Use of Adaptive Supporting Ventilation after Cardiac Surgery under Extracorporeal Circulation

Abstract

Objective: to reveal the impact of adaptive supporting ventilation (ASV) on the time of patients’ activation after cardiac surgery under extracorporeal circulation. Methods. A randomized controlled study was performed. The study covered patients with aortic or mitral valve replacement under extracorporeal circulation. The patients were divided into groups: 1) those in whom ventilation was maintained in the ASV mode (a study group); 2) those in whom a ventilator was disconnected in accordance with the standard protocol (a control group). Both disconnection protocols were divided into 3 phases. In the study group, the setup of a ventilator in the ASV mode (minute ventilation) was 100% of the theoretical value. In the control group, spontaneous intermittent mandatory ventilation was applied (p support 10 mm H2O). In the study group, phase II was characterized by a 50% decrease in minute ventilation. In the control group, the ventilator-induced respiration rate in phase II decreased to 6 breaths/min (p support 5 mm H2O). In phase III, ventilation decreased by more 50% in the study group; in the control group, the apparatus was switched to the spontaneous mode. At the end of Phase III, the patient was extubated. Results. Thirty-four of the 45 included patients completed the protocol and only their results were taken into account when statistically processed. In failure or violation of the protocol, none patient was excluded from the study. According to the scheduled exclusion criteria, the data of 11 subjects (6 from the study group and 5 from the control one) were not processed. There were no great differences between the groups, by taking into account the total parameters, clinical data, inotropic support, and the results of a study of oxygen transport. The basic result of the study was the total artificial ventilation time that was significantly shorter in the ASV group. Conclusion. The present study has provided evidence that the protocol for patients’ early activation using the ASV mode is practical and may accelerate patients’ extuba-tion after valve replacement under extracorporeal circulation. Key words: adaptive supporting ventilation, artificial ventilation, cardiosurgery, extracorporeal circulation.