A pre-post retrospective study of patients with cystic fibrosis and gastrostomy tubes

Objectives: The aim of the study was to assess the efficacy of gastrostomy tube (GT) placement on improving nutritional status and pulmonary function in patients with cystic fibrosis (CF). Patients and Methods: Data were collected from the Minnesota Cystic Fibrosis Database. Subjects with at least 5 percent-predicted forced expiratory volume in 1 second (ppFEV1) and 1 BMI percentile (pBMI) measurements before and after GT placement were included. Median pBMI values were compared 2 years before and 1, 2, and 4 years after GT placement using a signed rank test. Longitudinal mixed model analysis was used to assess the effect of GT placement on ppFEV1. To assess the effect of ppFEV1 at GT placement on efficacy, the estimated ppFEV1 change was regressed against the ppFEV1 level at placement. Results: Forty-six subjects with CF who met entry criteria were identified. Mean estimated step changes in ppFEV1 at placement for men, women, boys, and girls were 2.16% (P=0.52), 0.43% (P=0.92), 0.99% (P=0.65), and -0.91% (P=0.74), respectively. Mean estimated slope changes of ppFEV1 after GT placement were 5.01% (P=0.02), 4.48% (P=0.07), 1.49% (P=0.23), and 4.02% (P=0.01) per year for men, women, boys, and girls, respectively. Median change in pBMI in the second year after GT placement was 13.3% (P≤0.0001). Estimated coefficients for the effect of ppFEV1 level at placement on the ppFEV1 step and slope change were -0.041 (P=0.28) and -0.005 (P=0.84), respectively. Conclusions: GT placement in patients with CF results in significant improvement in both pBMI and ppFEV1, except in women. The change in lung function after GT placement is not dependent on the level of lung function at placement.