Large amount of heterogeneous medical data is generated every day in various healthcare organizations. Those data could derive insights for improving monitoring and care delivery in the Intensive Care Unit. Conversely, these data presents a challenge in reducing this amount of data without information loss. Dimension reduction is considered the most popular approach for reducing data size and also to reduce noise and redundancies in data. In this paper, we are investigate the effect of the average laboratory test value and number of total laboratory in predicting patient deterioration in the Intensive Care Unit, where we consider laboratory tests as features. Choosing a subset of features would mean choosing the most important lab tests to perform. Thus, our approach uses state-of-the-art feature selection to identify the most discriminative attributes, where we would have a better understanding of patient deterioration problem. If the number of tests can be reduced by identifying the most important tests, then we could also identify the redundant tests. By omitting the redundant tests, observation time could be reduced and early treatment could be provided to avoid the risk. Additionally, unnecessary monetary cost would be avoided. We apply our technique on the publicly available MIMIC-II database and show the effectiveness of the feature selection. We also provide a detailed analysis of the best features identified by our approach.