Cystic Fibrosis Practice Questions

Which of the following organisms is typically found earliest in respiratory cultures of patients with cystic fibrosis?

A. Staphylococcus aureus

B. Pseudomonas aeruginosa

C. Burkholderia cepacia

D. Haemophilus Influenza

D. Haemophilus Influenza - Haemophilus influenza. The patient is typically colonized with Staphylococcus aureus second and nonmucoid pseudomonas after that. Burkholderia cepacia is typically found in older patients with more advanced lung disease.

What class of Mutation is Delta F508 (the most common mutation found in cystic fibrosis)?

A. Class 2

B. Class 3

C. Class 5

D. Class 6

A. Class 2 - class 2 mutations occur when the mutant protein is made in its entirety but fails to fold properly inside the cell, This results in the absence of mature CFTR in the cellular membrane to perform its specific chloride ion conductance function.

Which tests is used to diagnose cystic fibrosis?

A. Sweat Test

B. Nasal potential difference

C. Genetic testing

D. All of the above

D. All of the above - Sweat test is still the gold standard all can be used in the diagnosis of CF. Genetic testing is used to determine the patient's specific mutations and is helpful in determining which modulators the patient will qualify for. Nasal potential difference provides evidence of the abnormal function of the cystic fibrosis transmembrane conductance regulator as values less than −40 mV is abnormal.

Which of the following BEST describes the genetic acquisition of cystic fibrosis?

A. Only one parent is a carrier of the CF gene

B. Only one grandparent is a carrier of the CF gene

C. Both parents are carriers of the CF gene

D. Cystic fibrosis is not acquired genetically

C. Both parents are carriers of the CF gene - Cystic Fibrosis occurs in a classic singlegene (Mendelian) autosomal recessive pattern. Autosomal recessive patterns of inheritance require both parents to be carriers of the gene.

A 6yearold patient is admitted for a pulmonary exacerbation. The patient typically grows methicillinresistant S. aureus (MRSA) and Pseudomonas. Which of the following antibiotic regimens would be the best initial treatment?

A. Nafcillin and tobramycin

B. Vancomycin and ciprofloxacin

C. Vancomycin Tobramycin and Ceftazidime

D. Linezolid and Ceftazadime

C. Vancomycin Tobramycin and Ceftazidime - Nafcillin does not typically cover methicillinResistant staph aureus. Vancomycin is one preferred IVC treatment for MRSA. Ciprofloxacin is typically reserved for outpatient therapy, as it is one of the few oral antibiotics that can treat pseudomonas. Pseudomonas is typically treated with 2 antibiotics to decrease the development of antibiotic resistance.

You are seeing a 16yearold CF patient for their yearly visit. While taking a history, the patient mentioned that she almost had an accident 3 nights ago as they were unable to see the oncoming car that merged into the lane. Which of the following should be the next step in evaluating this patient?

A. refer to ophthalmology

B. check vitamin levels

C. perform vision screen in clinic

D. check fecal elastase

B. check vitamin levels - pancreatic insufficiency causes decreased absorption of fats and which then leads to malabsorption of fatsoluble vitamins. In a 16yearold

patient, symptoms would be likely related to suboptimal adherence to vitamin therapy as opposed to malabsorption. An early symptom of vitamin A deficiency is night blindness. Vitamin E can cause neurologic deficits, Vitamin K clotting disorders and easy bleeding, and Vitamin D rickets

Which of the following CFTR modulators is indicated in sevenyearold patients with only one delta F 508 mutation?

A. Ivacaftor

B. Elexacaftor/tezacaftor/ivacaftor

C. Lumacaftor/ivacaftor

D. Tezacaftor/ivacaftor

B. Elexacaftor/tezacaftor/ivacaftor - Is the only CFTR modulator agent that is indicated for patients six and older with at least one delta F 508 mutation.

AA's family is thinking about initiating lumacaftor/ivacaftor. AA is four years old. What monitoring parameter is most appropriate to obtain prior to

initiating lumacaftor/ivacaftor?

A. Complete blood count

B. DEXA scan

C. Hearing exam

D. Liver function panel

D. Liver function panel - When initiating a CFTR modulator it is important to assess baseline transaminases such as ALT and AST as well as obtaining an eye exam in pediatric patients.

BA is found to be indicated for pancreatic enzyme replacement therapy (PERT). BA weights 20 kg. Accounting for all of BA's meals and snacks, what

is the max dose that should be prescribed for BA and their PERT therapy.

