Statistics
The RBANS scores were compared pre and postoperatively and analyzed
using a univariate analysis against characteristics including laboratory
data and interventions intra-operatively and during their hospital stay.
For laboratory data such as white blood cell counts and creatinine,
measurements were compared on the morning of postoperative day four or
the closest lab measurement within 24 hours of this timepoint. These
RBANS scores were also compared to the cytokines analyzed at the three
time points: pre-op, six hours post-op, and POD4, as well as the
genetics pre- and post-operatively. Patient randomization was not
performed because the patients were compared to themselves pre and
post-operatively.
Neurocognitive data are presented as a change from baseline to POD4 in
standardized score for age and gender on RBANS. Data were analyzed by an
unpaired Mann-Whitney U test.