The Obstructive and Restrictive Spirometry Pattern and Post-Cardiac Surgery Pulmonary Complications

We sought to determine the frequency of postoperative pulmonary complications (PPCs) after cardiac surgeries in patients with obstructive, restrictive, and normal spirometry tests. 

This cohort study enrolled 623 patients who underwent cardiac surgeries at Rajaie Cardiovascular Medical and Research Center between 2017 and 2018 in 3 groups: obstructive, restrictive, and normal. The incidence of PPCs and their risk factors were noted. Associations between the incidence of PPCs and spirometry patterns and preoperative and intraoperative risk factors were evaluated statistically. 

Among all the PPCs evaluated in the patients, pulmonary edema/acute respiratory distress syndrome was much less common in the group with obstructive airflow limitations than in the groups with restrictive or normal lung patterns (P=0.010). The frequencies of other PPCs were not statistically significantly different between the 3 study groups (P>0.05). Among all the evaluated outcomes, the mean ventilation time was statistically different between the groups (P=0.059). Additionally, the incidence rate of pulmonary edema/acute respiratory distress was statistically significantly higher in the group with restrictive airflow limitations than in the other 2 groups. Operative mortality occurred in 15 cases (2.4%), and there were no significant differences in outcomes between the group with PPCs and those without them (P>0.05). 

Whereas there were no statistically significant differences concerning PPCs and in-hospital outcomes between the groups with obstructive, restrictive, and normal lung patterns, the 3 groups were meaningfully different regarding the estimated glomerular filtration rate, diabetes, thyroid-stimulating hormone, and history of morning fatigue.