The researchers report that they completed a post hoc t-test and evaluated the average PaO₂ level for patients who had open ES from baseline to as soon as the suctioning was terminated. Was it significant?

Let’s look at the use of ANOVA in the following nursing research article:
Özden, D., & Görgülü, R. S. (2015). Effects of open and closed suction systems on the haemodynamic parameters in cardiac surgery patients. Nursing in Critical Care, 20(3), 118–125. doi:10.1111/nicc.12094