Effects of Sigh on Regional Lung Strain and Ventilation Heterogeneity in Acute Respiratory Failure Patients Undergoing Assisted Mechanical Ventilation*

Abstract

Sigh decreases regional lung strain and intratidal ventilation heterogeneity. Our study generates the hypothesis that in ventilated acute respiratory failure patients, Sigh may enhance regional lung protection.

Physiologic Effects of High-Flow Nasal Cannula in Acute Hypoxemic Respiratory Failure

“…An EIT-dedicated belt was placed around each patient's chest and connected to a commercial EIT monitor. During the whole study, EIT data were registered at 20 Hz and stored for offline analysis by dedicated software (18).…”

Ventilator-induced Lung Injury

“…3,5 We speculate the dose-response curve for the relationship between frequency of high-volume breaths and VILI may be J-shaped. Occasional high-volume breaths, such as sighs, may be protective by preventing derecruitment, 96 increasing lung homogeneity, 97 and increasing baby lung size (maintained if PEEP exceeds small airways closing pressure). 25 However, frequent high tidal volumes cause VILI in at-risk patients.…”

Recruitment Maneuvers and PEEP Titration

“…Several studies have evaluated the effect of sighs. [38][39][40][41][42] In the most recent of these, Mauri et al 42 examined the effect of adding a sigh to pressure-support ventilation in 20 critically ill subjects with a P aO 2 /F IO 2 Ͻ300. They used biphasic positive airway pressure at 35 cm H 2 O for 3-4 s at rates of 2 sighs/min, 1 sigh/min, and 1 sigh/2 min.…”