Oxygen supplementation and cardiac-autonomic modulation in COPD

Chest. 2000 Sep;118(3):691-6. doi: 10.1378/chest.118.3.691.


Study objectives: Patients with COPD have an increased sympathetic modulation and reduced baroreflex sensitivity (BRS). Therefore, we studied the effects of breathing 31% supplemental oxygen (SuppO(2)) on autonomic modulation in a group of COPD patients.

Design: We measured autonomic modulation before and during the administration of SuppO(2) on 51 patients with COPD using time-frequency analysis of R-R intervals and BP before and after intervention. This was done via a counterbalanced crossover design. The BRS index was determined using the sequence method.

Results: Significant differences were seen in oxygen saturation levels following breathing with SuppO(2) ([mean +/- SD] 96.4+/-1.5%) when compared to those seen after breathing with compressed air (CA) (92.8+/-2.9%; p<0.0001). Significant increases were seen in the natural log-transformed high-frequency modulation (HFln) (SuppO(2), 10.8+/-1.3 natural logarithm [ln] ms(2)/Hz; CA, 10.6+/-1.3 ln ms(2)/Hz; p<0.028) and BRS (SuppO(2), 3.3+/-2.2 ms/mm Hg; CA, 2.8+/-1.8 ms/mm Hg) following the supplemental oxygen treatment (p<0.015). The low-frequency/high-frequency ratio of heart rate variability revealed significant differences between the two treatments (SuppO(2), 2.7 +/-1.2; CA, 3.1+/-1.3; p<0.008). The analysis of BP variability data revealed significant decreases in the HFln (CA, 6.9+/-1.0 mm Hg(2)/Hz; SuppO(2), 6.5+/-1.2 mm Hg(2)/Hz; p<0.0001). Hemodynamic data also revealed a decrease in mean heart rate after breathing SuppO(2) compared with that after breathing CA (CA, 87.3+/-13.3 beats/min; SuppO(2), 85.0+/-12.4 beats/min; p<0.0004). The arterial pulse pressure significantly decreased when breathing SuppO(2) compared with that when breathing CA (CA, 57.2+/-13.5 mm Hg; SuppO(2), 53.3+/-13.0 mm Hg; p<0.0023).

Conclusion: Oxygen supplementation in COPD patients significantly and favorably alters autonomic modulation.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Autonomic Nervous System / drug effects
  • Autonomic Nervous System / physiopathology*
  • Baroreflex / drug effects
  • Baroreflex / physiology
  • Blood Pressure / drug effects
  • Blood Pressure / physiology*
  • Circadian Rhythm / drug effects
  • Circadian Rhythm / physiology
  • Cross-Over Studies
  • Electrocardiography
  • Exercise Test
  • Heart Rate / drug effects
  • Heart Rate / physiology*
  • Humans
  • Lung Diseases, Obstructive / physiopathology
  • Lung Diseases, Obstructive / therapy*
  • Middle Aged
  • Oxygen Inhalation Therapy*
  • Prognosis