What Ventilation and Blood Gases Are "desirable'' in Adult Mechanically Ventilated Patients

INTRODUCTION. Transfer of clinical/physiological knowledge in medical devices such as mechanical ventilators is getting popular in order to shorten the time spent on the ventilator and to improve patient's safety. Several closed loop systems (SmartCare®, IntelliVent®) already available on the market need further investigations to assess whether ventilation and arterial blood gases obtained with such closed loop systems fit the user's expectations as compared to conventional ventilation i.e. manual setting of the ventilator. However little is known on what ventilation and arterial blood gases are “desirable”. OBJECTIVES. The aim of the present investigation is to estimate from a panel of clinicians the ranges of “desirable” tidal volume (TV), plateau pressure (Pplat), SpO2, EtCO2 and respiratory rate (RR). METHODS. The Delphi method[1] was used to achieve an agreement regarding “desirable” TV, Pplat, SpO2, EtCO2 and RR. Between October 2009 and April 2010, four intensivists and one respiratory therapist from 5 hospitals/3 countries (Canada, France, Belgium) and having different adult ICU populations were entering rounds to find an agreement regarding the “desirable” values for 4 different underlying conditions (ALI/ARDS - Chronic hypercapnia - Brain injury - none of the previous) and for 2 respiratory muscles states (active or passive). RESULTS. Three rounds were needed to find an agreement. “Desirable“ values are summarized in the table. They were more discussions on “desirable” ranges in chronic hypercapanic patients as compared to ALI/ARDS patients. CONCLUSIONS. The present “desirable” values will be further estimate on a larger panel of clinicians and should help evaluating how much closed loop systems keep the patient in such “desirable” ranges.