Acute Application of Bilevel Positive Airway Pressure Influences the Cardiac Autonomic Nervous System

Abstract

INTRODUCTIONNoninvasive positive pressure has been used to treat several diseases. However, the physiological response of the cardiac autonomic system during bilevel positive airway pressure (Bilevel) remains unclear.OBJECTIVEThe aim of this study was to evaluate the heart rate variability (HRV) during Bilevel in young healthy subjects.METHODSTwenty men underwent 10-minute R-R interval recordings during sham ventilation (SV), Bilevel of 8–15 cmH2O and Bilevel of 13–20 cmH2O. The HRV was analyzed by means of the parallel R-R interval (mean R-Ri), the standard deviation of all R-Ri (SDNN), the root mean square of the squares of the differences between successive R-Ri (rMSSD), the number of successive R-Ri pairs that differ by more than 50 milliseconds (NN50), the percentage of successive R-Ri that differ by more than 50 milliseconds (pNN50), the low frequency (LF), the high frequency (HF) and SD1 and SD2. Additionally, physiological variables, including blood pressure, breathing frequency and end tidal CO2, were collected. Repeated-measures ANOVA and Pearson correlation were used to assess the differences between the three studied conditions and the relationships between the delta of Bilevel at 13–20 cmH2O and sham ventilation of the HRV indexes and the physiological variables, respectively.RESULTSThe R-Ri mean, rMSSD, NN50, pNN50 and SD1 were reduced during Bilevel of 13–20 cmH2O as compared to SV. An R-Ri mean reduction was also observed in Bilevel of 13–20 cmH2O compared to 8–15 cmH2O. Both the R-Ri mean and HF were reduced during Bilevel of 8–15 cmH2O as compared to SV, while the LF increased during application of Bilevel of 8–15 cmH2O as compared to SV. The delta (between Bilevel at 13–20 cmH2O and sham ventilation) of ETCO2 correlated positively with LF, HF, the LF/HF ratio, SDNN, rMSSD and SD1. Acute application of Bilevel was able to alter the cardiac autonomic nervous system, resulting in a reduction in parasympathetic activity and an increase in sympathetic activity and higher level of positive pressure can cause a greater influence on the cardiovascular and respiratory system.

The effects of nasal continuous positive airway pressure and high flow nasal cannula on heart rate variability in extremely preterm infants after extubation: A randomized crossover trial

“…Analysis of HRV is an attractive tool for evaluating differences in physiological effects of non‐invasive respiratory support modes. As demonstrated by various studies in animals and adults, the addition of continuous distending pressure increases intrathoracic pressure and thereby decreases venous return, stroke volume, and cardiac output; this leads to changes in autonomic cardiorespiratory control in order to maintain homeostasis, thus altering HRV . Therefore, we anticipated that the different distending pressures provided by NCPAP and HFNC may lead to detectable changes in HRV.…”

Heart Rate Variability in Extremely Preterm Infants Receiving Nasal CPAP and Non-Synchronized Noninvasive Ventilation Immediately After Extubation

“…20 Thus, one could hypothesize that, in preterm infants, the application of higher mean airway pressures with ns-NIV would also alter intrathoracic pressure and modulate HRV. [21][22][23] However, transmission of positive pressure to the lungs may not always be reliable, and HRV behavior may vary according to patient stability. In a study evaluating stable preterm infants, ns-NIV was associated with highly variable PIP levels around the set value, 24 depending on the timing of inflation in relation to each spontaneous inspiration, presence of leaks, or an apneic event.…”

Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease

“…During respiration, there is an identifiable relationship between inspiration and increased in HR, caused by the withdrawal of vagal tone, and between expiration and reduced in HR, caused by increased vagal activity on the sinus node. An increase in the HR range during the respiratory cycle reflects increased cardiac health 10–11…”