In Cystic Fibrosis (CF) poor nutritional status is associated with decreased pulmonary function and increased Pseudomonas aeruginosa (PA) colonization; recognizing failure to thrive (FTT) and its causes is of paramount importance so that an aggressive and early treatment can be instituted. Obstructive sleep apnea syndrome (OSAS) is a well-recognized cause of FTT in non-CF children, and catch-up growth has been observed in pediatric patients after the resolution of OSAS. At present time however, there are no reported cases of OSAS as a cause of FTT in CF. We report a case of FTT secondary to OSAS in a CF patient.
BS is a 3-
y.o. twin boy, full term (BW 2496 G) with CF and pancreatic insufficiency (PI). He and his twin sister were diagnosed with CF by sweat test (99 mEq Cl/139.3 mg sweat) after a positive neonatal screening. Genotyping revealed one copy of Delta F 508 mutation and one copy of K710X mutation, and pancreatic fecal elastase was elevated.Pancreatic enzyme replacement was started at 1 month of age, with an average daily weight increase of 50 g until 6 months of age, when weight gain fell to 11.5/day, despite CF therapy with daily DNAase, chest physiotherapy, nebulizations, and oral antibiotics. There were many factors identified that may have contributed to poor weight gain, such as malabsorption, poor social situation (low family income, and older sister with Down syndrome having several needs), recurrent low grade URI. Enzyme replacement was increased to 1000 U/kg, and caloric density of feeds increased to 27 cal/oz. In addition daily in-house nursing visits (8 hours/day x 5 days/week) were instituted to help the family take care of the twins increased nutritional and respiratory needs.At 14 months of age, despite the interventions, weight persisted along the 0-5th percentile. At this time, PA was retrieved from a throat culture; TOBI™ and ciprofloxacin were started in an effort to eradicate it. A feeding gastrostomy was considered, but it was hoped that PA eradication would alleviate the poor weight gain.Despite PA eradication, proper enzyme replacement, and caloric supplementation, as well as in-home nursing, weight gain did not improve. Although subsequent cultures showed absence of PA, symptoms of nasal congestion, mouth breathing, and snoring persisted, so at 17 months of age a sleep study was performed to evaluate for OSAS as a contribution to FTT and snoring. In fact, it showed several obstructive apneas (5.3/hr), most of which were brief in duration. Episodes of desaturation were short and related to obstructive apnea.The study confirmed the suspicion of severe OSAS, based on the number of events, so adenotonsillectomy was performed. After surgery, snoring resolved, work of breathing, growth parameters, and appetite all improved considerably, and at 29 months old, BS’s weight was in 32nd %ile, height was in 57th %ile.
This patient represents the point that OSAS is a contributor to FTT in CF patients. There are several publications pointing out FTT as secondary to OSAS in non-CF infants and children, showing improvement in weight and height after surgery. The cause of poor growth is not known, the most cited causes are increased sleep energy expenditure (SEE) and impaired growth hormone secretion. OSAS could be overlooked in the CF population, because of many other common reasons for FTT, such as PI, chronic infection, increased work of breathing, increased energy expenditure, feeding behavior problems, social issues. Physicians may also be reluctant to overwhelm the family with secondary diagnosis. These same reasons may increase the risk of non-treated OSAS sequelae in CF patients.
We stress the point of early recognition of OSAS in the differential diagnosis of FTT in CF children.
Ignacio Tapia, None.