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Neuro-ventilatory coupling rose with reduced pressure support, revealing diaphragm readiness for ventilator liberation in ICU care.  

A study published in June 2025 issue of Critical Care highlighted the importance of aligning ventilatory support with neural respiratory drive (NRD) to prevent diaphragm dysfunction in individuals of intensive care units (ICU).  

Researchers conducted a retrospective study to examine the effect of pressure support (PS) levels on the coupling between surface electrical activity of the diaphragm (sEAdi) and ventilatory output during an ICU stay.  

They evaluated 17 clinically stable individuals in the ICU by applying 4 PS levels on alternate days: −3, +0, +3, and +6 cmH₂O. The sEAdi time-product (ETPdi) was derived from high-quality sEAdi waveforms using an advanced signal analysis method. Neuro-ventilatory coupling (NVC) was defined by the breath-by-breath correlation between ETPdi and tidal volume (TV), allowing quantification of the neuro-ventilatory response.  

The results showed that in 13 individuals across 26 PS trials, ETPdi and respiratory rate (RR) increased by 2.4 and 1.6 percentage points (pp)/cmH₂ O respectively, as PS levels decreased, while TV declined by 2.5 pp/cmH₂ O. In a longitudinal subset of 4 individuals over 14 PS trials, NVC strengthened during weaning, with median NVC rising from 3.4% (IQR 2.9) to 26.3% (IQR 21.7) between the initial and final trials.  

Investigators concluded that NVC increased as individuals neared liberation from mechanical ventilation (MV), highlighting its potential as a non-invasive marker to guide adjustment of ventilatory support levels. 

Source: ccforum.biomedcentral.com/articles/10.1186/s13054-025-05424-5