Cystic Fibrosis [Suppurative disorders]

What is cystic fibrosis (CF)?

A progressive, multisystem genetic disorder caused by mutations affecting the CFTR protein, resulting in abnormal salt and water transport and thick, sticky secretions.

What population has historically had the highest prevalence of cystic fibrosis?

Caucasian populations.

What is the approximate incidence of cystic fibrosis in Caucasian populations?

Approximately 1 in 2,500 live births.

Approximately how many people are carriers of a CFTR mutation?

Approximately 1 in 25 people in the referenced population.

What factors influence the disease severity of cystic fibrosis?

CFTR gene type/mutation, how well the patient is managed, and access to and effectiveness of CFTR modulator therapies.

What is CFTR?

Cystic fibrosis transmembrane conductance regulator, a protein involved in regulating chloride and therefore salt and water movement across epithelial surfaces.

What is the fundamental problem with CFTR function in cystic fibrosis?

Abnormal CFTR function disrupts salt and water transport, producing dehydrated, thick and sticky secretions.

Which respiratory pathological changes are characteristic of cystic fibrosis?

Submucosal gland hypertrophy, increased goblet cells, destruction of the airway wall/bronchiectasis, and cyst formation.

How is cystic fibrosis commonly detected in newborns?

Through newborn screening using a heel-prick blood test.

What test is performed following a positive newborn screening result for cystic fibrosis?

A sweat test is performed to support diagnosis.

What symptoms may suggest cystic fibrosis in a child?

Failure to thrive, recurrent chest infections, and smelly stools.

What is meconium ileus?

A neonatal intestinal obstruction caused by thick, sticky meconium that the newborn is unable to pass.

What percentage of newborns with cystic fibrosis develop meconium ileus?

Approximately 10–20%.

Why does cystic fibrosis affect multiple organ systems?

CFTR is involved in salt and water exchange across epithelial tissues, including the exocrine glands of multiple organs.

What are the major respiratory consequences of cystic fibrosis?

Viscous airway secretions, chronic airway obstruction, bacterial colonisation, chronic infection, inflammation, airway destruction, and bronchiectasis.

How do viscous secretions cause airway obstruction in cystic fibrosis?

Thick mucus accumulates within the airways, narrowing or plugging them and impairing airflow and secretion clearance.

Why does chronic infection develop in cystic fibrosis?

Thick mucus is difficult to clear, allowing pathogenic bacteria to become trapped and multiply.

What is the relationship between chronic infection and bronchiectasis in cystic fibrosis?

Chronic infection and inflammation progressively damage the airway walls, resulting in bronchiectasis.

Which respiratory pathogens commonly occur early in cystic fibrosis?

Haemophilus influenzae, Staphylococcus aureus, and Pseudomonas aeruginosa.

At what age can respiratory pathogens occur in cystic fibrosis?

Some pathogens can occur as early as the first year of life.

What is unusual about Pseudomonas aeruginosa in cystic fibrosis?

It can acquire a mucoid phenotype that is characteristic of the CF environment and is associated with rapid decline in lung function.

What is the mucoid phenotype of Pseudomonas aeruginosa?

A phenotype in which P. aeruginosa produces abundant alginate, contributing to a thick biofilm and persistent infection.

What pancreatic problem occurs in cystic fibrosis?

Pancreatic duct obstruction reduces enzyme secretion and causes pancreatic insufficiency.

What are the consequences of pancreatic insufficiency in cystic fibrosis?

Malabsorption of fats and some proteins, steatorrhoea/smelly stools, vitamin deficiencies, and risk of malnutrition.

Which vitamins are particularly at risk of deficiency in cystic fibrosis?

Vitamins A, D, E, and K.

How is pancreatic insufficiency managed in cystic fibrosis?

With pancreatic enzyme replacement therapy.

What is Creon Forte used for in cystic fibrosis?

Pancreatic enzyme replacement to aid digestion and absorption, particularly of fats.

When should pancreatic enzymes such as Creon be taken?

With meals and food containing fat.

How is glucose metabolism affected in cystic fibrosis?

It can be variable, including insulin deficiency, delayed insulin secretion, and altered insulin resistance.

What is cystic fibrosis-related diabetes (CFRD)?

Diabetes associated with cystic fibrosis, commonly related to pancreatic disease and impaired insulin production.

How common is CFRD in adults with cystic fibrosis according to the notes?

Approximately 15–30%.

Why is CFRD clinically important in cystic fibrosis?

It indicates greater disease severity and is associated with increased morbidity and mortality.

Why is BMI important in cystic fibrosis?

Nutritional status and BMI are closely related to lung disease and can provide an indication of disease severity.

