Combined high frequency ventilation and kinetic therapy for the management of severe hypoxia in adult respiratory distress syndrome

Abstract

Listen

Translate article

Pressure controlled inverse ratio ventilation (PCIRV) is often used as the initial therapeutic manoeuvre to improve oxygenation in severe adult respiratory distress syndrome (ARDS). When this alone fails, however, there is no consensus as to which therapy to resort to. We have used combined high frequency ventilation (CHFV) along with kinetic therapy (KT) to treat three patients with ARDS and resistant hypoxia. The basis for this treatment was our previous clinical observation that the two techniques together produced a greater improvement in oxygenation than either used alone. In CHFV a Monsoon jet ventilator was used to superimpose high frequency jet ventilation (rate 300 cycles min−1, inspiratory time 0.3, driving pressure 1 bar) on pressure controlled ventilation (rate 10 breaths min−1, inspiratory pressure 30 mbar). At the same time patients were positioned on a kinetic therapy pressure relief low air-loss bed (KCI) and rotated through a total angle of 90°. ThreePaO2/FIO2 values for each patient are shown in Table 14 and these correspond to (a) PCIRV alone (b) after 1 h of combined therapy and (c) after 24 h of combined therapy. The combination of CHFV with kinetic therapy produced improvement in oxygenation in all patients. Each of these individual therapies is believed to act through a different physiological mechanism.1 2 It is possible that the two together may, therefore, produce greater improvement than either therapy applied on its own. The number of such cases that present to one institution limits our small study, but we believe the significant improvement in oxygenation warrants further investigation.