To determine the incremental cost-effectiveness ratio of the VAP decontamination modality compared to the CPAP + PSV modality, to achieve IMV-free days in ARF patients hospitalized in the ICU of the HUSJ. Method: Prospective-descriptive cross-sectional study with an institutional perspective. From a total of 57 patients who were admitted to the HUSJ ICU service in the period from April 21 to May 21, 2014, 31 adult patients with ARF were selected according to the following inclusion criteria: diagnoses other than neurosurgical commitments (from the central nervous system or level of consciousness). The costs are those invoiced for each day of stay in the ICU, taking into account the difference by type of equipment. The designed model is a decision tree. Result: The estimate by confidence intervals at 95% of the average days in the ICU of patients assisted with MV by the CPAP + PSV method was presented between 4.58 to 8.9 days and by the PAV method between 4.9 and 15.1 days; with a 95% confidence, the percentage of MV use over the total time of ICU hospitalization days was between 22.9% and 64.2% for the CPAP + PSV method and for the PAV method between 5.6% and 75%. The application of the CPAP + PSV modality is cost-effective compared to the VAP modality for the deconditioning of patients in IMV. Conclusions: Because the CPAP + PSV modality is the most cost-effective in terms of de-habit, it is a useful tool for the fulfillment of institutional goals.