What dietary requirements are common in cystic fibrosis?

A diet high in fats and proteins, often with nutritional supplements.

Why might people with cystic fibrosis require supplementary feeding?

Severe nutritional compromise may make oral intake insufficient, requiring nasogastric or PEG feeding.

What is DIOS?

Distal intestinal obstructive syndrome, an intestinal obstruction associated with thick intestinal contents in cystic fibrosis.

Approximately what percentage of people with cystic fibrosis develop DIOS?

Approximately 20%.

How can DIOS risk be reduced or managed?

Maintaining hydration and using laxatives to reduce constipation and blockage; severe obstruction may require surgery.

What happens to bile in cystic fibrosis?

Bile becomes thick and tenacious.

What can thick bile cause in cystic fibrosis?

Bile duct obstruction, cholestasis, gallstones, and cirrhosis.

What percentage of people with cystic fibrosis have liver disease according to the notes?

Approximately 33%.

What is the most common non-pulmonary cause of mortality in cystic fibrosis according to the notes?

Liver disease.

What is cystic fibrosis-associated liver disease?

Liver disease caused by CFTR dysfunction affecting the hepatobiliary system, including abnormal thick bile and biliary obstruction.

What is a major musculoskeletal complication of cystic fibrosis?

Low bone mineral density (BMD).

Why is low BMD in cystic fibrosis multifactorial?

It can involve decreased bone accretion and increased bone loss along with nutritional, inflammatory, hormonal, and disease-related factors.

Why is adolescence/puberty particularly important for bone health in cystic fibrosis?

It is normally a major period for peak bone growth velocity and bone-density accrual.

What can happen to peak bone mass accrual in adolescents with cystic fibrosis?

It can be inadequate, resulting in substantially lower BMD than healthy counterparts.

What types of exercise are useful for maximising bone mass in adolescents with cystic fibrosis?

Weight-bearing and impact exercise such as jumping, hopping and skipping, together with strength/resistance training.

What happens to bone health in adults with cystic fibrosis?

Adults can experience accelerated bone loss.

What percentages of adults with cystic fibrosis are reported to have osteoporosis or osteopenia in the notes?

Approximately 24% have osteoporosis and 38% have osteopenia.

How can bone mass be maintained in adults with cystic fibrosis?

Weight-bearing activity, physical activity, resistance training, appropriate diet, and medications where indicated.

What is a potential adverse effect of bisphosphonate therapy in cystic fibrosis?

Bone pain during infusion, which may reduce willingness to adhere to treatment.

Which fractures are particularly common in people with cystic fibrosis?

Thoracic vertebral and rib fractures.

How can vertebral fractures affect posture in cystic fibrosis?

They may contribute to thoracic kyphosis.

How can fractures affect physiotherapy in cystic fibrosis?

Pain can interfere with airway clearance techniques and exercise.

What is CF-related arthropathy?

Episodes of joint pain and swelling associated with cystic fibrosis.

What percentage of patients with cystic fibrosis experience CF-related arthropathy according to the notes?

Approximately 2–9%.

How is CF-related arthropathy generally managed?

Similarly to other inflammatory joint conditions, with rest followed by gradual introduction of exercise.

Why is musculoskeletal pain important in cystic fibrosis?

It is increasingly prevalent, can reduce quality of life, and is often undertreated or overlooked.

Why should musculoskeletal pain be screened for in cystic fibrosis?

Patients are living longer, making identification and management of acute and chronic musculoskeletal problems increasingly important.

What postural problems can occur in cystic fibrosis?

Hyperinflated chest, tight pectoral/postural muscles, limited shoulder and neck flexion, and thoracic kyphosis.

Why can hyperinflation contribute to postural problems in cystic fibrosis?

Chronic hyperinflation can shorten and tighten postural muscles and the pectorals, contributing to altered posture and restricted movement.

What is a physiotherapy goal regarding posture in cystic fibrosis?

Prevent postural problems before they develop.

What should CF treatment regimens include to help prevent postural problems?

A stretching programme.

What physiotherapy treatments can be used for musculoskeletal/postural problems in cystic fibrosis?

Postural correction and education, postural taping, mobilisation techniques, intercostal stretches, rib springing, positioning, and taping for compression/rib fractures when appropriate.

What is the prevalence of urinary incontinence in nulliparous women with cystic fibrosis according to the notes?

Approximately 22–64%.

How does this compare with healthy women aged 18–24?

The reported prevalence is substantially higher than the approximately 13% reported in healthy women aged 18–24.

What factors may contribute to urinary incontinence in cystic fibrosis?

