Verification of Ventilatory Muscle Strength
The preoperative assessment of inspiratory muscle strength (Maximum Inspiratory Pressure (MIP)) was performed using an Indumed® analog manovacuometer. During the evaluation, the patient was asked for a maximum expiration until the residual volume and, then, a maximum and prolonged inspiration until his Total Pulmonary Capacity. This test was carried out with the unidirectional valve method, allowing flow through a millimeter orifice in order to exclude the action of the buccinator muscle, the test will be repeated three times, using the highest value obtained as long as it was not the last.
Another aspect evaluated was the expiratory muscle strength (Maximum Expiratory Pressure (MEP)), which was measured with the same device, but changing the way it was performed. Initially, the patient was instructed to perform a maximum inspiration until reaching his total pulmonary capacity. Then, after the mask was positioned, a maximum expiration was requested, until reaching the residual capacity, following the same rule of MIP, using the highest value, except when this is the last12.