🫁 NAVA vs PSV in Obese ICU Patients: First Evidence of Safety and Benefit
Abstract: This randomized crossover study is the first to test Neurally Adjusted Ventilatory Assist (NAVA) in critically ill obese patients. Twenty-one ventilated patients (10 obese, 11 non-obese) underwent 30 minutes of NAVA and PSV each. Researchers assessed safety, patient-ventilator synchrony, oxygenation, and variability.
Key Insights
-
Feasibility: NAVA was feasible in all obese patients—signal acquisition and ventilation were successful.
-
Triggering: In obese patients, NAVA significantly reduced trigger delay (0 vs 106 ms) and inspiratory time in excess (96 vs 145 ms) compared to PSV.
-
Dyssynchrony: Ineffective efforts were markedly lower with NAVA (0 vs 0.33/min), although overall dyssynchrony index remained similar due to technical double triggering.
-
Oxygenation: PaO₂/FiO₂ ratio improved with NAVA (238 vs 207 mmHg).
-
Ventilatory pattern: Tidal volumes were slightly lower with NAVA (6.7 vs 7.2 mL/kg PBW), but variability in airway pressure and ventilation was greater, reflecting more physiologic breathing.
-
Obesity effect: Outcomes with NAVA were similar in obese and non-obese patients; obesity did not impair safety or efficacy.
-
Safety: No adverse events were observed in either group.
Why This Matters
Obesity complicates mechanical ventilation due to impaired lung mechanics and higher risk of dyssynchrony. This study shows NAVA is both feasible and advantageous in obese patients, enhancing synchrony and oxygenation while maintaining physiologic variability.
Conclusion
NAVA is safe, feasible, and beneficial for critically ill obese patients compared with PSV. Larger studies are needed to determine if these physiological gains translate into shorter weaning times, fewer complications, and improved survival.
Take-Home for Clinicians
-
Consider NAVA in obese ICU patients when PSV yields dyssynchrony.
-
Expect better oxygenation, reduced ineffective efforts, and improved trigger performance.
-
Recognize that technical double triggering may occur, but without harm.
Discussion Question: Should NAVA replace PSV as the preferred mode for obese ICU patients during weaning, given its synchrony and oxygenation benefits?
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Upcoming events
