The majority of patients requiring mechanical ventilation in the intensive care unit are safely weaned from mechanical ventilation within a short period of time. Less than 10% of these patients require mechanical ventilation support for more than 7 days.

Although maximal inspiratory pressure is used as an index of inspiratory muscular strength, there is no consensus on how to measure it. We compared, during weaning from mechanical ventilation, two methods of measurement to determine which shows the greater values (MIPbest) and is more reproducible.