Automated vs. conventional ventilation in the ICU: a randomized controlled crossover trial comparing blood oxygen saturation during daily nursing procedures (I-NURSING)

Abstract

Background: Hypoxia is common during daily nursing procedures (DNPs) routinely performed on mechanically ventilated patients. The impact of automated ventilation on the incidence and severity of blood oxygen desaturation during DNPs remains unknown.

Methods: A prospective randomized controlled crossover trial was carried out in a French intensive care unit to compare blood oxygen pulse saturation (SpO₂) during DNPs performed on patients mechanically ventilated in automated and conventional ventilation modes (AV and CV, respectively). All patients with FiO₂ ≤ 60% and without prone positioning or neuromuscular blocking agents were included. Patients underwent two DNPs on the same day using AV (INTELLiVENT-ASV®) and CV (volume control, biphasic positive airway pressure, or pressure support ventilation) in a randomized order. The primary outcome was the percentage of time spent with SpO₂ in the acceptable range of 90-95% during the DNP.

Results: Of the 265 included patients, 93% had been admitted for a medical pathology, the majority for acute respiratory failure (52%). There was no difference between the two periods in terms of DNP duration, sedation requirements, or ventilation parameters, but patients had more spontaneous breaths and lower peak airway pressures during the AV period (p < 0.001). The percentage of time spent with SpO₂ in the acceptable range during DNPs was longer in the AV period than in the CV period (48 ± 37 vs. 43 ± 37, percentage of DNP period; p = 0.03). After adjustment, AV was associated with a higher number of DNPs carried out with SpO₂ in the acceptable range (odds ratio, 1.82; 95% CI, 1.28 to 2.6; p = 0.001) and a lower incidence of blood oxygen desaturation ≤ 85% (adjusted odds ratio, 0.50; 95% CI, 0.30 to 0.85; p = 0.01).

Conclusion: AV appears to reduce the incidence and severity of blood oxygen desaturation during daily nursing procedures (DNPs) in comparison to CV.

Trial registration: This study was registered in clinical-trial.gov ( NCT03176329 ) in June 2017.

Keywords: Automated ventilation; Mechanical ventilation; Nursing procedure.

Fig. 1

I-NURSING trial flow diagram (DNP, daily nursing procedures; CV, conventional ventilation; AV, automated ventilation)

Fig. 2

Comparison between conventional and automated ventilation in terms of minimal, mean, and maximal blood oxygen saturation (SpO₂) during daily nursing procedures (*p <  0.05)