Safety of adaptive ventilation modes ISV and PSV when weaning the patient from a respirator

Abstract

Introduction.Currently there are no reports or recommendations concerning the ventilator weaning process. Appliance of the intellectual adaptive ventilation mode (iSV) represented in indigenous Russian unit ALV ZISLINE МV200 К 1.19 («Triton» Yekaterinburg) is highly potential. It provides minute ventilation target volume regardless of spontaneous patient’s respiratory activity and controls the pressure-support ventilation level (PSV) after each ventilatory cycle. Object was to increase safety of a patient’s spontaneous breathing adaptation period after longtime artificial lung ventilation.Materials and methods.Using the continuous sampling method we’ve surveyed 46 patients at the ages from 34 to 81 y.o. (median is 65.5 y.o.) being under prolonged artificial lung ventilation treatment at ICU from 5 to 28 full days. The groups are divided into 2 depending on the assisted respiration method for spontaneous breathing adaptation. In the 1st group (n = 25) the PSV mode was used for the purpose of spontaneous breathing adaptation. In the 2nd group (n = 21) the iSV mode was employed. The safety of conducting artificial lung ventilation was estimated by the dynamic of the arterial CO2 level, arterial oxygen saturation, pressure-support value, oxygen and energy intake value and a 24-hour fluid balance.Results.The comparison study of the metabolic indicants showed a higher rate of estimated energy requirement in the PSV mode authentically different by 3-5 full days, positive fluid balance conditioned by positive airway pressure and certain fluid retention which confirms more active respiratory load in the PSV mode. In the iSV mode from the 3rd till the 5th full day there’s negative fluid balance. By the 7th-10th full day it becomes slightly positive which proves electrolyte and fluid balance stabilization.Discussion.Most of the studies related to the study of the advantages of one or another method of auxiliary ventilation used the success of weaning as the primary indicator. In our study, we focused on the main respiratory indicators and the adequacy of ventilation when using auxiliary modes, as well as metabolic costs. In our study, we noted a decrease in the number of days spent by patients in IUC when using the iSV mode compared with the use of the PSV mode. We have determined a significant reduction in the estimated energy demand when using the adaptive ventilation mode compared to the pressure support mode, regardless of the PS level, as well as an increase in VO2 and VCO2.Conclusion.Thus, the iSV mode is believed to be more physiological than the PSV as it not only makes less demands on the respiratory system but it also allows to stabilize a patient's fluid balance during recovery after his/her critical condition.