Random Flashcards
31. A boy with well controlled asthma presents with status asthmaticus. He is treated aggressively in Resus and becomes hypotensive and bradycardic. What is the culprit agent? A. Magnesium B. Aminophylline C. Ipratropium D. Salbutamol E. Hydrocortisone
IV Magnesium
- bronchodilator activity in acute asthma, possibly due to inhibition of calcium influx into airway smooth muscle cells
- causes
- coronary and systemic vasodilation
- antiarrhythmic effects
- slight decrease in heart rate, and prolongs the PR interval
- decreases the sympathetic tone by causing a sympathetic ganglia blockade
Eosinophilic pneumonia
- a/w
- mx
strongly a/w new onset or resumption of smoking
very steroid responsive
Where should CVC tip sit
SVC - should be seen before carina splaying
Control of respiration
Central - location, chemoreceptors
Peripheral - location, chemoreceptors
Central - medulla, pons. Responds to H+ in ECF
Peripheral - Carotid bodies and Aortic bodies
Responds to CO2 and H+
Carotid bodies respond to O2 to some extent
Cause for falsely high SPO2
Carboxyhaemoglobin
Elevated A-a gradient that does NOT correct with 100% O2
Shunt
Causes of high and normal A-a gradient
VQ mismatch
Shunt
ILD
normal - hypoventilation, high altitude
Q82
Pulse oximetry is commonly used as a non-invasive measure of arterial oxygen saturation.
In which of the following situations is pulse oximetry most reliable?
A. Anaemia with a haemoglobin of 80 g/L
B. Carbon monoxide poisoning with a carboxyhaemoglobin of 15%
C. Congenital methaemoglobinaemia with a methaemoglobin of 30%
D. Hypotension with a systolic blood pressure of 80mmHg
E. Hypothermia with a core temperature of 30o
A. Anaemia with a haemoglobin of 80 g/L
-usually not significant until Hb <50
Falsely elevated - carboxyhemoglobin
Non cardiogenic cause of APO - ix
normal PWP
High fraction of exhaled NO indicates…
Asthma
-exhaled NO levels rise in association with acute airway inflammation, sputum eosinophilia, viral upper respiratory infections, and other clinical parameters associated with deteriorating asthma control
CTEPH Imaging
VQ Scan
Caffeine effects in lung
bronchodilation
Sarcoid predominant white cell
Macrophage
Which parameter in the pulmonary function test has the greatest measurement variability?
a) FVC
b) FEV1
c) TLC
d) RV
e) DLCO
FEV1
Requires person to maximally exhale - user dependent
A 25-year-old secretary presents with excessive daytime sleepiness, vivid dreams at the onset of sleep and the sensation of her legs “giving way” with laughter or emotional response.
She does not take any medications and has no other medical history. She reports that she has to consume caffeine-containing beverages to maintain alertness at work.
Which of the following investigations would be most likely to provide a diagnosis:
A) MRI of brainstem
B) Maintenance of wakefulness test
C) Mean sleep latency test
D) Overnight polysomnography
E) Sleep deprived EEG
Ans: C Mean sleep latency test
To diagnose narcolepsy
Diagnosed by: sleep latency <8minutes and 2 SOREMPs (sleep onset REM periods) - abnormal to have REM sleep straight away but narcoleptics have that
“sensation of giving way” - cataplexy sx
A 60yo patient of yours who is a current smoker has an incidental finding of a 6mm left lung nodule on CT chest. What is your next step?
a. No further investigation required
b. Observe with annual CT
c. Biopsy
d. PET scan
e. Bronchoscopy
Ans: B
Consider PET/CT or tissue sampling if >8mm especially if solitary nodule
- Obstructive sleep apnoea is associated with an increased prevalence of systemic hypertension. What is the predominant mechanism for this?
A . Increased cardiac output.
B . Increased sympathetic tone.
C . Resetting of renal pressure-natriuresis.
D . Upregulation of carotid chemoreceptor sensitivity.
E . Vasoconstriction secondary to intermittent hypercapnia.
B. Increased sympathetic tone.
Apnea–>intermittent hypoxemia and ?hypercapnia –>increased sympathetic activity–>hypertension
Foetal Hb O2 dissociation curve - left or right?
Left
Foetal Hb – Strucurally, foetal haemoglobin (HbF) is made up of two α-subunits and two γ-subunits (instead of two β-subunits)
• This decreases the affinity of HbF for 2,3-DPG
• As 2,3-DPG normally decreases the affinity of hameoglobin for oxygen, in the absence of 2,3-DPG binding the oxyhaemoglobin dissociation curve of HbF is left-shifted
So, baby’s blood will have high affinity to O2 to absorb it from mom’s blood and because there is so much metabolic activity in the fetus, will have no problem with release of O2.
What is the main cause of infertility in patients with Cystic Fibrosis? A. Medications B. Gonadal agenesis C. Obstructive azoospermia D. Ciliary dysfunction
Infertilityin cystic fibrosis—More than 95 percent of men with CF are infertile because of defects in sperm transport, although spermatogenesis is not affected. Most of these men have incompletely developed Wolffian structures, most commonly, absent vas deferens.
Pul fibrosis drugs
nitrofurantoin, bleomycin, amiodarone, cyclophosphamide, procainamide, penicillamine
- What is the mechanism of action of inhaled mannitol in the treatment of cystic fibrosis?
A . Augments action of aminoglycosides.
B . Augments function of cystic fibrosis transmembrane conductance regulator.
C . Directly toxic to Gram-negative bacteria.
D . Increases hydration of airway surface liquid.
E . Inhibition of the biofilm matrix.
D . Increases hydration of airway surface liquid.
Mannitol
- osmotic agent, draws out water into epithelium
- need to do Mannitol sens test prior – can cause bronchoconstriction
What is the most common cause of death in patients with mod-severe COPD? A. Acute exacerbations of COPD B. Cardiovascular disease C. Intrathoracic malignancy D. Pneumonia E. Progressive respiratory failure
C. Intrathoracic malignancy
ETT indications for COPD
Prediction of need for invasive ventilation - DECAF score and BAP-65
DECAF score Dyspnea - On a good day, within the last 3 months ?too SOB to leave house, able to do stuff in house, able to leave house Eosinopenia - <0.5 Consolidation on CXR Acidemia pH <7.30 atrial Fibrillation – on admission ECG
BAP65 score BUN > 29 (or 8.9) Altered Mental Status – GSC <14 Pulse >109 >65 YOA
ILD RA Lung pattern
UIP
