A pressão positiva contínua nas vias aéreas (cpap) é capaz de reverter as alterações pulmonares promovidas pela imersão em água?

Abstract

The increased pressure in the pulmonary capillaries during immersion induces a restrictive pulmonary pattern, similar to that found in pulmonary congestion in several cardiopulmonary diseases. Among the therapeutic armamentarium used to treat lung congestion there is the Noninvasive Positive Pressure Ventilation (NIPPV). The aim of the study was to determine whether NIPPV (CPAP) at different pressures improves lung volume and capacity of healthy subjects in immersion. The sample was submitted to three NIPPV protocols in immersion for 20 minutes: a) Control - in which there was not the CPAP application; b) CPAP with 5 cmH2O; c) CPAP with 10 cmH2O. Heart Rate (HR), Peripheral Oxygen Saturation (SpO2), Forced Vital Capacity (FVC), Forced Expiratory Volume in ne second (FEV1), relationship between these parameters (FEV1 / FVC%), Peak Expiratory Flow Rate (PEFR) and Forced Expiratory Flow at the midpoint of the maneuver (FEF 25-75%) were evaluated before immersion, 10 minutes after immersion and 10 minutes after application of the protocols. The CPAP with pressure of 10 cmH2O was able to restore the restrictive pulmonary pattern induced by immersion in water in healthy subjects, keeping the volumes and lung capacity in normal levels for a longer period compared to lower CPAP pressures. In conclusion, we demonstrated that in situations in which the hemodynamic change that causes lung disorder is persistent, only the application of higher positive pressure is effective in maintaining improvements in lung function for a longer time after application.