Feasibility study on full closed-loop control ventilation (IntelliVent-ASV™) in ICU patients with acute respiratory failure: a prospective observational comparative study

Abstract

IntroductionIntelliVent-ASV™ is a full closed-loop ventilation mode that automatically adjusts ventilation and oxygenation parameters in both passive and active patients. This feasibility study compared oxygenation and ventilation settings automatically selected by IntelliVent-ASV™ among three predefined lung conditions (normal lung, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD)) in active and passive patients. The feasibility of IntelliVent-ASV™ use was assessed based on the number of safety events, the need to switch to conventional mode for any medical reason, and sensor failure.MethodThis prospective observational comparative study included 100 consecutive patients who were invasively ventilated for less than 24 hours at the time of inclusion with an expected duration of ventilation of more than 12 hours. Patients were ventilated using IntelliVent-ASV™ from inclusion to extubation. Settings, automatically selected by the ventilator, delivered ventilation, respiratory mechanics, and gas exchanges were recorded once a day.ResultsRegarding feasibility, all patients were ventilated using IntelliVent-ASV™ (392 days in total). No safety issues occurred and there was never a need to switch to an alternative ventilation mode. The fully automated ventilation was used for 95% of the total ventilation time. IntelliVent-ASV™ selected different settings according to lung condition in passive and active patients. In passive patients, tidal volume (VT), predicted body weight (PBW) was significantly different between normal lung (n = 45), ARDS (n = 16) and COPD patients (n = 19) (8.1 (7.3 to 8.9) mL/kg; 7.5 (6.9 to 7.9) mL/kg; 9.9 (8.3 to 11.1) mL/kg, respectively; P 0.05). In passive ARDS patients, FiO2 and positive end-expiratory pressure (PEEP) were statistically higher than passive normal lung (35 (33 to 47)% versus 30 (30 to 31)% and 11 (8 to 13) cmH2O versus 5 (5 to 6) cmH2O, respectively; P< 0.05).ConclusionsIntelliVent-ASV™ was safely used in unselected ventilated ICU patients with different lung conditions. Automatically selected oxygenation and ventilation settings were different according to the lung condition, especially in passive patients.Trial RegistrationClinicalTrials.gov: NCT01489085

Automated Weaning from Mechanical Ventilation after Off-Pump Coronary Artery Bypass Grafting

“…Our study has shown that the automated weaning after OPCAB using INTELLiVENT-ASV was well tolerated by the overwhelming majority of patients. This is consistent with findings of other authors (7, 9, 10, 14, 15). The possible problems during automated weaning can be related with poor quality of SpO 2 signal during tissue hypoperfusion in patients with vasoconstriction, shock, and cold extremities that requires temporary deactivation of the oxygenation controller (15).…”

“…The possible problems during automated weaning can be related with poor quality of SpO 2 signal during tissue hypoperfusion in patients with vasoconstriction, shock, and cold extremities that requires temporary deactivation of the oxygenation controller (15). The patients with respiratory failure and increased gradient between arterial and end-tidal CO 2 can require deactivation of the EtCO 2 controller for 5% of the total ventilation time (15). However, in elective OPCAB, we did not register such problems.…”

Recruitment Maneuvers and PEEP Titration

“…12 Intellivent is a ventilator mode that incorporates the ARDS Network tables into the ventilator software. [60][61][62] PEEP/F IO 2 tables were also used in the Lung Open Ventilation study, 51 very similar to those used by the ARDS Network. In 51 subjects, Chiumello et al 17 compared the use of this table against 3 other approaches for setting PEEP: compliance, 63 stress index, 64 and esophageal manometry.…”

The Equilibration of Pco 2 in Pigs Is Independent of Lung Injury and Hemodynamics

“…In addition to that, the time it takes before the new Pco 2 level will be reached can be estimated and used in automated ventilation systems. This is of particular interest as the timing of repeated readjustments of the frequency controller in a closedloop setting (15) has to be tuned to the equilibration time of the biological system (16). It would thus be possible to time the controller to initiate well-defined adjustments after the equilibration time is over to avoid excessive regulation.…”