Patient-Ventilator Interaction During Noninvasive Ventilation

Abstract

There is arguably more evidence to support the use of noninvasive ventilation (NIV) than any other practice related to the care of patients with acute respiratory failure. Despite this strong evidence base, NIV seems to be under-utilized and the failure rate (need for intubation) may be as high as 40%. Some of these failures potentially relate to asynchrony, although the relationship between asynchrony and NIV failure has not been well studied. Good NIV tolerance has been associated with success of NIV, and improved comfort has been associated with better synchrony. In one study a high rate of asynchrony occurred in 43% of patients during NIV. Asynchrony is commonly associated with leaks. Thus, reducing the leak related to the interface and using a ventilator with good leak compensation should reduce the rate of asynchrony. Asynchronies can also be related to the underlying disease process. This paper reviews issues related to asynchrony during NIV and suggests strategies that might be used to correct asynchrony when it occurs.

Noninvasive Ventilation Intolerance: Characteristics, Predictors, and Outcomes

“…These factors can be due to patient-ventilator asynchrony. 19 However, some factors, such as NIV giving subjects a continuous cough or headache, cannot be ex- Fig. 3.…”

Identifying Patient-Ventilator Asynchrony Using Waveform Analysis

“…The Asynchrony Index (AI) is defined as the number of asynchrony events divided by the total respiratory rate (Number of asynchronies / Number of total respiratory rate (Number of asynchrony events + Number of cycles effectively delivered by the mechanical ventilator) x 100 [11].…”

A Comparison of Leak Compensation in Acute Care Ventilators During Noninvasive and Invasive Ventilation: A Lung Model Study

“…1 Leaks may be due to the endotracheal tube cuff, ventilator circuit, or chest drain during invasive ventilation. The incidence of endotracheal tube cuff leaks has been reported at ranges from 11% to 24%.…”

“…2,3 With noninvasive ventilation (NIV), leaks around the face or nasal mask are a common cause of system leak. 1 Patient-ventilator asynchronies have been reported to occur with a high incidence during both invasive 4,5 and NIV. 6,7 Thille et al reported that 24% of patients showed patient-ventilator asynchrony in Ͼ 10% of their total ventilatory rate during invasive ventilation.…”