RT Journal Article
SR Electronic
T1 Reliability of Tidal Volume in Average Volume Assured Pressure Support Mode
JF Respiratory Care
FD American Association for Respiratory Care
SP 1139
OP 1146
DO 10.4187/respcare.05917
VO 63
IS 9
A1 Stagnara, André
A1 Baboi, Loredana
A1 Nesme, Pascale
A1 Subtil, Fabien
A1 Louis, Bruno
A1 Guérin, Claude
YR 2018
UL http://rc.rcjournal.com/content/63/9/1139.abstract
AB BACKGROUND: Remote monitoring is increasingly used in patients who receive home mechanical ventilation. The average volume assured pressure support mode is a target volume pressure preset mode that delivers a given tidal volume (VT) within a range of controlled inspiratory pressures. In a mode such as this, it is important to verify that the VT value retrieved from the ventilator SD card is accurate.METHODS: A lung model was set with C (Compliance) 0.075 L/cm H2O and RI (Inspiratory resistance)-RE (Expiratory resistance) 15–25 cm H2O/L/s (model 1) or with C 0.050 L/cm H2O and RI 6 cm H2O/L/s (model 2) and 6 cm H2O effort. Three home-care ventilators (A40, PrismaST30, and Vivo40) were set to average volume assured pressure support mode with 0.3 and 0.6 L VT each at PEEP 5 and 10 cm H2O, and were connected to the lung model with and without nonintentional leak. The reference airway pressure and flow were measured by a data logger. VT was expressed in body temperature and pressure saturated. We assessed the difference in VT between the ventilator SD card and a data logger relative to set VT and factors associated with its magnitude.RESULTS: For A40, PrismaST30, and Vivo40, the adjusted mean VT differences between the ventilator SD card and the data logger were −0.053 L (95% CI −0.067 to −0.039 L) (P < .001), −0.002 L (95%CI −0.022 to 0.019 L) (P = .86), and −0.067 L (95% CI −0.007 to 0.127 L) (P = .03), respectively. The partial Spearman correlation coefficients between the ventilator SD card and a data logger were 0.89 (P < .001), 0.59 (P < .001), and 0.78 (P < .001), respectively to the ventilators. The relative variations in measured VT from the set VT were 16.0, −12.0, and 6.7% for the ventilator SD card, and were −2.5, −7.5, and −27.2% for the data logger, respectively. The discrepancy in ventilator between SD card and data logger were influenced by PEEP for the PrismaST30 ventilator, nonintentional leak for the Vivo40 ventilator and PEEP, nonintentional leak, and underlying disease, the effect of each depending on the levels of the other factors, for the A40 ventilator.CONCLUSIONS: In the 3 home-care ventilators, the ventilator SD card underestimated VT. Factors involved in this difference differed among the ventilators.