Cystic fibrosis (CF) is a hereditary disorder tending to start in early childhood that affects the exocrine glands. It triggers the production of incredibly thick mucus which can block the intestines, pancreatic ducts, liver, kidneys and most notably, the lungs. Chronic respiratory infections are common, as are gastrointestinal abnormalities that result in malabsorption and nutritional deficits.
One in 25 people are thought to carry the cystic fibrosis gene, but both parents must carry it for a baby to be born with the disorder. If both parents carry the gene, their children have a one in four chance of having CF. It occurs in around 1 in 2500 live births in the UK, with around 10,000 people currently living with the disease in the UK according to the Cystic Fibrosis Trust.([FOOTNOTE=Cystic Fibrosis Trust. Family Genetic Testing: the family cascade screening programme for cystic fibrosis. CFT. 2015],[ANCHOR=],[LINK=])
The most common symptoms of cystic fibrosis are:
Following the implementation of universal newborn screening in 2007 in the UK, children are generally diagnosed in the first few months of life, although some individuals are diagnosed into adulthood.([FOOTNOTE=Taylor-Robinson D, Archangeligi O, Carr SB, et al. Data Resource Profile: The UK Cystic Fibrosis Registry. Int J Epidemiol. 2018;47(1): 9–10e],[ANCHOR=],[LINK=])
Definitive diagnosis of cystic fibrosis is made using a sweat test. A sweat chloride concentration of more than 66 mmol/ litre determined on two or more occassions remains the 'gold standard' for diagnosis.([FOOTNOTE=Farell PM, Rosenstein BJ, White TB, et al. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic Fibrosis Foundation consensus report. J Pediatr. 2008;153(2)S4-S16.],[ANCHOR=],[LINK=])
Pulmonary disease remains the leading cause of mortality in patients with CF.([FOOTNOTE=Ratjen F, Döring G. Cystic fibrosis. Lancet 2003; 361:681. ],[ANCHOR=],[LINK=]),([FOOTNOTE=Davis PB, Drumm M, Konstan MW. Cystic fibrosis. Am J Respir Crit Care Med 1996; 154:1229.],[ANCHOR=],[LINK=]),([FOOTNOTE=Elborn JS. Cystic fibrosis. The Lancet. 2016;388:2519-2531.],[ANCHOR=],[LINK=]),([FOOTNOTE=Brennan AL, Geddes DM. Cystic fibrosis. Curr Opin Infect Dis. 2002; 15:175.],[ANCHOR=],[LINK=]) One of the major health consequences faced by of CF sufferers is lung infection.([FOOTNOTE=Gibson RL, Burns JL, Ramsey BW. Pathophysiology and management of pulmonary infections in cystic fibrosis. Am J Respir Crit Care Med 2003; 168:918.],[ANCHOR=],[LINK=]),([FOOTNOTE=Sagel SD, Gibson RL, Emerson J, et al. Impact of Pseudomonas and Staphylococcus infection on inflammation and clinical status in young children with cystic fibrosis. J Pediatr 2009; 154:183.],[ANCHOR=],[LINK=]) The approach to treating infection in CF is multifaceted, involving antibiotics, chest physiotherapy, inhaled medications (to clear mucus) and anti-inflammatory agents.
Although chronic respiratory failure remains the primary cause of mortality in cystic fibrosis, patients are surviving longer. Longer lifespans have, however, led to increased incidence of critically-ill patients in ICUs. It was barely conceivable 30 years ago that a CF patient would come under the care of the inensivist, but times have changed.
Lung transplantation is an effective treatment option for selected cystic fibrosis (CF) patients with end-stage respiratory failure([FOOTNOTE=Rosenblatt RL. Lung transplantation in cystic fibrosis. Respir Care. 2009;54(6):777-786.],[ANCHOR=],[LINK=]). With careful attention to pre-operative assessment and postoperative medical care, survival of CF lung-transplant recipients is similar non-CF patients, and 12-month survival rates are in the region of 75%.([FOOTNOTE=Stephenson A, Sykes J, Berthiaume Y, et al. Clinical and demographic factors associated with post-lung transplantation survival in individuals with cystic fibrosis. J Heart Lung Transplant. 2015; 34(9):1139-45.],[ANCHOR=],[LINK=]),([FOOTNOTE=Thabut G, Christie JD, Fournier M, et al. Survival benefit of lung translplant for cystic fibrosis since lung allocation score implementation. Am J Respir Crit Med. 2013; 187(12):1335-40],[ANCHOR=],[LINK=])
Noninvasive ventilation is useful in the treatment of CF patients with acute episodes of respiratory failure, or end-stage lung disease who are being evaluated for lung transplantation. For these patients, noninvasive ventilation could be an option of prolonging life if they are successfully treated for their acute episode of respiratory failure until transplantation.([FOOTNOTE=Madden BP, Kariyawasam H, Siddiqi AJ, et al. Noninvasive ventilation in cystic fibrosis patients with acute or chronic respiratory failure. European Respiratory Journal. 2002;19: 310-313.],[ANCHOR=],[LINK=])