Objective: To observe the risk factors of intensive care unit (ICU) admission for postoperative patients with stable chronic obstructive pulmonary disease (COPD).
Methods: Patients with stable COPD who were admitted to Shengjing Hospital of China Medical University for proposed surgical procedures from March 2014 to December 2020 were enrolled. Based on the criteria of the global initiative for chronic obstructive lung disease (GOLD), the patients were classified according to the severity of airflow limitation as grade 1 [forced expiratory volume in one second as a percentage of expected value (FEV1%) ≥ 80%], grade 2 (50% ≤ FEV1% < 80%), grade 3 (30% ≤ FEV1% < 50%), and grade 4 (FEV1% < 30%). Then the patients were divided into groups A, B, C, D according to symptom level and history of moderate/severe acute exacerbation within 1 year. The patients in the group A had the lightest symptoms, the lowest frequency and degree of acute exacerbation, while those in the group D had the most severe symptoms, the most frequent and degree of acute exacerbation. Data of general information, COPD-related factors, surgical-related factors and postoperative admission to ICU were collected. The correlation between different degree of airflow limitation subgroups as well as different comprehensive assessment of symptom subgroups and risk of postoperative ICU admission was analyzed. Multivariate Logistic regression models were used to analyze the risk factors affecting postoperative ICU admission.
Results: A total of 143 patients were enrolled in the analysis. According to the degree of airflow limitation, there were 34 patients in GOLD grade 1, 72 in grade 2, 32 in grade 3 and 5 in grade 4. According to the comprehensive assessment of symptoms, there were 78 patients in group A, 31 in group B, 5 in group C and 29 in group D. There were no statistically significant differences in the general data of gender, age, height and weight of patients in each group with different degrees of airflow limitation and different comprehensive assessment of symptoms. Univariate analysis showed that the degree of airflow limitation and comprehensive assessment of symptoms were not associated with postoperative ICU admission [degree of airflow limitation: odds ratio (OR) = 1.526, 95% confidence interval (95%CI) was 0.682-3.415, P = 0.304; comprehensive assessment of symptoms: OR = 1.508, 95%CI was 0.921-2.469, P = 0.103]. There was also no statistically significant difference in the surgical-related factors such as surgical site, surgical method, anesthesia, and surgical duration among the patients with different degrees of airflow limitation and different comprehensive assessment of symptoms. Among the 143 patients, 10 were admitted to ICU postoperation and 133 were not. Compared with the non-admitted ICU patients, patients admitted ICU were older (years old: 73.10±10.56 vs. 65.14±9.79, P < 0.05), had a higher modified Medical Research Council (mMRC) classification [1.5 (1.0, 2.0) vs. 1.0 (0, 2.0), P < 0.05], and had more frequent acute exacerbations per year [times: 1 (1, 2) vs. 1 (0, 1), P < 0.05]. There was also significant difference in surgical method between the two. Multivariate Logistic regression analysis showed that age and frequency of acute exacerbations per year were risk factors for postoperative admission to the ICU (age: OR = 1.093, 95%CI was 1.010-1.183, P = 0.028; frequency of acute exacerbations per year: OR = 2.400, 95%CI was 1.015-5.676, P = 0.046).
Conclusions: Different levels of airflow restriction and symptom comprehensive assessment groupings in stable COPD patients are not associated with the risk of postoperative ICU admission. Age and frequency of acute exacerbations per year were risk factors for postoperative ICU admission.