Understanding Asynchrony

Patient-ventilator asynchrony is typically uncomfortable for the patient. In addition, it may have an impact on patient outcomes. Epstein([FOOTNOTE=Sassoon C. Triggering of the ventilator in patient-ventilator interactions. Respiratory Care. 2011;56(1):39-51.],[ANCHOR=],[LINK=]) put together a list of adverse effects associated with poor patient-ventilator interaction:

• A higher or wasted work of breathing
• Patient discomfort
• An increased need for sedation
• Confusion during the weaning process
• Prolonged mechanical ventilation
• A longer stay
• The possibility of higher mortality

Investigators have examined the relationship between patient-ventilator asynchrony and outcomes. Thille et al([FOOTNOTE=Thille AW et al. Patient-ventilator asynchrony during assisted mechanical ventilation. Intensive Care Med. 2006;32(10):1515-1522.],[ANCHOR=],[LINK=]) found patients with an asynchrony index >10% had a longer duration of mechanical ventilation and were more likely to need a tracheostomy. de Wit et al([FOOTNOTE=de Wit M. Monitoring of patient ventilator interaction at the bedside. Respiratory Care. 2011;56(1):61-68.],[ANCHOR=],[LINK=]) found that those patients who had an ineffective trigger index of >10% had a longer duration of mechanical ventilation, a worse 28-day ventilator-free survival, and a longer ICU time and hospital stay. Patients in the ineffective trigger group were less likely to be discharged to home. Varon et al([FOOTNOTE=Puritan Bennett™ 980 Ventilator Operator's Manual],[ANCHOR=],[LINK=]) found that mortality was higher in patients with an asynchrony index >30%.