Hiroaki Tokioka

The Effect of Breath Termination Criterion on Breathing Patterns and the Work of Breathing During Pressure Support Ventilation

With pressure support ventilation (PSV), each PSV breath is flow-cycled, and the breath termination criterion (TC) is usually nonadjustable. When TC does not match the interaction between the patient’s inspiratory-expiratory efforts to the opening and closing of the inspiratory and expiratory valves, patient-ventilator asynchrony may occur, and the work of breathing (WOB) may increase. Therefore, we studied the effect of TC on breathing patterns and WOB during PSV in eight patients with acute respiratory distress syndrome or acute lung injury. We studied five levels of TC during PSV—1%, 5%, 20%, 35%, and 45% of the peak inspiratory flow. With increasing levels of TC, the tidal volume decreased and respiratory frequency increased, along with a decrease in duty cycle. WOB markedly increased with increasing levels of TC from 0.31 ± 0.12 J/L with TC 1% to 0.51 ± 0.11 J/L with TC 45%. Premature termination with double breathing occurred in one patient with TC 35% and four patients with TC 45%. Delayed termination with a duty cycle of >0.5 occurred in two patients with TC 1%. In conclusion, the proper adjustment of TC improves patient-ventilator synchrony and decreases WOB during PSV. IMPLICATIONS Although termination criterion (TC) is usually nonadjustable, it influences the effectiveness of pressure support ventilation for mechanical ventilation. The proper adjustment of TC is crucial to improve patient-ventilator synchrony and decrease work of breathing. TC 5% of the peak inspiratory flow may be the optimal value for patients with acute respiratory distress syndrome or acute lung injury.

Effect of pressure support ventilation on breathing patterns and respiratory work

AbstractWe assessed the effect of pressure support ventilation (PSV) on breathing patterns and the work of breathing in 10 postoperative patients. Minute ventilation (

Comparison of pressure support ventilation and assist control ventilation in patients with acute respiratory failure.

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Pressure support ventilation augments spontaneous breathing with improved thoracoabdominal synchrony in neonates with congenital heart disease

E) increased by 8% with 5 cm H2O PSV and 10% with 10 cm H2O PSV compared to 0 cm H2O PSV. The increase in

Effectiveness of pressure support ventilation for mechanical ventilatory support in patients with status asthmaticus

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Inspiratory pressure-volume curves at different positive end-expiratory pressure levels in patients with ALI/ARDS.

E was achieved by increased mean inspiratory flow (24% with 5 cm H2O PSV and 67% with 10 cm H2O PSV) and a decrease in duty cycle (13% with 5 cm H2O PSV and 39% with 10 cm H2O PSV). The decrease in duty cycle along with a decrease in respiratory frequency allowed a greater expiratory time including a rest period for the respiratory muscles, which might minimize the risk of muscle fatigue. Furthermore, the inspiratory work added by the ventilator was near zero with 5 cm H2O PSV and 10 cm H2O PSV. Oxygen consumption also decreased significantly with 5 cm H2O PSV. We conclude that PSV improves the breathing patterns and minimizes the work of breathing spontaneously via a ventilator.