Chronic cough or prolonged coughing, pelvic-floor demands during airway clearance and exercise, and underlying structural differences.

Why can coughing contribute to urinary incontinence in cystic fibrosis?

Repeated increases in intra-abdominal pressure place repeated stress on the pelvic floor.

What reproductive abnormality occurs in most males with cystic fibrosis?

Approximately 98% have congenital bilateral absence of the vas deferens.

Can males with cystic fibrosis father children?

Yes. Sperm harvesting and assisted reproductive techniques have allowed many males with CF to father children.

What factors influence female fertility in cystic fibrosis?

Nutritional status and lung function.

Why should women with cystic fibrosis optimise nutrition and lung function before pregnancy?

To aid conception and minimise the detrimental effects pregnancy may have on health and symptoms.

Which less common organisms can be cultured in people with cystic fibrosis?

Burkholderia cepacia complex, Stenotrophomonas maltophilia, MRSA, Achromobacter xylosoxidans, non-tuberculous mycobacteria such as M. abscessus, and Aspergillus.

What is the overall respiratory cycle of disease progression in cystic fibrosis?

Thick mucus → impaired clearance → bacterial retention → recurrent infection → chronic inflammation → airway damage/bronchiectasis → further impairment of mucus clearance.

What is the primary mucus problem in cystic fibrosis?

Mucus is abnormally thick and sticky due to abnormal salt and water transport.

How does abnormal CFTR function affect airway mucus?

Abnormal chloride movement reduces water availability in airway secretions, making mucus dehydrated, thick, and sticky.

How does thick mucus affect mucociliary clearance in cystic fibrosis?

It makes mucus difficult for cilia to transport and therefore impairs mucociliary clearance.

What happens when mucus cannot be cleared effectively in cystic fibrosis?

Mucus plugging and bacterial retention occur, leading to recurrent infections.

How does recurrent infection affect the airways in cystic fibrosis?

It causes persistent inflammation and progressive destruction of the bronchial walls.

How does cystic fibrosis lead to bronchiectasis?

Repeated infection and inflammation progressively destroy and weaken the bronchial walls, producing permanent airway dilation.

What happens to airway resistance as cystic fibrosis lung disease progresses?

Airway resistance increases due to mucus obstruction, inflammation, and bronchiectasis.

What happens to lung compliance as pulmonary fibrosis develops in cystic fibrosis?

Lung compliance decreases and the lungs become stiffer.

Why does fibrosis reduce lung compliance?

Fibrotic lung tissue is less elastic and more difficult to expand.

How does decreased lung compliance affect breathing?

Greater inspiratory effort is required and inspired volumes may decrease.

How does increased airway resistance affect breathing?

It makes it harder to move air through the airways, increasing the work of breathing.

Why can expiration become particularly difficult in cystic fibrosis?

Destroyed and dilated airways can become floppy and collapse during expiration, causing expiratory flow limitation.

What does EFR stand for?

Expiratory Flow Rate.

What happens to expiratory flow rate in cystic fibrosis with bronchiectasis?

It decreases because of expiratory airway collapse and obstruction.

What are clinical consequences of expiratory obstruction in cystic fibrosis?

Air trapping, wheeze, prolonged expiration, and increased work of breathing.

How does fibrosis affect oxygen diffusion in cystic fibrosis?

Fibrosis can thicken the alveolar/interstitial barrier, increasing diffusion distance and reducing diffusion efficiency.

Why does fibrosis reduce oxygen diffusion?

Oxygen must travel across a greater distance through thickened lung tissue.

What are the consequences of reduced diffusion in cystic fibrosis?

Lower oxygen levels, hypoxaemia, and reduced exercise tolerance.

How does fibrosis produce a restrictive component of lung disease in cystic fibrosis?

Fibrosis makes the lungs stiff, decreasing compliance and limiting inspired volumes.

What breathing pattern may occur with restrictive disease in cystic fibrosis?

Smaller tidal volumes and a more rapid respiratory rate.

Why can inspired volume decrease in cystic fibrosis?

Fibrosis reduces lung compliance, making full inflation more difficult.

What happens when inspired volume decreases in cystic fibrosis?

Less fresh air reaches the alveoli, contributing to impaired gas exchange.

What are the major factors that impair gas movement in cystic fibrosis?

Thick mucus, mucus plugging, airway obstruction, fibrosis, and reduced lung compliance.

How does cystic fibrosis affect oxygen movement?

Thick mucus, airway obstruction, reduced inspired volume, and impaired diffusion reduce oxygen movement.

How does cystic fibrosis affect carbon dioxide movement?

Airway obstruction and impaired ventilation can reduce effective carbon dioxide removal.