Ventilation-Perfusion Mismatch in Chronic Lung Diseases

Strategic Insights -

Chronic obstructive and interstitial lung diseases lead to impaired pulmonary gas exchange, resulting in wasted ventilation and perfusion. Scientists in the United States report that the fundamental types of abnormality represent opposite ends of the spectrum of ventilation-perfusion mismatch, with V˙/Q˙ ratios of infinity and zero. Treatment approaches that improve airway function and reduce air trapping have received attention, but patients with low V˙/Q˙ abnormality often have few therapeutic options, including supplemental oxygen during exercise.

Key Takeaways:

  • Ventilation-perfusion mismatch in chronic lung diseases leads to wasted ventilation and perfusion, resulting in impaired gas exchange.
  • Patients with low V˙/Q˙ abnormality often experience refractory hypoxemia, particularly during exercise, with limited therapeutic options.
  • An arterio-venous fistula could potentially increase mixed venous oxygen content and ameliorate the deleterious effects of venous admixture.
  • This approach is novel, simple, and minimally invasive, with reason to believe that complications would be minor and have a favorable risk-benefit analysis.
  • This treatment could have a significant impact on patients with COPD and chronic hypoxemia that impair exercise performance.
  • Cooper and colleagues from the University of California, David Geffen School of Medicine, proposed this approach in their study published in the COPD - Journal of Chronic Obstructive Pulmonary Disease (Venous Admixture in COPD: Pathophysiology and Therapeutic Approaches. COPD - Journal of Chronic Obstructive Pulmonary Disease, 2008;5(6):376-381).

Statistics:

  • V˙/Q˙ ratios of infinity and zero represent opposite ends of the spectrum of ventilation-perfusion mismatch (see Chronic Obstructive Pulmonary Disease).
  • 60-80% of patients with COPD experience hypoxemia (COPD - Journal of Chronic Obstructive Pulmonary Disease, 2008;5(6):376-381).
  • Arterio-venous fistulas are a novel and minimally invasive approach to increasing mixed venous oxygen content (Cooper et al., COPD - Journal of Chronic Obstructive Pulmonary Disease, 2008;5(6):376-381).
  • The University of California, David Geffen School of Medicine, is part of the University of California system (Contact details: C.B. Cooper, University of California, David Geffen School of Medical, 10833 Conte Avenue, 37-131 CHS, Los Angeles, CA 90095, USA).

Sources:

  • Chronic Obstructive Pulmonary Disease
  • COPD - Journal of Chronic Obstructive Pulmonary Disease (Venous Admixture in COPD: Pathophysiology and Therapeutic Approaches. COPD - Journal of Chronic Obstructive Pulmonary Disease, 2008;5(6):376-381)
  • Cooper, C.B. et al. (2008). Venous Admixture in COPD: Pathophysiology and Therapeutic Approaches. COPD - Journal of Chronic Obstructive Pulmonary Disease, 5(6), 376-381.