NEW ORLEANS – Hypertonic saline alone does not affect length of stay among infants hospitalized for bronchiolitis, according to preliminary results of an ongoing randomized, prospective U.S. trial.
Among 127 evaluable patients, the median length of stay was 2.2 days with hypertonic saline and 2.0 days with normal saline (P = .65).
Infants in one still-blinded group were significantly younger (3.3 vs. 4.4 months), but hospital stay did not differ between groups, even when adjusted for age.
"Preliminary results suggest little utility for the routine use of hypertonic saline in treating infants hospitalized with bronchiolitis," Dr. Alyssa Silver said at Pediatric Hospital Medicine 2013.
However, she added, the results do show that 3% hypertonic saline without adjunctive bronchodilators is safe for infants, including those with a history of prior wheeze, even in a population with a high endemic prevalence of asthma.
Patrice Wendling/IMNG Medical Media
Dr. Alyssa Silver
A theoretical risk of bronchospasm has been identified in patients with cystic fibrosis at much higher concentrations and quantities.
This is the first prospective, randomized, double-blind, controlled clinical trial of nebulized hypertonic saline conducted in the United States.
Several studies have been conducted outside the United States, but adjuvant bronchodilators were used in all but one, patients with a history of wheeze were excluded, and they had long lengths of stay that make the data difficult to generalize to the United States, said Dr. Silver, a pediatric hospitalist with the Children’s Hospital at Montefiore in New York.
Dr. Shawn Ralston, cochair of the American Academy of Pediatrics subcommittee on diagnosis and management of bronchiolitis, which is revising the 2006 AAP clinical practice guidelines for bronchiolitis,said in an interview that a clearer picture of the utility of hypertonic saline is beginning to emerge. All of the studies where hypertonic saline is used in the ED or short-stay units show no utility, and the only inpatient studies that show benefit seem to be in settings where there is longer length of stay. Further, Montefiore has a very short length of stay, which is typical of U.S. hospitals.
"I think what we’re learning about hypertonic saline as the studies come in is that any treatment effect, if there does prove to be one, will be seen over several days," said Dr. Ralston, chief of the pediatrics section, Dartmouth-Hitchcock Medical Center, Lebanon, N.H.
"From a guidelines standpoint, it is very important for us to keep up with the emerging data, and we are unlikely to be able to recommend the use of hypertonic saline given what has been published or presented within the last year. That said, I would actually welcome studies of outpatient use of hypertonic saline, as I think that is where the real utility may lie, based on my review of the literature in preparation for the guideline."
The current study included 156 infants, less than 12 months of age, admitted with a diagnosis of bronchiolitis from November 2011 through January 2013 and randomized by the pharmacy to 4 mL of hypertonic saline or 4 mL of normal saline every 4 hours until discharge.
The readmission rate was identical at 6.3% in both study groups (P = 1.0), Dr. Silver reported. Also similar were clinically important adverse events, including readmission (four events in each group) and worsening respiratory status (six events in each group; both P = 1.0).
A subgroup analysis showed no difference in length of stay among patients treated with hypertonic saline vs. normal saline who were positive for respiratory syncytial virus (2.5 vs. 2.0 days; P = .35), had a history of previous wheeze (1.8 vs. 2.0 days; P = .58), or had a history of prematurity (3.5 vs. 2.5 days; P = .11).
The study was limited by the single-center design and the inability to randomize all patients within 12 hours of admission. Despite the lack of funding, however, the study captured 80% of bronchiolitis admissions among infants during the study period, Dr. Silver noted.
"These findings cast significant doubt on the utility of nebulized 3% hypertonic saline for the routine treatment of infants hospitalized with bronchiolitis," she said in an interview. "Unfortunately, the mainstay of routine inpatient treatment remains supportive care."
Future directions include enrolling patients directly from the emergency department with a minimum severity score for study entry, use of higher concentrations of sodium chloride, and possibly an outpatient study.
Dr. Silver reported having no relevant financial disclosures.