Abstract
Background: Chronic lung diseases (CLDs) are a major cause of chronic morbidity and mortality throughout the world. Many people suffer from this disease for years and die prematurely from it or its complications. Chronic lung diseases are chronic diseases of the airways and other parts of the lung. Some of the most common are asthma, chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, sleep apnea and occupational lung diseases. Respiratory diseases affect all ages: children, teens, adults and elderly.

Aims of the study: This study was aimed to study and compare some demographic changes in hypoxic and non-hypoxic groups of patients with chronic lung diseases (CLDs) and to illustrate the correlations of pericardial effusion with hypoxia due chronic lung diseases and its correlation with severity of obstructive and restrictive lung diseases. Design and method: The study was performed in Merjan teaching hospital of Babylon province in the period from December 2010 to April 2012, the study included one hundred eighty two (182) patients with history of chronic lung diseases were studied clinically and by spirometry, pulse oximetry, electrocardiography and echocardiography. According to the results of oximeter, patients were divided into two groups, hypoxic and non-hypoxic group. Hypoxic group included 96 patients ( mean age was 57.14±11.24, 66% was male) while the non-hypoxic group included 86 patients (mean age was 54.42±12.75, 62% was male).

Results and conclusions: The study also found that the numbers of patients with pericardial effusion (PE) were more in hypoxic group than non-hypoxic group, study also showed no significant correlation between PE and severity of hypoxia in both groups. Moreover, the study revealed no significant correlation between PE and severity of obstructive and restrictive diseases in both groups. In addition, there was significant correlation between PE and right ventricular systolic pressure (RVSP) in both
groups.