Combination of clonidine sedation and spontaneous breathing- pressure support upon acute respiratory distress syndrome : a feasibility study in four patients

Introduction : As alpha-2 agonists preserve ventilator drive, patients presenting with acute respiratory distress syndrome (ARDS, Pa02/FiO2 < 200) were managed using sedation with an alpha-2 agonist, clonidine, combined to spontaneous ventilation (SV) + pressure support ventilation (PS). Methods : Sedation was provided by an alpha-2 agonist, clonidine 1-2 mu g.kg-1.h-1, without bolus administration, and supplemented with a neuroleptic, loxapine, if needed. Four patients presenting with ARDS were managed with pressure support ventilation (PS = 8 cm H2O, rarely 10-12 cm 1120) and high PEEP (10-20 cm 1120). Energy requirements were minimized, if appropriate, with hypothermia caused by extra-renal replacement therapy or intentional hypothermia (35-36 degrees C). Repeated echocardiographic examinations revealed no right ventricular failure. Results : Recovery of ARDS, i.e. sustained increase of P/F > 200 for > 24 h, was observed, over 2-5 days. Conclusion : Use of an alpha-2 agonist as first-line sedative agent led to absence of respiratory depression and spontaneous ventilation. Upon ARDS, the lowered intrathoracic pressure observed with SV+PSV allowed one to recruit alveoli with high levels of PEEP, without impairing right ventricle function.