Describe EEG findings seen in night terrors

Answer 11

-A simultaneously obtained EEG may show high amplitude, rhythmic delta, or theta activity.

Question 12

Above what mean inhibitory concentation (MIC) is a bacteria considered resistant to penicillin?

Answer 12

> 2micrograms/ml

Question 13

CPAM 1) Types, including if macro or microcystic 2) what are associated with childhood malignancy 3) indications for surgical management 4) which is associated with hybrid forms 5) Which forms are severe?

Answer 13

1) 0-4; 1, 3, 4 are macro
2) 1 and 4 associated with malignancy, 4 more commonly in childhood
3) Family history of pulmonary malignancy, >20% of lobe affected, large regions affected, bilateral or multifocal disease, pneumothorax
4) Type 2- i.e. associated with bronchopulmonary sequestration
5) Type 0- fatal post partum. Type 4- tension pneumothoraces. Lesions causing fetal hydrops

Question 14

What are the differential diagnoses of cystic lung lesions?

Answer 14

• CPAM
• Bronchopulmonary sequestration
• CLE
• CDH
• bronchogenic cyst

Question 15

What are the most common bacterial organisms causing CAP in 1) neonates 2) 1-3 months 3 ) >3 months

Answer 15

1) GBS, listeria, E.coli
2) Hib strep pneumonia, chlamydia trachomatic
3) Hib, s aureus, s pneumoniae

Question 16

In a patient with polycythaemia clinical cyanosis is easily apparent with low sats. What is the explanation?

Answer 16

Polycythemia can cause cyanosis due to the increased red blood cell mass and relatively increased amount of deoxygenated hemoglobin. Infants may appear cyanotic with a normal oxygen saturation and PO2 because of their elevated hemoglobin concentration.

Question 17

Delta F508 is the most prevalent mutation in cystic fibrosis. What is the defect at molecular level?

Answer 17

Deletion of phenylalanine in the protein