Impact of Decreasing Respiratory Rate on Lung Injury Biomarkers in ARDS Patients

"During the Low RR and High RR periods, respiratory rate will be set depending on baseline ABG and according a nomogram so as to have an approximate difference of 10 points between groups, while maintining PaCO2 and pH values within safety limits (pH 7.20 to 7.45, and PaCO2 35 to 60 mmHg).~Once defined the target respiratory rate, this will be decreased or increased in 4 points each 30 to 45 min, and ABG repeated at 2 hours. At this time, changes will be made to keep PaCO2 and pH values within safety limits, and ABG repeated at 6 and finally 12 hours.~During the whole period, inspiratory to expiratory ratio will be maintained constant, and only changed to keep inspiratory time above 0.6 seconds (usually at high resp rate)."