TITLE:
Vasoactive-Ventilation-Renal Score Predicts Cardiac Care Unit Length of Stay in Patients Undergoing Re-Entry Sternotomy: A Derivation Study
AUTHORS:
Vicki L. Mahan, Monika Gupta, Stephen Aronoff, David Bruni, Randy M. Stevens, Achintya Moulick
KEYWORDS:
Re-Entry Sternotomy, Vasoactive-Ventilation-Renal Score, VVR Score, Recursive Partitioning Analysis, Congenital Heart Disease (CHD)
JOURNAL NAME:
World Journal of Cardiovascular Surgery,
Vol.8 No.1,
January
18,
2018
ABSTRACT: Background: The
vasoactive-ventilation-renal (VVR) score includes pulmonary and renal
dysfunctions not previously addressed by the vasoactive inotrope score (VIS)
and may be a better predictor of cardiac care unit (CCU) length of stay (LOS)
in patients undergoing re-entry sternotomy (defined as no earlier than 30 days
after previous sternotomy) for congenital heart disease (CHD). Methods: Patients
undergoing re-entry sternotomy for CHD from August 1, 2009 to June 30, 2016
were studied retrospectively. A total of 96 patients undergoing 133 re-entry
procedures were identified. VVR scores were calculated on CCU admission post-procedure (at 0 hour), 24-hour,
and 48-hour after admission to the CCU. The response variable was CCU LOS. Recursive partition analysis identified
variables predicting LOS. Results: 133
re-entry sternotomies in 96 patients made up the samples of the database; 11
samples were removed due to incomplete data or placement on ECMO. Of the
initial 25 features, 5 were removed for near zero variance and 3 categorical
features were removed for non-information. Covariance analysis did not
demonstrate any significant correlation amongst the remaining features. Initial
recursive tree regression using ANOVA, cross validation and conditional
predictive p-value (cp) = 0.01 produced 3 trees. The tree with lowest cross
validation error was selected. The resulting 2 split trees with ventilator days
less than 20 days and VVR score at 48 hours greater than 23 identified three
CCU LOS groups with mean CCU LOS
of 77.6, 55.1, and 9.5 days. Conclusions: Recursive
partition analysis identified ventilator days greater than 20 days and the
sub-population VVR at 48 hours as predictive of CCU LOS in patients undergoing
re-entry sternotomy for CHD.