Objective: To evaluate the acute effects of volume-targeted non-invasive ventilation (NIV) on hemodynamic parameters assessed by impedance cardiography in patients with obesity hypoventilation syndrome (OHS).
Background: Despite the well-described beneficial effects of NIV using volume-targeted pressure support ventilation modes on respiration in OHS patients, questions were raised about the impact of this treatment on the cardiovascular system.
Methods: In 15 patients (10 men; mean age, 55.8±9.3 years) impedance cardiography recordings were taken at baseline, after 120 minutes while on NIV and 20 minutes after NIV termination. A repeated-measures analysis of variance was used for comparisons.
Results: Compared to baseline, a reduction in heart rate (from 80±11 to 73±10 beats per min, p<0.05) was observed on NIV whereas the stroke volume and cardiac index remained stable throughout all three assessed intervals (p=0.347, p=0.344; respectively). The pre-ejection period increased on NIV (from 113±16 to 127±20 ms, p<0.05), and the left ventricular ejection time increased after NIV termination compared to baseline (from 259±25 to 269±25 ms, p<0.05).
Conclusion: Volume-targeted NIV may acutely improve systolic time intervals without any negative impact on the left ventricular function in OHS patients (Tab. 2, Ref. 17).
Keywords: hypercapnia; impedance cardiography cardiac output.; non-invasive ventilation; obesity hypoventilation syndrome; obstructive sleep apnoea.