A. 50,000 lipase units per meal and 25,000 lipase units per snack

B. 20 lipase units per meal and 10 lipase units per snack

C. 40,000 lipase units per meal and 10,000 lipase units per snack

D. 40 lipase units per meal and 20 lipase units per snack

A. 50,000 lipase units per meal and 25,000 lipase units per snack - The maximum dose per meal is 2,500 lipase units per kilogram per meal with snacks being half the dose at mealtimes.

Which is the most appropriate treatment for a patient with CFRD with impaired glucose tolerance?

A. Metformin

B. Pioglitazone

C. Insulin Glargine

D. Insulin Aspart

D. Insulin Aspart - Due to patients with CFRD having multimodal reasons for impaired glucose tolerance. CFRD may be related to a loss of insulinproducing islet cells due to autolysis and fatty infiltration of the pancreas. As this is not a process due to entirely glucose resistance processes large doses of aspart may not be needed with impaired postprandial glucose. Insulin is usually the most appropriate treatment for CFRD, however, a patient's fasting glucose becomes impaired later in disease progression whereas prandial glucose is affected earlier on therefore not requiring insulin glargine

initially.

When assessing a 13yearold patient with CF who may have a high disease burden. This patient has anxiety involving their treatment as well the team has seen a decrease in lung function over the last year, lower BMI over the last year, and the patient has been skipping their treatments in the evening. This patient refuses a referral to a mental health professional. What is the most appropriate next treatment step for this patient?

A. Initiate citalopram 40 mg daily

B. Initiate CBT

C. Initiate mirtazapine 15 mg nightly

D. Initiate melatonin 5 mg nightly

C. Initiate mirtazapine 15 mg nightly - May help with weight gain as well as anxiety and depression symptoms. Initiating citalopram may put the patient at QT prolongation. The patient is refusing counseling at this time and melatonin may not help with anxiety.

The purpose of using hypertonic saline in a cystic fibrosis patient is to

A. Decrease bacterial growth

B. Decrease sweat chloride content

C. Hydrate pulmonary secretions

D. Increase serum sodium content

C. Hydrate pulmonary secretions - Hypertonic saline acts as an osmotic agent which draws water into luminal secretions resulting in the restoration of airway hydration. It is a solution possessing an osmotic pressure greater than that of a physiologic isotonic salt solution (0.9%NaCl). By drawing water from CFTR defective airway epithelial cells, the periciliary layer becomes rehydrated and mucociliary clearance reestablished.

A cystic fibrosis patient is using the following inhaled medications:

Cayston

Hypertonic saline

Albuterol

Pulmozyme

In what order should these medications be administered (listed first to last)?

A. Cayston, Hypertonic saline, Albuterol, Pulmozyme

B. Pulmozyme, Albuterol, Hypertonic Saline, Cayston

C. Albuterol, Pulmozyme, Cayston, Hypertonic Saline

D. Albuterol, Hypertonic Saline, Pulmozyme, Cayston

E. Hypertonic Saline, Albuterol, Cayston, Pulmozyme

D. Albuterol, Hypertonic Saline, Pulmozyme, Cayston - Bronchodilators will open the airways and make it easier to expel mucus and allow medications to penetrate deeper into the lung. Hypertonic saline will mobilize the mucus and improve airway clearance by hydrating the airways. Pulmozyme will thin the mucus. All of these agents work to open and clear the airways of mucus allowing the inhaled antibiotics to work on the remaining bacteria.

Chronic management of airway inflammation in cystic fibrosis should (typically) includes which of the following?

A. Hypertonic Saline

B. Aerosolized aztreonam

C. Azithromycin

D. Cholecalciferol

C. Azithromycin - Azithromycin has demonstrated benefits in CF patients with chronic infection with P. aeruginosa . These benefits do not appear to be exclusively related to its antimicrobial effects but also an antiinflammatory effect. The antimicrobial effects center around the ability of macrolides to reduce the ability of Pseudomonas to produce biofilms whereas the antiinflammatory effect relates to azithromycin's ability to suppress the excessive inflammatory response noted in CF patients.

The Cystic Fibrosis Foundation recommends all individuals with cystic fibrosis maintain a serum 25hydroxyvitamin D goal of at least

__________________ ng/mL.

A. 15 (37 nmol/L)

B. 30 (75 nmol/L)

C. 60 (150 nmol/L)

D. 90 (225 nmol/L)

B. 30 (75 nmol/L) - Vitamin D deficiency is probably the most commonly studied vitamin deficiency in CF patients and appears to have an impact on inflammation and maintenance of bone health. The cystic fibrosis foundation has guidelines specifically for vitamin D to ensure that the serum 25-hydroxyvitamin D levels remain at least at 30ng/mL (75 nmol/L) or higher in all patients with cystic fibrosis.