Comparison of arterial and venous blood gases in patients with obesity hypoventilation syndrome and neuromuscular disease.

Obesity hypoventilation syndrome (OHS) and some neuromuscular diseases (NMD) present with hypercapnic respiratory failure. Arterial blood gas (ABG) analysis is important in the diagnosis, follow-up, and treatment response of these diseases. However, ABG sampling is difficult in these patients because of excessive subcutaneous fat tissue, muscle atrophy, or contracture. The aim of this study is to investigate the value of venous blood gas (VBG), which is an easier and less complicated method, among stable patients with OHS and NMD.The study included stable OHS and NMD patients who had been previously diagnosed and followed up between March 2017 and May 2017 in the outpatient clinic. ABG was taken from all patients in room air, and peripheral VBG was taken within 5 min after ABG sampling.

Thirty-six patients with OHS and 46 patients with NMD were included in the study. There was a moderate positive correlation between arterial and venous pH values for all patients (r_s = 0.590, P < 0.001). There were a strong and very strong positive correlations between arterial and venous pCO₂ and HCO₃ values (r_s = 0.725 and r_s = 0.934, respectively) (P < 0.001). There was no correlation between arterial and venous pO₂ and saturation values. There was an agreement in Bland-Altman method for the values of ABG and VBG (pH, pCO₂, and HCO₃).

There was a correlation between ABG and VBG values (pH, pCO₂, and HCO₃). VBG parameters (pH, pCO₂, and HCO₃) can be used safely instead of ABG parameters which have many risks, during treatment and follow-up of patients with OHS and NMD.