Protocol
The association between antibiotics and necrotizing enterocolitis in neonatal intensive care unit
infants Jamie Lombardo, MS3 and Elizabeth Gray, MS3
Faculty Advisor: James R. Beal, Ph.D.
4.
Necrotizing enterocolitis (NEC) is the most common and serious gastrointestinal
disorder that occurs primarily in premature infants with a mortality rate of 25-33%. Risk
factors for NEC include low birth rate, prematurity, enteral feeding, antenatal corticosteroid
exposure, respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), infection, and
alterations in bacterial colonization of the gastrointestinal tract. The widespread use of
antibiotics in the NICU may reduce the diversity of microbes in the fetal intestinal tract and
delay colonization with beneficial gastrointestinal flora. In addition, use of antibiotics in the
NICU promotes proliferation of pathogenic and antibiotic-resistant organisms. The purpose of
this study is to determine whether there is an association between antibiotic exposure and
necrotizing enterocolitis (NEC) in neonatal intensive care unit (NICU) infants. We will also try to
discover which antibiotics and duration are more likely to cause NEC.
5-7, & 9.
We will perform a case-control retrospective medical records review of infants
admitted to the NICU from January 1, 2003 to October 31, 2013 at Altru Hospital in Grand
Forks, ND. Altru has a 16 bed, level IIIB NICU for critically ill infants. A 2:1 control/case ratio will
be gathered. Cases will include neonates diagnosed with NEC modified Bell’s stage greater
than or equal to IIA. Each identified case will be matched to three control subject. The control
population will include neonates without NEC matched on age (number of hospital days before
NEC in matched cases), , gestational age (±1 week), birth weight (±200 g) and year of hospital
admission (±1 year). Infants transferred from outside hospitals will be excluded from the study,
as well as neonates with major congenital abnormalities.
Data to be collected will include: gestational age, gender, weight, prenatal
corticosteroids, respiratory distress syndrome, patent ductus arteriosus, bloodstream infection,
using formula instead of breast milk, first day of feeding, full feeds achieved, small for
gestational age, 5-minute Apgar score, umbilical catheter use, antibiotic exposure, duration of
antibiotic use, presence or absence of bronchopulmonary dysplasia (BPD), congenital
abnormalities, transfer status, duration of mechanical ventilation, duration of total parenteral
nutrition, length of hospital stay, and death.
SPSS 21.0 for Windows will be used to analyze demographic and clinical characteristics of
patients. Frequencies and relative percentages will be computed for each categorical variable.
Chi-square tests or Fisher’s exact tests will be performed to determine which categories were
significantly different from one another, and t-test and/or ANOVA will be used to compare
continuous variables. All p-values will be two-sided, and p-value < 0.05 will be considered
significant. Missing data will be excluded from analysis.
8 & 10. For the purpose of this study, there will be no physical interaction between the
principal investigators and the patients whose charts are being reviewed. Furthermore, no
procedures will be performed or direct interaction will occur with patients of this study. Data
will be stored securely on password protected computers and files. The data file will not
contain any identifying information such as patients’ names or medical record numbers. Only
those involved in the research project will be able to access the data. Data will be stored in the
Department of Family and Community Medicine at the UND School of Medicine and Health
Sciences for a period of six years after analysis.