Relationship between arterial blood gas values, pulmonary function tests and treadmill exercise testing parameters in patients with COPD

Sodium Hydrosulfide Protects Rats from Hypobaric-Hypoxia-Induced Acute Lung Injury

Hydrogen sulfide (H2S), as a key gas signaling molecule, plays an important role in regulating various diseases, with appropriate concentrations providing antioxidative, anti-inflammatory, and anti-apoptotic effects. The specific role of H2S in acute hypoxic injury remains to be clarified. This study focuses on the H2S donor sodium hydrosulfide (NaHS) and explores its protective effects and mechanisms against acute hypoxic lung injury. First, various mouse hypoxia models were established to evaluate H2S's protection in hypoxia tolerance. Next, a rat model of acute lung injury (ALI) induced by hypoxia at 6500 m above sea level for 72 h was created to assess H2S's protective effects and mechanisms. Evaluation metrics included blood gas analysis, blood routine indicators, lung water content, and lung tissue pathology. Additionally, LC-MS/MS and bioinformatic analyses were combined in performing quantitative proteomics on lung tissues from the normoxic control group, the hypoxia model group, and the hypoxia model group with NaHS treatment to preliminarily explore the protective mechanisms of H2S. Further, enzyme-linked immunosorbent assays (ELISA) were used to measure oxidative stress markers and inflammatory factors in rat lung tissues. Lastly, Western blot analysis was performed to detect Nrf2, HO-1, P-NF-κB, NF-κB, HIF-1α, Bcl-2, and Bax proteins in lung tissues. Results showed that H2S exhibited significant anti-hypoxic effects in various hypoxia models, effectively modulating blood gas and blood routine indicators in ALI rats, reducing pulmonary edema, improving lung tissue pathology, and alleviating oxidative stress, inflammatory responses, and apoptosis levels.

Correlation between Six Minute Walk Test and Spirometry in Chronic Pulmonary Disease

INTRODUCTION

Six minute walk test (6MWT), is an exercise test, used as a clinical indicator of the functional capacity, in patients with cardiopulmonary diseases. The present study assessed the correlation of six minute walk test with pulmonary function variables, in patients with chronic pulmonary diseases, in local population.

AIMS & OBJECTIVES

The objectives were to study correlation of different spirometry variables with variables of six minute walk test like percent predicted 6 minute walk distance (% Predicted 6MWD) as per Enright et al., formula and Indian reference equation, pre and post exercise pO2 and pCO2 and exercise desaturation.

MATERIALS AND METHODS

All consecutive patients with confirmed diagnosis of chronic pulmonary diseases were included from January 2013 to June 2014 in tertiary care institute. 6MWT was performed as per the ATS guidelines. Among 130 patients 108 were also subjected to arterial blood gases pre and post test. Spirometry was performed as per ATS guidelines. Percent (%) predicted 6MWD was calculated. Correlation between spirometry and 6MWT was assessed.

RESULTS

One hundred and thirty patients with chronic pulmonary disease were taken. Out of them there was 102 patients with obstructive airway disease and 58 patients with interstitial lung disease. FEV1 significantly correlated with %predicted 6MWD &; with basal pO2 and pCO2 and with post exercise pCO2 and pO2. FVC also correlated with %predicted 6MWD, with basal pO2 and pCO2 and post exercise pO2. FEV1/FVC correlated only with post exercise pCO2 while MVV correlated with %predicted 6MWD and only basal pCO2. Exercise desaturation correlated only with FVC. Percent predicted 6MWD also correlated with basal pO2 & post exercise pO2.

CONCLUSION

Thus significant correlation found between 6MWT & spirometry variables (FEV1, FVC, MVV & FEV1/FVC).