Tolerance of 7% Hypertonic Saline in Pediatric Cystic Fibrosis Patients

Background: Clinical trials of 7% hypertonic saline (HTS) in cystic fibrosis (CF) show short- and long-term benefits, including improved pulmonary function and reduced exacerbation risk. Adverse effects of HTS include bronchospasm, and guidelines recommend tolerance be tested in a clinical environment before prescribing. We evaluated the rate of, and risk factors for, intolerance of HTS at a single pediatric CF program. Methods: Single-center retrospective study in patients with CF, aged 6-20 years, who received an HTS test dose between 2006 and 2017. HTS intolerance was defined as either a ≥10% decline in forced expiratory volume in 1 s (FEV₁) percent predicted or wheezing/severe cough. Results: Fifty-one patients met inclusion criteria, and 13 (25%) showed intolerance of 7% HTS. There were trends toward higher rates of comorbidities in the patients intolerant versus tolerant of HTS, including allergies and/or rhinitis 85% versus 66% (P = 0.30) and sinus disease 85% versus 58% (P = 0.10). A trend toward more methicillin-sensitive Staphylococcus aureus (58% vs. 31%, P = 0.09) and asthma (42% vs. 24%, P = 0.09) was seen in patients tolerant of HTS. Demographics, pulmonary function, nutritional parameters, laboratory tests, respiratory cultures, chronic therapies, and antibiotics for exacerbations did not differ. Conclusions: In our program, 1:4 children with CF exhibited objective findings of HTS intolerance. There were trends suggesting higher frequency of allergies and rhinosinusitis in intolerant children. Assessing tolerance of HTS before prescribing chronic daily therapy is important. Larger studies are needed to more accurately define the incidence of intolerance and risk factors.