Preoperative Risk Stratification of Chronic Obstructive Pulmonary Disease Patients Undergoing Non-thoracic Surgery Using American Society of Anaesthesiologists Classification, ARISCAT Score and GOLD Criteria for Predicting Postoperative Pulmonary Com

Background and Aims: Postoperative pulmonary complications (PPC) pose significant problems, especially in patients with chronic obstructive pulmonary disease (COPD). We aimed to assess the risk of developing PPC in COPD patients undergoing non-thoracic surgeries along with its correlation to the type of surgery, anaesthesia technique and patient-related factors. Material and Methods: We prospectively collected data such as the comorbidities, preoperative pulmonary risk scores, recent history of respiratory infection, investigations, surgical (type, duration, surgical urgency and site) and anaesthesia data (general or regional, airway intervention if any), American Society of Anaesthesiologists (ASA) scores, the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) risk index scores and Global Initiative for Chronic Obstructive Lung Diseases (GOLD) classification of COPD in 196 patients. We tried to find a correlation between these factors to the development of PPC. Results: The risk of PPC in patients with an ASA category 3 was 3.24 times higher than in those with an ASA 2. It was 1.22 times higher in patients with COPD classified as GOLD criteria 3 compared with those classified as GOLD criteria 1 and 2. PPC in high-risk ARISCAT scores was 4.97 times higher than in patients with intermediate to low-risk ARISCAT scores. The risk factors which had a significant association with PPC were patients more than 65 years of age, patients with metabolic equivalent (MET) score less than 4, respiratory infection in the last 1 month, haemoglobin less than 10 gm/dl, pre-operative oxygen saturation (SpO 2 ) less than 95% on room air, administration of general anaesthesia over regional anaesthesia, emergency surgery and surgical time more than 3 hours. Conclusion: ASA classification and GOLD criteria are useful to assess preoperative health status and the severity of COPD and reasonably predict the risk of PPC. The ARISCAT risk index, however, is a stronger modality to predict PPC.