Pendelluft in hypoxemic patients resuming spontaneous breathing: proportional modes versus pressure support ventilation

Annals of Intensive Care

Table 1 Respiratory variables during crossover trial

	NAVA	PAV +	PSV	p-value
Tidal volume, ml/kg PBW, median [IQR]	7.8 [7.4–8.9]	7.9 [7.2 – 8.8]	7.7 [7.2–9.3]	0.8589
Respiratory rate, bpm, mean ± SD	24.9 ± 7	24.9 ± 7	22.3 ± 6	0.0604
Volume minute ventilation, mean ± SD	11.6 ± 2.6	11.2 ± 2.8	10.4 ± 3.1	0.2312
Peak P_aw, cm H₂O, mean ± SD	21.1 ± 4.9*	16.7 ± 4.0*	18.7 ± 3.9	< 0.0001
ΔP_es, cm H₂O, mean ± SD	−8.4 ± 3.1	−10.9 ± 3.9*	−7.3 ± 3.4	0.0004
ΔP_L, cm H₂O, median [IQR]	17.8 [16.4–24.8]*	17.5 [14.7–21.1]	15.4 [14.4–17.3]	0.0083
ΔP_di, cm H₂O, median [IQR]	7.5 [5.3–9.8]	9.2 [7.6–11.4]*	7.3 [4.6–9.1]	< 0.0001
PaO_2, mmHg, median [IQR]	75.7 [72.7–83.1]	80.9 [72.9–97.3]	80.7 [74.3–88.7]	0.3867
PaO₂:FiO_2, mean ± SD	276 ± 80	284 ± 74	285 ± 68	0.6730
PaCO₂, mmHg, mean ± SD	39.2 ± 5.2	39.5 ± 5.2	39.5 ± 4.9	0.7729
pH, median [IQR]	7.4 [7.4–7.5]	7.4 [7.4–7.5]	7.4 [7.4–7.5]	0.4813
Ventilatory ratio	2.1 ± 0.7*	2.0 ± 0.5	1.8 ± 0.4	0.0310

p-value: significance of repeated measures ANOVA or Friedman test
NAVA neurally-adjust ventilatory assist, PAV proportional assist ventilation, PSV pressure support ventilation, PBW predicted body weight, IQR interquartile range, SD standard deviation, P_aw airway pressure, ΔP_es esophageal pressure swing, ΔP_L dynamic transpulmonary pressure, ΔP_di transdiaphragmatic pressure, PaO₂ arterial pressure of oxygen, FiO_2, inspired fraction of oxygen, PaCO₂ arterial pressure of carbon dioxide; Ventilatory ratio is a unit less index calculated as (minute ventilation in ml/min x PaCO₂) / (Ideal body weight × 100 × 37.5)
^*p < 0,05 compared with PSV