Association between hemodynamic instability and noninvasive ventilation failure: A large multicenter observational...

Hemodynamic instability is a relative contraindication for noninvasive ventilation (NIV). However, there is limited evidence supporting this contraindication.

This prospective multicenter observational study across 18 Chinese and Turkish hospitals enrolled acute hypoxemic respiratory failure patients receiving NIV. Hemodynamic instability was defined as requiring vasoactive agents to maintain mean arterial pressure (MAP) >70 mmHg within 24 h of NIV. Reversible instability indicated vasoactive agent discontinuation by 24 h, while irreversible instability required persistent vasopressor use.

Among 2137 enrolled patients, 279 (13 %) developed hemodynamic instability. Compared to hemodynamically stable patients, those with instability had significantly higher rates of NIV failure (56 % vs. 37 %; adjusted OR =1.89, 95 % CI: 1.37-2.59). NIV failure rates increased with the severity of hemodynamic impairment: 37 % in patients requiring no vasopressors, 54 % in those on one vasopressor, and 70 % in those requiring multiple vasopressors (p < 0.01 across groups). Within the unstable cohort, 55 patients (20 %) achieved hemodynamic stabilization within 24 h. Subsequent analysis showed that reversible instability was not significantly associated with NIV failure (adjusted OR =0.60, 95 % CI: 0.30-1.21), whereas irreversible instability was strongly associated with NIV failure (adjusted OR =2.48, 95 % CI: 1.75-3.53).

Hemodynamic instability is associated with NIV failure. The likelihood of failure increases with the severity of the hemodynamic instability. However, if the instability is effectively reversed within the first 24 h, it is no longer associated with an increased risk of NIV failure.